A system and method for heat recovery, storage and utilization in a solar thermal power project

Abstract

This invention discloses a system and method for heat recovery, storage, and utilization in a concentrated solar power (CSP) project, belonging to the field of CSP energy storage technology. It includes a turbine main steam system, a reheat steam system, a high- and low-pressure bypass system, a high-pressure exhaust ventilation system, a condensate drain system, a heat exchanger, and a heat accumulator. The heat exchanger is connected to the high-pressure exhaust ventilation system, the high- and low-pressure bypass system, and the condensate drain system, respectively. The heat exchanger is also connected to a condenser or exhaust steam device. The heat accumulator is connected to the heat exchanger via heating pipes and return water pipes. The heat accumulator is connected to a heating system. This invention recovers and stores the heat discharged into the condenser or exhaust steam device through the high- and low-pressure bypass system, the condensate drain system, and the high-pressure exhaust ventilation system during frequent start-ups and shutdowns of the CSP unit. The heat stored in the heat accumulator can be directly used as a heating source for the CSP plant building or provided to other heat users, effectively reducing heat loss during frequent start-ups and shutdowns of the CSP unit.

Description

Technical Field

[0001] This invention relates to the field of concentrated solar power (CSP) energy storage technology, and in particular to a system and method for heat recovery, storage and utilization in CSP projects. Background Technology

[0002] Concentrated solar power (CSP) is a technology that uses solar thermal energy to generate electricity by concentrating solar thermal energy and converting it into electrical energy. There are three main types of CSP systems: parabolic trough systems, tower systems, and dish systems. These systems concentrate solar thermal energy in different ways and convert it into electricity. The biggest advantage of CSP is its stable power output, which can be used for base station power generation and peak shaving; in addition, its mature and reliable energy storage (thermal storage) configuration allows for continuous power generation at night.

[0003] In recent years, the installed capacity of new energy power generation such as photovoltaics and wind power has grown rapidly. While contributing to the green and low-carbon transformation of energy, their significant volatility, randomness, and intermittency also pose considerable challenges to the stable operation of the power system, putting considerable pressure on grid peak regulation. To address the issue of nighttime grid connection problems, solar thermal energy storage can be implemented to supplement photovoltaic power generation, which does not generate electricity at night. This involves storing solar energy in molten salt tanks during the day, and then releasing heat from the molten salt tanks at night to heat steam and drive a steam turbine to generate electricity. However, this operational method involves the frequent start-stop of the steam turbine. During turbine startup and load reduction shutdown, the high and low pressure bypass valves open, and steam is discharged to the exhaust device or condenser through the bypass system. The drain valves on the turbine body, main steam system, reheat steam system, and extraction system open, and the drain water is discharged to the exhaust device or condenser. During the turbine's speed increase under load, when the high pressure cylinder blower exhaust temperature rises to the set value, the high pressure exhaust vent valve opens to release pressure and cool down. The high temperature gas is discharged into the condenser or exhaust device after being cooled by the high pressure exhaust vent valve and desuperheater. Whether it is the steam discharged from the bypass and vent valves or the drain water from the high temperature steam pipeline, the temperature is very high. This frequent start-up and shutdown process causes a lot of heat loss. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a system and method for heat recovery, storage and utilization in solar thermal power generation projects, thereby improving the economy and efficiency of solar thermal power generation projects.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] A system for heat recovery, storage, and utilization in a concentrated solar power (CSP) project includes a main steam system for a steam turbine, a reheat steam system, a high- and low-pressure bypass system, a high-pressure exhaust ventilation system, a condensate system, a heat exchanger, and a heat accumulator. The heat exchanger is connected to the high-pressure exhaust ventilation system, the high- and low-pressure bypass system, and the condensate system, respectively. The heat exchanger is also connected to a condenser or an exhaust steam device. The heat accumulator is connected to the heat exchanger via heating pipes and return water pipes. The heat accumulator is connected to a heating device.

