A power generation system and an operating method thereof

Abstract

The present invention discloses a power generation system comprising a water working medium circulation system and a heat storage medium circulation and energy storage system. The water working medium circulation system comprises a steam boiler, a steam turbine, a condensing system, a feedwater pump, and a generator connected to the power output of the steam turbine. The heat storage medium circulation and energy storage system comprises a heat storage medium boiler, a heat storage device, a heat exchange device, and several heat storage medium delivery pipelines. The heat storage device includes a high-temperature heat storage medium storage structure and a low-temperature heat storage medium storage structure. The heat storage medium delivery pipelines sequentially connect the heat storage medium boiler, the high-temperature heat storage medium storage structure of the heat storage device, the heat exchange device, and the low-temperature heat storage medium storage structure of the heat storage device, allowing the heat storage medium to circulate within the heat storage medium circulation and energy storage system. The dual boiler configuration allows for independent operation, resulting in high system operational flexibility, a long service life for the newly added heat storage device, and low maintenance costs.

Description

Technical Field

[0001] The present invention belongs to the technical field of power generation in power stations, and in particular relates to a power generation system and an operating method thereof. Background Art

[0002] Conventional flexibility retrofit solutions for thermal power units present a number of problems. First, deep peak shaving can significantly deviate from design operating conditions, reducing boiler unit efficiency and operational economics. Second, prolonged low-load operation can impact equipment life and safety. For example, frequent deep peak shaving can easily lead to material fatigue, shortening equipment life. Extremely low-load operation can lead to significant deviations in the internal dynamic and temperature fields, increasing safety risks. Furthermore, operating a boiler at low load increases the difficulty and workload. Summary of the Invention

[0003] To solve the above problems, the purpose of the present invention is to provide a power generation system and an operating method thereof, which has a larger peak-shaving range, maintains high economy when performing deep peak-shaving, and does not have adverse effects on the system itself.

[0004] To achieve the above-mentioned purpose, the technical solution of the present invention is: a power generation system, comprising: a water working medium circulation system and a heat storage medium circulation and energy storage system; wherein,

[0005] The water working medium circulation system includes: a steam boiler, a steam turbine, a condensing system, a feed water pump, which are sequentially connected to form a circulation, and a generator connected to the power output end of the steam turbine;

[0006] The heat storage medium circulation and energy storage system includes: a heat storage medium boiler, a heat storage device, a heat exchange device, and a plurality of heat storage medium delivery pipelines. The heat storage device includes a high-temperature heat storage medium storage structure and a low-temperature heat storage medium storage structure. The heat storage medium delivery pipelines sequentially connect the heat storage medium boiler, the high-temperature heat storage medium storage structure of the heat storage device, the heat exchange device, and the low-temperature heat storage medium storage structure of the heat storage device, allowing the heat storage medium to circulate in the heat storage medium circulation and energy storage system.

[0007] In which, the water working medium circulation system also includes a water working medium branch, and the heat exchange device is connected to the water working medium branch of the water working medium circulation system through a pipeline, so that the water working medium to be heated passes through the heat exchange device and exchanges heat with the heat storage medium at the heat exchange device. The water working medium is heated by the heat storage medium, and the heated water working medium enters the steam turbine to participate in power generation.

[0008] The dual-boiler design for the power generation system, with each boiler capable of independent operation, offers low technical complexity and high system flexibility. The power plant can customize its operating mode and energy storage solution based on its peak-shaving needs. The newly added heat storage device has a long service life and low maintenance costs. The unit's operating mode switching is simple and convenient, with rapid peak-shaving speeds, meeting the requirements for regulating large fluctuations in the power system's load. This also improves the unit's start-up and shutdown speeds and variable load capacity. The dual-boiler design allows for stable operation even when one boiler is shut down for maintenance. The heat storage device ensures that even if both units are shut down simultaneously, they still have the ability to generate electricity and start the boilers.

[0009] Preferably, the heat storage device has a dual-tank structure, wherein the low-temperature heat storage medium storage structure is a low-temperature storage tank, and the high-temperature heat storage medium storage structure is a high-temperature storage tank; or, the heat storage device has a single-tank structure, wherein the high-temperature heat storage medium storage structure is the high-temperature heat storage medium storage area of ​​the single tank, and the low-temperature heat storage medium storage structure is the low-temperature heat storage medium storage area of ​​the single tank, and the high-temperature heat storage medium storage area and the low-temperature heat storage medium storage area are independent of each other.

[0010] Preferably, a high-temperature delivery pump is provided on the heat storage medium delivery pipeline connecting the output end of the high-temperature heat storage medium storage structure of the heat storage device and the heat exchange device, and the high-temperature delivery pump can adjust the flow rate of the heat storage medium pumped into the heat exchange device between closed and fully open.

[0011] Preferably, a low-temperature delivery pump is provided on the heat storage medium delivery pipeline connecting the output end of the low-temperature heat storage medium storage structure of the heat storage device and the heat storage medium boiler.

[0012] Preferably, a heat storage medium valve is further provided on the heat storage medium delivery pipeline connecting the output end of the low-temperature heat storage medium storage structure of the heat storage device and the heat storage medium boiler.

[0013] Preferably, the main steam output end of the steam boiler is connected to the main steam input end of the steam turbine through a first water working medium delivery pipeline, the exhaust steam output end of the steam turbine is connected to the input end of the condensing system through a third water working medium delivery pipeline, the output end of the condensing system is connected to a feed water pump, the output end of the feed water pump is divided into two branches, one of which is connected to the first feed water input end of the heat exchange device through a fourth water working medium delivery pipeline, and the other branch is connected to the feed water input end of the steam boiler through a fifth water working medium delivery pipeline, the main steam output end of the heat exchange device is connected to the first feed water input end of the steam turbine through a second water working medium delivery pipeline. The main steam input end is connected; the output end of the high-temperature heat storage medium storage structure of the heat storage device is connected to the heat storage medium input end of the heat exchange device through a second heat storage medium delivery pipeline, the heat storage medium output end of the heat exchange device is connected to the input end of the low-temperature heat storage medium storage structure of the heat storage device through a third heat storage medium delivery pipeline, the output end of the low-temperature heat storage medium storage structure of the heat storage device is connected to the input end of the heat storage medium boiler through a fourth heat storage medium delivery pipeline, and the output end of the heat storage medium boiler is connected to the input end of the high-temperature heat storage medium storage structure of the heat storage device through a first heat storage medium delivery pipeline.

