Modular high-temperature gas-cooled reactor secondary loop start-up and shutdown system

Abstract

This disclosure provides a modular high-temperature gas-cooled reactor (HTGR) secondary loop start-up and shutdown system. The system is configured with a corresponding number of deaerators based on the number of reactors. Each reactor is supplied with water by its own corresponding deaerator, and the start-up and shutdown processes of each reactor are independent of each other. Each deaerator controls its feedwater temperature according to the reactor's stage, reducing mutual interference between reactors, simplifying system operation, and minimizing temporary measures and operating procedures during startup. This system makes the modular HTGR secondary loop system more independent and rational, reduces coupling between reactors, enhances operational adaptability, aligns with the development trend of HTGRs, and provides a more rational and streamlined modular HTGR secondary loop system, making its start-up and operation more flexible and reliable, and better conforming to the modular development trend of HTGRs.

Description

Technical Field

[0001] This disclosure pertains to the field of nuclear power technology, specifically relating to a modular high-temperature gas-cooled reactor secondary loop start-up and shutdown system. Background Technology

[0002] The high-temperature gas-cooled reactor (HTGR) nuclear power plant demonstration project operates in a dual-reactor-generator mode, comprising two nuclear steam supply systems and one turbine generator unit. The current secondary loop system of the HTGR has the following shortcomings:

[0003] (1) Only one common deaerator is configured. The high-temperature gas-cooled reactor is a modular reactor. During startup, the two reactors are started one after another. After the #1 reactor is started, the feedwater temperature of the deaerator is required to reach 160°C. However, when the #2 reactor is started, the primary loop temperature is low. In order to prevent the large temperature difference between the primary and secondary loops from causing excessive thermal stress to the heat transfer tubes and tube sheets of the steam generator, it is not allowed to directly supply 160°C feedwater to the #2 reactor which is in a shutdown state. As a result, when the #1 reactor is already started and operating with power, the #2 reactor cannot be started smoothly and normally from the shutdown state.

[0004] (2) Using the steam-water separator as a side system of the steam pipeline at the outlet of each steam generator makes the system structure complex and the start-up process control complex and variable, which is not conducive to operator operation and system stability.

[0005] (3) The two bypass valves need to control both the outlet pressure of their respective steam generators and the pressure of the main steam header. The coupling of their operation processes makes the control process complex and difficult.

[0006] (4) The atmospheric relief valve and safety valve are both located at the steam generator outlet, and there is a lack of effective means of overpressure protection for the main steam header.

[0007] To address the aforementioned issues, it is necessary to propose a modular high-temperature gas-cooled reactor secondary loop start-up and shutdown system that is reasonably designed and effectively solves these problems. Summary of the Invention

[0008] The present disclosure aims to at least solve one of the technical problems existing in the prior art, and to provide a modular high-temperature gas-cooled reactor secondary loop start-up and shutdown system.

[0009] This disclosure provides a modular high-temperature gas-cooled reactor secondary loop start-up and shutdown system, characterized in that the system includes a first deaerator, a second deaerator, a feedwater pump group, a first steam generator, a second steam generator, a first steam-water separator, a second steam-water separator, a bypass pipeline for the second steam-water separator, a steam turbine, and a condenser;

[0010] The outlet of the condenser is connected to the first inlet of the first deaerator and the first inlet of the second deaerator via condensate pipes.

[0011] The first outlet of the first deaerator and the first outlet of the second deaerator are both connected to the inlet of the first steam generator and the inlet of the second steam generator, respectively, via water supply pipes;

[0012] The water supply pump set is connected in series with the water supply pipeline;

[0013] The outlet of the first steam generator is connected to the inlet of the first steam-water separator via the inlet pipe of the first steam-water separator;

[0014] The outlet of the second steam generator is connected to the inlet of the second steam-water separator via the inlet pipe of the second steam-water separator.

[0015] The outlets of the first steam-water separator and the second steam-water separator are both connected to the first inlet of the steam turbine via the main steam pipeline;

[0016] The turbine outlet is connected to the first inlet of the condenser.

[0017] Optionally, it also includes a bypass pipe for the first steam-water separator and a bypass pipe for the second steam-water separator;

[0018] The bypass pipe for the first steam-water separator is connected in parallel to both ends of the first steam-water separator; wherein...

[0019] A first steam-water separator bypass valve is connected in series on the first steam-water separator bypass pipeline;

[0020] The bypass pipe for the second steam-water separator is connected in parallel to both ends of the second steam-water separator; wherein,

[0021] A second steam-water separator bypass valve is connected in series on the bypass pipeline of the second steam-water separator.

[0022] Optionally, it also includes a first steam-water separator inlet regulating valve and a second steam-water separator inlet regulating valve;

[0023] The first steam-water separator inlet regulating valve is installed in the first steam-water separator inlet pipe and is used to regulate the outlet pressure of the first steam generator;

[0024] The second steam-water separator inlet regulating valve is installed in the inlet pipe of the second steam-water separator and is used to regulate the outlet pressure of the second steam generator.

[0025] Optionally, it may also include a first steam bypass pipe and a second steam bypass pipe;

[0026] The first end of the first steam bypass pipe is connected to the outlet of the first steam-water separator, and the second end of the first steam bypass pipe is connected to the second inlet of the condenser.

[0027] The first end of the second steam bypass pipe is connected to the outlet of the second steam-water separator, and the second end of the second steam bypass pipe is connected to the third inlet of the condenser; wherein...

[0028] A first bypass valve is installed on the first steam bypass pipe, and a second bypass valve is installed on the second steam bypass pipe.

[0029] Optionally, the water supply pipeline includes a first water supply pipeline and a second water supply pipeline, wherein a first high-pressure heater is connected in series on the first water supply pipeline and a second high-pressure heater is connected in series on the second water supply pipeline;

[0030] The first end of the first water supply pipe is connected to the first outlet of the first deaerator, and the second end of the first water supply pipe is connected to the inlet of the first steam generator.

