阅读说明：本技术 一种高温气冷堆核电厂二回路给水系统 (Two return circuits water supply system of high temperature gas cooled reactor nuclear power plant ) 是由 陈付军 朱信义 董正方 郑卫贞 于 2020-11-18 设计创作，主要内容包括：一种高温气冷堆核电厂二回路给水系统,包括#1、#2、#3电动调速给水泵,其入口通过#1、#2、#3手动隔离阀和除氧器连接,出口和#1、#2、#3止回阀入口连接,#1止回阀出口通过#1带旁路阀的电动截止止回阀和#1给水加热器入口连接,#2止回阀出口通过#2带旁路阀的电动截止止回阀和#2给水加热器入口连接,#3止回阀出口和#3、#4带旁路阀的电动截止止回阀入口连接,#3带旁路阀的电动截止止回阀出口和#1给水加热器入口连接,#4带旁路阀的电动截止止回阀出口和#2给水加热器入口连接；#1和#3电动调速给水泵、#2和#3电动调速给水泵设有备用联锁开关,将#3电动调速给水泵作为#1或#2电动调速给水泵的备用泵；本发明提高核电机组运行的可靠性及经济性。(A two-loop water supply system of a high-temperature gas cooled reactor nuclear power plant comprises a #1, #2 and #3 electric speed-regulating water supply pump, wherein the inlet of the two-loop water supply pump is connected with a deaerator through a #1, #2 and #3 manual isolation valve, the outlet of the two-loop water supply pump is connected with the inlets of #1, #2 and #3 check valves, the outlet of the #1 check valve is connected with the inlet of a #1 water supply heater through a #1 electric stop check valve with a bypass valve, the outlet of the #2 check valve is connected with the inlet of a #2 water supply heater through a #2 electric stop check valve with a bypass valve, the outlet of the #3 check valve is connected with the inlets of #3 and #4 electric stop check valves with bypass valves, the outlet of the #3 electric stop check valve with the bypass valve is connected with the inlet of the #1 water supply heater, and; the #1 and #3 electric speed regulation water supply pumps, the #2 and #3 electric speed regulation water supply pumps are provided with standby interlocking switches, and the #3 electric speed regulation water supply pump is used as a standby pump of the #1 or #2 electric speed regulation water supply pump; the invention improves the reliability and the economical efficiency of the operation of the nuclear power unit.)

1. A two-loop water supply system of a high-temperature gas cooled reactor nuclear power plant comprises a #1 electric speed regulation water supply pump (8), a #2 electric speed regulation water supply pump (10) and a #3 electric speed regulation water supply pump (9), and is characterized in that: the inlet of a #1 electric speed regulation water supply pump (8), a #2 electric speed regulation water supply pump (10) and a #3 electric speed regulation water supply pump (9) is connected with the outlet of a #1 filter screen (5), a #2 filter screen (7), a #3 filter screen (6) and a #1 manual isolation valve (2), a #2 manual isolation valve (4) and a #3 manual isolation valve (3), and the inlet of the #1 manual isolation valve (2), the #2 manual isolation valve (4) and the #3 manual isolation valve (3) is connected with the outlet of a deaerator (1); the outlets of a #1 electric speed regulation water feed pump (8), a #2 electric speed regulation water feed pump (10) and a #3 electric speed regulation water feed pump (9) are connected with the inlets of a #1 check valve (11), a #2 check valve (13) and a #3 check valve (12), the outlets of the #1 electric speed regulation water feed pump (8), the #2 electric speed regulation water feed pump (10) and the #3 electric speed regulation water feed pump (9) are respectively provided with a branch for recirculation and are respectively connected with a deaerator (1), the outlet of the #1 check valve (11) is connected with the inlet of a #1 water feed heater through an electric stop check valve (14) with a bypass valve of the #1, the outlet of the #2 check valve (13) is connected with the inlet of the #2 water feed heater through an electric stop check valve (15) with a bypass valve of the #2, the outlet of the #3 check valve (12) is connected with the inlet of an electric stop check valve (16) with a bypass valve of the #3 and an electric check valve, the outlet of a #3 electric stop check valve (16) with a bypass valve is connected with the inlet of a #1 feed water heater, and the outlet of a #4 electric stop check valve (17) with a bypass valve is connected with the inlet of a #2 feed water heater;

