Boiler complementary steam supply system and method coupled with thermocline solar photo-thermal energy storage

Abstract

The invention provides a boiler complementary steam supply system and method coupled with thermocline solar photo-thermal energy storage. The system comprises a solar tower, a main heat exchanger, a thermocline heat storage tank, a fused salt storage heat exchanger, a first heat exchanger and a coal-fired unit. A hot end inlet and a cold end outlet of the fused salt storage heat exchanger are respectively connected with a high-temperature fused salt outlet and a low-temperature fused salt inlet of the solar tower; a hot end inlet and a cold end outlet of the main heat exchanger are respectively connected with a high-temperature fused salt outlet and a low-temperature fused salt inlet of the solar tower; the thermocline heat storage tank is connected with the fused salt storage heat exchanger, and the fused salt storage heat exchanger is used for conducting heat exchange on fused salt in the thermocline heat storage tank; the main heat exchanger is connected with the fused salt storage heat exchanger and the first heat exchanger. A cold end inlet of the first heat exchanger is connected with a water supply pipeline at a first inlet of a boiler of the coal-fired unit, and a hot end outlet of the first heat exchanger is connected with a main steam pipeline at a first outlet of the boiler. The system can assist in energy conservation and emission reduction, and the dual-carbon target is achieved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of energy utilization, and particularly relates to a boiler complementary steam supply system and method coupled with a thermocline solar photothermal energy storage. BACKGROUND

[0002] Under the double-carbon index requirements of current carbon peak and carbon neutralization, the proportion of renewable energy such as wind and light is becoming more and more significant. However, renewable energy such as wind and light has the characteristics of intermittency and volatility, which brings new challenges to the power grid. Under this background, combined heat and power generation thermal power units need to frequently participate in peak regulation to meet the demand of industrial steam supply, which leads to the fact that the existing thermal power units meet the parameter requirements of two-stage industrial steam supply by adopting the method of reducing the temperature and pressure of the main steam under low load conditions, thereby causing poor thermal economy of the unit and increasing coal consumption.

[0003] The existing combined heat and power generation unit commonly used high-pressure industrial steam supply technology includes cold re-steam extraction heat supply, hot re-steam extraction heat supply, main steam temperature and pressure reduction heat supply, and main steam back pressure machine heat supply. Among them, for the most commonly used 300MW level thermal power unit in China, cold re-steam extraction heat supply and hot re-steam extraction heat supply are difficult to provide industrial parameters of 3MPa and steam supply demand of 100t / h under 50%THA conditions; main steam temperature and pressure reduction heat supply can meet the high-pressure steam supply demand under low load conditions, but its economy is poor; through the main steam back pressure machine heat supply, new back pressure machine plant needs to be built, and back pressure machine and supporting related valves need to be purchased, which has high investment cost in the early stage, and the economic benefit is unstable especially under the condition of steam supply demand fluctuation.

[0004] In view of the above problems, it is necessary to provide a boiler complementary steam supply system and method coupled with a thermocline solar photothermal energy storage which is reasonable in design and effectively solves the above problems. SUMMARY

[0005] The present application aims to at least solve one of the technical problems existing in the prior art, and provides a boiler complementary steam supply system and method coupled with a thermocline solar photothermal energy storage.

[0006] One aspect of the present application provides a boiler complementary steam supply system coupled with a thermocline solar photothermal energy storage, which comprises a solar tower, a main heat exchanger, a thermocline heat storage tank, a molten salt storage and heat exchanger, a first heat exchanger and a coal-fired unit. The hot end inlet and the cold end outlet of the molten salt storage and heat exchanger are connected with the high-temperature molten salt outlet and the low-temperature molten salt inlet of the solar tower, respectively. The hot end inlet and the cold end outlet of the main heat exchanger are connected with the high-temperature molten salt outlet and the low-temperature molten salt inlet of the solar tower, respectively. The thermocline heat storage tank comprises high-temperature molten salt stored above the thermocline heat storage tank and low-temperature molten salt stored below the thermocline heat storage tank; the thermocline heat storage tank is connected with the molten salt storage heat exchanger, and the molten salt storage heat exchanger is used for heat exchange of the molten salt in the thermocline heat storage tank. The main heat exchanger is connected with the molten salt storage heat exchanger and the first heat exchanger respectively. The cold end inlet of the first heat exchanger is connected with a feedwater pipeline at a first inlet of a boiler of the coal-fired unit, and the hot end outlet of the first heat exchanger is connected with a main steam pipeline at a first outlet of the boiler.

