Auxiliary water supply system of steam generator

Abstract

The utility model discloses an auxiliary water supply system of a steam generator, which belongs to the technical field of nuclear power and is characterized in that a first-section steam extraction opening of a steam turbine is communicated with an inlet of a steam header, a second-section steam extraction opening of the steam turbine is communicated with an inlet of a deaerator, and an outlet of a main steam bypass valve is divided into two paths, wherein one path is communicated with an inlet of the steam header through a bypass steam supply header adjusting valve, the other path is communicated with an inlet of the condenser, an outlet of the steam header is communicated with an inlet of the small steam turbine, an outlet of the small steam turbine is communicated with an inlet of the auxiliary water feeding pump, and an outlet of the condenser is communicated with an inlet of the auxiliary water feeding pump. According to the system, after the water supply flow of the steam generator fluctuates or the main water supply pump loses the water supply function, water can be supplied to the secondary side of the steam generator in time, the water supply flow of the steam generator is dynamically adjusted, and the unit operation load requirement is met.

Description

Technical Field

[0001] The utility model belongs to the technical field of nuclear power and relates to an auxiliary water supply system of a steam generator. Background Art

[0002] During the start-up and shutdown and normal operation of the once-through steam generator, the internal working fluid will undergo three phase changes from the inlet to the outlet, namely, cold water, steam-water two-phase flow, and superheated steam. The internal heat exchange is relatively complex, and the internal working fluid flow must be stable during operation. The high-temperature gas-cooled reactor steam generator adopts a direct-current spiral structure. The primary shell side of the steam generator is high-temperature helium, and the secondary tube side is a steam-water mixture. When the feed water flow fluctuates during the operation of the unit, the original system design is to dynamically adjust the feed water flow through the main feed water pump. If the feed water flow still deviates from the normal operating load requirement of the unit during the adjustment period, the reactor will be shut down urgently. The above design scheme has at least the following disadvantages: First, when the load of the reactor or generator changes greatly, the feed water flow of the steam generator fluctuates greatly, and the main feed water pump regulation function is difficult to meet the load demand of the unit, which often causes the unit to be forced to shut down; Second, when the load of the reactor or generator changes little, although the main feed water pump regulation function can meet the low-load operating conditions of the unit, the steam turbine cannot extract steam to supply the deaerator heating steam source under low load, and the steam generator feed water temperature will drop significantly, causing the feed water flow to fluctuate, and the unit cannot operate stably under low load conditions; Third, the original design system has no backup feed water circuit. Once the main feed water pump fails and loses the feed water function, the reactor needs to be shut down urgently. Utility Model Content

[0003] The purpose of the utility model is to overcome the shortcomings of the above-mentioned prior art and provide an auxiliary water supply system for a steam generator, which can supply water to the secondary side of the steam generator in time after the water supply flow of the steam generator fluctuates or the main water supply pump loses its water supply function, and dynamically adjust the water supply flow of the steam generator to meet the operating load requirements of the unit.

[0004] To achieve the above object, the utility model discloses an auxiliary feedwater system for a steam generator, comprising a steam generator, a steam turbine, a generator, a main steam bypass valve, a condenser, a deaerator, a main feedwater pump, a steam header, a small steam turbine and an auxiliary feedwater pump;

[0005] The secondary side outlet of the steam generator is divided into three routes, wherein the first route is connected to the inlet of the main steam bypass valve, the second route is connected to the inlet of the steam turbine, the third route is connected to the inlet of the steam manifold, the exhaust port of the steam turbine is connected to the inlet of the condenser, the outlet of the main steam bypass valve is divided into two routes, one of which is connected to the inlet of the steam manifold, and the other is connected to the inlet of the condenser, the outlet of the steam manifold is connected to the inlet of the small steam turbine, the outlet of the small steam turbine is connected to the inlet of the auxiliary feed water pump, the outlet of the condenser is connected to the inlet of the auxiliary feed water pump, the outlet of the auxiliary feed water pump is connected to the secondary side inlet of the steam generator, the outlet of the condenser is connected to the inlet of the deaerator, the outlet of the deaerator is connected to the secondary side inlet of the steam generator, and the generator is connected to the steam turbine.

[0006] The reactor is in communication with the primary side of the steam generator;

[0007] The outlet of the main steam bypass valve is connected to the inlet of the steam manifold through the bypass steam supply manifold regulating valve.