the #1 electric speed-regulating water-feeding pump (8) and the #3 electric speed-regulating water-feeding pump (9) are provided with a standby #1 electric speed-regulating water-feeding pump (8) interlocking switch, the #2 electric speed-regulating water-feeding pump (10) and the #3 electric speed-regulating water-feeding pump (9) are provided with a standby #2 electric speed-regulating water-feeding pump (10) interlocking switch, and after the standby electric speed-regulating water-feeding pump interlocking switch is switched on, the #3 electric speed-regulating water-feeding pump (9) is respectively used as a standby pump of the #1 electric speed-regulating water-feeding pump (8) and the #2 electric speed-.

2. The secondary loop water supply system of the high temperature gas cooled reactor nuclear power plant as claimed in claim 1, wherein: the interlocking protection logic of the standby #1 electric speed regulation water supply pump interlocking switch and the standby #2 electric speed regulation water supply pump interlocking switch is as follows: after the nuclear power unit is put into normal operation, the #1 electric speed-regulating water-feeding pump (8) starts to operate to supply water to a steam generator of a corresponding nuclear island #1 reactor, namely, an operation signal of the #1 electric speed-regulating water-feeding pump (8) is changed into a high level '1'; after the #3 electric speed regulation water feed pump (9) has no abnormal starting condition, namely the corresponding #3 electric speed regulation water feed pump (9) allows the starting signal to be changed into high level 1; the #1 electric speed regulation water supply pump (8) runs signals ' 1 ' and the #3 electric speed regulation water supply pump (9) allows a starting signal ' 1 ' to be simultaneously input into a #1 ' and a ' gate (18), the #1 ' and the ' gate (18) is triggered, an output signal of the #1 electric speed regulation water supply pump allows an electric stop check valve (16) with a bypass valve to be opened and becomes high-level ' 1 ', and a hand operates the electric stop check valve (16) with the bypass valve to open the #3 electric stop check valve (16), so that a valve rod is lifted to a ' full-on ' position, and a valve core is still in a ' full-off;

the #2 electric speed-regulating water-feeding pump (10) starts to operate to supply water to a steam generator of the corresponding nuclear island #2 reactor, namely, a signal of the #2 electric speed-regulating water-feeding pump (10) is changed into a high level 1; after the #3 electric speed regulation water feed pump (9) has no abnormal starting condition, namely the corresponding #3 electric speed regulation water feed pump (9) allows the starting signal to be changed into high level 1; the #2 electric speed-regulating water-feeding pump (10) runs signals '1' and the #3 electric speed-regulating water-feeding pump (9) allows a starting signal '1' to be simultaneously input into a #2 'and a' gate (19), the #2 'and the' gate (19) is triggered, an output signal of the #2 electric speed-regulating water-feeding pump allows an electric cut-off check valve (17) with a bypass valve to be opened to become high-level '1', the #4 electric cut-off check valve (17) with the bypass valve is manually opened to lift a valve rod to a 'full-on' position, and a valve core is still in a 'full-off' position;