[0007] A further improvement of the technical solution of the present invention is that: the high and low pressure bypass system consists of two stages connected in series, a high pressure bypass and a low pressure bypass; the high pressure bypass includes a high pressure bypass pipe connecting the main steam pipe and the low temperature reheat steam pipe and a high pressure bypass valve connected to the desuperheating water installed on the high pressure bypass pipe; the low pressure bypass includes a low pressure bypass pipe connecting the high temperature reheat steam pipe and the condenser or exhaust device and a low pressure bypass valve connected to the desuperheating water installed on the low pressure bypass pipe; a three-stage desuperheater is installed at the end of the low pressure bypass pipe connected to the condenser or exhaust device.

[0008] A further improvement of the technical solution of the present invention is that: a first pipe is led out from the low-pressure bypass valve through a first tee and connected to the heat exchanger, and a first electric shut-off valve and a first check valve are provided on the first pipe.

[0009] A further improvement of the technical solution of the present invention is that: the high-pressure exhaust ventilation system includes a high-pressure exhaust ventilation duct connecting the low-temperature reheat steam pipeline and the condenser or exhaust device; a sixth electric shut-off valve, a first high-pressure cylinder ventilation valve, a seventh electric shut-off valve and a desuperheater connected to the desuperheating water are sequentially arranged on the high-pressure exhaust ventilation duct; a high-pressure exhaust check valve is arranged on the low-temperature reheat steam pipeline; a bypass pipeline is arranged in parallel at both ends of the sixth electric shut-off valve and the first high-pressure cylinder ventilation valve; and a second high-pressure cylinder ventilation valve is arranged on the bypass pipeline.

[0010] A further improvement of the technical solution of the present invention is that: a second pipe is led out from the first high-pressure cylinder ventilation valve and the seventh electric shut-off valve through a second three-way valve and connected to the heat exchanger, and a second electric shut-off valve and a second check valve are provided on the second pipe.

[0011] A further improvement of the technical solution of the present invention is that: the drainage system includes turbine body drainage, main steam system drainage, extraction steam system drainage, reheat system drainage, drainage manifold and drainage expansion container; the drainage manifold is connected to the turbine body drainage pipe, the main steam system drainage pipe, the extraction steam system drainage pipe and the reheat system drainage pipe respectively, and is connected to the drainage expansion container.

[0012] A further improvement of the technical solution of the present invention is that a third pipe is led out from the drain manifold and connected to the heat exchanger, and a third electric shut-off valve and a third check valve are provided on the third pipe.

[0013] A further improvement of the technical solution of the present invention is that a fourth electrically operated shut-off valve is provided on the heating pipe connecting the heat accumulator and the heat exchanger; and a fifth electrically operated shut-off valve is provided on the return water pipe connecting the heat accumulator and the heat exchanger.

[0014] A method for heat recovery, storage, and utilization in a concentrated solar power (CSP) project includes:

[0015] During the startup and load reduction shutdown of the solar thermal power unit's steam turbine, the main steam generated by the superheater of the steam generator is de-cooled by the high-pressure bypass valve before the high-pressure main steam valve is opened, and then enters the low-temperature reheat steam pipeline. After being heated by the reheater of the steam generator, it enters the high-temperature reheat steam pipeline. Some or all of the high-temperature reheat steam is de-cooled by the low-pressure bypass valve and then enters the condenser or exhaust device. Some or all of the high-temperature reheat steam is introduced into the heat exchanger before entering the low-pressure bypass valve, and after recovering heat in the heat exchanger, it is discharged into the condenser or exhaust device.

[0016] During the startup of the solar thermal power unit's steam turbine, during the turbine's speed increase phase under load, when the high-pressure cylinder blower exhaust temperature rises to the set value, the first high-pressure cylinder ventilation valve opens to release pressure and cool down. Some or all of the high-temperature steam is discharged into the condenser or exhaust device after being cooled by the first high-pressure cylinder ventilation valve and desuperheater. Some or all of the high-temperature steam is directly discharged into the heat exchanger after the first high-pressure cylinder ventilation valve and before the desuperheater to recover heat before being discharged into the condenser or exhaust device.