[0007] Optionally, the system further comprises a second heat exchanger. The cold end inlet of the second heat exchanger is connected with a condensate pipeline at an outlet of a deaerator of the coal-fired unit, and the hot end outlet of the second heat exchanger is connected with a reheat steam pipeline at a second outlet of the boiler; wherein the condensate pipeline is provided with a water pump for boosting the condensate.

[0008] Optionally, the outlet of the main heat exchanger is connected with the inlet of the first heat exchanger and the inlet of the second heat exchanger respectively. The inlet of the main heat exchanger is connected with the outlet of the first heat exchanger and the outlet of the second heat exchanger respectively.

[0009] Optionally, the system further comprises a third heat exchanger. The inlet of the third heat exchanger is connected with the outlet of the first heat exchanger and the outlet of the second heat exchanger respectively, and the outlet of the third heat exchanger is connected with the inlet of the main heat exchanger.

[0010] Optionally, the cold end inlet of the third heat exchanger is connected with the condensate pipeline at the outlet of the deaerator; wherein The condensate is boosted to absorb heat in the third heat exchanger to form industrial steam supply and then supply heat externally.

[0011] Optionally, a cold reheat steam main pipeline is arranged at a second inlet of the boiler; wherein Steam is extracted from the cold reheat steam main pipeline to directly form industrial steam supply.

[0012] Another aspect of the present application provides a boiler complementary steam supply method coupled with a thermocline solar light and heat energy storage, which adopts the boiler complementary steam supply system coupled with the thermocline solar light and heat energy storage as described above, and the method comprises the following steps: In the case of sufficient sunlight, a part of the high-temperature molten salt in the solar tower is discharged into the molten salt storage heat exchanger to release heat and heat the molten salt in the tilted stratification heat storage tank; a part of the high-temperature molten salt in the solar tower is discharged into the main heat exchanger to release heat and heat the first heat exchanger; the low-temperature molten salt in the tilted stratification heat storage tank is discharged into the molten salt storage heat exchanger to absorb heat and become high-temperature molten salt, which is returned to the tilted stratification heat storage tank for heat storage; In the case of insufficient sunlight, the high-temperature molten salt in the tilted stratification heat storage tank is discharged into the molten salt storage heat exchanger to release heat and become low-temperature molten salt, which is returned to the tilted stratification heat storage tank; the molten salt medium in the main heat exchanger absorbs heat in the molten salt storage heat exchanger, and then is returned to the main heat exchanger to release heat and heat the first heat exchanger; During the operation of the coal-fired unit, the feed water at the first inlet of the boiler is transported to the first heat exchanger to absorb heat and form high-temperature and high-pressure steam, which is then transported to the main steam pipeline at the first outlet of the boiler through the first outlet of the first heat exchanger.

[0013] Optionally, the method further comprises: The condensed water at the outlet of the deaerator is pressurized and then transported to the second heat exchanger to absorb heat and form high-temperature steam, which is then transported to the reheated steam pipeline at the second outlet of the boiler.

[0014] Optionally, the method further comprises: The condensed water at the outlet of the deaerator is pressurized and then transported to the third heat exchanger to absorb heat and form 3MPa industrial steam supply, which is used for external heat supply.

[0015] Optionally, the method further comprises: Steam is directly extracted from the cold re-steam main pipe for 1.5MPa industrial steam supply.

[0016] The boiler complementary steam supply system coupled with the tilted stratification solar photo-thermal energy storage and the method thereof form a steam production system complementary to solar photo-thermal energy and coal-fired boilers, which creatively combines a solar photo-thermal energy storage system with a traditional coal-fired unit, realizes the combination of new energy clean and low carbon and coal power continuous and reliable, realizes multi-stage utilization of solar energy, can guarantee industrial steam supply demand in the deep peak regulation state of the unit and reduce coal consumption of the unit, can help energy saving and emission reduction, and realizes the double carbon target. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 FIG. 1 is a structural schematic diagram of a boiler complementary steam supply system coupled with the tilted stratification solar photo-thermal energy storage according to an embodiment of the present application; Figure 2A flowchart of a complementary steam supply method of a boiler coupled with a thermocline solar energy light and heat energy storage according to another embodiment of the present application. DETAILED DESCRIPTION

[0018] In order for those skilled in the art to better understand the technical solutions of the present application, the present application will be further described in detail below in combination with the drawings and specific embodiments.

