Multi-module high-temperature gas cooled reactor steam system and control method

Abstract

The invention relates to the technical field of nuclear power, in particular to a multi-module high-temperature gas cooled reactor steam system and a control method. The invention relates to a multi-module high-temperature gas cooled reactor steam system, which comprises at least two steam supply subsystems including a first steam supply subsystem and a second steam supply subsystem; the main steam pipeline is suitable for being communicated with a steam turbine generator unit; the first steam supply subsystem comprises a first nuclear steam supply module and a first steam outlet pipeline, and the first nuclear steam supply module is communicated with the main steam pipeline through the first steam outlet pipeline; the second steam supply subsystem comprises a second nuclear steam supply module, a second steam mixer, a second steam discharge pipeline and a second steam recovery pipeline, and the second nuclear steam supply module supplies second pressure main steam. According to the invention, the problem that steam generated by other subsequent nuclear steam supply modules cannot enter a steam turbine generator unit for power generation after the initial reactor core of the first nuclear steam module is established is solved.

Description

Technical Field

[0001] The present invention relates to the field of nuclear power technology, and in particular to a multi-module high-temperature gas-cooled reactor steam system and a control method thereof. Background Art

[0002] The high-temperature gas-cooled reactor unit adopts a multi-reactor-with-one-machine design, that is, the steam generated by multiple nuclear steam supply modules is collected on the main steam main pipe to drive a steam turbine generator unit. Each nuclear steam supply module contains a reactor and a steam generator. The heat of the reactor is transferred to the steam generator to heat the feed water to generate superheated steam to drive the steam turbine generator unit to generate electricity. Among them, the 200MW demonstration reactor has 2 nuclear steam supply modules, and the 600MW commercial reactor has six nuclear steam supply modules.

[0003] The high-temperature gas-cooled reactor adopts a non-stop fuel replacement system. To establish the initial core, it is necessary to operate at less than 30% power. The fuel loading and unloading system is used to load mixing balls from the top of the core, and simultaneously unload the pre-loaded graphite balls from the bottom of the core. The process is not completed until all the graphite balls are unloaded and the core is filled with mixed fuel balls. Only then can the reactor be capable of full power operation. It takes about 80 days for a single module to establish the initial core and operate at full power.

[0004] After the first nuclear steam module completed the initial core construction, the main steam temperature rose to 540°C. Subsequently, other nuclear steam supply modules were still continuing to replace materials and build the initial core. The main steam temperature generated by other nuclear steam supply modules was 264°C, the flow rate was 36kg / s, and the pressure was about 5MPa. The main steam at this temperature and pressure could not enter the steam turbine generator set to generate electricity. The high-quality steam was not effectively utilized, and the economic benefits were poor. Summary of the invention

[0005] In view of this, the present invention provides a multi-module high-temperature gas-cooled reactor steam system and control method to solve the problem that after the initial core of the first nuclear steam module is established, the steam generated by other subsequent nuclear steam supply modules when establishing the initial core cannot enter the steam turbine generator set to generate electricity, resulting in the inability to effectively utilize high-quality steam and poor economic benefits.

[0006] In a first aspect, the present invention provides a multi-module high temperature gas-cooled reactor steam system, comprising:

[0007] at least two steam supply subsystems, including a first steam supply subsystem and a second steam supply subsystem;

[0008] A main steam pipeline, the main steam pipeline is suitable for communicating with a steam turbine generator set, and the steam turbine generator set is provided with a medium-pressure cylinder;

[0009] A first steam supply subsystem, the first steam supply subsystem comprising a first core steam supply module and a first steam outlet pipeline, the first core steam supply module is connected to the main steam pipeline through the first steam outlet pipeline, and the first core steam supply module supplies first pressure main steam;

[0010] a second steam supply subsystem, the second steam supply subsystem comprising a second nuclear steam supply module, a second steam mixer, a second steam exhaust pipeline and a second steam recovery pipeline, the second nuclear steam supply module supplies second pressure main steam;

[0011] One end of the second steam exhaust pipeline is in communication with the second nuclear steam supply module, and a second steam mixer is provided on the second steam exhaust pipeline;

[0012] The second steam mixer is connected to the main steam pipeline through a second heating steam branch pipe;

[0013] One end of the second steam recovery pipeline is communicated with the second steam mixer, and the other end of the second steam recovery pipeline is communicated with the intermediate pressure cylinder.

[0014] When the first nuclear steam supply module is operating normally, the first-pressure main steam generated is transported to the steam turbine generator set through the main steam pipeline; when the second nuclear steam supply module is in the initial core installation process, the second-pressure main steam generated by the second nuclear steam supply module, the pressure of the first-pressure main steam is greater than that of the second-pressure main steam, the second-pressure main steam enters the second steam mixer through the second steam exhaust pipeline, part of the first-pressure main steam in the main steam pipeline enters the second steam mixer and is mixed with the second-pressure main steam, and the mixed steam enters the intermediate-pressure cylinder through the second steam recovery pipeline, avoiding the waste of the main steam supplied by the second nuclear steam supply module before the pressure reaches the first-pressure main steam, and there is no need to discharge it into the condenser. The steam formed by the mixture of the two main steam pressures enters the intermediate-pressure cylinder to make full use of the second-pressure main steam and improve economic benefits.