[0031] The first end of the second water supply pipe is connected to the first outlet of the second deaerator, and the second end of the second water supply pipe is connected to the inlet of the second steam generator;

[0032] The water supply pump set includes a first water supply pump, a second water supply pump, and a standby water supply pump; wherein...

[0033] The first water supply pump is connected in series with the first water supply pipeline;

[0034] The second water supply pump is connected in series with the second water supply pipeline;

[0035] The inlet of the standby water pump is connected to the second outlet of the first deaerator and the second outlet of the second deaerator, respectively, and the outlet of the standby water pump is connected to the first water supply pipeline and the second water supply pipeline, respectively.

[0036] Optionally, the condensate pipeline includes a condensate main pipe section, a first condensate branch pipe section, and a second condensate branch pipe section;

[0037] The inlet of the condensate main pipe section is connected to the condenser, and the outlet of the condensate main pipe section is connected to the inlet of the first condensate branch pipe section and the inlet of the second condensate branch pipe section, respectively.

[0038] The outlet of the first condensate branch pipe section is connected to the first inlet of the first deaerator, and the outlet of the second condensate branch pipe section is connected to the first inlet of the second deaerator.

[0039] The system also includes a condensate pump set, a low-pressure heater, a first condensate regulating valve, and a second condensate regulating valve;

[0040] The condensate pump unit and the low-pressure heater are both connected in series in the condensate header section, wherein,

[0041] The inlet of the condensate pump set is connected to the outlet of the condenser, and the outlet of the condensate pump set is connected to the inlet of the low-pressure heater.

[0042] The first condensate regulating valve is connected in series in the first condensate branch pipe section, and the second condensate regulating valve is connected in series in the second condensate branch pipe section.

[0043] Optional components also include a demineralized water tank, a condensate water supply pump, a water supply regulating valve, a first water supply pipe, a second water supply pipe, and a third water supply pipe;

[0044] The demineralized water tank is connected to the fourth inlet of the condenser via the first water supply pipe;

[0045] The condensate water supply pump and the water supply regulating valve are connected in series in the first water supply pipeline, wherein the inlet of the condensate water supply pump is connected to the outlet of the demineralized water tank.

[0046] The inlet of the second water supply pipe is connected between the condensate water supply pump and the water supply regulating valve, and the outlet of the second water supply pipe is connected to the first condensate branch pipe section.

[0047] The inlet of the third water supply pipe is connected between the condensate water supply pump and the water supply regulating valve, and the outlet of the third water supply pipe is connected to the second condensate branch pipe section.

[0048] Optionally, it also includes an auxiliary steam header, auxiliary steam pipelines, a first auxiliary steam regulating valve, and a second auxiliary steam regulating valve; among which,

[0049] The auxiliary steam pipeline includes an auxiliary steam main pipeline, a first auxiliary steam branch pipeline, and a second auxiliary steam branch pipeline.

[0050] The inlet of the auxiliary steam main pipeline is connected to the outlet of the auxiliary steam header, and the outlet of the auxiliary steam main pipeline is connected to the inlet of the first auxiliary steam branch pipeline and the inlet of the second auxiliary steam branch pipeline, respectively.

[0051] The outlet of the first auxiliary steam branch pipe is connected to the second inlet of the first deaerator;

[0052] The outlet of the inlet of the second auxiliary steam branch pipe is connected to the second inlet of the second deaerator;

[0053] The first auxiliary steam regulating valve is connected in series with the first auxiliary steam branch pipe;

[0054] The second auxiliary steam regulating valve is connected in series in the second auxiliary steam branch pipeline.

[0055] Optionally, it also includes an extraction steam pipeline, a first extraction steam electric valve, and a second extraction steam electric valve; among which,

[0056] The extraction steam pipeline includes an extraction steam main pipeline, a first extraction steam branch pipeline, and a second extraction steam branch pipeline.

[0057] The inlet of the extraction steam main pipe is connected to the high-pressure cylinder of the steam turbine, and the outlet of the extraction steam main pipe is connected to the inlet of the first extraction steam branch pipe and the inlet of the second extraction steam branch pipe, respectively.

[0058] The outlet of the first extraction steam branch pipe is connected to the third inlet of the first deaerator;

[0059] The outlet of the second extraction branch pipe is connected to the third inlet of the second deaerator;

[0060] The first extraction steam electric valve is connected in series with the first extraction steam branch pipe;

[0061] The second extraction steam electric valve is connected in series in the second extraction steam branch pipe.

[0062] Optionally, the main steam pipeline includes a main steam header, a first steam branch pipeline, a second steam branch pipeline, and a main steam bypass pipeline;

[0063] The inlet of the first steam branch pipe is connected to the outlet of the first steam-water separator, and the outlet of the first steam branch pipe is connected to the inlet of the main steam header; wherein,

[0064] A first isolation valve is installed in series on the first steam branch pipe;

[0065] The inlet of the second steam branch pipe is connected to the outlet of the second steam-water separator, and the outlet of the second steam branch pipe is connected to the inlet of the main steam header; wherein,

[0066] A second isolation valve is installed in series on the second steam branch pipe;

[0067] The main steam header is equipped with a turbine main regulating valve near the turbine.

[0068] The inlet of the main steam bypass pipe is connected to the main steam main pipe, and the outlet of the main steam bypass pipe is connected to the fifth inlet of the condenser.

[0069] Optionally, it may also include a first atmospheric relief valve and a second atmospheric relief valve;

[0070] The first atmospheric release valve is connected in series in the first steam branch pipe near the outlet of the first steam-water separator.

[0071] The second atmospheric release valve is connected in series in the second steam branch pipe near the outlet of the second steam-water separator.