[0014] Preferably, the first water working medium delivery pipeline and the second water working medium delivery pipeline are connected to the main steam input end of the high-pressure cylinder of the steam turbine after being connected through a first three-way valve.

[0015] Preferably, the first water working medium delivery pipeline is provided with a second steam-water valve; the second water working medium delivery pipeline is provided with a third steam-water valve; and the fourth water working medium delivery pipeline is provided with a first steam-water valve.

[0016] Preferably, the steam turbine includes a high-pressure cylinder and a low-pressure cylinder; the main steam output end of the steam boiler is connected to the main steam input end of the high-pressure cylinder of the steam turbine through a first water working medium delivery pipe, and the cold reheat steam output end of the high-pressure cylinder of the steam turbine is connected to the cold reheat steam input end of the steam boiler through a sixth water working medium delivery pipe; at the same time, the hot reheat steam output end of the steam boiler is connected to the hot reheat steam input end of the low-pressure cylinder of the steam turbine through an eighth water working medium delivery pipe, the cold reheat steam output end of the high-pressure cylinder of the steam turbine is connected to the cold reheat steam input end of the heat exchange device through a seventh water working medium delivery pipe, and the hot reheat steam output end of the heat exchange device is connected to the hot reheat steam input end of the low-pressure cylinder of the steam turbine through a ninth water working medium delivery pipe.

[0017] Preferably, the sixth water working medium delivery pipeline and the seventh water working medium delivery pipeline are connected to the cold reheat steam output end of the high-pressure cylinder of the steam turbine through a third three-way valve, and the eighth water working medium delivery pipeline and the ninth water working medium delivery pipeline are connected to the hot reheat steam inlet of the low-pressure cylinder of the steam turbine through a fourth three-way valve.

[0018] Preferably, the eighth water working medium delivery pipeline is provided with a fourth steam-water valve; the ninth water working medium delivery pipeline is provided with a fifth steam-water valve; and the seventh water working medium delivery pipeline is provided with a sixth steam-water valve.

[0019] Preferably, the sum of the thermal power output by the heat exchange device at 100% load and the thermal power output by the steam boiler at 100% load is the thermal power that needs to be input to the steam turbine when the entire power generation system outputs the highest power generation power.

[0020] Preferably, the steam boiler operates under the lowest steady-state load state, and when the heat exchange device does not output thermal power, the thermal power output by the steam boiler is the thermal power that needs to be input to the steam turbine when the entire power generation system outputs the lowest power generation power.

[0021] Preferably, the sum of the thermal power output by the heat storage medium boiler at 100% load and the thermal power output by the steam boiler at 100% load is the thermal power that needs to be input to the steam turbine when the entire power generation system operates in a state where the output power generation power is equal to the normal power generation power; the normal power generation power of the power generation system refers to the power generation power that can be output by the power generation system when both the heat storage medium boiler and the steam boiler output thermal power at 100% load, and the heat absorbed by the heat storage device from the heat storage medium boiler is equal to the heat released by the heat storage device at the heat exchange device. This power generation power value of the power generation system is the normal power generation power of the power generation system.

[0022] Based on the same concept, the present invention also provides a method for operating a power generation system, which is applied to any of the power generation systems described above, including: receiving a dispatch instruction from the power grid and determining a target operating mode of the power generation system according to a preset program; maintaining the current operating mode when the current operating mode of the power generation system is consistent with the target operating mode; switching to the target operating mode when the current operating mode of the power generation system is inconsistent with the target operating mode; wherein the target operating mode includes: the steam boiler is running, the heat exchange device is not running, and the output thermal power of the steam boiler is adjusted to meet the power generation power requirement; the steam boiler and the heat exchange device are both running, and the flow rate of the heat storage medium supplied by the heat storage device to the heat exchange device and the flow rate of the water working medium supplied by the water feed pump to the heat exchange device are adjusted so that the sum of the thermal power output by the heat exchange device and the thermal power output by the steam boiler meets The thermal power that needs to be input to the steam turbine when the power generation system outputs the target power generation power; the steam boiler and the heat exchange device are both in operation, and the output thermal power of the steam boiler is adjusted so that the sum of the thermal power output by the heat exchange device and the thermal power output by the steam boiler meets the thermal power that needs to be input to the steam turbine when the power generation system outputs the target power generation power; the steam boiler and the heat exchange device are both in operation, and while adjusting the output thermal power of the steam boiler, the flow rate of the heat storage medium supplied by the heat storage device to the heat exchange device and the flow rate of the water working medium supplied by the feed water pump to the heat exchange device are also synchronously adjusted, so that ultimately the sum of the thermal power output by the heat exchange device and the thermal power output by the steam boiler meets the thermal power that needs to be input to the steam turbine when the power generation system outputs the target power generation power; the steam boiler stops operating, the heat exchange device operates, and the power of the heat exchange device is adjusted to meet the power generation power requirement.

[0023] Preferably, when the energy stored in the heat storage device is lower than a first preset threshold, the heat storage medium boiler operates and supplies high-temperature heat storage medium to the heat storage device; when the energy stored in the heat storage device is higher than a second preset threshold, the heat storage medium boiler stops operating.

[0024] Based on the same concept, the present invention further provides a power generation system operating method, which is applied to any of the power generation systems described above, comprising:

[0025] When the power generation system is required to operate at a power output equal to or higher than the normal power generation power, the steam boilers all output thermal power at 100% load, and the flow rate of the heat storage medium supplied by the heat storage device to the heat exchange device and the flow rate of the water working medium supplied by the feed water pump to the heat exchange device are adjusted so that the sum of the thermal power output by the heat exchange device and the thermal power output by the steam boiler meets the thermal power required when the power generation system outputs the target power generation power. The power generation power output of the power generation system is adjusted by adjusting the output thermal power of the heat exchange device;

[0026] When the power generation system is required to operate at a power output lower than the normal power generation state, the following steps are performed:

[0027] S1: Determine whether the steam boiler operating alone can meet the thermal power required by the power generation system to output the target power generation power. If not, proceed to step S2; if so, proceed to step S3;

[0028] S2: If the steam boiler operating alone cannot meet the thermal power required by the power generation system to output the target power generation power, then adjust the flow rate of the heat storage medium supplied by the heat storage device to the heat exchange device and the flow rate of the water working medium supplied by the feed water pump to the heat exchange device so that the sum of the thermal power output by the heat exchange device and the thermal power output by the steam boiler meets the thermal power required by the power generation system to output the target power generation power. The power generation power output of the power generation system is adjusted by adjusting the output thermal power of the heat exchange device.