[0017] During the startup and load reduction shutdown of the solar thermal power unit's steam turbine, the steam turbine body drain valve, the main steam system drain valve, the extraction steam system drain valve, and the reheat system drain valve are opened. The high-temperature water after mixing in the drain manifold is introduced into the heat exchanger to recover heat before being discharged into the condenser or exhaust device.

[0018] During the startup and load reduction shutdown of the solar thermal power unit's steam turbine, heat from the high and low pressure bypass system, high exhaust ventilation system, and condensate system is introduced into the heat exchanger for recovery. The recovered heat is stored in the heat accumulator through hot and cold water circulation, and the heat stored in the heat accumulator is directly used as a heating source.

[0019] A further improvement of the technical solution of the present invention is that the heating heat source can be used for heating the solar thermal power plant building, and can also be provided to heat users outside the plant.

[0020] The technological advancements achieved by this invention due to the adoption of the above technical solutions are as follows:

[0021] This invention achieves the recovery and storage of heat discharged into the condenser or exhaust device through the high and low pressure bypass system, condensate system, and high exhaust ventilation system of a solar thermal power generation project by adding heat exchangers and heat accumulators to the high and low pressure bypass system, condensate system, and high exhaust ventilation system. The heat stored in the heat accumulator can be directly used as a heating source for the solar thermal power plant building or provided to other heat users, effectively reducing heat loss during the frequent start-up and shutdown of the solar thermal power unit. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of a system for heat recovery, storage, and utilization in a concentrated solar power (CSP) project, provided in an embodiment of the present invention.

[0024] The components are as follows: 1. Heat exchanger; 2. Heat accumulator; 3. Condenser or exhaust device; 4. Generator; 5. Medium and low pressure cylinder; 6. High pressure cylinder; 7. Steam generator superheater; 8. Steam generator reheater; 9. High pressure bypass valve; 10. Low pressure bypass valve; 11. Sixth electric shut-off valve; 12. First high pressure cylinder ventilation valve; 13. Desuperheater; 14. Second high pressure cylinder ventilation valve; 15. High pressure exhaust check valve; 16. Drainage manifold; 17. Drainage expansion tank; 18. Third-stage desuperheater; 19. High pressure main steam valve; 20. Reheat main steam valve; 21. Seventh electric shut-off valve. Detailed Implementation

[0025] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification, claims and accompanying drawings of this invention are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such processes, methods, products or devices.

[0026] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments:

[0029] In conventional photothermal systems, such as Figure 1 As shown, the high-temperature, high-pressure steam generated by the superheater 7 of the solar thermal system's steam generator enters the high-pressure cylinder 6 of the turbine through the main steam pipeline and high-pressure main steam valve 19, expanding and doing work to drive the generator 4 to generate electricity. The steam discharged from the high-pressure cylinder 6 after doing work enters the reheater 8 of the solar thermal system's steam generator through the low-temperature reheat steam pipeline. The high-temperature steam heated by the reheater 8 enters the high-temperature reheat steam pipeline, passes through the reheat main steam valve 20, and enters the intermediate-low-pressure cylinder 5 to expand and do work, driving the generator 4 to generate electricity. The exhaust steam passes through the low-pressure cylinder in the intermediate-low-pressure cylinder 5 and is discharged into the condenser or exhaust device 3. After condensation, it enters the condensate feedwater system and is then sent to the solar thermal system's heat exchanger to be heated into steam, completing the cycle and generating electricity.