[0015] In an optional embodiment, the second steam subsystem also includes a second start-up pipe, one end of the second start-up pipe is suitable for communicating with a second nuclear steam supply module, the other end of the second start-up pipe is suitable for communicating with a start-up expansion vessel, a second regulating valve and a second stop valve are provided on the second start-up pipe, and the connection between the second steam exhaust pipe and the second start-up pipe is located between the second regulating valve and the second stop valve.

[0016] In an optional embodiment, the second steam subsystem also includes a second steam outlet pipe, one end of the second steam outlet pipe is connected to the second nuclear steam supply module, the other end of the second steam outlet pipe is connected to the main steam pipe, and the second steam outlet pipe is provided with a seventh stop valve and an eighth stop valve.

[0017] In an optional embodiment, it also includes a second steam discharge pipe, one end of which is connected to the second steam outlet pipe, the other end of which is connected to the second steam mixer, the connection between the second steam discharge pipe and the second steam outlet pipe is located between the seventh stop valve and the eighth stop valve, and the second steam discharge pipe is provided with a tenth stop valve.

[0018] In an optional embodiment, the first steam supply subsystem also includes a first starting pipe, one end of which is connected to the first nuclear steam supply module, and the other end of the first starting pipe is suitable for connecting to the starting expansion vessel, and the first starting pipe is provided with a first regulating valve and a first stop valve.

[0019] In an optional embodiment, it also includes a first steam exhaust pipe, one end of which is suitable for communicating with a condenser, and the other end of the first steam exhaust pipe is connected to a first start-up pipe. The connection between the first steam exhaust pipe and the first start-up pipe is arranged between the first regulating valve and the first stop valve, and the first steam exhaust pipe is provided with a first steam mixer and a first bypass valve.

[0020] In an optional embodiment, it also includes a first steam discharge pipe, one end of which is connected to the first steam outlet pipe, the other end of which is connected to the first steam mixer, a fifth stop valve and a sixth stop valve are provided on the first steam outlet pipe, the connection between the first steam discharge pipe and the first steam outlet pipe is located between the fifth stop valve and the sixth stop valve, and a ninth stop valve is provided on the first steam discharge pipe.

[0021] In an optional embodiment, it further includes a first heating steam branch pipe, one end of which is connected to the first steam mixer, and the other end of which is connected to the main steam pipeline.

[0022] In an optional embodiment, the first steam mixer includes a suction chamber, a diffusion chamber and an outlet chamber which are connected in sequence, a mixing section is provided between the suction chamber and the diffusion chamber, a diffusion section is provided between the diffusion chamber and the outlet chamber, a nozzle and a heating steam inlet are provided on the side wall of the suction chamber, the nozzle is provided with a low-pressure steam inlet, and a temperature gauge and a pressure gauge are provided on the side wall of the outlet chamber.

[0023] In an optional embodiment, a drain pipe is provided between the startup expansion tank and the condenser, and the drain pipe is provided with a drain regulating valve and a third stop valve in sequence from the startup expansion tank toward the condenser.

[0024] In an optional embodiment, a deoxygenation pipeline is further included, wherein the deoxygenation pipeline is connected to the drain pipeline, and a deaerator and a fourth stop valve are provided on the deoxygenation pipeline.

[0025] In a second aspect, the present invention further provides a method for controlling a steam system of a multi-module high temperature gas-cooled reactor, comprising:

[0026] The first nuclear steam supply module operates normally, and the first pressure main steam generated by the first nuclear steam supply module enters the main steam pipeline through the first steam outlet pipeline, and is then transported to the steam turbine generator set by the main steam pipeline;

[0027] When the second nuclear steam supply module is in the process of initial core installation, the second nuclear steam supply module generates second-pressure main steam, the pressure of the first-pressure main steam is greater than that of the second-pressure main steam, the second-pressure main steam enters the second steam mixer through the second steam exhaust pipe, part of the first-pressure main steam in the main steam pipe enters the second steam mixer and is mixed with the second-pressure main steam, and the mixed steam enters the intermediate-pressure cylinder through the second steam recovery pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 A schematic diagram of a multi-module high temperature gas-cooled reactor steam system according to an embodiment of the present invention;

[0030] Figure 2 Schematic diagram of a steam mixer according to an embodiment of the present invention.