after the interlocking switches of the #3 electric speed-regulating water-feeding pump (9) and the #1 electric speed-regulating water-feeding pump (8) are switched on, namely, the interlocking switch switching signal of the standby #1 electric speed-regulating water-feeding pump (8) which inputs the #3 'and the' door (20) is changed into high level '1'; the reactor of the nuclear island #1 corresponding to the #1 electric speed-regulating feed water pump (8) is in operation, namely a #1 reactor operation signal of an input #3 'and' gate (20) is changed into a high level '1'; when the #1 electric speed-regulating water-feeding pump (8) runs, namely a #1 electric speed-regulating water-feeding pump (8) running signal which is input into a #3 and a ' door (20) is changed into a high level ' 1 '; the #1 electric speed regulation water supply pump (8) trips in operation, namely a #1 electric speed regulation water supply pump (8) tripping signal of an input #3 'and' door (20) becomes high level '1', and a #1 electric speed regulation water supply pump (8) operation signal of the input #3 'and' door (20) is disconnected in a delayed way and still keeps high level '1'; the AND gate (20) is triggered to output a high level "1", which is sent to the AND gate (24) and the OR gate (22) of #6, and the OR gate (22) is triggered to output a high level "1", which is sent to the AND gate (23) of # 5; the #3 electric speed regulation water feed pump (9) has no abnormality and has a starting condition, namely the #3 electric speed regulation water feed pump (9) which inputs the #5 'and the' door (23) allows a starting signal to be changed into a high level '1'; the #5 AND gate (23) is triggered, the output signal is changed into high level '1', the signal firstly starts the #3 electric speed regulation water feeding pump (9) by unlocking, and secondly is respectively sent to the #6 AND gate (24) and the #7 AND gate (25), the #6 AND gate (24) is triggered, the output signal is changed into high level '1' to unlock and close the #4 electric stop check valve (17) with the bypass valve;

after the interlocking switches of the #3 electric speed-regulating water-feeding pump (9) and the #2 electric speed-regulating water-feeding pump (10) are switched on, namely, the interlocking switch switching signal of the standby #2 electric speed-regulating water-feeding pump (10) which inputs the #4 'and the' door (21) is changed into high level '1'; the reactor #2 of the nuclear island corresponding to the #2 electric speed-regulating feed pump (10) is in operation, namely a #2 reactor operation signal input to a #4 'and' gate (21) is changed into a high level '1'; when the #2 electric speed-regulating water-feeding pump (10) runs, namely a #2 electric speed-regulating water-feeding pump (10) running signal input into a #4 'and' gate (21) is changed into a high level '1'; the #2 electric speed regulation water supply pump (10) trips in operation, namely a #2 electric speed regulation water supply pump (10) tripping signal of an input #4 'and' gate (21) becomes high level '1', and a #2 electric speed regulation water supply pump (10) operation signal of an input #4 'and' gate (21) is disconnected in a delayed way and still keeps high level '1'; the #4 AND gate (21) is triggered, the output signal thereof becomes high level '1', the signal is sent to the #7 AND gate (25) and the OR gate (22), the OR gate (22) is triggered, the output signal thereof becomes high level '1' and then is sent to the #5 AND gate (23); the #3 electric speed regulation water feeding pump (9) has no abnormality and has a starting condition, namely the #3 electric speed regulation water feeding pump (9) sent to the #5 'and' gate (23) allows a starting signal to be changed into a high level '1'; the #5 AND gate (23) is triggered, the output signal is changed into high level '1', the signal firstly starts the #3 electric speed regulation water feeding pump (9) by unlocking, and secondly is respectively sent to the #6 AND gate (24) and the #7 AND gate (25), the #7 AND gate (25) is triggered, the output signal is changed into high level '1' to unlock and close the #3 electric stop check valve (16) with the bypass valve.

Technical Field

The invention relates to a water supply system, in particular to a two-loop water supply system of a high-temperature gas cooled reactor nuclear power plant.

Background

The water supply system of the two-loop two-reactor three-pump expansion unit of the current modularized high-temperature gas-cooled reactor nuclear power generating unit consists of a deaerator, three electric speed-regulating water supply pumps, a water supply pump inlet filter screen, a water supply pump inlet manual gate valve, a check valve at the downstream of the water supply pump, a water supply pump outlet electric gate valve with a bypass valve, two high-pressure water supply heaters and corresponding connecting pipelines. If one of the water feeding pumps is tripped in accident, the third public spare water feeding pump cannot be automatically started to be put into operation in an interlocking manner, so that the flow ratio of the cooling medium in the first loop and the second loop exceeds the allowable range required by the nuclear island reactor, the reactor is protected to jump, and the reliability and the economical efficiency of the operation of the system and the unit are greatly reduced.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a two-loop water supply system of a high-temperature gas cooled reactor nuclear power plant, which adopts an electric stop check valve as a water supply pump outlet shutoff valve, keeps a common standby water supply pump outlet shutoff valve rod lifted to a full-open state during the running of a unit, designs corresponding interlocking protection starting logic, realizes the emergency standby function of the common standby water supply pump, reduces the occurrence of reactor protection action shutdown events caused by the emergency trip of the running water supply pump, and improves the running reliability and economy of the system and the unit.