[0019] As shown in Figure 1 An aspect of the present application provides a complementary steam supply system of a boiler coupled with a thermocline solar energy light and heat energy storage, which comprises a solar tower 1, a main heat exchanger 2, a thermocline heat storage tank 3, a molten salt storage and heat exchanger 4, a first heat exchanger 5, and a coal-fired unit.

[0020] The coal-fired unit comprises a boiler 6, a high-pressure cylinder 7, a medium-pressure cylinder 8, and a low-pressure cylinder 9 connected in sequence, a generator G connected with the low-pressure cylinder 9, a deaerator 10 connected with the medium-pressure cylinder 8, and a feedwater pipeline between the outlet of the deaerator 10 and the first inlet of the boiler 6, which is provided with three high-pressure heaters 11 in sequence, and a condenser 12 connected with the low-pressure cylinder 9 and the deaerator 10, respectively. That is, the coal-fired unit is a conventional coal-fired unit, and its composition can refer to the composition of the existing coal-fired unit in the prior art, which will not be described here in detail.

[0021] The hot end inlet and the cold end outlet of the molten salt storage and heat exchanger 4 are connected with the high-temperature molten salt outlet and the low-temperature molten salt inlet of the solar tower 1, respectively.

[0022] Specifically, under the condition of sufficient sunlight, a part of high-temperature molten salt absorbing solar energy in the solar tower 1 is transported from the high-temperature molten salt outlet of the solar tower 1 to the hot end inlet of the molten salt storage and heat exchanger 4, and the high-temperature molten salt becomes low-temperature molten salt after heat release in the molten salt storage and heat exchanger 4, and the low-temperature molten salt is transported from the cold end outlet of the molten salt storage and heat exchanger 4 to the low-temperature molten salt inlet of the solar tower 1. Among them, the high-temperature molten salt entering the molten salt storage and heat exchanger 4 for heat release is used to heat the molten salt in the thermocline heat storage tank 3.

[0023] The hot end inlet and the cold end outlet of the main heat exchanger 2 are connected with the high-temperature molten salt outlet and the low-temperature molten salt inlet of the solar tower 1, respectively.

[0024] Specifically, under the condition of sufficient sunlight, a part of high-temperature molten salt absorbing solar energy in the solar tower 1 is transported from the high-temperature molten salt outlet of the solar tower 1 to the hot end inlet of the main heat exchanger 2 for heat release to become low-temperature molten salt, and the low-temperature molten salt is transported from the cold end outlet of the main heat exchanger 2 to the low-temperature molten salt inlet of the solar tower 1. Among them, the high-temperature molten salt entering the main heat exchanger 2 for heat exchange is used to supply the heat exchange amount required by the first heat exchanger 5, and then replace the boiler 6 of the coal-fired unit to provide part of the main steam.

[0025] The inclined thermosphere thermal storage tank 3 includes high-temperature molten salt stored above it and low-temperature molten salt stored below it; the inclined thermosphere thermal storage tank 3 is connected to the molten salt storage and release heat exchanger 4, which is used to exchange heat with the molten salt in the inclined thermosphere thermal storage tank 3.

[0026] Specifically, under conditions of sufficient sunlight, solar heat is stored in the inclined thermocentric thermal storage tank 3 via a molten salt storage heat exchanger 4. During the heat storage process, the low-temperature molten salt in the inclined thermocentric thermal storage tank 3 flows out from the lower outlet of the tank, absorbs heat through the molten salt storage heat exchanger 4, and becomes high-temperature molten salt. The high-temperature molten salt then enters the high-temperature molten salt side of the inclined thermocentric thermal storage tank 3 through the upper inlet for storage. Under conditions of insufficient sunlight, the high-temperature molten salt in the inclined thermocentric thermal storage tank 3 flows out from the upper inlet, enters the molten salt storage heat exchanger 4, releases heat, and becomes low-temperature molten salt. The low-temperature molten salt then enters the low-temperature molten salt side of the inclined thermocentric thermal storage tank 3 through the lower inlet.