[0072] This disclosure discloses a modular high-temperature gas-cooled reactor secondary loop start-up and shutdown system. The system is equipped with a corresponding number of deaerators based on the number of reactors. Each reactor is supplied with water by its own corresponding deaerator. The start-up and shutdown processes of each reactor are independent of each other, reducing start-up coupling and improving start-up and shutdown flexibility. Each deaerator for each reactor controls its feedwater temperature according to the reactor's stage, reducing mutual influence between reactors, simplifying system operation, and reducing temporary measures and operating modes during start-up. This system makes the modular high-temperature reactor secondary loop system more independent and rational, reduces coupling between reactors during operation, enhances operational adaptability, aligns with the development trend of high-temperature reactors, and provides a more rational and streamlined modular high-temperature gas-cooled reactor secondary loop system, making its start-up and operation more flexible and reliable, and better conforming to the modular development trend of high-temperature reactors. Attached Figure Description

[0073] Figure 1 This is a schematic diagram of the structure of a modular high-temperature gas-cooled reactor secondary loop start-up and shutdown system according to one embodiment of the present disclosure. Detailed Implementation

[0074] To enable those skilled in the art to better understand the technical solutions of the embodiments of this disclosure, the embodiments of this disclosure will be further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0075] like Figure 1 As shown, this disclosure provides a modular high-temperature gas-cooled reactor secondary loop start-up and shutdown system, which is applied to a multi-module reactor. This disclosure describes a multi-module reactor that includes two reactors.

[0076] Specifically, such as Figure 1 As shown, the modular high-temperature gas-cooled reactor secondary loop start-up and shutdown system of this embodiment includes a first deaerator 1, a second deaerator 2, a feedwater pump group 3, a first steam generator 4, a second steam generator 5, a first steam-water separator 6, a second steam-water separator 7, a steam turbine 8, and a condenser 9.

[0077] The outlet of condenser 9 is connected to the first inlet of the first deaerator 1 and the first inlet of the second deaerator 2 via condensate pipes. Specifically, condenser 9 supplies condensate to the first deaerator 1 and the second deaerator 2 via condensate pipes.

[0078] The first outlet of the first deaerator 1 and the first outlet of the second deaerator 2 are both connected to the inlet of the first steam generator 4 and the inlet of the second steam generator 5, respectively, via feedwater pipes. It should be noted that in this embodiment, two medium-volume deaerators are used. In this embodiment, the dual deaerator setup reduces start-up coupling and improves start-up and shutdown flexibility.

[0079] Feedwater pump set 3 is connected in series in the feedwater pipeline. Specifically, feedwater pump set 3 is used to supply condensate from each deaerator to the corresponding steam generator.

[0080] The outlet of the first steam generator 4 is connected to the inlet of the first steam-water separator 6 via the inlet pipe 10 of the first steam-water separator. Specifically, the subcooled or saturated steam generated by the first steam generator 4 is transported to the first steam-water separator 6 through the inlet pipe 10 of the first steam-water separator.

[0081] The outlet of the second steam generator 5 is connected to the inlet of the second steam-water separator 7 via the inlet pipe 11 of the second steam-water separator. Specifically, the subcooled or saturated steam generated by the second steam generator 5 is transported to the second steam-water separator 7 via the inlet pipe 11 of the second steam-water separator.

[0082] The outlets of both the first steam-water separator 6 and the second steam-water separator 7 are connected to the first inlet of the steam turbine 8 via the main steam pipeline. Specifically, the steam generated by the outlets of the first steam-water separator 6 and the second steam-water separator 7 is transported to the steam turbine 8 via the main steam pipeline to drive the turbine 8 to generate electricity. It should be noted that the condensate from each steam-water separator is drained to the condenser expansion tank (not shown in the figure) through a bottom drain valve.

[0083] The outlet of steam turbine 8 is connected to the first inlet of condenser 9.

[0084] This disclosure discloses a modular high-temperature gas-cooled reactor secondary loop start-up and shutdown system. The system is equipped with a corresponding number of deaerators based on the number of reactors. Each reactor is supplied with water by its own corresponding deaerator. The start-up and shutdown processes of each reactor are independent of each other, reducing start-up coupling and improving start-up and shutdown flexibility. Each deaerator for each reactor controls its feedwater temperature according to the reactor's stage, reducing mutual influence between reactors, simplifying system operation, and reducing temporary measures and operating modes during start-up. This system makes the modular high-temperature reactor secondary loop system more independent and rational, reduces coupling between reactors during operation, enhances operational adaptability, aligns with the development trend of high-temperature reactors, and provides a more rational and streamlined modular high-temperature gas-cooled reactor secondary loop system, making its start-up and operation more flexible and reliable, and better conforming to the modular development trend of high-temperature reactors.

[0085] like Figure 1As shown, a first outlet safety valve 12 is connected in series near the first steam generator 4 in the inlet pipe 10 of the first steam-water separator. The first outlet safety valve 12 can ensure the safety of the first steam generator 4 and the inlet pipe 10 of the first steam-water separator in case of an accident, and prevent the inlet pipe 10 of the first steam-water separator from being overpressurized.

[0086] At the same time, such as Figure 1 As shown, a second outlet safety valve 13 is connected in series near the second steam generator 5 in the inlet pipe 11 of the second steam-water separator. The second outlet safety valve 13 can ensure the safety of the second steam generator 5 and the inlet pipe 11 of the second steam-water separator in case of an accident, and prevent the inlet pipe 11 of the second steam-water separator from being overpressurized.

[0087] like Figure 1 As shown, the first steam-water separator inlet pipe 10 is also provided with a first steam generator outlet isolation valve 14 and a first steam-water separator inlet isolation valve 15 in series, wherein one end of the first steam generator outlet isolation valve 14 is connected to the first outlet safety valve 12.

[0088] In this embodiment, the opening and closing of the first steam generator outlet isolation valve 14 and the first steam-water separator inlet isolation valve 15 can control the opening and closing of the first steam-water separator inlet pipe 10.

[0089] Similarly, such as Figure 1 As shown, the second steam-water separator inlet pipe 11 is also connected in series with the second steam generator outlet isolation valve 16 and the second steam-water separator inlet isolation valve 17, wherein one end of the second steam generator outlet isolation valve 16 is connected to the second outlet safety valve 13.

[0090] In this embodiment, the opening and closing of the second steam generator outlet isolation valve 16 and the second steam-water separator inlet isolation valve 17 can control the opening and closing of the second steam-water separator inlet pipe 11.