In order to achieve the purpose, the invention adopts the technical scheme that:

a two-loop water supply system of a high-temperature gas cooled reactor nuclear power plant comprises a #1 electric speed regulation water supply pump 8, a #2 electric speed regulation water supply pump 10 and a #3 electric speed regulation water supply pump 9, wherein the inlet of the #1 electric speed regulation water supply pump 8, the #2 electric speed regulation water supply pump 10 and the #3 electric speed regulation water supply pump 9 is connected with the outlet of a #1 filter screen 5, a #2 filter screen 7, a #3 filter screen 6 and a #1 manual isolation valve 2, a #2 manual isolation valve 4 and a #3 manual isolation valve 3, and the inlet of the #1 manual isolation valve 2, the #2 manual isolation valve 4 and the #3 manual isolation valve 3 is connected with the outlet of a deaerator 1; the outlets of a #1 electric speed-regulating feed water pump 8, a #2 electric speed-regulating feed water pump 10 and a #3 electric speed-regulating feed water pump 9 are connected with the inlets of a #1 check valve 11, a #2 check valve 13 and a #3 check valve 12, the outlets of the #1 electric speed-regulating feed water pump 8, the #2 electric speed-regulating feed water pump 10 and the #3 electric speed-regulating feed water pump 9 are respectively connected with a deaerator 1 through a branch recirculation, the outlet of the #1 check valve 11 is connected with the inlet of a #1 feed water heater through an electric stop check valve 14 with a bypass valve, the outlet of the #2 check valve 13 is connected with the inlet of the #2 feed water heater through an electric stop check valve 15 with a bypass valve, the outlet of the #3 check valve 12 is connected with the inlets of an electric stop check valve 16 with a bypass valve and an electric stop check valve 17 with a bypass valve, the outlet of the #3 electric stop check valve 16 with a bypass valve is connected with, #4 electric check valve with bypass valve 17 outlet connected to #2 feedwater heater inlet;

the #1 electric speed-regulating water-feeding pump 8 and the #3 electric speed-regulating water-feeding pump 9 are provided with a standby #1 electric speed-regulating water-feeding pump interlocking switch, the #2 electric speed-regulating water-feeding pump 10 and the #3 electric speed-regulating water-feeding pump 9 are provided with a standby #2 electric speed-regulating water-feeding pump interlocking switch, and after the standby electric speed-regulating water-feeding pump interlocking switch is switched on, the #3 electric speed-regulating water-feeding pump 9 is respectively used as a standby pump of the #1 electric speed-regulating water-feeding pump 8 or the #2 electric.

The interlocking protection logic of the standby #1 electric speed regulation water supply pump interlocking switch and the standby #2 electric speed regulation water supply pump interlocking switch is as follows:

after the nuclear power generating unit is put into normal operation, the #1 electric speed-regulating water-feeding pump 8 is started to operate to supply water to a steam generator of a corresponding nuclear island #1 reactor, namely an operation signal of the #1 electric speed-regulating water-feeding pump 8 is changed into a high level '1'; after the #3 electric speed-regulating water-feeding pump 9 has no abnormal starting condition, namely the corresponding #3 electric speed-regulating water-feeding pump 9 allows the starting signal to be changed into high level "1"; the #1 electric speed-regulating water feed pump 8 runs the signal "1" and the #3 electric speed-regulating water feed pump 9 allows the starting signal "1" to be simultaneously input into the #1 "and gate 18, the # 1" and gate 18 is triggered, and the output signal thereof allows the #3 electric stop check valve 16 with the bypass valve to be opened and becomes the high level "1"; the #3 electric stop check valve 16 with the bypass valve is opened by hand, the valve rod is lifted to the full-open position, and the valve core is still in the full-closed position; the #2 electric speed-regulating water-feeding pump 10 starts to operate to supply water to a steam generator of the corresponding nuclear island #2 reactor, namely, a signal of the #2 electric speed-regulating water-feeding pump 10 is changed into high level "1"; after the #3 electric speed-regulating water-feeding pump 9 has no abnormal starting condition, namely the corresponding #3 electric speed-regulating water-feeding pump 9 allows the starting signal to be changed into high level "1"; the #2 electric speed-regulating water-feeding pump 10 runs the signal "1" and the #3 electric speed-regulating water-feeding pump 9 allows the starting signal "1" to be simultaneously input into the #2 "and" gate 19, the #2 "and" gate 19 is triggered, the output signal allows the #4 electric stop check valve 17 with the bypass valve to be opened and changed into high level "1", the #4 electric stop check valve 17 with the bypass valve is opened by hand, the valve rod is lifted to the "full-on" position, and the valve core is still in the "full-off" position;