[0031] Description of reference numerals: 1. first nuclear steam supply module; 2. second nuclear steam supply module; 3. first regulating valve; 4. first stop valve; 5. start-up expansion tank; 6. second regulating valve; 7. second stop valve; 8. condensate desuperheater; 9. desuperheating water regulating valve; 10. condenser; 11. drain regulating valve; 12. third stop valve; 13. deaerator; 14. fourth stop valve; 15. first steam mixer; 1501. low-pressure steam inlet; 1502 , heating steam inlet; 1503, nozzle; 1504, suction chamber; 1505, mixing section; 1506, expansion chamber; 1507, expansion section; 1508, mixed steam outlet; 1509, cooling water pipe; 1510, pressure gauge; 1511, temperature gauge; 1512, outlet chamber; 16, first bypass valve; 17, second steam mixer; 18, second bypass valve; 19, fifth stop valve; 20, sixth stop valve; 21, seventh stop valve ; 22, the eighth stop valve; 23, the main steam pipeline; 24, the high-pressure cylinder steam inlet regulating valve; 25, the high-pressure cylinder; 26, the medium-pressure cylinder; 27, the low-pressure cylinder; 28, the power generation rotor group; 29, the medium-pressure cylinder steam inlet regulating valve; 30, the ninth stop valve; 31, the tenth stop valve; 32, the heating steam regulating valve; 33, the first steam regulating valve; 34, the second steam regulating valve; 35, the check valve; 36, the first start-up pipeline; 37, the second start-up pipeline; 38, the first steam outlet Inlet pipe; 39, second steam outlet pipe; 40, high-pressure steam inlet pipe; 41, medium-pressure steam inlet pipe; 42, low-pressure steam inlet pipe; 43, drain pipe; 44, first steam discharge pipe; 45, second steam discharge pipe; 46, first steam discharge pipe; 47, second steam discharge pipe; 48, first steam recovery pipe; 49, second steam recovery pipe; 50, first heating steam branch pipe; 51, second heating steam branch pipe; 52, deaeration pipe. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0033] Combine the following Figure 1 to Figure 2 , describing an embodiment of the present invention.

[0034] According to an embodiment of the present invention, on the one hand, a multi-module high temperature gas-cooled reactor steam system is provided, comprising: at least two steam supply subsystems, including a first steam supply subsystem and a second steam supply subsystem; a main steam pipeline 23, the main steam pipeline 23 is suitable for communicating with a steam turbine generator set, and the steam turbine generator set is provided with an intermediate pressure cylinder 26;

[0035] A first steam supply subsystem, the first steam supply subsystem comprises a first core steam supply module 1 and a first steam outlet pipeline 38, the first core steam supply module 1 is connected to the main steam pipeline 23 through the first steam outlet pipeline 38, and the first core steam supply module 1 supplies first pressure main steam;

[0036] A second steam supply subsystem, the second steam supply subsystem comprises a second nuclear steam supply module 2, a second steam mixer 17, a second steam exhaust pipeline 45 and a second steam recovery pipeline 49, and the second nuclear steam supply module 2 supplies second pressure main steam;

[0037] One end of the second steam exhaust pipeline 45 is in communication with the second nuclear steam supply module 2, and a second steam mixer 17 is disposed on the second steam exhaust pipeline 45;

[0038] The second steam mixer 17 is connected to the main steam pipeline 23 through the second heating steam branch pipe 51;

[0039] One end of the second steam recovery pipeline 49 is in communication with the second steam mixer 17 , and the other end of the second steam recovery pipeline 49 is in communication with the intermediate pressure cylinder 26 .

[0040] In this embodiment, when the first nuclear steam supply module is working normally, the first pressure main steam generated is transported to the steam turbine generator set through the main steam pipeline 23; when the second nuclear steam supply module is in the initial core loading process, the second pressure main steam generated by the second nuclear steam supply module 2, the pressure of the first pressure main steam is greater than the second pressure main steam, the second pressure main steam enters the second steam mixer 17 through the second steam discharge pipeline 45, part of the first pressure main steam in the main steam pipeline 23 enters the second steam mixer 17 and mixes with the second pressure main steam, and the mixed steam enters the medium pressure cylinder 26 through the second steam recovery pipeline 49, avoiding the waste of the main steam supplied by the second nuclear steam supply module 2 before the pressure reaches the first pressure main steam, and there is no need to discharge it into the condenser 10. The steam formed by the mixture of the two main steam pressures enters the medium pressure cylinder 26 to drive the medium pressure cylinder 26 to move, so as to make full use of the second pressure main steam and improve economic benefits. It should be noted that the value of the first pressure main steam in this embodiment is 11MPa and 540℃.

[0041] It should be noted that the end of the second steam exhaust pipe 45 facing away from the second nuclear steam supply module 2 is suitable for connecting with the condenser 10, and the two ends of the second steam mixer 17 are respectively connected with the second steam exhaust pipe 45. The second steam exhaust pipe 45 is provided with a second bypass valve 18; the second heating steam branch pipe 51 is provided with a heating steam regulating valve 32; the second steam recovery pipe 49 is provided with a second steam recovery regulating valve 34.