[0091] For example, the system also includes a first steam-water separator bypass pipe 18 and a second steam-water separator bypass pipe 19.

[0092] The first steam-water separator bypass pipe 18 is connected in parallel to both ends of the first steam-water separator 6. A first steam-water separator bypass valve 20 is connected in series on the first steam-water separator bypass pipe 18. The opening and closing of the first steam-water separator bypass valve 20 controls the opening and closing of the first steam-water separator bypass pipe 18.

[0093] The second steam-water separator bypass pipe 19 is connected in parallel to both ends of the second steam-water separator 7. A second steam-water separator bypass valve 21 is connected in series on the second steam-water separator bypass pipe 19. The opening and closing of the second steam-water separator bypass valve 21 controls the opening and closing of the second steam-water separator bypass pipe 19.

[0094] In this embodiment, a first steam-water separator bypass pipe 18 is connected in parallel at both ends of the first steam-water separator 6, and a second steam-water separator bypass pipe 19 is connected in parallel at both ends of the second steam-water separator 7. This means that each steam-water separator is equipped with a bypass pipe and corresponding valves. When the steam at the steam generator outlet becomes superheated, the steam-water separator stops operating, and the steam generated by the steam generator directly enters the main steam pipeline through the bypass pipe and related valves. During the start-up and shutdown phases, when the medium contains water, it undergoes steam-water separation through the steam-water separator before entering the main steam pipeline. In this way, each steam-water separator bypass pipe serves as the steam supply pipeline under normal conditions, eliminating the need for separate main steam pipelines at each steam generator outlet. This simplifies the system structure, reduces the number of valves, and decreases the number of condensate drain points and valves. The switching between upstream and downstream processes is also simpler, simplifying the steam cut-off operation.

[0095] For example, the system also includes a first steam-water separator inlet regulating valve 23 and a second steam-water separator inlet regulating valve 24.

[0096] The first steam-water separator inlet regulating valve 23 is installed in the first steam-water separator inlet pipe 10 and is used to regulate the outlet pressure of the first steam generator 4.

[0097] The second steam-water separator inlet regulating valve 24 is installed in the inlet pipe 11 of the second steam-water separator and is used to regulate the outlet pressure of the second steam generator 5.

[0098] In this embodiment, inlet regulating valves are installed on the inlet pipes of each steam-water separator, that is, inlet regulating valves are installed at the inlet of the steam-water separator to control the outlet pressure of each reactor steam generator at a set value. This ensures that the outlet pressure of the steam generator is not affected by the downstream pressure when abnormalities occur. During start-up, shutdown, and normal operation, the steam-water separator inlet regulating valves control the steam generator outlet pressure to stabilize, reducing the impact of transients on the steam generator from the turbine side.

[0099] For example, such as Figure 1 As shown, the system also includes a first steam bypass pipe 25 and a second steam bypass pipe 26.

[0100] The first end of the first steam bypass pipe 25 is connected to the outlet of the first steam-water separator 6, and the second end of the first steam bypass pipe 25 is connected to the second inlet of the condenser 9.

[0101] The first end of the second steam bypass pipe 26 is connected to the outlet of the second steam-water separator 7, and the second end of the second steam bypass pipe 26 is connected to the third inlet of the condenser 9.

[0102] The first steam bypass pipe 25 is equipped with a first bypass valve 27, and the second steam bypass pipe 26 is equipped with a second bypass valve 28.

[0103] In this embodiment, during the start-up and shutdown phase, the first steam bypass pipe 25 and the second steam bypass pipe 26 can discharge the wet steam generated by the first steam-water separator 6 and the second steam-water separator 7 to the condenser 9 after de-heating and de-pressure treatment; when the dual stacks are running in parallel, the first bypass valve 27 and the second bypass valve 28 automatically control the pressure of the first steam bypass pipe 25 and the second steam bypass pipe 26 to the set value, respectively.

[0104] like Figure 1 As shown, the main steam pipeline includes a main steam main pipeline 29a, a first steam branch pipeline 29b, a second steam branch pipeline 29c, and a main steam bypass pipeline 29d.

[0105] The inlet of the first steam branch pipe 29b is connected to the outlet of the first steam-water separator 6, and the outlet of the first steam branch pipe 29b is connected to the inlet of the main steam pipe 29a; wherein, a first isolation valve 30 is connected in series on the first steam branch pipe 29b.

[0106] The inlet of the second steam branch pipe 29c is connected to the outlet of the second steam-water separator 7, and the outlet of the second steam branch pipe 29c is connected to the inlet of the main steam header pipe 29a. A second isolation valve 31 is connected in series on the second steam branch pipe 29c.

[0107] The main steam pipe 29a is connected in series with the main turbine regulating valve 32 near the turbine 8.

[0108] The inlet of the main steam bypass pipe 29d is connected to the main steam mother pipe 29a, and the outlet of the main steam bypass pipe 29d is connected to the fifth inlet of the condenser 9. The main steam bypass pipe 29d is equipped with a main steam bypass valve 33.

[0109] In this embodiment, the two steam branch pipes at the outlets of the two steam-water separators are combined into a main steam header to supply steam to the turbine, driving the turbine generator set to generate electricity. Each steam-water separator outlet is equipped with a steam branch pipe as a steam discharge path during start-up and shutdown, controlling the pressure of the steam-water separator outlet pipe at the required value. Specifically, a main steam bypass valve is installed on the main steam bypass pipe. During normal power operation, it works in conjunction with the turbine inlet main regulating valve to control the pressure of the main steam header at the set value. Under large transient conditions such as load shedding or rapid power reduction, the main steam bypass valve is responsible for discharging excess steam to the condenser 9, maintaining stable pressure in the main steam header.

[0110] In the above embodiments, by setting a main steam bypass pipe connected to the main steam pipe, and a first steam bypass pipe and a second steam bypass pipe connected to the steam-water separator outlet respectively, the pressure of the steam branch pipe at the outlet of the single-unit steam-water separator and the main steam mother pipe are controlled separately. This avoids the problems of inconsistent opening time and difficulty in controlling the opening degree of the bypass valves of each unit under large transient conditions such as load shedding and rapid power reduction, improves the transient response capability, and reduces the interference fluctuation problem of the original dual bypass valve control.