after the interlocking switches of the #3 electric speed-regulating water-feeding pump 9 and the #1 electric speed-regulating water-feeding pump 8 are switched on, namely, the interlocking switch switching-on signal of the standby #1 electric speed-regulating water-feeding pump 8 input into the #3 and the gate 20 is changed into high level "1"; the reactor #1 of the nuclear island corresponding to the #1 electric speed-regulating feed pump 8 is in operation, namely the reactor #1 operation signal of the input #3 ' and ' gate 20 ' is changed into high level ' 1 '; when the #1 electric speed-regulating water-feeding pump 8 runs, namely the running signal of the #1 electric speed-regulating water-feeding pump 8 which is input into the #3 and the gate 20 is changed into high level "1"; the #1 electric speed regulation water supply pump 8 trips in operation, namely the #3 input and the #1 electric speed regulation water supply pump 8 tripping signal of the gate 20 are changed into high level "1", and the #3 input and the #1 electric speed regulation water supply pump 8 operation signal of the gate 20 are disconnected in a delayed way, so that the high level "1" is still kept; the #3 and gate 20 is triggered, and its output signal becomes high level "1"; this signal is sent to #6 and gate 24 and or gate 22, or gate 22 is triggered, and its output signal goes to high level "1", and is sent to #5 and gate 23; the #3 electric speed-regulating water-feeding pump 9 has no abnormality and has a starting condition, namely the #3 electric speed-regulating water-feeding pump 9 which inputs the #5 'and the' door 23 allows a starting signal to be changed into a high level '1'; the #5 and gate 23 is triggered, and its output signal becomes high level "1"; the signal is that firstly, the #3 electric speed regulation feed pump 9 is started by interlocking, and secondly, the signal is respectively sent to a #6 AND gate 24 and a #7 AND gate 25; the #6 AND gate 24 toggles and its output signal goes high level "1" to interlock the #4 motorized stop check valve 17 with the bypass valve closed.

After the interlocking switches of the #3 electric speed-regulating water-feeding pump 9 and the #2 electric speed-regulating water-feeding pump 10 are switched on, namely, the interlocking switch switching-on signal of the standby #2 electric speed-regulating water-feeding pump 10 input into the #4 and the gate 21 is changed into high level "1"; the reactor #2 of the nuclear island corresponding to the #2 electric speed-regulating feed pump 10 is in operation, namely, the reactor #2 operation signal of the input #4 and the gate 21 is changed into high level "1"; when the #2 electric speed-regulating water-feeding pump 10 runs, namely the running signal of the #2 electric speed-regulating water-feeding pump 10 input into the #4 and the gate 21 is changed into high level "1"; the #2 electric speed-regulating water-feeding pump 10 trips in operation, namely the #4 and the #2 electric speed-regulating water-feeding pump 10 tripping signal of the gate 21 is changed into high level "1", and the #2 electric speed-regulating water-feeding pump 10 operation signal of the gate 21 is disconnected in a delayed way, so that the high level "1" is still kept; the #4 and gate 21 is triggered, and the output signal thereof becomes high level "1"; this signal is sent to #7 AND gate 25 and OR gate 22; the or gate 22 is triggered, and the output signal thereof changes to high level "1" and then is sent to the #5 and gate 23; the #3 electric speed-regulating water-feeding pump 9 has no abnormal condition and has a starting condition, namely the #3 electric speed-regulating water-feeding pump 9 sent to the #5 'and' door 23 allows a starting signal to be changed into a high level '1'; the #5 AND gate 23 is triggered to output a signal of high level "1", which is to unlock and start the #3 electric speed-regulating water-feeding pump 9, and to send the signal to the #6 AND gate 24 and the #7 AND gate 25, respectively, and the #7 AND gate 25 is triggered to output a signal of high level "1" to unlock and close the #3 electric stop check valve 16 with bypass valve.