[0029] S3: If the steam boiler operating alone can meet the thermal power required by the power generation system to output the target power, the steam boiler will output thermal power to the power generation system alone, the heat exchange device will stop operating, and the power generation output of the power generation system will be regulated entirely by the steam boiler's own regulation capability;

[0030] Wherein, for any of the above operation modes, when it is necessary to supplement heat energy to the heat storage device, the heat storage medium boiler operates, and when it is not necessary to supplement heat energy to the heat storage device, the heat storage medium boiler stops operating.

[0031] Preferably, in step S1, when the steam boiler is shut down, the heat exchange device outputs thermal power to the power generation system alone, and the adjustment of the power generation power output of the power generation system is achieved by adjusting the output thermal power of the heat exchange device. At the same time, the thermal power output by the heat exchange device to the power generation system can at least meet the thermal power required to be input when the power generation system operates at the minimum allowable power generation state.

[0032] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art:

[0033] (1) This power generation system has a larger peak-shaving range. When performing deep peak-shaving, it maintains high economic efficiency and will not have adverse effects on its own system. The operating mode and energy storage plan can be customized according to its own peak-shaving needs. The dual-boiler solution allows each boiler to operate independently, which is technically less difficult. The newly added heat storage device has a long service life and low maintenance cost. The unit operation mode switching is simple and convenient, and the peak-shaving speed is fast, which can meet the regulation requirements of large fluctuations in the power system load. At the same time, it improves the start-up and shutdown speed and variable load capacity of the entire unit. At the same time, the dual-boiler design mode can maintain stable operation when one boiler is shut down for maintenance. The configuration of the heat storage device can ensure that when both units are shut down at the same time, they still have the ability to generate electricity and have the function of starting the boiler.

[0034] (2) The power of the heat exchange device is designed according to the peak load demand. Its power can be higher than that of the heat storage medium boiler. The stored energy can be used to output high-power steam in a short time to meet the requirements of peak operation.

[0035] (3) There is no loss of heat storage medium in the entire system circulation, the storage and heat exchange efficiency is high, the overall efficiency of the system is high, the energy loss is small, and the economic benefits are good; the heat storage parameters are high, the heat storage temperature of the heat storage medium can reach above 550℃, and the exothermic steam parameters are high. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings, wherein:

[0037] Figure 1 Schematic diagram of the composition of a power generation system of the present invention;

[0038] Figure 2 A schematic diagram of another embodiment of a power generation system of the present invention;

[0039] Description of reference numerals:

[0040] 1: Heat storage medium boiler; 2: High-temperature heat storage medium tank; 3: High-temperature delivery pump; 4: Heat exchange device; 5: Low-temperature heat storage medium tank; 6: Low-temperature delivery pump; 7: Steam boiler; 801: First heat storage medium delivery pipeline; 802: Second heat storage medium delivery pipeline; 803: Third heat storage medium delivery pipeline; 804: Fourth heat storage medium delivery pipeline; 9: Heat storage medium valve; 1001: First water working medium delivery pipeline; 1002: Second water working medium delivery pipeline; 1003: Third water working medium delivery pipeline Pipe; 1004: Fourth water working medium conveying pipeline; 1005: Fifth water working medium conveying pipeline; 1006: Sixth water working medium conveying pipeline; 1007: Seventh water working medium conveying pipeline; 1008: Eighth water working medium conveying pipeline; 1009: Ninth water working medium conveying pipeline; 11: Condensation system; 12: Feed water pump; 1301: First steam-water valve; 1302: Second steam-water valve; 1303: Third steam-water valve; 1304: Fourth steam-water valve; 1305: Fifth steam-water valve; 1306: Sixth steam-water valve; 14: Steam turbine. DETAILED DESCRIPTION

[0041] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description and claims. It should be noted that the drawings are greatly simplified and not to exact ratios, and are intended solely to facilitate and clearly illustrate the embodiments of the present invention.

[0042] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0043] Example 1

[0044] like Figure 1As shown, a power generation system includes a condensing system 11, a water feed pump 12, a heat storage medium circulation and energy storage system, and a water working medium circulation system; the heat storage medium circulation and energy storage system includes: a heat storage medium boiler 1, a high-temperature heat storage medium tank 2, a high-temperature delivery pump 3, a heat exchange device 4, a low-temperature heat storage medium tank 5, a low-temperature delivery pump 6, and a plurality of heat storage medium delivery pipelines, wherein the output end of the heat storage medium boiler 1 is connected to the high-temperature heat storage medium tank 2 through a first heat storage medium delivery pipeline 801, the high-temperature heat storage medium tank 2 is connected to the heat storage medium input end of the heat exchange device 4 through a second heat storage medium delivery pipeline 802, the heat storage medium output end of the heat exchange device 4 is connected to the low-temperature heat storage medium tank 5 through a third heat storage medium delivery pipeline 803, the low-temperature heat storage medium tank 5 is connected to the input end of the heat storage medium boiler 1 through a fourth heat storage medium delivery pipeline 804, and the high-temperature delivery pump 3 is arranged on the second heat storage medium delivery pipeline 802 near the high The high-temperature heat storage medium storage tank 2 is connected to the low-temperature heat storage medium storage tank 5, and the low-temperature delivery pump 6 is arranged on the fourth heat storage medium delivery pipeline 804 near the low-temperature heat storage medium storage tank 5; the water working medium circulation system includes: a steam boiler 7, a steam turbine 14, a condensing system 11, a feed water pump 12 and several water working medium delivery pipelines, wherein the main steam output end of the steam boiler 7 is connected to the main steam input end of the steam turbine 14 through the first water working medium delivery pipeline 1001, the exhaust steam output end of the steam turbine 14 is connected to the input end of the condensing system 11 through the third water working medium delivery pipeline 1003, the output end of the condensing system 11 is connected to the feed water pump 12, and the output end of the feed water pump 12 is connected to the first feed water input end of the heat exchange device 4 and the feed water input end of the steam boiler 7 through the fourth water working medium delivery pipeline 1004 and the fifth water working medium delivery pipeline 1005 respectively, and the main steam output end of the heat exchange device 4 is connected to the main steam input end of the steam turbine 14 through the second water working medium delivery pipeline 1002.