[0111] like Figure 1 As shown, a first steam-water separator outlet isolation valve 34 and a first atmospheric release valve 35 are sequentially connected in series on the first steam branch pipe 29b. One end of the first steam-water separator outlet isolation valve 34 is connected to the outlet of the first steam-water separator 6, and the other end of the first steam-water separator outlet isolation valve 34 is connected to the first atmospheric release valve 35. That is to say, the first atmospheric release valve 35 is connected in series on the first steam branch pipe 29b near the outlet of the first steam-water separator 6.

[0112] Similarly, a second steam-water separator outlet isolation valve 36 and a second atmospheric release valve 37 are sequentially connected in series on the second steam branch pipe 29c. One end of the second steam-water separator outlet isolation valve 36 is connected to the outlet of the second steam-water separator 7, and the other end of the second steam-water separator outlet isolation valve 36 is connected to the second atmospheric release valve 37. That is to say, the second atmospheric release valve 37 is connected in series on the second steam branch pipe 29c near the outlet of the second steam-water separator 7.

[0113] It should be noted that, as Figure 1 As shown, the first end of the first steam-water separator bypass pipe 18 is connected between the first steam-water separator inlet regulating valve 23 and the first steam-water separator inlet isolation valve 15, and the second end of the first steam-water separator bypass pipe 18 is connected between the first steam-water separator outlet isolation valve 34 and the first atmospheric release valve 35.

[0114] Similarly, the first end of the second steam-water separator bypass pipe 19 is connected between the second steam-water separator inlet regulating valve 24 and the second steam-water separator inlet isolation valve 17, and the second end of the second steam-water separator bypass pipe 19 is connected between the second steam-water separator outlet isolation valve 36 and the second atmospheric release valve 37.

[0115] In this embodiment, an atmospheric release valve is installed on the steam branch pipe at the outlet of each steam-water separator, so that it is closely matched with the first bypass valve and the second bypass valve. Under the transient operating conditions of the second loop, such as load shedding and rapid power reduction, when the first bypass valve, the second bypass valve and the main steam bypass valve cannot quickly reduce the steam pipeline pressure, the atmospheric release valve will open to ensure that the steam pipeline is not over-pressurized, while reducing the impact of pressure shock on the steam generator and extending the service life of the steam generator.

[0116] Specifically, each nuclear steam supply module includes its own deaerator, feedwater pump set, steam generator, steam-water separator, and their connecting control valve set. Taking the first steam-water separator 6 as an example, during the low-power start-up and shutdown phases, the steam at the outlet of the first steam generator 4 is subcooled or saturated steam, which first enters the first steam-water separator 6. The condensate from the first steam-water separator 6 is discharged to the condenser 9 (not shown in this circuit diagram) through the condensate regulating valve at the bottom of the first steam-water separator 6. The steam is discharged to the condenser 9 after being desuperheated and depressurized through the first bypass valve 27. When the outlet of the first steam generator 4 is superheated steam, the bypass valve 20 of the first steam-water separator is opened, and the inlet isolation valve 15 and the outlet isolation valve 34 of the first steam-water separator are closed. The steam enters the main steam header 29a through the first steam branch pipe 29b to drive the turbine 8 to generate electricity. The second steam-water separator 7 is the same as the first steam-water separator 6.

[0117] In the above embodiments, when the dual-reactor system is operating with turbines, the main steam bypass valve 33 controls the pressure of the main steam header 29a to the required value, and the first bypass valve 27 and the second bypass valve 28 control the outlet pressures of the first steam-water separator 6 and the second steam-water separator 7 to the set values, respectively. When the single-reactor system is operating with turbines, the first bypass valve 27 and the second bypass valve 28 are taken out of operation, and the main steam bypass valve 33 controls the pressure of the main steam header 29a to the required value. In this way, the outlet pressure of the steam-water separator and the pressure of the main steam header are controlled separately, avoiding the problems of inconsistent opening times and difficulty in controlling the opening degree of the bypass valves of each reactor under large transient conditions such as load shedding and rapid power reduction.

[0118] For example, such as Figure 1 As shown, the water supply pipeline includes a first water supply pipeline 38 and a second water supply pipeline 39, wherein a first high-pressure heater 40 is connected in series on the first water supply pipeline 38, and a second high-pressure heater 42 is connected in series on the second water supply pipeline 39.

[0119] The first end of the first water supply pipe 38 is connected to the first outlet of the first deaerator 1, and the second end of the first water supply pipe 38 is connected to the inlet of the first steam generator 4.

[0120] The first end of the second water supply pipe 39 is connected to the first outlet of the second deaerator 2, and the second end of the second water supply pipe 39 is connected to the inlet of the second steam generator 5.

[0121] The water supply pump group 3 includes a first water supply pump 3a, a second water supply pump 3b, and a standby water supply pump 3c. The first water supply pump 3a is connected in series with the first water supply pipeline 38, and the second water supply pump 3b is connected in series with the second water supply pipeline 39.

[0122] The inlet of the standby water pump 3c is connected to the second outlet of the first deaerator 1 and the second outlet of the second deaerator 2, respectively. The outlet of the standby water pump 3c is connected to the first water supply pipe 38 and the second water supply pipe 39, respectively.

[0123] It should be noted that the first water supply pipeline 38 is equipped with a first main water supply isolation valve 38a. The first end of the first main water supply isolation valve 38a is connected to the inlet of the first steam generator 4, and the second end of the first main water supply isolation valve 38a is connected to the first high-pressure heater 40. The opening and closing of the first main water supply isolation valve 38a controls the opening and closing of the first water supply pipeline 38.

[0124] Similarly, the second water supply pipeline 39 is equipped with a second main water supply isolation valve 39a. The first end of the second main water supply isolation valve 39a is connected to the inlet of the second steam generator 5, and the second end of the second main water supply isolation valve 39a is connected to the second high-pressure heater 42. The opening and closing of the second main water supply isolation valve 39a controls the opening and closing of the second water supply pipeline 39.