[0042] like Figure 1 As shown, in one embodiment, the second steam subsystem also includes a second start-up pipe 37, one end of the second start-up pipe 37 is suitable for communicating with the second nuclear steam supply module 2, and the other end of the second start-up pipe 37 is suitable for communicating with the start-up expansion vessel 5. The second start-up pipe 37 is provided with a second regulating valve 6 and a second stop valve 7, and the connection between the second steam exhaust pipe 45 and the second start-up pipe 37 is located between the second regulating valve 6 and the second stop valve 7.

[0043] In this embodiment, by providing a second startup pipeline 37, the second nuclear steam supply module 2 can recover the drain heat to the startup expansion tank 5 during the startup phase, thereby reducing the steam extraction amount of the turbine, so that more steam can be used for power generation and the economy of the unit is improved.

[0044] like Figure 1 As shown, the second steam exhaust pipe 45 is also provided with a second bypass valve 18, and the second bypass valve 18 is located between the second steam mixer 17 and the condenser 10. Figure 1 As shown, the connection between the second steam recovery pipeline 49 and the second steam exhaust pipeline 45 is located between the second bypass valve 18 and the second steam mixer 17 .

[0045] like Figure 1 As shown, in one embodiment, the second steam subsystem also includes a second steam outlet pipe 39, one end of the second steam outlet pipe 39 is connected to the second nuclear steam supply module 2, and the other end of the second steam outlet pipe 39 is connected to the main steam pipe 23, and the second steam outlet pipe 39 is provided with a seventh stop valve 21 and an eighth stop valve 22.

[0046] In this embodiment, after the second nuclear steam supply module 2 is started up, the supplied main steam pressure reaches the first pressure main steam, and is transported to the main steam pipe 23 by the second steam outlet pipe 39. The seventh stop valve 21 and the eighth stop valve 22 control the second steam outlet pipe 39.

[0047] like Figure 1As shown, in one embodiment, it also includes a second steam discharge pipe 47, one end of the second steam discharge pipe 47 is connected to the second steam outlet pipe 39, the other end of the second steam discharge pipe 47 is connected to the second steam mixer 17, the connection between the second steam discharge pipe 47 and the second steam outlet pipe 39 is located between the seventh stop valve 21 and the eighth stop valve 22, and the second steam discharge pipe 47 is provided with a tenth stop valve 31.

[0048] In this embodiment, when the main steam pressure supplied by the second nuclear steam supply module 2 slowly rises from the second pressure main steam to the first pressure main steam, at this time, it is impossible to switch between the second steam recovery pipe 49 and the second steam outlet pipe 39, and it can only be switched through the second steam discharge pipe 47.

[0049] like Figure 1 As shown, in one embodiment, the first steam supply subsystem also includes a first start-up pipe 36, one end of the first start-up pipe 36 is connected to the first nuclear steam supply module 1, and the other end of the first start-up pipe 36 is suitable for connecting to the start-up expansion vessel 5, and the first start-up pipe 36 is provided with a first regulating valve 3 and a first stop valve 4.

[0050] In this embodiment, by providing the first startup pipeline 36, the first nuclear steam supply module 1 can recover the drain heat to the startup expansion tank 5 for feed water heating during the startup phase, thereby reducing the steam extraction amount of the turbine, so that more steam can be used for power generation and the economy of the unit is improved.

[0051] like Figure 1 As shown, in one embodiment, it also includes a first steam exhaust pipe 44, one end of the first steam exhaust pipe 44 is suitable for being connected to the condenser 10, and the other end of the first steam exhaust pipe 44 is connected to the first start-up pipe 36. The connection between the first steam exhaust pipe 44 and the first start-up pipe 36 is arranged between the first regulating valve 3 and the first stop valve 4, and the first steam exhaust pipe 44 is provided with a first steam mixer 15 and a first bypass valve 16.

[0052] In this embodiment, when the first nuclear steam supply module 1 generates main steam during the startup phase, when the pressure of the main steam is lower than the second pressure main steam, the main steam is discharged into the condenser 10 through the first steam discharge pipe 44. Figure 1 As shown, it also includes a first steam recovery pipeline 48, one end of which is connected to the medium pressure cylinder 26, and the other end is arranged on the first steam discharge pipeline 44 between the first bypass valve 16 and the first steam mixer 15, and the first steam recovery pipeline 48 is provided with a first steam regulating valve 33.

[0053] like Figure 1As shown, in one embodiment, it also includes a first steam discharge pipe 46, one end of the first steam discharge pipe 46 is connected to the first steam outlet pipe 38, the other end of the first steam discharge pipe 46 is connected to the first steam mixer 15, the first steam outlet pipe 38 is provided with a fifth stop valve 19 and a sixth stop valve 20, the connection between the first steam discharge pipe 46 and the first steam outlet pipe 38 is located between the fifth stop valve 19 and the sixth stop valve 20, and the first steam discharge pipe 46 is provided with a ninth stop valve 30.