[0027] The main heat exchanger 2 is connected to the molten salt storage heat exchanger 4 and the first heat exchanger 5, respectively.

[0028] Specifically, when there is insufficient sunlight, the molten salt medium in the main heat exchanger 2 absorbs heat in the molten salt storage heat exchanger 4, and then returns to the main heat exchanger 2 to release heat to supply heat to the first heat exchanger 5, thereby replacing the boiler 6 of the coal-fired unit to provide part of the main steam.

[0029] The cold end inlet of the first heat exchanger 5 is connected to the water supply pipe 13 at the first inlet of the boiler 6 of the coal-fired unit, and the hot end outlet of the first heat exchanger 5 is connected to the main steam pipe 14 at the first outlet of the boiler 6.

[0030] Specifically, the feedwater at the first inlet of the boiler 6 is transported to the first heat exchanger 5 through the cold end inlet to absorb heat and form high-temperature, high-pressure steam. Then, it is transported through the hot end outlet of the first heat exchanger 5 to the main steam pipeline 14 at the first outlet of the boiler 6, and merges into the main steam cycle of the coal-fired unit. In other words, the first heat exchanger 5 provides part of the main steam instead of the boiler 6, and this steam production process forms a complementary steam system of solar thermal energy and coal-fired boiler.

[0031] The present invention relates to a boiler complementary steam supply system and method with coupled thermotropic layer solar thermal energy storage. This system forms a steam production system that complements solar thermal energy and coal-fired boilers. It creatively combines a solar thermal energy storage system with a traditional coal-fired unit, realizing the combination of clean and low-carbon new energy and continuous and reliable coal power. It achieves multi-level utilization of solar energy, which can not only ensure the industrial steam supply demand under deep peak shaving conditions of the unit, but also reduce the coal consumption of the unit for power generation, thus contributing to energy conservation and emission reduction and achieving dual carbon goals.

[0032] Optional, such as Figure 1 As shown, the system also includes a second heat exchanger 15; the cold end inlet of the second heat exchanger 15 is connected to the condensate pipe 16 at the outlet of the deaerator 10 of the coal-fired unit, and the hot end outlet of the second heat exchanger 15 is connected to the reheat steam pipe 17 at the second outlet of the boiler 6; wherein, the condensate pipe 16 is equipped with a water pump 18 for pressurizing the condensate.

[0033] Specifically, the condensate at the outlet of deaerator 10 is pressurized by water pump 18 to the pressure required for industrial steam supply and then transported to the second heat exchanger 15. In the second heat exchanger 15, it absorbs heat to form high-temperature steam, which is then transported to the reheat steam pipeline 17 at the second outlet of boiler 6. This steam production process forms a complementary steam system of solar thermal and coal-fired boiler.

[0034] For example, such as Figure 1 As shown, the outlet of the main heat exchanger 2 is connected to the inlet of the first heat exchanger 5 and the inlet of the second heat exchanger 15, respectively; the inlet of the main heat exchanger 2 is connected to the outlet of the first heat exchanger 5 and the outlet of the second heat exchanger 15, respectively.

[0035] Specifically, the molten salt medium in the main heat exchanger 2 absorbs heat and then releases heat in the first heat exchanger 5 and the second heat exchanger 5 respectively, providing the required heat to the first heat exchanger 5 and the second heat exchanger 5.

[0036] For example, such as Figure 1 As shown, the system also includes a third heat exchanger 19; the inlet of the third heat exchanger 19 is connected to the outlet of the first heat exchanger 5 and the outlet of the second heat exchanger 15 respectively, and the outlet of the third heat exchanger 19 is connected to the inlet of the main heat exchanger 2.

[0037] Specifically, after absorbing heat, the molten salt medium in the main heat exchanger 2 releases heat in the first heat exchanger 5 and the second heat exchanger 5 respectively, providing the required heat to the first heat exchanger 5 and the second heat exchanger 5. After that, the heat is collected and flows into the third heat exchanger 19 for heat exchange before returning to the main heat exchanger 2. In other words, the molten salt medium that has absorbed heat in the main heat exchanger 2 is used to supply the required heat exchange to the first heat exchanger 5, the second heat exchanger 15, and the third heat exchanger 19.