[0125] Specifically, the first feedwater pump 3a draws water from the first deaerator 1, pressurizes it, and then heats it further through the first high-pressure heater 40 before supplying it to the first steam generator 4 via the first feedwater pipeline 38. The second feedwater pump 3b draws water from the second deaerator 2, pressurizes it, and then heats it further through the second high-pressure heater 42 before supplying it to the second steam generator 5 via the second feedwater pipeline 39. The standby feedwater pump 3c serves as a standby feedwater pump for both reactors. It is normally in a hot standby state and will be started immediately to restore water supply after the operating feedwater pump stops operating. The standby feedwater pump 3c can draw water from either the first deaerator 1 or the second deaerator 2. When one reactor deaerator is under maintenance, the standby pump can also be started to draw water from the other reactor deaerator, temporarily ensuring the reactor water supply and greatly improving operational flexibility.

[0126] In this embodiment, the standby feedwater pump can draw water from two deaerators, allowing the two deaerators to serve as backups for each other under special operating conditions. For example, when the reactor needs to be started due to the failure of one deaerator for maintenance or the maintenance of the inlet isolation valve of one feedwater pump, the standby feedwater pump can be started to supply water from the other deaerator, ensuring that the normal startup of the reactor is not affected.

[0127] For example, such as Figure 1 As shown, the condensate pipeline includes a condensate main pipe section 43a, a first condensate branch pipe section 43b, and a second condensate branch pipe section 43c.

[0128] The inlet of the condensate main pipe section 43a is connected to the condenser 9, and the outlet of the condensate main pipe section 43a is connected to the inlet of the first condensate branch pipe section 43b and the inlet of the second condensate branch pipe section 43c, respectively.

[0129] The outlet of the first condensate branch pipe section 43b is connected to the first inlet of the first deaerator 1, and the outlet of the second condensate branch pipe section 43c is connected to the first inlet of the second deaerator 2.

[0130] like Figure 1 As shown, the system also includes a condensate pump set 44, a low-pressure heater 45, a first condensate regulating valve 46, and a second condensate regulating valve 47.

[0131] Condensate pump set 44 and low-pressure heater 45 are both connected in series in condensate header section 43a. The inlet of condensate pump set 44 is connected to the outlet of condenser 9, and the outlet of condensate pump set 44 is connected to the inlet of low-pressure heater 45.

[0132] Specifically, in this embodiment, the condensate pump group 44 includes three condensate pumps. The three condensate pumps serve as backups for each other and are connected to the condenser 9 and the condensate header section 43a. Depending on the number of reactors to be started, one, two, or three condensate pumps can be started. After passing through the low-pressure heater 45, the condensate is supplied to the first deaerator 1 of reactor #1 or the second deaerator 2 of reactor #2. The first condensate regulating valve 46 and the second condensate regulating valve 47 can automatically control the liquid levels of the first deaerator 1 and the second deaerator 2, respectively.

[0133] The first condensate regulating valve 46 is installed in the first condensate branch pipe section 43b, and the second condensate regulating valve 47 is installed in the second condensate branch pipe section 43c.

[0134] In this embodiment, the condensate mother pipe section and the low-pressure heater are shared by both reactors. The first condensate regulating valve and the second condensate regulating valve supply water to their respective deaerators. This method facilitates deaerator water level control, and neither three-impulse nor single-impulse control affects each other.

[0135] For example, such as Figure 1 As shown, the system also includes a demineralized water tank 48, a condensate water replenishment pump 49, a water replenishment regulating valve 50, a first water replenishment pipe 51, a second water replenishment pipe 52, and a third water replenishment pipe 53.

[0136] The demineralized water tank 48 is connected to the fourth inlet of the condenser 9 via the first makeup water pipe 51.

[0137] A condensate water supply pump 49 and a water supply regulating valve 50 are connected in series in the first water supply pipeline 51. The inlet of the condensate water supply pump 49 is connected to the outlet of the demineralized water tank 48.

[0138] The inlet of the second water supply pipe 52 is connected between the condensate water supply pump 49 and the water supply regulating valve 50, and the outlet of the second water supply pipe 52 is connected to the first condensate branch pipe section 43b.

[0139] The inlet of the third water supply pipe 53 is connected between the condensate water supply pump 49 and the water supply regulating valve 50, and the outlet of the third water supply pipe 53 is connected to the second condensate branch pipe section 43c.

[0140] Specifically, the demineralized water tank 48 serves as the makeup water source for the secondary loop. Driven by the condensate makeup water pump 49, water is drawn from the demineralized water tank 48 to provide initial water supply for the first deaerator 1 of #1 and the second deaerator 2 of #2 reactor and subsequent pipelines. This completes the initial water supply and cold initial flushing of the secondary loop pipelines. The condensate makeup water pump 49 can also automatically compensate for the condensate loss in the secondary loop by supplying water to the condenser 9 through the makeup water regulating valve 50, thereby maintaining a stable condenser liquid level.

[0141] On the other hand, a condensate makeup water pump initially supplies water to the first deaerator 1 and the second deaerator 2 through the second makeup water pipe 52 and the third makeup water pipe 53 respectively. When one reactor is already in operation (its deaerator temperature has reached 160°C), the other reactor can achieve a transition from cold flushing to hot flushing, and finally the deaerator slowly heats up to 160°C for stable operation.

[0142] For example, such as Figure 1 As shown, the system also includes an auxiliary steam header 54, an auxiliary steam pipeline, a first auxiliary steam regulating valve 56 and a second auxiliary steam regulating valve 57. The auxiliary steam pipeline includes an auxiliary steam main pipeline 55a, a first auxiliary steam branch pipeline 55b and a second auxiliary steam branch pipeline 55c.

[0143] The inlet of the auxiliary steam main pipeline 55a is connected to the outlet of the auxiliary steam header 54, and the outlet of the auxiliary steam main pipeline 55a is connected to the inlet of the first auxiliary steam branch pipeline 55b and the inlet of the second auxiliary steam branch pipeline 55c.