[0054] In this embodiment, when the main steam pressure supplied by the first nuclear steam supply module 1 is between the upper limit of the second pressure main steam and the lower limit of the first pressure main steam, at this time, switching between the first steam recovery pipe 48 and the first steam outlet pipe 38 cannot be achieved, and switching can only be achieved through the first steam discharge pipe 46.

[0055] like Figure 1 As shown, in one embodiment, it also includes a first heating steam branch pipe 50 , one end of the first heating steam branch pipe 50 is connected to the first steam mixer 15 , and the other end of the first heating steam branch pipe 50 is connected to the main steam pipeline 23 .

[0056] In this embodiment, when the pressure of the main steam generated by the first nuclear steam supply module 1 during the startup phase reaches the second pressure main steam, the first pressure main steam in the main steam pipeline 23 is introduced into the first steam mixer 15 through the first heating branch pipe, and after the two are mixed, the mixed steam enters the intermediate pressure cylinder 26 through the first steam recovery pipeline 48. It should be noted that, if Figure 1 As shown, in this embodiment, the first heating steam branch pipe 50 and the second heating steam branch pipe 51 are provided with a common pipe at the end connected to the main steam pipe 23, and the common pipe is provided with a heating steam regulating valve 32.

[0057] like Figure 1 As shown, in one embodiment, the first steam mixer 15 includes an intake chamber 1504, a diffusion chamber 1506 and an outlet chamber 1512 which are connected in sequence, a mixing section 1505 is provided between the intake chamber 1504 and the diffusion chamber 1506, a diffusion section 1507 is provided between the diffusion chamber 1506 and the outlet chamber 1512, a nozzle 1503 and a heating steam inlet 1502 are provided on the side wall of the intake chamber 1504, the nozzle 1503 is provided with a low-pressure steam inlet 1501, and a temperature gauge 1511 and a pressure gauge 1510 are provided on the side wall of the outlet chamber 1512.

[0058] In this embodiment, the heating steam inlet 1502 of the first steam mixer 15 is connected to the first heating steam branch pipe 50, and the first pressure main steam entering from the first heating steam branch pipe 50 enters the suction chamber 1504 and the adiabatic expansion pressure is reduced, and the low pressure steam inlet 1501 is connected to the first steam discharge pipe 44, so that the first pressure main steam and the second pressure main steam are mixed in the mixing section 1505, and then flow out through the expansion chamber 1506 and the mixed steam outlet 1508 of the outlet chamber 1512. It should be noted that a cooling water pipe 1509 is provided on the side wall of the outlet chamber 1512, and the cooling water pipe 1509 flows through the cooling water to the first steam mixer 15 to control the temperature of the mixed steam, and the temperature and pressure of the mixed steam are monitored in real time through the temperature gauge 1511 and the pressure gauge 1510 provided on the side wall of the outlet chamber 1512. It should be noted that the second steam mixer 17 in this embodiment has the same structure as the first steam mixer 15.

[0059] like Figure 1 As shown, in one embodiment, a drain pipe 43 is provided between the startup expansion tank 5 and the condenser 10, and the drain pipe 43 is provided with a drain regulating valve 11 and a third stop valve 12 in sequence from the startup expansion tank 5 toward the condenser 10, and the drain pipe 43 is connected to the bottom of the startup expansion tank 5 to transfer the excess steam in the startup expansion tank 5 to the condenser 10. Figure 1 As shown, a condensate desuperheater 8 is connected to the side wall of the start-up expansion vessel 5 through a pipeline, and a desuperheating water regulating valve 9 is provided on the pipeline.

[0060] like Figure 1 As shown, in one embodiment, a deoxygenation pipeline 52 is further included. The connection point between the deoxygenation pipeline 52 and the drain pipeline 43 is located between the third stop valve 12 and the drain regulating valve 11. The deoxygenation pipeline 52 is provided with a deaerator 13 and a fourth stop valve 14.

[0061] like Figure 1 As shown, the steam turbine generator set also includes a high-pressure steam inlet pipe 40, one end of which is connected to the main steam pipe 23, and the other end is connected to the high-pressure cylinder 25. A high-pressure cylinder steam inlet regulating valve 24 is provided on the high-pressure steam inlet pipe 40; a medium-pressure steam inlet pipe 41 is provided between the high-pressure cylinder 25 and the medium-pressure cylinder 26, and a medium-pressure cylinder steam inlet regulating valve 29 is provided on the medium-pressure steam inlet pipe 41. It should be noted that the medium-pressure steam inlet pipe 41 is respectively connected to the first steam recovery pipe 48 and the second steam recovery pipe 49, and the first steam recovery pipe 48 and the second steam recovery pipe 49 share a pipe when connected to the medium-pressure steam inlet pipe 41. A check valve 35 is provided on the shared pipe to prevent steam from entering the steam recovery pipe from the medium-pressure cylinder 26. Figure 1As shown, it also includes a low-pressure cylinder 27 , a low-pressure steam inlet pipeline 42 is provided between the low-pressure cylinder 27 and the medium-pressure cylinder 26 , and the low-pressure cylinder 27 is connected to the generator rotor group 28 .