[0045] Because this power generation system is equipped with a steam boiler 7 and a heat storage medium boiler 1, it has a larger peak-shaving range. It maintains high economic efficiency during deep peak-shaving without adversely affecting the system itself. The operating mode and energy storage solution can be customized according to the peak-shaving needs. In this power generation system, the steam boiler 7 and the heat storage medium boiler 1 can operate independently, with low technical difficulty, and their output load can be flexibly adjusted according to load demand. Furthermore, the dual-boiler design allows for stable operation even when one boiler is shut down for maintenance.

[0046] In this embodiment, molten salt can be used as the heat storage medium. This is just a specific method. In other embodiments, other heat storage media that can meet the needs can also be used.

[0047] Preferably, in this embodiment, the first water medium delivery pipeline 1001 and the second water medium delivery pipeline 1002 can be connected to the main steam input end of the turbine 14 after being merged through the first three-way valve, thereby reducing the laying of pipelines and lowering costs.

[0048] In particular, in this embodiment, a heat storage medium valve 9 is provided on the fourth heat storage medium delivery pipeline 804, which can be used to adjust the heat storage medium flow rate within the fourth heat storage medium delivery pipeline 804. A second steam-water valve 1302, a third steam-water valve 1303, and a first steam-water valve 1301 are provided on the first water working medium delivery pipeline 1001, the second water working medium delivery pipeline 1002, and the fourth water working medium delivery pipeline 1004, respectively. The first steam-water valve 1301 is used to adjust the flow rate of the water working medium entering the heat exchanger 4. When the heat exchanger 4 is not required to output load according to the load regulation requirements of the power generation system, the first steam-water valve 1301 is closed. The second steam-water valve 1302 and the third steam-water valve 1303 are both used to adjust the flow rate of main steam entering the steam turbine 14 from the corresponding water working medium pipeline. When the steam boiler 7 is not required to output load, the second steam-water valve 1302 is closed, and when the heat exchanger 4 is not required to output load, the third steam-water valve 1303 is closed.

[0049] In a possible solution of this embodiment, the high-temperature heat storage medium tank 2 and the low-temperature heat storage medium tank 5 may be different storage areas of an integral tank body.

[0050] In one possible solution of this embodiment, the sum of the thermal power output by the heat exchange device 4 at 100% load and the thermal power output by the steam boiler 7 at 100% load is the thermal power that needs to be input to the steam turbine 14 when the entire power generation system outputs the highest power generation power.

[0051] In one possible solution of this embodiment, the steam boiler 7 operates under the lowest steady-state combustion load state. When the heat exchange device 4 does not output thermal power, the thermal power output by the steam boiler 7 is the thermal power that needs to be input to the steam turbine 14 when the entire power generation system outputs the lowest power generation power.

[0052] In one possible solution of this embodiment, the sum of the thermal power output by the heat storage medium boiler 1 at 100% load and the thermal power output by the steam boiler 7 at 100% load is the thermal power that needs to be input to the steam turbine 14 when the entire power generation system operates in a state where the output power generation power is equal to the normal power generation power; the normal power generation power of the power generation system refers to the power generation power that can be output by the power generation system when both the heat storage medium boiler 1 and the steam boiler 7 output thermal power at 100% load, and the heat absorbed by the heat storage device from the heat storage medium boiler 1 is equal to the heat released by the heat storage device at the heat exchange device 4. This power generation power value of the power generation system is the normal power generation power of the power generation system. It should be noted that in order for the power generation system to output normal power, the thermal power that needs to be input to the power generation system is equal to the thermal power that can be output when the heat storage medium boiler 1 and the steam boiler 7 are both operating at 100% load. However, this does not mean that when the power generation system outputs normal power, the heat storage medium boiler 1 and the steam boiler 7 must be in a 100% load operation state. When the power generation system is actually operating, the thermal power required for the power generation system to output normal power may also come from the heat storage device and the steam boiler 7, as long as the thermal power value meets the requirement.

[0053] In one possible solution of this embodiment, the power of the heat exchange device 4 is designed according to the peak-shaving demand. Its power can be higher than the power of the heat storage medium boiler. The stored energy can be used to output high-power steam in a short time to meet the peak operation requirements.

[0054] Since there is no loss of heat storage medium circulating in the entire system, the storage and heat exchange efficiency is high, the overall efficiency of the system is high, the energy loss is small, and the economic benefits are good; the heat storage parameters are high, the heat storage temperature of the heat storage medium can reach above 550°C, and the exothermic steam parameters are high.

[0055] In some possible solutions of this embodiment, instruments such as a pressure gauge, a thermometer, a flow meter, and a remote control system are provided on the water working medium delivery pipeline and / or the heat storage medium delivery pipeline.