[0144] The outlet of the first auxiliary steam branch pipe 55b is connected to the second inlet of the first deaerator 1, and the outlet of the second auxiliary steam branch pipe 55c is connected to the second inlet of the second deaerator 2.

[0145] The first auxiliary steam regulating valve 56 is connected in series in the first auxiliary steam branch pipe 55b, and the second auxiliary steam regulating valve 57 is connected in series in the second auxiliary steam branch pipe 55c.

[0146] In this embodiment, the auxiliary steam pipeline supplies the deaerator via a main pipe and two branch pipes, ensuring the independent heating of the deaerator.

[0147] For example, such as Figure 1 As shown, the system also includes an extraction steam pipeline, a first extraction steam electric valve 59, and a second extraction steam electric valve 60. The extraction steam pipeline includes an extraction steam main pipeline 58a, a first extraction steam branch pipeline 58b, and a second extraction steam branch pipeline 58c.

[0148] The inlet of the extraction steam main pipe 58a is connected to the high-pressure cylinder of the steam turbine, and the outlet of the extraction steam main pipe 58a is connected to the inlet of the first extraction steam branch pipe 58b and the inlet of the second extraction steam branch pipe 58c.

[0149] The outlet of the first extraction steam branch pipe 58b is connected to the third inlet of the first deaerator 1, and the outlet of the second extraction steam branch pipe 58c is connected to the third inlet of the second deaerator 2.

[0150] The first extraction steam electric valve 59 is installed in series in the first extraction steam branch pipe 58b, and the second extraction steam electric valve 60 is installed in series in the second extraction steam branch pipe 58c.

[0151] In this embodiment, the extraction steam pipeline supplies the deaerator via a main pipe and two branch pipes, ensuring the independent heating of the deaerator.

[0152] In this embodiment, during the start-up or low-power phase, the auxiliary steam header 54 supplies steam to the first deaerator 1 and the second deaerator 2 via two branch pipes: the first auxiliary steam branch pipe 55b and the second auxiliary steam branch pipe 55c. The pressure of the first deaerator 1 is automatically controlled by the first auxiliary steam regulating valve 56, and the pressure of the second deaerator 2 is automatically controlled by the second auxiliary steam regulating valve 57. As the load increases, when the extraction steam pipeline becomes available, the first extraction steam electric valve 59 or the second extraction steam electric valve 60 is opened as needed, allowing the deaerators to operate under sliding pressure via the extraction steam pipeline. The first auxiliary steam regulating valve 56 and the second auxiliary steam regulating valve 57 then cease operation.

[0153] It should be noted that this embodiment uses a multi-module reactor comprising two reactors as an example. Two deaerators are provided, corresponding to the number of reactors: a first deaerator and a second deaerator. The number of feedwater pumps, high-pressure heaters, steam generators, steam-water separators, and their inlet and outlet valve assemblies are also the same as the number of reactors, each dedicated to a specific reactor. The turbine generator set and condensate system are shared by both reactors.

[0154] It should be further clarified that when a multi-module reactor includes two or more reactors, the corresponding system includes the same number of deaerators as the reactors, i.e., a first deaerator, a second deaerator, a third deaerator, and so on. The corresponding number of feedwater pumps, high-pressure heaters, steam generators, steam-water separators, and their inlet and outlet valve assemblies will also increase to the same number of reactors. In other words, excluding the turbine generator set and condensate system, for each additional reactor, the secondary loop system equipment, including the main feedwater system, steam generator, steam-water separator, and their associated valves, will increase by one row, and so on.

[0155] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the embodiments of this disclosure, and the embodiments of this disclosure are 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 embodiments of this disclosure, and these modifications and improvements are also considered to be within the protection scope of the embodiments of this disclosure.

Claims

1. A modular high-temperature gas-cooled reactor secondary loop start-up and shutdown system, characterized in that, The system includes a first deaerator, a second deaerator, a feedwater pump set, a first steam generator, a second steam generator, a first steam-water separator, a second steam-water separator, a bypass pipeline for the second steam-water separator, a steam turbine, and a condenser. The outlet of the condenser is connected to the first inlet of the first deaerator and the first inlet of the second deaerator via condensate pipes. The first outlet of the first deaerator and the first outlet of the second deaerator are both connected to the inlet of the first steam generator and the inlet of the second steam generator, respectively, via water supply pipes; The water supply pump set is connected in series with the water supply pipeline; The outlet of the first steam generator is connected to the inlet of the first steam-water separator via the inlet pipe of the first steam-water separator; The outlet of the second steam generator is connected to the inlet of the second steam-water separator via the inlet pipe of the second steam-water separator. The outlets of the first steam-water separator and the second steam-water separator are both connected to the first inlet of the steam turbine via the main steam pipeline; The outlet of the steam turbine is connected to the first inlet of the condenser; wherein, It also includes the auxiliary steam header, auxiliary steam pipeline, first auxiliary steam regulating valve, and second auxiliary steam regulating valve; among which... The auxiliary steam pipeline includes an auxiliary steam main pipeline, a first auxiliary steam branch pipeline, and a second auxiliary steam branch pipeline. The inlet of the auxiliary steam main pipeline is connected to the outlet of the auxiliary steam header, and the outlet of the auxiliary steam main pipeline is connected to the inlet of the first auxiliary steam branch pipeline and the inlet of the second auxiliary steam branch pipeline, respectively. The outlet of the first auxiliary steam branch pipe is connected to the second inlet of the first deaerator; The outlet of the inlet of the second auxiliary steam branch pipe is connected to the second inlet of the second deaerator; The first auxiliary steam regulating valve is connected in series with the first auxiliary steam branch pipe; The second auxiliary steam regulating valve is connected in series in the second auxiliary steam branch pipeline.

2. The system according to claim 1, characterized in that, It also includes the bypass pipe for the first steam-water separator and the bypass pipe for the second steam-water separator. The bypass pipe for the first steam-water separator is connected in parallel to both ends of the first steam-water separator; wherein... A first steam-water separator bypass valve is connected in series on the first steam-water separator bypass pipeline; The bypass pipe for the second steam-water separator is connected in parallel to both ends of the second steam-water separator; wherein, A second steam-water separator bypass valve is connected in series on the bypass pipeline of the second steam-water separator.