[0038] For example, such as Figure 1 As shown, the cold end inlet of the third heat exchanger 19 is connected to the condensate pipe at the outlet of the deaerator 10 by 16; wherein, after the condensate is pressurized, it absorbs heat in the third heat exchanger 19 to form industrial steam for external heating.

[0039] Specifically, the condensate from the outlet of the deaerator 10 is pressurized by the water pump 18 to the pressure required for industrial steam supply, and then absorbed by the third heat exchanger 19 to form 3MPa-level industrial steam for external heating.

[0040] For example, a cold resteam header 20 is provided at the second inlet of the boiler 6; wherein, steam is extracted from the cold resteam header 20 and then directly supplied to the industrial steam source.

[0041] Specifically, a portion of steam is extracted from the unit's cold reheat steam header 20 for 1.5MPa-level industrial steam supply. A portion of the main steam (Q1) is provided by the molten salt energy storage system, and the main steam provided by the boiler is Q2. Considering the boiler reheater overheating limit, the extractable amount of cold reheat steam is Q1 + r × Q2 (where r is the allowable extraction coefficient, typically 5%~8%). Corresponding to conventional cogeneration boiler steam supply, when the main steam provided by the boiler is Q1 + Q2, considering the boiler reheater overheating limit, the extractable amount of cold reheat steam is r × (Q1 + Q2) (where r is the allowable extraction coefficient). In summary, with the same amount of main steam entering the turbine high-pressure cylinder, this invention proposes a system with a larger cold reheat steam extraction capacity, increasing the extraction capacity by (1-r) × Q1.

[0042] like Figure 1 As shown, the system also includes a mirror field 21, which reflects the collected solar radiation energy into the solar tower 1 and converts it into high-temperature thermal energy for storage.

[0043] The boiler complementary steam supply system of the coupled thermotropic layer solar thermal energy storage of the present invention, compared with a conventional 350MW supercritical unit (main steam pressure 24.2MPa, main steam temperature 566℃, reheat steam temperature 566℃, back pressure set at 4.9kPa), when the industrial steam supply parameters are pressure 3MPa, temperature 280℃, steam extraction rate 100t / h, and main steam flow rate set at 1008.51t / h, the coal consumption for power generation of the present invention is only 235.12g / kWh, while the coal consumption for power generation of the conventional cogeneration scheme is only 276.57 g / kWh. The coal consumption for power generation of the present invention is reduced by 41.45 g / kWh, and the coal saving effect is significant.

[0044] For example, such as Figure 2 As shown, another aspect of the present invention provides a boiler complementary steam supply method S100 coupled with thermotropical layer solar thermal energy storage, employing the boiler complementary steam supply system coupled with thermotropical layer solar thermal energy storage described above. The specific composition of this boiler complementary steam supply system coupled with thermotropical layer solar thermal energy storage has been described in detail above and will not be repeated here.

[0045] Specifically, the boiler complementary steam supply method S100 coupled with thermotropic solar thermal energy storage can include: S110. Under sufficient sunlight, a portion of the high-temperature molten salt in the solar tower enters the molten salt storage heat exchanger to release heat and heat the molten salt in the inclined temperature layer heat storage tank; a portion of the high-temperature molten salt in the solar tower enters the main heat exchanger to release heat and supply heat to the first heat exchanger; the low-temperature molten salt in the inclined temperature layer heat storage tank enters the molten salt storage heat exchanger to absorb heat and becomes high-temperature molten salt, and then returns to the inclined temperature layer heat storage tank for heat storage.

[0046] Specifically, under sufficient sunlight, a portion of the high-temperature molten salt absorbed by the solar energy in the solar tower 1 is transported from the high-temperature molten salt outlet of the solar tower 1 to the hot end inlet of the main heat exchanger 2 to release heat and transform into low-temperature molten salt. The low-temperature molten salt is then transported from the cold end outlet of the main heat exchanger 2 to the low-temperature molten salt inlet of the solar tower 1. The high-temperature molten salt, after entering the main heat exchanger 2, is used to supply the heat required by the first heat exchanger 5, thereby replacing the boiler 6 of the coal-fired unit in providing a portion of the main steam.