[0056] Example 2

[0057] like Figure 2As shown, the difference between this embodiment and embodiment 1 is the water working medium circulation system. The steam turbine 14 in this embodiment adopts a steam turbine including a high-pressure cylinder and a low-pressure cylinder. The water working medium circulation system adds a reheat steam circulation loop on the basis of embodiment 1. Specifically, in this embodiment, the water working medium circulation system includes: a steam boiler 7, a steam turbine 14 including a high-pressure cylinder and a low-pressure cylinder, a condensation system 11, a feed water pump 12 and a plurality of water working medium conveying pipelines, wherein the main steam output end of the steam boiler 7 is connected to the main steam input end of the high-pressure cylinder of the steam turbine through a first water working medium conveying pipeline 1001, the cold reheat steam output end of the high-pressure cylinder of the steam turbine is connected to the cold reheat steam input end of the steam boiler 7 through a sixth water working medium conveying pipeline 1006, the hot reheat steam output end of the steam boiler 7 is connected to the hot reheat steam inlet of the low-pressure cylinder of the steam turbine through an eighth water working medium conveying pipeline 1008, and the exhaust steam output end of the low-pressure cylinder of the steam turbine is connected to the cold The input end of the condensing system 11 is connected, the output end of the condensing system 11 is connected to the feed water pump 12, the output end of the feed water pump 12 is connected to the first feed water input end of the heat exchange device 4 and the feed water input end of the steam boiler 7 through the fourth water working medium delivery pipeline 1004 and the fifth water working medium delivery pipeline 1005 respectively, the main steam output end of the heat exchange device 4 is connected to the main steam input end of the high-pressure cylinder of the steam turbine through the second water working medium delivery pipeline 1002, the cold reheat steam output end of the high-pressure cylinder of the steam turbine is connected to the cold reheat steam input end of the heat exchange device 4 through the seventh water working medium delivery pipeline 1007, and the hot reheat steam output end of the heat exchange device 4 is connected to the hot reheat steam input end of the low-pressure cylinder of the steam turbine through the ninth water working medium delivery pipeline 1009. In this embodiment, the main steam from the steam boiler 7 and / or the heat exchange device 4 first enters the high-pressure cylinder of the steam turbine to perform work, and then the cold reheat steam discharged from the cold reheat steam output end of the high-pressure cylinder of the steam turbine enters the steam boiler 7 and / or the heat exchange device 4 again to absorb heat, is converted into hot reheat steam, and re-enters the low-pressure cylinder of the steam turbine to perform work, which can improve the utilization rate of thermal energy.

[0058] Preferably, in this embodiment, the eighth water working medium delivery pipeline 1008 and the ninth water working medium delivery pipeline 1009 can be connected to the hot reheat steam input port of the steam turbine high-pressure cylinder after merging via a fourth three-way valve. Cold reheat steam from the cold reheat steam output port of the steam turbine high-pressure cylinder can be connected to the sixth water working medium delivery pipeline 1006 and the seventh water working medium delivery pipeline 1007, respectively, via a third three-way valve. This pipeline arrangement can reduce pipeline laying and lower costs.

[0059] Specifically, in this embodiment, a fourth steam-water valve 1304, a fifth steam-water valve 1305, and a sixth steam-water valve 1306 are installed on the eighth water working medium delivery pipeline 1008, the ninth water working medium delivery pipeline 1009, and the seventh water working medium delivery pipeline 1007, respectively. The fourth steam-water valve 1304 and the fifth steam-water valve 1305 are each used to regulate the flow of hot reheat steam entering the low-pressure cylinder of the steam turbine from the corresponding water working medium pipeline. When the steam boiler 7 is not required to output load, the fourth steam-water valve 1304 is closed, and when the heat exchanger 4 is not required to output load, the fifth steam-water valve 1305 is closed. The sixth steam-water valve 1304 is used to regulate the flow of cold reheat steam entering the heat exchanger 4. When the heat exchanger is not required to output load according to the load regulation requirements of the power generation system, the sixth steam-water valve 1306 is closed. By installing these steam-water valves, power can be flexibly adjusted, thereby improving the economic efficiency of the power generation system.

[0060] The power generation system in this embodiment has substantially the same operating modes as in Example 1, depending on the load regulation requirements of the power grid. The difference is that, in each operating mode, the main steam output from the steam boiler 7 and / or heat exchanger 4 first enters the high-pressure cylinder of the steam turbine to perform work. The cold reheated steam discharged from the high-pressure cylinder of the steam turbine then re-enters the steam boiler 7 and / or heat exchanger 4 for reheating. The hot reheated steam output from the steam boiler 7 and / or heat exchanger 4 enters the low-pressure cylinder of the steam turbine to perform work a second time. This fully utilizes the heat of the steam, improving energy utilization and addressing energy issues.

[0061] The power plant's peak-shaving energy storage system features a dual-boiler design, with each boiler capable of independent operation. This approach offers low technical complexity and high system flexibility, allowing the power generation system to customize its operating mode and energy storage solution based on its peak-shaving needs. Furthermore, the dual-boiler design allows for stable operation even when one boiler is down for maintenance.

[0062] In some possible solutions of this embodiment, instruments such as pressure gauges, thermometers, flow meters, and remote control systems are also provided on the water working medium delivery pipeline and / or the heat storage medium delivery pipeline.

[0063] Example 3

[0064] In this embodiment, an existing power station having only one or more steam boilers or heat storage medium boilers may be upgraded and renovated to realize the power generation system of the present invention.

[0065] For example, an existing power station only has a steam boiler 7, which generates steam to drive a steam turbine 14, thereby driving a generator connected to its power output terminal to generate electricity. Based on this existing power station, a modification is performed to add the heat storage medium boiler 1, heat storage device, heat exchange device 4, and first heat storage medium delivery pipeline 801, second heat storage medium delivery pipeline 802, third heat storage medium delivery pipeline 803, and fourth heat storage medium delivery pipeline 804 described in the above two embodiments to implement the power generation system with deep peak shaving function of the present invention.

[0066] Furthermore, a sixth water working medium delivery pipeline 1006, a seventh water working medium delivery pipeline 1007, an eighth water working medium delivery pipeline 1008, and a ninth water working medium delivery pipeline 1009 in Example 2 can be added, so that the main steam from the steam boiler 7 and / or the heat exchange device 4 first enters the high-pressure cylinder of the steam turbine to perform work, and then the cold reheated steam discharged from the cold reheat steam output end of the high-pressure cylinder of the steam turbine enters the steam boiler 7 and / or the heat exchange device 4 again to absorb heat, is converted into hot reheated steam, and re-enters the low-pressure cylinder of the steam turbine to perform work, which can improve the utilization rate of thermal energy.

[0067] Similarly, it is also possible to renovate and upgrade an existing power station that only has a heat storage medium boiler, which will not be described in detail here.

[0068] Since the power generation system can be modified and upgraded based on the original power station, it can greatly save the construction time of the power station, and also save material resources and labor costs.