[0008] The first stage steam extraction port of the steam turbine is connected to the inlet of the steam header, and the second stage steam extraction port of the steam turbine is connected to the inlet of the deaerator.

[0009] The secondary side outlet of the steam generator is divided into three routes, wherein the first route is connected to the inlet of the main steam bypass valve, the second route is connected to the inlet of the steam turbine through the main steam regulating valve, and the third route is connected to the inlet of the steam manifold through the main steam pressure reducing regulating valve.

[0010] A steam extraction port of the steam turbine is connected to the inlet of the steam header through the first steam extraction regulating valve of the steam turbine.

[0011] The second-stage steam extraction port of the steam turbine is connected to the inlet of the deaerator through the second steam extraction regulating valve of the steam turbine.

[0012] The outlet of the auxiliary feed water pump is connected to the secondary side inlet of the steam generator through the auxiliary feed water pump outlet regulating valve.

[0013] The outlet of the deaerator is connected to the secondary side inlet of the steam generator through the main feed water pump and the main feed water pump outlet regulating valve.

[0014] The outlet of the condenser is connected to the inlet of the auxiliary feedwater pump through the condenser auxiliary feedwater pump outlet isolation valve.

[0015] The utility model has the following beneficial effects:

[0016] During the specific operation of the auxiliary water supply system of the steam generator described in the utility model, during the normal operation of the unit, the steam supply source of the steam header is supplied by the steam extraction of the steam turbine, the steam generator feed water is supplied by the main feed water pump, and the auxiliary feed water pump is on standby; during the fluctuation of the feed water flow of the steam generator, the steam supply source of the steam header is supplied by the steam extraction of the steam turbine, and the heat storage in the steam header is used to supply the small steam turbine to drive the auxiliary feed water pump to operate, the feed water of the steam generator is supplied by the main feed water pump and the auxiliary feed water pump, and the auxiliary feed water pump is used to quickly adjust the feed water flow to stabilize; during the failure of the main feed water pump, the steam supply source of the steam header is supplied by the main steam turbine. The steam source is supplied by the steam main pipe and bypass, and the heat storage in the steam manifold is used to supply the small steam turbine to drive the auxiliary feedwater pump. The feedwater of the steam generator is supplied by the auxiliary feedwater pump, and the feedwater flow rate is quickly restored to be stable, thereby ensuring the stability of the feedwater flow rate under various operating conditions of the unit, greatly reducing the probability of unplanned shutdown of the unit due to fluctuation or loss of the feedwater flow of the steam generator. At the same time, the steam supply source of the steam manifold is switched without disturbance under different operating conditions, ensuring the steam demand of the driving steam source of the small steam turbine and the rapid start-up of the auxiliary feedwater pump, avoiding the problem of overpressure in the main steam pipeline under various operating conditions of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the utility model.

[0018] Among them, 1 is the reactor, 2 is the steam generator, 3 is the main steam regulating valve, 4 is the steam turbine, 5 is the generator, 6 is the main steam bypass valve, 7 is the condenser, 8 is the condensate pump, 9 is the deaerator, 10 is the main feedwater pump, 11 is the bypass steam supply manifold regulating valve, 12 is the steam manifold, 13 is the main steam pressure reducing regulating valve, 14 is the first steam extraction regulating valve of the steam turbine, 15 is the small steam turbine, 16 is the auxiliary feedwater pump, 17 is the condenser auxiliary feedwater pump outlet isolation valve, 18 is the second steam extraction regulating valve of the steam turbine, 19 is the auxiliary feedwater pump outlet regulating valve, and 20 is the main feedwater pump outlet regulating valve. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the solution of the utility model, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is only an embodiment of a part of the utility model, not all embodiments, and is not intended to limit the scope of the disclosure of the utility model. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concepts disclosed in the utility model. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the utility model.