[0030] To achieve heat recovery, storage, and utilization in concentrated solar power (CSP) projects and improve their economic efficiency and effectiveness, this invention adds heat exchangers and heat accumulators to the high and low pressure bypass systems, high-pressure exhaust ventilation systems, and drainage systems of CSP projects. This enables the recovery and storage of heat dissipated through these systems during frequent start-ups and shutdowns of the CSP units. This heat can be directly used for heating the CSP plant building or provided to other heat users. The specific solution is as follows:

[0031] like Figure 1 As shown, a system for heat recovery, storage, and utilization in a concentrated solar power (CSP) project includes a main steam system for a steam turbine, a reheat steam system, a high- and low-pressure bypass system, a high-pressure exhaust ventilation system, a condensate system, a heat exchanger 1, and a heat accumulator 2. The heat exchanger 1 is connected to the high-pressure exhaust ventilation system, the high- and low-pressure bypass system, and the condensate system, respectively. The heat exchanger 1 is also connected to a condenser or an exhaust steam device 3. The heat accumulator 2 is connected to the heat exchanger 1 through a heating pipe and a return water pipe. The heat accumulator 2 is connected to a heating device.

[0032] Furthermore, the high and low pressure bypass system consists of two stages connected in series: a high-pressure bypass and a low-pressure bypass. The high-pressure bypass includes a high-pressure bypass pipe connecting the main steam pipe and the low-temperature reheat steam pipe, and a high-pressure bypass valve 9 connected to the desuperheating water on the high-pressure bypass pipe. The low-pressure bypass includes a low-pressure bypass pipe connecting the high-temperature reheat steam pipe and the condenser or exhaust device 3, and a low-pressure bypass valve 10 connected to the desuperheating water on the low-pressure bypass pipe. A three-stage desuperheater 18 is installed at the end of the low-pressure bypass pipe connected to the condenser or exhaust device 3.

[0033] Specifically, the turbine high and low pressure bypass system consists of two-stage bypasses connected in series, one for high pressure and one for low pressure. During unit startup, the main steam pressure and temperature are controlled according to the main unit's startup curve. The main steam pressure is controlled by the high-pressure bypass. Before turbine startup, the main steam valve is closed. The high-temperature, high-pressure steam generated from the superheater 7 of the solar thermal system's steam generator is de-cooled by water spraying through the high-pressure bypass valve 9 and then enters the solar thermal system's steam generator reheater 8 through the low-temperature reheat steam pipeline. After heating, it enters the high-temperature reheat system, and after de-cooling by water spraying through the low-pressure bypass valve 10, it enters the condenser or exhaust steam device 3, where it condenses and enters the condensate feedwater system. When the main steam pressure and temperature reach the startup curve requirements, the high-pressure main steam valve and the reheat main steam valve are opened, and the high-pressure bypass valve 9 and the low-pressure bypass valve 10 are closed. The turbine starts up, generates power, and increases the load to normal operation. When the unit load changes or trips, the high and low pressure bypass system has a good regulating effect, ensuring that the steam generation system and turbine load are matched and operate stably. In this invention, high-temperature reheat steam is introduced into heat exchanger 1 before entering low-pressure bypass valve 10, and after heat is recovered by heat exchanger 1, it is discharged into condenser or exhaust device 3.

[0034] Furthermore, a first pipeline is led out from the low-pressure bypass valve 10 via a first tee and connected to the heat exchanger 1. A first electric shut-off valve and a first check valve are installed on the first pipeline.

[0035] Furthermore, the high-pressure exhaust ventilation system includes a high-pressure exhaust ventilation duct that connects the low-temperature reheat steam pipeline to the condenser or exhaust device 3; a sixth electric shut-off valve 11, a first high-pressure cylinder ventilation valve 12, a seventh electric shut-off valve 21, and a desuperheater 13 connected to the desuperheating water are sequentially installed on the high-pressure exhaust ventilation duct; a high-pressure exhaust check valve 15 is installed on the low-temperature reheat steam pipeline; a bypass pipeline is installed in parallel at both ends of the sixth electric shut-off valve 11 and the first high-pressure cylinder ventilation valve 12; and a second high-pressure cylinder ventilation valve 14 is installed on the bypass pipeline.