The invention has the beneficial effects that:

the invention can simplify the system configuration, and not only reduces the risk of normal operation of the unit and the safety of the standby feed pump caused by backflow of feed water after the current check valve and related pipelines from the outlet of the public standby feed pump of the high-temperature gas cooled reactor nuclear power station to the check valve on the side pipeline of each feed water heater are still prevented by adopting the electric stop check valve with the bypass valve as the outlet stop valve of the electric speed-regulating feed pump (equivalent to that 2 check valves are still respectively arranged on the pipelines from the outlet pipeline of the public standby feed pump to the #1 feed water heater and from the #2 feed water heater); and the related interlocking protection logic is designed to open the electric stop check valve with the bypass valve at the outlet of the public standby water feeding pump to lift the valve rod of the electric stop check valve to the full-open position, so that the emergency function of the public standby water feeding pump is realized, the risk of emergency reactor tripping caused by accidental tripping of the water feeding pump is reduced, the problem that the public standby water feeding pump does not have the emergency standby capability is thoroughly solved, and the reliability and the economical efficiency of unit operation are improved.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

FIG. 2 shows the interlock protection logic of the interlock switch of the standby #1 electric speed-regulating water-feeding pump and the interlock switch of the standby #2 electric speed-regulating water-feeding pump according to the present invention.

Detailed Description

The invention is described in detail below with reference to the following figures and examples:

as shown in fig. 1, a two-loop water supply system of a high temperature gas cooled reactor nuclear power plant comprises a #1 electric speed regulation water supply pump 8, a #2 electric speed regulation water supply pump 10 and a #3 electric speed regulation water supply pump 9, wherein inlets of the #1 electric speed regulation water supply pump 8, the #2 electric speed regulation water supply pump 10 and the #3 electric speed regulation water supply pump 9 are connected with outlets of a #1 filter screen 5, a #2 filter screen 7, a #3 filter screen 6 and a #1 manual isolation valve 2, a #2 manual isolation valve 4 and a #3 manual isolation valve 3, and inlets of the #1 manual isolation valve 2, the #2 manual isolation valve 4 and the #3 manual isolation valve 3 are connected with an outlet of a deaerator 1; the outlets of a #1 electric speed-regulating feed water pump 8, a #2 electric speed-regulating feed water pump 10 and a #3 electric speed-regulating feed water pump 9 are connected with the inlets of a #1 check valve 11, a #2 check valve 13 and a #3 check valve 12, the outlets of the #1 electric speed-regulating feed water pump 8, the #2 electric speed-regulating feed water pump 10 and the #3 electric speed-regulating feed water pump 9 are respectively connected with a deaerator 1 through a branch recirculation, the outlet of the #1 check valve 11 is connected with the inlet of a #1 feed water heater through an electric stop check valve 14 with a bypass valve, the outlet of the #2 check valve 13 is connected with the inlet of the #2 feed water heater through an electric stop check valve 15 with a bypass valve, the outlet of the #3 check valve 12 is connected with the inlets of an electric stop check valve 16 with a bypass valve and an electric stop check valve 17 with a bypass valve, the outlet of the #3 electric stop check valve 16 with a bypass valve is connected with, #4 electric check valve with bypass valve 17 outlet connected to #2 feedwater heater inlet;

the #1 electric speed-regulating water-feeding pump 8 and the #3 electric speed-regulating water-feeding pump 9 are provided with a standby #1 electric speed-regulating water-feeding pump interlocking switch, the #2 electric speed-regulating water-feeding pump 10 and the #3 electric speed-regulating water-feeding pump 9 are provided with a standby #2 electric speed-regulating water-feeding pump interlocking switch, and after the standby electric speed-regulating water-feeding pump interlocking switch is switched on, the #3 electric speed-regulating water-feeding pump 9 is respectively used as a standby pump of the #1 electric speed-regulating water-feeding pump 8 or the #2 electric.