[0047] Solar heat is stored in the inclined thermosphere thermal storage tank 3 through the molten salt storage heat exchanger 4. During the heat storage process, the low-temperature molten salt in the inclined thermosphere thermal storage tank 3 flows out from the lower outlet of the inclined thermosphere thermal storage tank 3, and after absorbing heat through the molten salt storage heat exchanger 4, it becomes high-temperature molten salt. The high-temperature molten salt enters the high-temperature molten salt side of the inclined thermosphere thermal storage tank 3 from the upper inlet for storage.

[0048] S120. In the absence of sufficient sunlight, the high-temperature molten salt in the thermocline heat storage tank enters the molten salt storage and release heat exchanger, becomes low-temperature molten salt, and then returns to the thermocline heat storage tank; the molten salt medium in the main heat exchanger absorbs heat in the molten salt storage and release heat exchanger, and then returns to the main heat exchanger to release heat to supply heat to the first heat exchanger.

[0049] Specifically, under insufficient sunlight conditions, the high-temperature molten salt in the inclined thermosphere thermal storage tank 3 flows out from the upper inlet of the inclined thermosphere thermal storage tank 3, enters the molten salt storage heat exchanger 4 to release heat and becomes low-temperature molten salt, and then the low-temperature molten salt enters the low-temperature molten salt side of the inclined thermosphere thermal storage tank 3 from the lower inlet of the inclined thermosphere thermal storage tank 3.

[0050] The molten salt medium in the main heat exchanger 2 absorbs heat in the molten salt storage heat exchanger 4, and then returns to the main heat exchanger 2 to release heat to supply heat to the first heat exchanger 5, thereby replacing the boiler 6 of the coal-fired unit to provide part of the main steam.

[0051] S130. During the operation of the coal-fired unit, the feedwater at the first inlet of the boiler is transported to the first heat exchanger to absorb heat and form high-temperature and high-pressure steam, and then transported to the main steam pipeline at the first outlet of the boiler through the first outlet of the first heat exchanger.

[0052] Specifically, the feedwater at the first inlet of the boiler 6 is transported to the first heat exchanger 5 through the cold end inlet to absorb heat and form high-temperature, high-pressure steam. Then, it is transported through the hot end outlet of the first heat exchanger 5 to the main steam pipeline 14 at the first outlet of the boiler 6, and merges into the main steam cycle of the coal-fired unit. In other words, the first heat exchanger 5 provides part of the main steam instead of the boiler 6, and this steam production process forms a complementary steam system of solar thermal energy and coal-fired boiler.

[0053] Optionally, the method further includes: The condensate at the outlet of deaerator 10 is pressurized and sent to the second heat exchanger 15, where it absorbs heat to form high-temperature steam, which is then sent to the reheat steam pipeline 17 at the second outlet of boiler 6. This steam production process forms a complementary steam system of solar thermal and coal-fired boiler.

[0054] For example, the method further includes: The condensate at the outlet of the deaerator 10 is pressurized and transported to the third heat exchanger 19. After absorbing heat in the third heat exchanger 19, it forms 3MPa-level industrial steam for external heating.

[0055] For example, the method further includes: Steam is extracted directly from the cold resteam header 20 to provide industrial steam at a pressure of 1.5 MPa.

[0056] The boiler complementary steam supply method of the present invention, which couples a thermocentric solar thermal energy storage system, fully utilizes solar heat, forming a steam production system that complements solar thermal energy and coal-fired boilers. By combining multi-stage heating of condensate into superheated steam for industrial steam supply, multi-stage energy utilization of the thermal system is achieved. Through the main steam and molten salt system of the unit, the cold reheat steam heating flow rate can be significantly increased, reducing heating energy consumption. In summary, the present invention not only achieves multi-stage utilization of solar energy but also ensures industrial steam supply needs under deep peak-shaving conditions. Implementation of the patented solution of this invention can save energy and reduce emissions, contributing to the achievement of dual-carbon goals.