[0069] Example 4

[0070] This embodiment provides an operating method of the power generation system of embodiment 1, 2 or 3, including:

[0071] Receiving a dispatch instruction from the power grid and determining a target operating mode of the power generation system according to a preset program;

[0072] When the current operating mode of the power generation system is consistent with the target operating mode, maintaining the current operating mode;

[0073] When the current operating mode of the power generation system is inconsistent with the target operating mode, switching to the target operating mode;

[0074] Wherein, the target operation mode includes: the steam boiler 7 is running, the heat exchange device 4 is not running, and the output thermal power of the steam boiler 7 is adjusted to meet the power generation requirement; the steam boiler 7 and the heat exchange device 4 are both running, and the heat storage medium flow supplied by the heat storage device to the heat exchange device 4 and the water working medium flow supplied by the feed water pump 12 to the heat exchange device 4 are adjusted, so that the sum of the thermal power output by the heat exchange device 4 and the thermal power output by the steam boiler 7 meets the thermal power that needs to be input to the steam turbine when the power generation system outputs the target power generation; the steam boiler 7 and the heat exchange device 4 are both running, and the output thermal power of the steam boiler 7 is adjusted so that the thermal power output by the heat exchange device 4 The sum of the thermal power output by the steam boiler 7 and the thermal power output by the steam boiler 7 meets the thermal power that needs to be input to the steam turbine when the power generation system outputs the target power generation power; the steam boiler 7 and the heat exchange device 4 are both running, and while adjusting the output thermal power of the steam boiler 7, the heat storage medium flow rate supplied by the heat storage device to the heat exchange device 4 and the water working medium flow rate supplied by the feed water pump to the heat exchange device 4 are also synchronously adjusted, so that the sum of the thermal power output by the heat exchange device 4 and the thermal power output by the steam boiler 7 meets the thermal power that needs to be input to the steam turbine when the power generation system outputs the target power generation power; the steam boiler 7 stops running, the heat exchange device 4 runs, and the power of the heat exchange device 4 is adjusted to meet the power generation power requirement.

[0075] The power generation system receives the dispatching instructions of the power grid and determines the target operating mode, and can make intelligent judgments based on the actual needs of the power grid, so that the power generation system can operate at a more economical load, save energy, and improve the dispatching efficiency of the power grid.

[0076] Preferably, when the energy stored in the heat storage device is lower than a first preset threshold, the heat storage medium boiler 1 operates and delivers high-temperature heat storage medium to the heat storage device. When the energy stored in the heat storage device is higher than a second preset threshold, the heat storage medium boiler 1 stops operating. This allows the heat storage medium capacity in the heat storage device to be controlled within a reasonable range, ensuring the start-up and shutdown speed and load-variable capacity of the power generation system while minimizing heat waste.

[0077] Example 5

[0078] This embodiment provides an operating method of the power generation system of embodiment 1, 2 or 3, including:

[0079] When the power generation system is required to operate at a power output equal to or higher than the normal power generation power, the steam boilers all output thermal power at 100% load, and the flow rate of the heat storage medium supplied by the heat storage device to the heat exchange device and the flow rate of the water working medium supplied by the feed water pump to the heat exchange device are adjusted so that the sum of the thermal power output by the heat exchange device and the thermal power output by the steam boiler meets the thermal power required when the power generation system outputs the target power generation power. The power generation power output of the power generation system is adjusted by adjusting the output thermal power of the heat exchange device;

[0080] When the power generation system is required to operate at a power output lower than the normal power generation state, the following steps are performed:

[0081] S1: Determine whether the steam boiler operating alone can meet the thermal power required by the power generation system to output the target power generation power. If not, proceed to step S2; if so, proceed to step S3;

[0082] S2: If the steam boiler operating alone cannot meet the thermal power required by the power generation system to output the target power generation power, then adjust the flow rate of the heat storage medium supplied by the heat storage device to the heat exchange device and the flow rate of the water working medium supplied by the feed water pump to the heat exchange device so that the sum of the thermal power output by the heat exchange device and the thermal power output by the steam boiler meets the thermal power required by the power generation system to output the target power generation power. The power generation power output of the power generation system is adjusted by adjusting the output thermal power of the heat exchange device.

[0083] S3: If the steam boiler operating alone can meet the thermal power required by the power generation system to output the target power, the steam boiler will output thermal power to the power generation system alone, the heat exchange device will stop operating, and the power generation output of the power generation system will be regulated entirely by the steam boiler's own regulation capability;

[0084] Wherein, for any of the above operation modes, when it is necessary to supplement heat energy to the heat storage device, the heat storage medium boiler operates, and when it is not necessary to supplement heat energy to the heat storage device, the heat storage medium boiler stops operating.

[0085] Furthermore, in step S1, when the steam boiler is shut down, the heat exchange device outputs thermal power to the power generation system alone, and the adjustment of the power generation power output of the power generation system is achieved by adjusting the output thermal power of the heat exchange device. At the same time, the thermal power output by the heat exchange device to the power generation system can at least meet the thermal power required to be input when the power generation system operates at the minimum allowable power generation state.

[0086] When the power generation system is operated in a state where the output power is equal to the maximum power generation, the heat storage medium boiler 1 is operated at full load, and the low-temperature heat storage medium in the low-temperature heat storage medium tank 5 is pumped into the heat storage medium boiler 1 by the low-temperature delivery pump 6 to absorb heat, and then enters the high-temperature heat storage medium tank 2. The high-temperature delivery pump 3 provides power to pump the high-temperature heat storage medium in the high-temperature heat storage medium tank 2 into the heat exchange device 4 to exchange heat with the water working medium. At this time, the heat exchange device 4 is kept running at full load, and the main steam generated in the heat exchange device 4 is passed through the second water working medium delivery pipeline 10 02 enters the high-pressure cylinder of the steam turbine 14 to perform work; the exhaust steam from the high-pressure cylinder of the steam turbine is transported to the heat exchange device 4 through the seventh water working medium delivery pipeline 1007 for reheating, and the generated reheated steam enters the low-pressure cylinder of the steam turbine through the ninth water working medium delivery pipeline 1009 to perform work; the high-temperature heat storage medium after heat exchange becomes a low-temperature heat storage medium and enters the low-temperature heat storage medium storage tank 5. The low-temperature delivery pump 6 provides power to send the low-temperature heat storage medium back to the heat storage medium boiler 1 to absorb heat, thereby completing the cycle of the heat storage medium system; at this time, the heat storage medium valve 9 is in the open state.