As shown in fig. 2, the interlock protection logic of the standby #1 electric speed regulation water supply pump interlock switch and the standby #2 electric speed regulation water supply pump interlock switch is as follows:

after the nuclear power generating unit is put into normal operation, the #1 electric speed-regulating water-feeding pump 8 is started to operate to supply water to a steam generator of a corresponding nuclear island #1 reactor, namely an operation signal of the #1 electric speed-regulating water-feeding pump 8 is changed into a high level '1'; after the #3 electric speed-regulating water-feeding pump 9 has no abnormal starting condition, namely the corresponding #3 electric speed-regulating water-feeding pump 9 allows the starting signal to be changed into high level "1"; the #1 electric speed-regulating water feed pump 8 runs the signal "1" and the #3 electric speed-regulating water feed pump 9 allows the starting signal "1" to be simultaneously input into the #1 "and gate 18, the # 1" and gate 18 is triggered, and the output signal thereof allows the #3 electric stop check valve 16 with the bypass valve to be opened and becomes the high level "1"; the #3 electric stop check valve 16 with the bypass valve is opened by hand, the valve rod is lifted to the full-open position, and the valve core is still in the full-closed position; the #2 electric speed-regulating water-feeding pump 10 starts to operate to supply water to a steam generator of the corresponding nuclear island #2 reactor, namely, a signal of the #2 electric speed-regulating water-feeding pump 10 is changed into high level "1"; after the #3 electric speed-regulating water-feeding pump 9 has no abnormal starting condition, namely the corresponding #3 electric speed-regulating water-feeding pump 9 allows the starting signal to be changed into high level "1"; the #2 electric speed-regulating water-feeding pump 10 runs the signal "1" and the #3 electric speed-regulating water-feeding pump 9 allows the starting signal "1" to be simultaneously input into the #2 "and" gate 19, the #2 "and" gate 19 is triggered, the output signal allows the #4 electric stop check valve 17 with the bypass valve to be opened and changed into high level "1", the #4 electric stop check valve 17 with the bypass valve is opened by hand, the valve rod is lifted to the "full-on" position, and the valve core is still in the "full-off" position;

after the interlocking switches of the #3 electric speed-regulating water-feeding pump 9 and the #1 electric speed-regulating water-feeding pump 8 are switched on, namely, the interlocking switch switching-on signal of the standby #1 electric speed-regulating water-feeding pump 8 input into the #3 and the gate 20 is changed into high level "1"; the reactor #1 of the nuclear island corresponding to the #1 electric speed-regulating feed pump 8 is in operation, namely the reactor #1 operation signal of the input #3 ' and ' gate 20 ' is changed into high level ' 1 '; when the #1 electric speed-regulating water-feeding pump 8 runs, namely the running signal of the #1 electric speed-regulating water-feeding pump 8 which is input into the #3 and the gate 20 is changed into high level "1"; the #1 electric speed regulation water supply pump 8 trips in operation, namely the #3 input and the #1 electric speed regulation water supply pump 8 tripping signal of the gate 20 are changed into high level "1", and the #3 input and the #1 electric speed regulation water supply pump 8 operation signal of the gate 20 are disconnected in a delayed way, so that the high level "1" is still kept; the #3 and gate 20 is triggered, and its output signal becomes high level "1"; this signal is sent to #6 and gate 24 and or gate 22, or gate 22 is triggered, and its output signal goes to high level "1", and is sent to #5 and gate 23; the #3 electric speed-regulating water-feeding pump 9 has no abnormality and has a starting condition, namely the #3 electric speed-regulating water-feeding pump 9 which inputs the #5 'and the' door 23 allows a starting signal to be changed into a high level '1'; the #5 and gate 23 is triggered, and its output signal becomes high level "1"; the signal is that firstly, the #3 electric speed regulation feed pump 9 is started by interlocking, and secondly, the signal is respectively sent to a #6 AND gate 24 and a #7 AND gate 25; the #6 AND gate 24 toggles and its output signal goes high level "1" to interlock the #4 motorized stop check valve 17 with the bypass valve closed.