[0020] The accompanying drawings show schematic diagrams of structures according to the disclosed embodiments of the utility model. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0021] Embodiment 1

[0022] refer to Figure 1 The auxiliary feedwater system of the steam generator described in the utility model comprises a reactor 1, a steam generator 2, a main steam regulating valve 3, a steam turbine 4, a generator 5, a main steam bypass valve 6, a condenser 7, a condensate pump 8, a deaerator 9, a main feedwater pump 10, a bypass steam supply header regulating valve 11, a steam header 12, a main steam pressure reducing regulating valve 13, a first steam extraction regulating valve 14 of a steam turbine, a small steam turbine 15, an auxiliary feedwater pump 16, a condenser auxiliary feedwater pump outlet isolation valve 17, a second steam extraction regulating valve 18 of a steam turbine, an auxiliary feedwater pump outlet regulating valve 19 and a main feedwater pump outlet regulating valve 20;

[0023] The reactor 1 is connected to the primary side of the steam generator 2, and the secondary side outlet of the steam generator 2 is divided into three routes, wherein the first route is connected to the inlet of the main steam bypass valve 6, the second route is connected to the inlet of the steam turbine 4 through the main steam regulating valve 3, and the third route is connected to the inlet of the steam header 12 through the main steam pressure reducing regulating valve 13. The exhaust port of the steam turbine 4 is connected to the inlet of the condenser 7, the first stage steam extraction port of the steam turbine 4 is connected to the inlet of the steam header 12 through the first steam extraction regulating valve 14 of the steam turbine, and the second stage steam extraction port of the steam turbine 4 is connected to the inlet of the deaerator 9 through the second steam extraction regulating valve 18 of the steam turbine. The outlet of the main steam bypass valve 6 is divided into two routes, one of which is connected to the steam header regulating valve 18 through the bypass. The throttle valve 11 is connected to the inlet of the steam header 12, and the other way is connected to the inlet of the condenser 7. The outlet of the steam header 12 is connected to the inlet of the small steam turbine 15, and the outlet of the small steam turbine 15 is connected to the inlet of the auxiliary feedwater pump 16. The outlet of the condenser 7 is connected to the inlet of the auxiliary feedwater pump 16 through the condenser auxiliary feedwater pump outlet isolation valve 17, and the outlet of the auxiliary feedwater pump 16 is connected to the secondary side inlet of the steam generator 2 through the auxiliary feedwater pump outlet regulating valve 19. The outlet of the condenser 7 is connected to the inlet of the deaerator 9 through the condensate pump 8, and the outlet of the deaerator 9 is connected to the secondary side inlet of the steam generator 2 through the main feedwater pump 10 and the main feedwater pump outlet regulating valve 20.

[0024] Embodiment 2

[0025] refer to Figure 1, the working principle of this embodiment is:

[0026] 1) Normal load operation of the unit

[0027] The initial state of the unit: the reactor 1, steam generator 2, steam turbine 4, generator 5, condensate pump 8 and main feedwater pump 10 operate normally, the auxiliary feedwater pump 16 stops running, the main steam regulating valve 3, the first steam extraction regulating valve 14 of the steam turbine, the second steam extraction regulating valve 18 of the steam turbine and the main feedwater pump outlet regulating valve 20 are open; the main steam bypass valve 6, the bypass steam supply manifold regulating valve 11, the main steam pressure reducing regulating valve 13, the condenser supply auxiliary feedwater pump outlet isolation valve 17 and the auxiliary feedwater pump outlet regulating valve 19 are closed.

[0028] Reactor 1 operates normally, and the heat generated by reactor 1 enters the primary side of steam generator 2, and transfers the heat to the feed water on the secondary side of steam generator 2. The main steam output from the secondary side of steam generator 2 enters steam turbine 4 through main steam regulating valve 3, drives steam turbine 4 to do work, and generator 5 operates under load; exhaust steam after work of steam turbine 4 enters condenser 7 for cooling, and then is transported to deaerator 9 for heating by condensate pump 8, and then is transported to the secondary side of steam generator 2 for heat exchange through main feed water pump 10 and main feed water pump outlet regulating valve 20, so as to form a load operation loop of the unit.

[0029] Among them, the first stage extraction steam of the steam turbine 4 is supplied to the steam manifold 12 through the first steam extraction regulating valve 14 of the steam turbine, so as to serve as the operating steam source of the small steam turbine 15; the second stage extraction steam of the steam turbine 4 is supplied to the deaerator 9 through the second steam extraction regulating valve 18 of the steam turbine, so as to serve as the heating steam source of the main feed water, and the outlet regulating valve 20 of the main feed water pump is put into automatic regulation, and the feed water flow of the steam generator 2 is adjusted according to the different loads of the unit.