[0062] A control method for a multi-module high temperature gas-cooled reactor steam system comprises the following steps:

[0063] 1) When the entire system is stopped, no steam supply subsystem provides steam, and all stop valves and regulating valves in the system are in the closed state;

[0064] 2) The first steam supply subsystem is established in the initial core loading stage. First, the first regulating valve 3, the first stop valve 4, the drain regulating valve 11, and the third stop valve 12 are opened. After the feed water of the first nuclear steam supply module 1 enters the start-up expansion tank 5, it enters the condenser 10 through the drain pipe 43 to realize the recovery of the working medium. As the reactor power of the first nuclear steam supply module 1 is increased, the outlet temperature of the first nuclear steam supply module 1 is continuously increased. The desuperheating water regulating valve 9 is opened, and the water flow in the condensate desuperheater 8 is sprayed into the start-up expansion tank 5 to control the pressure. The pressure is controlled at 2MPa (corresponding to a temperature of 212°C). The fourth stop valve 14 is opened and the third stop valve 12 is closed. The drain in the start-up expansion tank 5 is recovered to the deaerator 13 to realize the recovery of the working medium and heat. The third pressure main steam (5MPa, 400°C) in the first start-up pipeline 36 is controlled by the first regulating valve 3, and the drain regulating valve 11 controls the liquid level in the start-up expansion tank 5;

[0065] 3) During the refueling process, the reactor power is controlled to be below 30% power. When the refueling accumulates enough reserve reactivity to be increased to full power, the reactor power is continued to be increased. When the outlet steam temperature of the first nuclear steam supply module 1 exceeds 400° C., the first bypass valve 16 is opened, the first stop valve 4 is closed, and the outlet steam of the first nuclear steam supply module 1 enters the condenser 10 through the first steam discharge pipe 44;

[0066] 4) Open the sixth stop valve 20, the high-pressure cylinder steam inlet regulating valve 24, and the medium-pressure cylinder steam inlet regulating valve 29. The main steam generated by the first nuclear steam supply module 1 enters the steam turbine generator set through the first steam discharge pipeline 46, the main steam pipeline 23, and the high-pressure cylinder 25 steam inlet pipeline in turn. The steam turbine generator set starts to run and connect to the grid. Then the steam temperature at the outlet of the first steam generator rises to 540°C. At this time, the main steam is the first pressure main steam (11MPa, 540°C). The main steam of the first nuclear steam supply module 1 in this process slowly changes from the third pressure main steam (5MPa, 400°C) to the first pressure main steam (11MPa, 540°C). The main steam The flow rate is gradually increased and the unit load is increased. The first regulating valve 3 is fully opened, the ninth stop valve 30 is opened, the first bypass valve 16 is gradually closed, the fifth stop valve 19 is opened, and the first regulating valve 3 is closed. The steam generated by the first nuclear steam supply module 1 is switched to the first steam outlet pipeline 38, so that the first pressure main steam enters the steam turbine generator set through the first steam outlet pipeline 38, the main steam pipeline 23, and the high-pressure cylinder 25 steam inlet pipeline in sequence. The reactor power is increased, and the main steam pipeline 23 continues to increase the flow rate. The main steam flow rate of the first nuclear steam supply module 1 continues to increase, and the high-pressure cylinder 25 steam inlet regulating valve is gradually opened until the reactor of the first nuclear steam supply module 1 reaches full power;

[0067] 5) The second steam supply subsystem is established in the initial core installation stage. The first steam supply subsystem is in full power operation. In the startup stage, the drain heat is recovered to the deaerator 13 for feed water heating. When the power rises to a certain value, the feed water flow rate and the reactor power are adjusted to make the main steam generated by the second nuclear steam supply module 2 reach the second pressure main steam (5MPa, 264°C). The heating steam regulating valve 32 is opened to extract part of the first pressure main steam in the main steam pipeline 23 to the second steam mixer 17. At the same time, the second stop valve 7 is closed and the second bypass valve 7 is opened. Valve 18, so that the second pressure main steam generated by the second nuclear steam supply module 2 enters the second steam mixer 17, when the pressure of the mixed steam is consistent with the steam pressure in the steam inlet pipe of the medium pressure cylinder 26, slowly open the first steam regulating valve 33, slowly close the second bypass valve 18, and merge the second pressure main steam generated by the second nuclear steam supply module 2 into the steam inlet pipe of the medium pressure cylinder 26 for power generation. In this process, the main steam of the second nuclear steam supply module is slowly changed from the second pressure main steam (5MPa, 264°C) to the third pressure main steam (5MPa, 400°C);

[0068] 6) When the refueling accumulates enough reserve reactivity and is ready to be increased to full power, the first steam regulating valve 33 is slowly closed, and the second bypass valve 18 is slowly opened to discharge the steam generated by the second nuclear steam supply module 2 into the condenser 10, and the steam parameters are adjusted at the same time. The main steam of the second nuclear steam supply module 2 in this process is slowly changed from the third pressure main steam (5MPa, 400°C) to the first pressure main steam (11MPa, 540°C);