After the interlocking switches of the #3 electric speed-regulating water-feeding pump 9 and the #2 electric speed-regulating water-feeding pump 10 are switched on, namely, the interlocking switch switching-on signal of the standby #2 electric speed-regulating water-feeding pump 10 input into the #4 and the gate 21 is changed into high level "1"; the reactor #2 of the nuclear island corresponding to the #2 electric speed-regulating feed pump 10 is in operation, namely, the reactor #2 operation signal of the input #4 and the gate 21 is changed into high level "1"; when the #2 electric speed-regulating water-feeding pump 10 runs, namely the running signal of the #2 electric speed-regulating water-feeding pump 10 input into the #4 and the gate 21 is changed into high level "1"; the #2 electric speed-regulating water-feeding pump 10 trips in operation, namely the #4 and the #2 electric speed-regulating water-feeding pump 10 tripping signal of the gate 21 is changed into high level "1", and the #2 electric speed-regulating water-feeding pump 10 operation signal of the gate 21 is disconnected in a delayed way, so that the high level "1" is still kept; the #4 and gate 21 is triggered, and the output signal thereof becomes high level "1"; this signal is sent to #7 AND gate 25 and OR gate 22; the or gate 22 is triggered, and the output signal thereof changes to high level "1" and then is sent to the #5 and gate 23; the #3 electric speed-regulating water-feeding pump 9 has no abnormal condition and has a starting condition, namely the #3 electric speed-regulating water-feeding pump 9 sent to the #5 'and' door 23 allows a starting signal to be changed into a high level '1'; the #5 AND gate 23 is triggered to output a signal of high level "1", which is to unlock and start the #3 electric speed-regulating water-feeding pump 9, and to send the signal to the #6 AND gate 24 and the #7 AND gate 25, respectively, and the #7 AND gate 25 is triggered to output a signal of high level "1" to unlock and close the #3 electric stop check valve 16 with bypass valve.

The working principle of the invention is as follows:

the #1 electric speed regulation water feed pump 8 and (or) #2 electric speed regulation water feed pump 10 run, when the #3 electric speed regulation water feed pump 9 is allowed to start, the corresponding #3 electric stop check valve 16 with the bypass valve and (or) #4 electric stop check valve 17 with the bypass valve can be manually opened, and the valve rod of the valve is lifted to the full-open position; after the interlocking switch of the standby #1 electric speed regulation feed water pump 8 and (or) the standby #2 electric speed regulation feed water pump 10 is put into operation, the #3 electric speed regulation feed water pump 9 can be respectively used as the standby pump of the #1 electric speed regulation feed water pump 8 and (or) #2 electric speed regulation feed water pump 10, when the #1 electric speed regulation feed water pump 8 and (or) #2 electric speed regulation feed water pump 10 trip in operation and the corresponding nuclear island #1 reactor and (or) #2 reactor operate, the interlocking protection logic action automatically starts the #3 electric speed regulation feed water pump 9 to operate and rapidly recover to provide cooling working media for the #1 reactor steam generator of the nuclear island or the #2 steam generator system of the nuclear island, and simultaneously closes the electric cut-off check valve 17 with a bypass valve at the #4 side of the #2 electric speed regulation feed water pump 10 or the #3 electric cut-off check valve 16 with a bypass valve at the #1 electric speed regulation feed water pump 8 side, the on-line emergency standby function of the #3 electric speed-regulating water-feeding pump 9 is realized, the risk of reactor protection action tripping caused by the transfinite ratio change of the two loops of cooling media is reduced, and the reliability and the safety of the reactor operation are improved.