[0057] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A boiler-complementary steam supply system coupled with spherical solar thermal energy storage, characterized in that, This includes solar towers, main heat exchangers, thermocline storage tanks, molten salt storage heat exchangers, the first heat exchanger, and coal-fired power units. The hot end inlet and cold end outlet of the molten salt storage heat exchanger are respectively connected to the high-temperature molten salt outlet and low-temperature molten salt inlet of the solar tower. The hot end inlet and cold end outlet of the main heat exchanger are respectively connected to the high-temperature molten salt outlet and low-temperature molten salt inlet of the solar tower. The inclined thermosphere thermal storage tank includes high-temperature molten salt stored above it and low-temperature molten salt stored below it; the inclined thermosphere thermal storage tank is connected to the molten salt storage and release heat exchanger, which is used to exchange heat with the molten salt in the inclined thermosphere thermal storage tank. The main heat exchanger is connected to the molten salt storage heat exchanger and the first heat exchanger, respectively. The cold end inlet of the first heat exchanger is connected to the feedwater pipe at the first inlet of the boiler of the coal-fired unit, and the hot end outlet of the first heat exchanger is connected to the main steam pipe at the first outlet of the boiler.

2. The system according to claim 1, characterized in that, The system also includes a second heat exchanger; The cold end inlet of the second heat exchanger is connected to the condensate pipe at the deaerator outlet of the coal-fired unit, and the hot end outlet of the second heat exchanger is connected to the reheat steam pipe at the second outlet of the boiler; wherein, the condensate pipe is equipped with a water pump for pressurizing the condensate.

3. The system according to claim 2, characterized in that, The outlet of the main heat exchanger is connected to the inlet of the first heat exchanger and the inlet of the second heat exchanger, respectively. The inlet of the main heat exchanger is connected to the outlet of the first heat exchanger and the outlet of the second heat exchanger, respectively.

4. The system according to claim 3, characterized in that, The system also includes a third heat exchanger; The inlet of the third heat exchanger is connected to the outlet of the first heat exchanger and the outlet of the second heat exchanger, respectively, and the outlet of the third heat exchanger is connected to the inlet of the main heat exchanger.

5. The system according to claim 4, characterized in that, The cold end inlet of the third heat exchanger is connected to the condensate pipe at the outlet of the deaerator; wherein... After the condensate is pressurized, it absorbs heat in the third heat exchanger to form industrial steam, which is then used for external heating.

6. The system according to claim 1, characterized in that, A cold resteam header is provided at the second inlet of the boiler; wherein... Steam is extracted from the cold resteam header and then directly supplied to the industry.

7. A boiler complementary steam supply method coupled with thermotropic solar thermal energy storage, characterized in that, The boiler complementary steam supply system using the coupled thermotropic solar thermal energy storage of any one of claims 1 to 6, the method comprising: Under sufficient sunlight, a portion of the high-temperature molten salt in the solar tower enters the molten salt storage heat exchanger to release heat and heat the molten salt in the inclined temperature layer heat storage tank; a portion of the high-temperature molten salt in the solar tower enters the main heat exchanger to release heat and supply heat to the first heat exchanger; the low-temperature molten salt in the inclined temperature layer heat storage tank enters the molten salt storage heat exchanger to absorb heat and becomes high-temperature molten salt before returning to the inclined temperature layer heat storage tank for heat storage; In the absence of sufficient sunlight, the high-temperature molten salt in the thermocline storage tank enters the molten salt storage and release heat exchanger, releases heat to become low-temperature molten salt, and then returns to the thermocline storage tank; the molten salt medium in the main heat exchanger absorbs heat in the molten salt storage and release heat exchanger, and then returns to the main heat exchanger to release heat to supply heat to the first heat exchanger. During the operation of the coal-fired unit, the feedwater at the first inlet of the boiler is delivered to the first heat exchanger to absorb heat and form high-temperature and high-pressure steam, which is then delivered to the main steam pipeline at the first outlet of the boiler through the first outlet of the first heat exchanger.

8. The method according to claim 7, characterized in that, The method further includes: The condensate at the outlet of the deaerator is pressurized and then sent to the second heat exchanger. After absorbing heat in the second heat exchanger, it forms high-temperature steam, which is then sent to the reheat steam pipeline at the second outlet of the boiler.

9. The method according to claim 8, characterized in that, The method further includes: The condensate at the outlet of the deaerator is pressurized and transported to the third heat exchanger, where it absorbs heat to form 3MPa-level industrial steam for external heating.

10. The method according to claim 7, characterized in that, The method further includes: Steam is extracted directly from the cold resteam header to provide industrial steam at a pressure of 1.5 MPa.

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