[0069] 7) Open the eighth stop valve 22, the high-pressure cylinder steam inlet regulating valve 24, and the medium-pressure cylinder steam inlet regulating valve 29. The main steam generated by the second nuclear steam supply module 2 enters the steam turbine generator set through the second steam discharge pipeline 47, the main steam pipeline 23, and the high-pressure cylinder 25 steam inlet pipeline in turn. The steam turbine generator set starts to run and connect to the grid. Then the steam temperature at the outlet of the second steam generator rises to 540°C, the main steam flow rate gradually increases, and the unit increases load. The second regulating valve 6 is fully opened, the tenth stop valve 31 is opened, and the second bypass valve 18 is gradually closed. The high-pressure cylinder 25 steam inlet regulating valve controls the second steam mixer 17. The outlet pressure is at the same level before and after the seventh stop valve 21. The seventh stop valve 21 is opened, and the second regulating valve 6 is closed. The steam generated by the second nuclear steam supply module 2 is switched to the second steam outlet pipe 39, so that the second pressure main steam enters the steam turbine generator set through the second steam outlet pipe 39, the main steam pipe 23, and the steam inlet pipe of the high-pressure cylinder 25 in turn. When the reactor increases power, the main steam pipe 23 continues to increase the flow rate, and the main steam flow rate of the second nuclear steam supply module 2 continues to increase. The steam inlet regulating valve of the high-pressure cylinder 25 is gradually opened until the reactor of the second nuclear steam supply module 2 reaches full power.

[0070] It should be noted that, in this system, if at least one nuclear steam supply module is operating at full power, the remaining nuclear steam supply modules need to repeat steps 5)-8) when establishing the initial core installation stage.

[0071] The multi-module high-temperature gas-cooled reactor steam system provided by the present invention has the following advantages: (1) During the startup phase, the heat of the drain is recovered to the deaerator 13 for heating feed water, which can reduce the steam extraction of the steam turbine, so that more steam can be used for power generation, thereby improving the economy of the unit; (2) The first pressure main steam of the nuclear steam supply module running at full power is extracted to heat the steam of other nuclear steam supply modules in the initial core installation stage, so that the steam enters the steam turbine for power generation, making full use of the steam originally discharged into the condenser 10, reducing the steam extraction of the steam turbine, and using more steam for power generation, thereby greatly improving the economic benefits; (3) The steam mixer has a simple structure and occupies a small area. Compared with the steam-water separation reheater used in a pressurized water reactor nuclear power plant to heat steam, it saves expenses and has high efficiency; (4) By recovering the drain in the startup expansion tank 5 to the deaerator 13 for heating feed water, the traditional auxiliary electric boiler can be shut down, saving a lot of electricity costs.

[0072] As an alternative embodiment, other steam subsystems such as a third steam supply subsystem and a fourth steam supply subsystem may also be included, and the structures of other steam subsystems are exactly the same as the first steam supply subsystem or the second steam supply subsystem of the present application.

[0073] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A multi-module high temperature gas-cooled reactor steam system, characterized in that: include: at least two steam supply subsystems, including a first steam supply subsystem and a second steam supply subsystem; A main steam pipeline (23), wherein the main steam pipeline (23) is suitable for communicating with a steam turbine generator set, wherein the steam turbine generator set is provided with a medium pressure cylinder (26); A first steam supply subsystem, the first steam supply subsystem comprising a first core steam supply module (1) and a first steam outlet pipeline (38), the first core steam supply module (1) being connected to a main steam pipeline (23) via the first steam outlet pipeline (38), the first core steam supply module (1) supplying first pressure main steam; a second steam supply subsystem, the second steam supply subsystem comprising a second core steam supply module (2), a second steam mixer (17), a second steam exhaust pipeline (45) and a second steam recovery pipeline (49), the second core steam supply module (2) supplying second pressure main steam; One end of the second steam exhaust pipe (45) is in communication with the second nuclear steam supply module (2), and a second steam mixer (17) is provided on the second steam exhaust pipe (45); The second steam mixer (17) is connected to the main steam pipeline (23) through a second heating steam branch pipe (51); One end of the second steam recovery pipeline (49) is in communication with the second steam mixer (17), and the other end of the second steam recovery pipeline (49) is in communication with the intermediate pressure cylinder (26).

2. The multi-module high temperature gas-cooled reactor steam system according to claim 1, characterized in that: The second steam subsystem also includes a second start-up pipeline (37), one end of which is suitable for communicating with the second nuclear steam supply module (2), and the other end of which is suitable for communicating with the start-up expansion vessel (5). The second start-up pipeline (37) is provided with a second regulating valve (6) and a second stop valve (7), and the connection between the second steam exhaust pipeline (45) and the second start-up pipeline (37) is located between the second regulating valve (6) and the second stop valve (7).