[0087] Synchronously, the steam boiler 7 operates at full load, and the main steam heated to the rated parameters enters the high-pressure cylinder of the steam turbine 14 through the first water medium delivery pipe 1001 to perform work; the exhaust steam of the high-pressure cylinder of the steam turbine enters the steam boiler 7 again through the sixth water medium delivery pipe 1006 for reheating, and the generated reheated steam enters the low-pressure cylinder of the steam turbine 14 through the eighth water medium delivery pipe 1008 to perform work; after performing work, the exhaust steam discharged from the steam turbine 14 enters the condensing device 11 and the feed water pump 12 through the third water medium delivery pipe 1003, and a part of it returns to the steam boiler 7 through the fifth water medium delivery pipe 1005, and a part returns to the heat exchange device 4 through the fourth water medium delivery pipe 1004, completing the double circulation of the steam-water system; during the above operation process, the first steam-water valve 1301 and the sixth steam-water valve 1306 are opened to the maximum.

[0088] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they still fall within the scope of protection of the present invention.

Claims

1. A power generation system, characterized in that: It includes water working medium circulation system, heat storage medium circulation and energy storage system; among which, The water working medium circulation system includes: a steam boiler, a steam turbine, a condensing system, a feed water pump, which are sequentially connected to form a circulation, and a generator connected to the power output end of the steam turbine; The heat storage medium circulation and energy storage system includes: a heat storage medium boiler, a heat storage device, a heat exchange device, and a plurality of heat storage medium delivery pipelines. The heat storage device includes a high-temperature heat storage medium storage structure and a low-temperature heat storage medium storage structure. The heat storage medium delivery pipelines sequentially connect the heat storage medium boiler, the high-temperature heat storage medium storage structure of the heat storage device, the heat exchange device, and the low-temperature heat storage medium storage structure of the heat storage device, allowing the heat storage medium to circulate in the heat storage medium circulation and energy storage system. In which, the water working medium circulation system also includes a water working medium branch, and the heat exchange device is connected to the water working medium branch of the water working medium circulation system through a pipeline, so that the water working medium to be heated passes through the heat exchange device and exchanges heat with the heat storage medium at the heat exchange device. The water working medium is heated by the heat storage medium, and the heated water working medium enters the steam turbine to participate in power generation.

2. The power generation system according to claim 1, characterized in that: The heat storage device is a dual-tank structure, wherein the low-temperature heat storage medium storage structure is a low-temperature storage tank, and the high-temperature heat storage medium storage structure is a high-temperature storage tank; or The heat storage device has a single tank structure, wherein the high-temperature heat storage medium storage structure is the high-temperature heat storage medium storage area of ​​the single tank, and the low-temperature heat storage medium storage structure is the low-temperature heat storage medium storage area of ​​the single tank, and the high-temperature heat storage medium storage area and the low-temperature heat storage medium storage area are independent of each other.

3. The power generation system according to claim 1 or 2, characterized in that: A high-temperature delivery pump is provided on the heat storage medium delivery pipeline connecting the output end of the high-temperature heat storage medium storage structure of the heat storage device and the heat exchange device. The high-temperature delivery pump can adjust the flow rate of the heat storage medium pumped into the heat exchange device between closed and fully open.

4. The power generation system according to claim 1 or 2, characterized in that: A low-temperature delivery pump is provided on the heat storage medium delivery pipeline connecting the output end of the low-temperature heat storage medium storage structure of the heat storage device and the heat storage medium boiler.

5. The power generation system according to claim 1 or 2, characterized in that: A heat storage medium valve is also provided on the heat storage medium delivery pipeline connecting the output end of the low-temperature heat storage medium storage structure of the heat storage device and the heat storage medium boiler.

6. The power generation system according to claim 1, characterized in that: The main steam output end of the steam boiler is connected to the main steam input end of the steam turbine through a first water working medium delivery pipe, the exhaust steam output end of the steam turbine is connected to the input end of the condensing system through a third water working medium delivery pipe, the output end of the condensing system is connected to a feed water pump, the output end of the feed water pump is divided into two branches, one of which is connected to the first feed water input end of the heat exchange device through a fourth water working medium delivery pipe, and the other branch is connected to the feed water input end of the steam boiler through a fifth water working medium delivery pipe, and the main steam output end of the heat exchange device is connected to the main steam input end of the steam turbine through a second water working medium delivery pipe; The output end of the high-temperature heat storage medium storage structure of the heat storage device is connected to the heat storage medium input end of the heat exchange device through a second heat storage medium delivery pipeline, the heat storage medium output end of the heat exchange device is connected to the input end of the low-temperature heat storage medium storage structure of the heat storage device through a third heat storage medium delivery pipeline, the output end of the low-temperature heat storage medium storage structure of the heat storage device is connected to the input end of the heat storage medium boiler through a fourth heat storage medium delivery pipeline, and the output end of the heat storage medium boiler is connected to the input end of the high-temperature heat storage medium storage structure of the heat storage device through a first heat storage medium delivery pipeline.

7. The power generation system according to claim 6, characterized in that: The first water working medium delivery pipeline and the second water working medium delivery pipeline are connected to the main steam input end of the high-pressure cylinder of the steam turbine after being communicated through a first three-way valve.

8. A power generation system according to claim 6 or 7, characterized in that: A second steam-water valve is provided on the first water working medium delivery pipeline; A third steam-water valve is provided on the second water working medium delivery pipeline; The fourth water working medium delivery pipeline is provided with a first steam-water valve.

9. The power generation system according to claim 1, characterized in that: The steam turbine includes a high-pressure cylinder and a low-pressure cylinder; the main steam output end of the steam boiler is connected to the main steam input end of the high-pressure cylinder of the steam turbine through a first water working medium conveying pipe, the cold reheat steam output end of the high-pressure cylinder of the steam turbine is connected to the cold reheat steam input end of the steam boiler through a sixth water working medium conveying pipe, and the hot reheat steam output end of the steam boiler is connected to the hot reheat steam input end of the low-pressure cylinder of the steam turbine through an eighth water working medium conveying pipe; at the same time, the cold reheat steam output end of the high-pressure cylinder of the steam turbine is connected to the cold reheat steam input end of the heat exchange device through a seventh water working medium conveying pipe, and the hot reheat steam output end of the heat exchange device is connected to the hot reheat steam input end of the low-pressure cylinder of the steam turbine through a ninth water working medium conveying pipe.