[0030] 2) Feedwater flow fluctuation operation of steam generator 2

[0031] The initial state of the unit: the reactor 1, steam generator 2, steam turbine 4, generator 5, condensate pump 8 and main feedwater pump 10 operate normally, the auxiliary feedwater pump 16 stops running, the main steam regulating valve 3, the first steam extraction regulating valve 14 of the steam turbine, the second steam extraction regulating valve 18 of the steam turbine and the main feedwater pump outlet regulating valve 20 are open; the main steam bypass valve 6, the bypass steam supply manifold regulating valve 11, the main steam pressure reducing regulating valve 13, the condenser supply auxiliary feedwater pump outlet isolation valve 17 and the auxiliary feedwater pump outlet regulating valve 19 are closed.

[0032] When the load of the reactor 1 or the generator 5 fluctuates greatly, the opening of the main feedwater pump outlet regulating valve 20 is increased, the feedwater flow of the steam generator 2 fluctuates frequently, the condenser auxiliary feedwater pump outlet isolation valve 17 and the auxiliary feedwater pump outlet regulating valve 19 are opened, and the auxiliary feedwater pump 16 is driven by the small steam turbine 15. The auxiliary feedwater pump 16 transports the condensate in the condenser 7 to the secondary side of the steam generator 2 for heat exchange.

[0033] Among them, one section of the steam extraction of the steam turbine 4 is supplied to the steam manifold 12 through the first steam extraction regulating valve 14 of the steam turbine, as the operating steam source of the small steam turbine 15, and the small steam turbine 15 drives the auxiliary feed water pump 16 to operate; the other section is supplied to the deaerator 9 through the second steam extraction regulating valve 18 of the steam turbine, as the heating steam source of the main feed water, and the auxiliary feed water pump outlet regulating valve 19 is automatically put into operation to maintain the feed water flow of the steam generator 2 stable, so that the feed water flow of the steam generator 2 meets the operating conditions of the reactor 1, the steam turbine 4 and the generator 5.

[0034] 3) Faulty operating condition of main feedwater pump 10

[0035] The initial state of the unit: the reactor 1, steam generator 2, steam turbine 4, generator 5, condensate pump 8 and main feedwater pump 10 operate normally, the auxiliary feedwater pump 16 stops running, the main steam regulating valve 3, the first steam extraction regulating valve 14 of the steam turbine, the second steam extraction regulating valve 18 of the steam turbine and the main feedwater pump outlet regulating valve 20 are open; the main steam bypass valve 6, the bypass steam supply manifold regulating valve 11, the main steam pressure reducing regulating valve 13, the condenser supply auxiliary feedwater pump outlet isolation valve 17 and the auxiliary feedwater pump outlet regulating valve 19 are closed.

[0036] When the main feedwater pump 10 fails and causes a sudden drop in the feedwater flow on the secondary side of the steam generator 2, the reactor 1 begins to operate at reduced power, the main feedwater pump 10 and the condensate pump 8 stop operating, the main feedwater pump outlet regulating valve 20 is closed, the generator 5 operates at reduced power, the main steam regulating valve 3 is closed to the minimum valve position, the steam turbine 4 is kept stable at 3000rpm, the first steam extraction regulating valve 14 of the steam turbine and the second steam extraction regulating valve 18 of the steam turbine are closed, the main steam bypass valve 6 is opened, the bypass steam supply manifold regulating valve 11 and the main steam pressure reducing regulating valve 13 are opened, so that the main steam output from the secondary side of the steam generator 2 is discharged into the steam manifold 12 and the condenser 7 to avoid overpressure in the main steam pipeline.

[0037] The auxiliary feed water pump outlet isolation valve 17 and the auxiliary feed water pump outlet regulating valve 19 of the condenser are opened, and the auxiliary feed water pump 16 is driven by the small steam turbine 15. The auxiliary feed water pump 16 transports the condensate in the condenser 7 to the secondary side of the steam generator 2, so as to quickly restore the feed water flow on the secondary side of the steam generator 2.