3. The system according to claim 1, characterized in that, It also includes the first steam-water separator inlet regulating valve and the second steam-water separator inlet regulating valve; The first steam-water separator inlet regulating valve is installed in the first steam-water separator inlet pipe and is used to regulate the outlet pressure of the first steam generator; The second steam-water separator inlet regulating valve is installed in the inlet pipe of the second steam-water separator and is used to regulate the outlet pressure of the second steam generator.

4. The system according to any one of claims 1 to 3, characterized in that, It also includes a first steam bypass pipe and a second steam bypass pipe; The first end of the first steam bypass pipe is connected to the outlet of the first steam-water separator, and the second end of the first steam bypass pipe is connected to the second inlet of the condenser. The first end of the second steam bypass pipe is connected to the outlet of the second steam-water separator, and the second end of the second steam bypass pipe is connected to the third inlet of the condenser; wherein... A first bypass valve is installed on the first steam bypass pipe, and a second bypass valve is installed on the second steam bypass pipe.

5. The system according to any one of claims 1 to 3, characterized in that, The water supply pipeline includes a first water supply pipeline and a second water supply pipeline, wherein a first high-pressure heater is connected in series on the first water supply pipeline and a second high-pressure heater is connected in series on the second water supply pipeline. The first end of the first water supply pipe is connected to the first outlet of the first deaerator, and the second end of the first water supply pipe is connected to the inlet of the first steam generator. The first end of the second water supply pipe is connected to the first outlet of the second deaerator, and the second end of the second water supply pipe is connected to the inlet of the second steam generator; The water supply pump set includes a first water supply pump, a second water supply pump, and a standby water supply pump; wherein... The first water supply pump is connected in series with the first water supply pipeline; The second water supply pump is connected in series with the second water supply pipeline; The inlet of the standby water pump is connected to the second outlet of the first deaerator and the second outlet of the second deaerator, respectively, and the outlet of the standby water pump is connected to the first water supply pipeline and the second water supply pipeline, respectively.

6. The system according to any one of claims 1 to 3, characterized in that, The condensate pipeline includes a condensate main pipe section, a first condensate branch pipe section, and a second condensate branch pipe section. The inlet of the condensate main pipe section is connected to the condenser, and the outlet of the condensate main pipe section is connected to the inlet of the first condensate branch pipe section and the inlet of the second condensate branch pipe section, respectively. The outlet of the first condensate branch pipe section is connected to the first inlet of the first deaerator, and the outlet of the second condensate branch pipe section is connected to the first inlet of the second deaerator. The system also includes a condensate pump set, a low-pressure heater, a first condensate regulating valve, and a second condensate regulating valve; The condensate pump unit and the low-pressure heater are both connected in series in the condensate header section, wherein, The inlet of the condensate pump set is connected to the outlet of the condenser, and the outlet of the condensate pump set is connected to the inlet of the low-pressure heater. The first condensate regulating valve is connected in series in the first condensate branch pipe section, and the second condensate regulating valve is connected in series in the second condensate branch pipe section.

7. The system according to claim 6, characterized in that, It also includes a demineralized water tank, a condensate water supply pump, a water supply regulating valve, a first water supply pipe, a second water supply pipe, and a third water supply pipe; The demineralized water tank is connected to the fourth inlet of the condenser via the first water supply pipe; The condensate water supply pump and the water supply regulating valve are connected in series in the first water supply pipeline, wherein the inlet of the condensate water supply pump is connected to the outlet of the demineralized water tank. The inlet of the second water supply pipe is connected between the condensate water supply pump and the water supply regulating valve, and the outlet of the second water supply pipe is connected to the first condensate branch pipe section. The inlet of the third water supply pipe is connected between the condensate water supply pump and the water supply regulating valve, and the outlet of the third water supply pipe is connected to the second condensate branch pipe section.

8. The system according to any one of claims 1 to 3, characterized in that, It also includes extraction steam pipelines, a first extraction steam electric valve, and a second extraction steam electric valve; among which... The extraction steam pipeline includes an extraction steam main pipeline, a first extraction steam branch pipeline, and a second extraction steam branch pipeline. The inlet of the extraction steam main pipe is connected to the high-pressure cylinder of the steam turbine, and the outlet of the extraction steam main pipe is connected to the inlet of the first extraction steam branch pipe and the inlet of the second extraction steam branch pipe, respectively. The outlet of the first extraction steam branch pipe is connected to the third inlet of the first deaerator; The outlet of the second extraction branch pipe is connected to the third inlet of the second deaerator; The first extraction steam electric valve is connected in series with the first extraction steam branch pipe; The second extraction steam electric valve is connected in series in the second extraction steam branch pipe.

9. The system according to any one of claims 1 to 3, characterized in that, The main steam pipeline includes a main steam header, a first steam branch pipeline, a second steam branch pipeline, and a main steam bypass pipeline; The inlet of the first steam branch pipe is connected to the outlet of the first steam-water separator, and the outlet of the first steam branch pipe is connected to the inlet of the main steam header; wherein, A first isolation valve is installed in series on the first steam branch pipe; The inlet of the second steam branch pipe is connected to the outlet of the second steam-water separator, and the outlet of the second steam branch pipe is connected to the inlet of the main steam header; wherein, A second isolation valve is installed in series on the second steam branch pipe; The main steam header is equipped with a turbine main regulating valve near the turbine. The inlet of the main steam bypass pipe is connected to the main steam main pipe, and the outlet of the main steam bypass pipe is connected to the fifth inlet of the condenser.

10. The system according to claim 9, characterized in that, It also includes a first atmospheric release valve and a second atmospheric release valve; The first atmospheric release valve is connected in series in the first steam branch pipe near the outlet of the first steam-water separator. The second atmospheric release valve is connected in series in the second steam branch pipe near the outlet of the second steam-water separator.

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