[0036] Specifically, a high-pressure exhaust check valve 15 and a high-pressure exhaust venting pipe are installed on the low-temperature reheat steam pipeline. During turbine start-up, the first high-pressure cylinder ventilation valve 12 is open to maintain the temperature of the high-pressure cylinder 6 from exceeding the limit. The high-temperature steam from the high-pressure exhaust ventilation system enters the desuperheater 13 for desuperheating through the first high-pressure cylinder ventilation valve 12 and the second high-pressure cylinder ventilation valve 14 before being discharged into the condenser or exhaust device 3. After the exhaust pressure of the high-pressure cylinder 6 increases, the high-pressure exhaust check valve 15 automatically opens, and the first high-pressure cylinder ventilation valve 12 and the second high-pressure cylinder ventilation valve 14 close. In this invention, the high-temperature steam is directly discharged into the heat exchanger 1 after the first high-pressure cylinder ventilation valve 12 and before the desuperheater 13 to recover heat before being discharged into the condenser or exhaust device 3.

[0037] Furthermore, a second pipe is led out from the first high-pressure cylinder ventilation valve 12 and before the seventh electric shut-off valve 21 via a second tee and connected to the heat exchanger 1. A second electric shut-off valve and a second check valve are installed on the second pipe.

[0038] Furthermore, the condensate drainage system includes turbine body condensate drainage, main steam system condensate drainage, extraction steam system condensate drainage, reheat system condensate drainage (including condensate drainage for reheat steam and bypass system), condensate manifold 16, and condensate expansion tank 17; condensate manifold 16 is connected to turbine body condensate drainage pipe, main steam system condensate drainage pipe, extraction steam system condensate drainage pipe, and reheat system condensate drainage pipe respectively, and is connected to condensate expansion tank 17.

[0039] Specifically, during the startup and load reduction shutdown processes of the solar thermal power unit's steam turbine, the turbine body drain valve, the main steam system drain valve, the reheat system drain valve, and the extraction steam system drain valve are opened. Generally, the condensate enters the drain manifold 16, is de-cooled by the drain empty container 17, and then enters the condenser or exhaust device 3. This invention introduces the high-temperature water, after mixing in the drain manifold 16, into the heat exchanger 1 to recover heat before discharging it into the condenser or exhaust device 3.

[0040] Furthermore, a third pipe is led out from the drain manifold 16 and connected to the heat exchanger 1. The third pipe is equipped with a third electric shut-off valve and a third check valve.

[0041] Furthermore, a fourth electrically operated shut-off valve is installed on the heating pipe connecting the heat accumulator 2 and the heat exchanger 1; and a fifth electrically operated shut-off valve is installed on the return water pipe connecting the heat accumulator 2 and the heat exchanger 1.

[0042] A method for heat recovery, storage, and utilization in a concentrated solar power (CSP) project includes the following:

[0043] During the start-up and load reduction shutdown of the solar thermal power unit's steam turbine, the main steam generated by the superheater 7 of the steam generator is de-cooled by the high-pressure bypass valve 9 before the high-pressure main steam valve 19 is opened, and then enters the low-temperature reheat steam pipeline. After being heated by the reheater 8 of the steam generator, it enters the high-temperature reheat steam pipeline. Part (or all) of the high-temperature reheat steam is de-cooled by the low-pressure bypass valve 10 and then enters the condenser or exhaust device 3. Part (or all) of the high-temperature reheat steam is introduced into the heat exchanger 1 before entering the low-pressure bypass valve 10, and after recovering heat through the heat exchanger 1, it is discharged into the condenser or exhaust device 3.