10. The power generation system according to claim 9, characterized in that: The sixth water working medium delivery pipeline and the seventh water working medium delivery pipeline are connected to the cold reheat steam output end of the high-pressure cylinder of the steam turbine through the third three-way valve, and the eighth water working medium delivery pipeline and the ninth water working medium delivery pipeline are connected to the hot reheat steam inlet of the low-pressure cylinder of the steam turbine through the fourth three-way valve.

11. A power generation system according to claim 9 or 10, characterized in that: The eighth water working medium delivery pipeline is provided with a fourth steam-water valve; The ninth water working medium delivery pipeline is provided with a fifth steam-water valve; The seventh water working medium delivery pipeline is provided with a sixth steam-water valve.

12. The power generation system according to claim 1, characterized in that The sum of the thermal power output by the heat exchange device at 100% load and the thermal power output by the steam boiler at 100% load is the thermal power that needs to be input to the steam turbine when the entire power generation system outputs the highest power generation power.

13. The power generation system according to claim 1, characterized in that When the steam boiler operates under the lowest steady-fire load state and the heat exchange device does not output thermal power, the thermal power output by the steam boiler is the thermal power that needs to be input to the steam turbine when the entire power generation system outputs the lowest power generation power.

14. The power generation system according to claim 1, characterized in that The sum of the thermal power output by the heat storage medium boiler at 100% load and the thermal power output by the steam boiler at 100% load is the thermal power that needs to be input to the steam turbine when the entire power generation system operates in a state where the output power generation is equal to the normal power generation; The normal power generation power of the power generation system refers to the power generation power that can be output by the power generation system when the heat storage medium boiler and the steam boiler both output thermal power at 100% load, and the heat absorbed by the heat storage device from the heat storage medium boiler is equal to the heat released by the heat storage device at the heat exchange device.

15. A method for operating a power generation system, characterized in that: The power generation system applied to any one of claims 1 to 14, comprising: Receiving a dispatch instruction from the power grid and determining a target operating mode of the power generation system according to a preset program; When the current operating mode of the power generation system is consistent with the target operating mode, maintaining the current operating mode; When the current operating mode of the power generation system is inconsistent with the target operating mode, switching to the target operating mode; The target operation mode includes: The steam boiler is running, the heat exchange device is not running, and the output thermal power of the steam boiler is adjusted to meet the power generation requirement; The steam boiler and the heat exchange device are both in operation, and the flow rate of the heat storage medium supplied by the heat storage device to the heat exchange device and the flow rate of the water working medium supplied by the feed water pump to the heat exchange device are adjusted so that the sum of the thermal power output by the heat exchange device and the thermal power output by the steam boiler meets the thermal power required to be input to the steam turbine when the power generation system outputs a target power generation; The steam boiler and the heat exchange device are both operated, and the thermal power output of the steam boiler is adjusted so that the sum of the thermal power output of the heat exchange device and the thermal power output of the steam boiler meets the thermal power required to be input to the steam turbine when the power generation system outputs a target power generation; The steam boiler and the heat exchange device are both in operation, and while adjusting the output thermal power of the steam boiler, the flow rate of the heat storage medium supplied by the heat storage device to the heat exchange device and the flow rate of the water working medium supplied by the feed water pump to the heat exchange device are also synchronously adjusted, so that the sum of the thermal power output by the heat exchange device and the thermal power output by the steam boiler meets the thermal power required to be input to the steam turbine when the power generation system outputs the target power; The steam boiler stops running, the heat exchange device starts running, and the power of the heat exchange device is adjusted to meet the power generation requirement.

16. The power generation system operating method according to claim 15, characterized in that: When the energy stored in the heat storage device is lower than a first preset threshold, the heat storage medium boiler operates and delivers high-temperature heat storage medium to the heat storage device. When the energy stored in the heat storage device is higher than a second preset threshold, the heat storage medium boiler stops operating.

17. A method for operating a power generation system, characterized in that: The power generation system applied to any one of claims 1 to 14, comprising: When the power generation system is required to operate at a power output equal to or higher than the normal power generation power, the steam boilers all output thermal power at 100% load, and the flow rate of the heat storage medium supplied by the heat storage device to the heat exchange device and the flow rate of the water working medium supplied by the feed water pump to the heat exchange device are adjusted so that the sum of the thermal power output by the heat exchange device and the thermal power output by the steam boiler meets the thermal power required when the power generation system outputs the target power generation power. The power generation power output of the power generation system is adjusted by adjusting the output thermal power of the heat exchange device; When the power generation system is required to operate at a power output lower than the normal power generation state, the following steps are performed: S1: Determine whether the steam boiler operating alone can meet the thermal power required by the power generation system to output the target power generation power. If not, proceed to step S2; if so, proceed to step S3; S2: If the steam boiler operating alone cannot meet the thermal power required by the power generation system to output the target power generation power, then adjust the flow rate of the heat storage medium supplied by the heat storage device to the heat exchange device and the flow rate of the water working medium supplied by the feed water pump to the heat exchange device so that the sum of the thermal power output by the heat exchange device and the thermal power output by the steam boiler meets the thermal power required by the power generation system to output the target power generation power. The power generation power output of the power generation system is adjusted by adjusting the output thermal power of the heat exchange device. S3: If the steam boiler operating alone can meet the thermal power required by the power generation system to output the target power, the steam boiler will output thermal power to the power generation system alone, the heat exchange device will stop operating, and the power generation output of the power generation system will be regulated entirely by the steam boiler's own regulation capability; Wherein, for any of the above operation modes, when it is necessary to supplement heat energy to the heat storage device, the heat storage medium boiler operates, and when it is not necessary to supplement heat energy to the heat storage device, the heat storage medium boiler stops operating.

18. The power generation system operating method according to claim 17, characterized in that: In step S1, when the steam boiler is shut down, the heat exchange device outputs thermal power to the power generation system alone. The adjustment of the power generation power output of the power generation system is achieved by adjusting the output thermal power of the heat exchange device. At the same time, the thermal power output by the heat exchange device to the power generation system can at least meet the thermal power input required when the power generation system operates at the minimum allowable power generation state.

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