[0038] The bypass steam supply manifold regulating valve 11, the main steam pressure reducing regulating valve 13 and the auxiliary feedwater pump outlet regulating valve 19 are automatically put into operation to adjust the steam source pressure and temperature in the steam manifold 12, and the heat storage of the steam manifold 12 is used to maintain the normal operation of the small steam turbine 15 driving the auxiliary feedwater pump 16. The auxiliary feedwater pump outlet regulating valve 19 is automatically put into operation to adjust the feedwater flow on the secondary side of the steam generator 2 to meet the low-load stable operation requirements of the reactor 1 until the main feedwater pump 10 can operate normally, and the system state is restored to the above-mentioned normal load operation condition of the unit.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model is described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the utility model can still be modified or replaced by equivalents, and any modification or equivalent replacement that does not depart from the spirit and scope of the utility model should be included in the scope of protection of the claims of the utility model.

Claims

1. An auxiliary water supply system for a steam generator, characterized in that: It includes a steam generator (2), a steam turbine (4), a generator (5), a main steam bypass valve (6), a condenser (7), a deaerator (9), a main feed water pump (10), a steam header (12), a small steam turbine (15) and an auxiliary feed water pump (16); The secondary side outlet of the steam generator (2) is divided into three paths, wherein the first path is connected to the inlet of the main steam bypass valve (6), the second path is connected to the inlet of the steam turbine (4), and the third path is connected to the inlet of the steam header (12). The exhaust port of the steam turbine (4) is connected to the inlet of the condenser (7). The outlet of the main steam bypass valve (6) is divided into two paths, wherein one path is connected to the inlet of the steam header (12), and the other path is connected to the inlet of the condenser (7). The outlet of the steam header (12) is connected to the The inlet of the small steam turbine (15) is connected, the outlet of the small steam turbine (15) is connected to the inlet of the auxiliary feed water pump (16), the outlet of the condenser (7) is connected to the inlet of the auxiliary feed water pump (16), the outlet of the auxiliary feed water pump (16) is connected to the secondary side inlet of the steam generator (2), the outlet of the condenser (7) is connected to the inlet of the deaerator (9), the outlet of the deaerator (9) is connected to the secondary side inlet of the steam generator (2), and the generator (5) is connected to the steam turbine (4).

2. The auxiliary water supply system for the steam generator according to claim 1, characterized in that: The reactor (1) is connected to the primary side of the steam generator (2); The outlet of the main steam bypass valve (6) is connected to the inlet of the steam header (12) via the bypass steam supply header regulating valve (11).

3. The auxiliary water supply system for the steam generator according to claim 1, characterized in that: The first stage steam extraction port of the steam turbine (4) is connected to the inlet of the steam header (12), and the second stage steam extraction port of the steam turbine (4) is connected to the inlet of the deaerator (9).

4. The auxiliary water supply system for a steam generator according to claim 1, characterized in that: The secondary side outlet of the steam generator (2) is divided into three paths, wherein the first path is connected to the inlet of the main steam bypass valve (6), the second path is connected to the inlet of the steam turbine (4) via the main steam regulating valve (3), and the third path is connected to the inlet of the steam header (12) via the main steam pressure reducing regulating valve (13).

5. The auxiliary water supply system for a steam generator according to claim 1, characterized in that: A steam extraction port of the steam turbine (4) is connected to the inlet of the steam header (12) via a first steam extraction regulating valve (14) of the steam turbine.

6. The auxiliary water supply system for a steam generator according to claim 1, characterized in that: The second-stage steam extraction port of the steam turbine (4) is connected to the inlet of the deaerator (9) via the second steam extraction regulating valve (18) of the steam turbine.

7. The auxiliary water supply system for a steam generator according to claim 1, characterized in that: The outlet of the auxiliary feed water pump (16) is connected to the secondary side inlet of the steam generator (2) via the auxiliary feed water pump outlet regulating valve (19).

8. The auxiliary water supply system for a steam generator according to claim 1, characterized in that: The outlet of the deaerator (9) is connected to the secondary side inlet of the steam generator (2) via the main feed water pump (10) and the main feed water pump outlet regulating valve (20).

9. The auxiliary water supply system for a steam generator according to claim 1, characterized in that: The outlet of the condenser (7) is connected to the inlet of the auxiliary feedwater pump (16) through the condenser auxiliary feedwater pump outlet isolation valve (17).

10. The auxiliary water supply system for a steam generator according to claim 1, characterized in that: The outlet of the condenser (7) is connected to the inlet of the deaerator (9) via a condensate pump (8).

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