3. The multi-module high temperature gas-cooled reactor steam system according to claim 2, characterized in that: The second steam subsystem also includes a second steam outlet pipe (39), one end of the second steam outlet pipe (39) is connected to the second nuclear steam supply module (2), and the other end of the second steam outlet pipe (39) is connected to the main steam pipe (23), and the second steam outlet pipe (39) is provided with a seventh stop valve (21) and an eighth stop valve (22).

4. The multi-module high temperature gas-cooled reactor steam system according to claim 3, characterized in that: The invention also comprises a second steam discharge pipe (47), one end of which is in communication with a second steam outlet pipe (39), and the other end of which is in communication with a second steam mixer (17). The connection between the second steam discharge pipe (47) and the second steam outlet pipe (39) is located between the seventh stop valve (21) and the eighth stop valve (22). The second steam discharge pipe (47) is provided with a tenth stop valve (31).

5. The multi-module high temperature gas-cooled reactor steam system according to claim 1, characterized in that: The first steam supply subsystem further comprises a first start-up pipeline (36), one end of which is connected to the first nuclear steam supply module (1), and the other end of which is suitable for connecting to the start-up expansion vessel (5). The first start-up pipeline (36) is provided with a first regulating valve (3) and a first stop valve (4).

6. The multi-module high temperature gas-cooled reactor steam system according to claim 5, characterized in that: The invention also comprises a first steam exhaust pipe (44), one end of which is suitable for being connected to the condenser (10), and the other end of which is connected to the first start-up pipe (36). The connection between the first steam exhaust pipe (44) and the first start-up pipe (36) is arranged between the first regulating valve (3) and the first stop valve (4). The first steam exhaust pipe (44) is provided with a first steam mixer (15) and a first bypass valve (16).

7. The multi-module high temperature gas-cooled reactor steam system according to claim 6, characterized in that: The invention also comprises a first steam discharge pipe (46), one end of which is in communication with a first steam outlet pipe (38), the other end of which is in communication with a first steam mixer (15), a fifth stop valve (19) and a sixth stop valve (20) being provided on the first steam outlet pipe (38), a connection point between the first steam discharge pipe (46) and the first steam outlet pipe (38) being located between the fifth stop valve (19) and the sixth stop valve (20), and a ninth stop valve (30) being provided on the first steam discharge pipe (46).

8. The multi-module high temperature gas-cooled reactor steam system according to claim 7, characterized in that: It also includes a first heating steam branch pipe (50), one end of which is connected to the first steam mixer (15), and the other end of which is connected to the main steam pipeline (23).

9. The multi-module high temperature gas-cooled reactor steam system according to claim 8, characterized in that: The first steam mixer (15) comprises a suction chamber (1504), a diffusion chamber (1506) and an outlet chamber (1512) which are connected in sequence, a mixing section (1505) is provided between the suction chamber (1504) and the diffusion chamber (1506), a diffusion section (1507) is provided between the diffusion chamber (1506) and the outlet chamber (1512), a nozzle (1503) and a heating steam inlet (1502) are provided on the side wall of the suction chamber (1504), a low-pressure steam inlet (1501) is provided on the nozzle (1503), and a temperature gauge (1511) and a pressure gauge (1510) are provided on the side wall of the outlet chamber (1512).

10. The multi-module high temperature gas-cooled reactor steam system according to claim 6, characterized in that: A drain pipe (43) is provided between the startup expansion tank (5) and the condenser (10), and the drain pipe (43) is provided with a drain regulating valve (11) and a third stop valve (12) in sequence from the startup expansion tank (5) toward the condenser (10).

11. The multi-module high temperature gas-cooled reactor steam system according to claim 10, characterized in that: The invention also comprises a deoxygenation pipeline (52), wherein the deoxygenation pipeline (52) is in communication with the drain pipeline (43), and the deoxygenation pipeline (52) is provided with a deaerator (13) and a fourth stop valve (14).

12. A control method for a multi-module high temperature gas-cooled reactor steam system, used for using the multi-module high temperature gas-cooled reactor steam system according to claim 1, characterized in that: include: The first nuclear steam supply module (1) operates normally, and the first pressure main steam generated by the first nuclear steam supply module (1) enters the main steam pipeline (23) through the first steam outlet pipeline (38), and is then transported to the steam turbine generator set through the main steam pipeline (23); When the second nuclear steam supply module (2) is in the process of initially loading the core, the second nuclear steam supply module (2) generates second-pressure main steam, the pressure of the first-pressure main steam is greater than that of the second-pressure main steam, the second-pressure main steam enters the second steam mixer (17) through the second steam discharge pipe (45), part of the first-pressure main steam in the main steam pipe (23) enters the second steam mixer (17) and is mixed with the second-pressure main steam, and the mixed steam enters the intermediate-pressure cylinder (26) through the second steam recovery pipe (49).

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