[0044] During the startup of the solar thermal power unit's steam turbine, during the turbine's speed increase phase under load, when the high-pressure cylinder 6 blower exhaust temperature rises to the set value, the first high-pressure cylinder ventilation valve 12 opens to release pressure and cool down. Part (or all) of the high-temperature steam is discharged into the condenser or exhaust device 3 after being cooled by the first high-pressure cylinder ventilation valve 12 and desuperheater 13. Part (or all) of the high-temperature steam is directly discharged into the heat exchanger 1 after the first high-pressure cylinder ventilation valve 12 and before the desuperheater 13 to recover heat before being discharged into the condenser or exhaust device 3.

[0045] During the startup and load reduction shutdown of the solar thermal power unit's steam turbine, the steam turbine body drain valve, the main steam system drain valve, the extraction steam system drain valve, and the reheat system drain valve are opened. The high-temperature water after mixing in the drain manifold 16 is introduced into the heat exchanger 1 to recover heat before being discharged into the condenser or exhaust device 3.

[0046] During the startup and load reduction shutdown of the solar thermal power unit's steam turbine, heat from the high and low pressure bypass system, high exhaust ventilation system, and condensate system is introduced into heat exchanger 1 for recovery. The recovered heat is stored in heat accumulator 2 through hot and cold water circulation, and the heat stored in heat accumulator 2 is directly used as a heating source.

[0047] Furthermore, the heating source can be used for heating the solar thermal power plant buildings, and can also be provided to external heat users.

[0048] In summary, this invention recovers and stores the heat discharged into the condenser or exhaust device by the steam turbine of a solar thermal power unit during startup and load reduction shutdown through a heat exchanger and an accumulator. The heat stored in the accumulator can be directly used as a heating source for the solar thermal power plant building or provided to other heat users, effectively reducing heat loss during the frequent start-up and shutdown of the solar thermal power unit.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A system for heat recovery, storage, and utilization in a concentrated solar power (CSP) project, characterized in that: It includes a steam turbine main steam system, a reheat steam system, a high and low pressure bypass system, a high-pressure exhaust ventilation system, a condensate system, a heat exchanger (1), and a accumulator (2); the heat exchanger (1) is connected to the high-pressure exhaust ventilation system, the high and low pressure bypass system, and the condensate system respectively; the heat exchanger (1) is also connected to a condenser or an exhaust device (3); the accumulator (2) is connected to the heat exchanger (1) through a heating pipe and a return water pipe; the accumulator (2) is connected to a heating device; The high and low pressure bypass system consists of two stages connected in series: a high pressure bypass and a low pressure bypass. The high pressure bypass includes a high pressure bypass pipe connecting the main steam pipe and the low temperature reheat steam pipe, and a high pressure bypass valve (9) connected to the desuperheating water on the high pressure bypass pipe. The low pressure bypass includes a low pressure bypass pipe connecting the high temperature reheat steam pipe and the condenser or exhaust device (3), and a low pressure bypass valve (10) connected to the desuperheating water on the low pressure bypass pipe. A three-stage desuperheater (18) is installed at the end of the low pressure bypass pipe connected to the condenser or exhaust device (3). The high-pressure exhaust ventilation system includes a high-pressure exhaust ventilation pipe that connects the low-temperature reheat steam pipe to the condenser or exhaust device (3); a sixth electric shut-off valve (11), a first high-pressure cylinder ventilation valve (12), a seventh electric shut-off valve (21) and a desuperheater (13) connected to the desuperheating water are sequentially installed on the high-pressure exhaust ventilation pipe; a high-pressure exhaust check valve (15) is installed on the low-temperature reheat steam pipe; a bypass pipe is installed in parallel at both ends of the sixth electric shut-off valve (11) and the first high-pressure cylinder ventilation valve (12); and a second high-pressure cylinder ventilation valve (14) is installed on the bypass pipe. The drainage system includes turbine body drainage, main steam system drainage, extraction steam system drainage, reheat system drainage, drainage manifold (16) and drainage expansion container (17); the drainage manifold (16) is connected to the turbine body drainage pipe, main steam system drainage pipe, extraction steam system drainage pipe and reheat system drainage pipe respectively, and is connected to the drainage expansion container (17).

2. The system for heat recovery, storage, and utilization in a concentrated solar power (CSP) project according to claim 1, characterized in that: A first pipeline is led out from the low-pressure bypass valve (10) and connected to the heat exchanger (1) via a first tee. A first electric shut-off valve and a first check valve are installed on the first pipeline.

3. The system for heat recovery, storage, and utilization in a concentrated solar power (CSP) project according to claim 1, characterized in that: A second pipe is led out from the first high-pressure cylinder ventilation valve (12) and before the seventh electric shut-off valve (21) and connected to the heat exchanger (1) via a second tee. A second electric shut-off valve and a second check valve are provided on the second pipe.

4. The system for heat recovery, storage, and utilization in a concentrated solar power (CSP) project according to claim 1, characterized in that: A third pipe is led out from the drain manifold (16) and connected to the heat exchanger (1). A third electric shut-off valve and a third check valve are installed on the third pipe.

5. A system for heat recovery, storage, and utilization in a concentrated solar power (CSP) project according to claim 1, characterized in that: A fourth electric shut-off valve is provided on the heating pipe connecting the heat accumulator (2) and the heat exchanger (1); a fifth electric shut-off valve is provided on the return water pipe connecting the heat accumulator (2) and the heat exchanger (1).

6. A method for heat recovery, storage, and utilization in a concentrated solar power (CSP) project, using the system described in any one of claims 1-5, characterized in that: The method includes: During the start-up and load reduction shutdown of the solar thermal power unit's steam turbine, the main steam generated by the superheater (7) of the steam generator is de-cooled by the high-pressure bypass valve (9) before the high-pressure main steam valve (19) is opened and then enters the low-temperature reheat steam pipeline. After being heated by the reheater (8) of the steam generator, it enters the high-temperature reheat steam pipeline. Part or all of the high-temperature reheat steam is de-cooled by the low-pressure bypass valve (10) and then enters the condenser or exhaust device (3). Part or all of the high-temperature reheat steam is introduced into the heat exchanger (1) before entering the low-pressure bypass valve (10), and after recovering heat through the heat exchanger (1), it is discharged into the condenser or exhaust device (3). During the startup of the solar thermal power unit's steam turbine, during the turbine's speed increase phase under load, when the high-pressure cylinder (6) blows high exhaust temperature rises to the set value, the first high-pressure cylinder ventilation valve (12) opens to release pressure and cool down. Part or all of the high-temperature steam is cooled by the first high-pressure cylinder ventilation valve (12) and desuperheater (13) and then discharged into the condenser or exhaust device (3). Part or all of the high-temperature steam is directly discharged into the heat exchanger (1) after the first high-pressure cylinder ventilation valve (12) and before the desuperheater (13) to recover heat before being discharged into the condenser or exhaust device (3). During the startup and load reduction shutdown of the solar thermal power unit turbine, the turbine body drain valve, the main steam system drain valve, the extraction steam system drain valve, and the reheat system drain valve are opened. The drains from each line enter the drain manifold (16). The high-temperature water after mixing is introduced into the heat exchanger (1) to recover heat and then discharged into the condenser or exhaust device (3). During the startup and shutdown of the solar thermal power unit turbine, heat from the high and low pressure bypass system, high exhaust ventilation system and condensate system is introduced into the heat exchanger (1) for recovery. The recovered heat is stored in the heat accumulator (2) through hot and cold water circulation. The heat stored in the heat accumulator (2) is directly used as a heating source.

7. A method for heat recovery, storage, and utilization in a concentrated solar power (CSP) project according to claim 6, characterized in that: The heating source can be used for heating the solar thermal power plant building, and can also be provided to external heat users.

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