Rapid commissioning method for condensate polishing system of nuclear power plant

Abstract

The invention belongs to the technical field of power plant condensate polishing, aims to solve the problem that in the prior art, a polishing system cannot be put into operation in time when the quality of condensate is deteriorated, and discloses a rapid putting-into-operation method for a nuclear power plant condensate polishing system to achieve remote control of a master control room DCS and local control of a polishing PLC. When transient states such as secondary loop water quality deterioration and condenser leakage occur, the precision processing system can be quickly recovered to a full-flow purification state, the water quality safety of steam generator feed water of a nuclear power unit is effectively guaranteed, few persons are on duty in a control room of the precision processing system, and the working efficiency is improved.

Description

Technical Field

[0001] The present application belongs to the technical field of condensate polishing in power plants, and in particular to a method for rapidly commissioning a condensate polishing system in a nuclear power plant. Background Art

[0002] The condensate polishing system is a key link in nuclear power plants to improve the quality of secondary loop circulating steam and water. Its purpose is to remove various harmful substances contained in the condensate and ensure that the feed water entering the steam generator is of extremely high purity, so as to maintain the safe and efficient operation of major equipment such as steam generators and steam turbines.

[0003] The principle is briefly described as follows: through the pre-cation bed filter, high-speed mixed bed and resin regeneration system designed and installed in the system, effective purification of condensate and repeated regeneration of resin are achieved. The pre-cation bed filter is used to remove Fe 3+ 、Al 3+ , Ca 2+ Mg 2+ , K + NH4 + 、Na + Cationic impurities such as Fe 3+ 、Al 3+ , Ca 2+ Mg 2+ , K + NH4 + 、Na + Isocations and SO4 2- 、NO3 - , Cl - OH - 、HCO3 - 、HSiO3 - It can remove anionic impurities such as condensate and deeply remove salt, so that the water quality meets strict usage standards; when the resin is saturated with various ions in the condensate, its ion exchange capacity must be restored through the acid-base regeneration process to achieve continuous and effective purification of the condensate.

[0004] During the normal operation of the nuclear power unit, when the condenser heat transfer tubes are well sealed, there are very few impurities leaking into the secondary circuit condensate, except for the ammonia water and ammonium ions produced by hydrazine added artificially to increase the anti-corrosion performance of the equipment and the pH value of the feed water. If the fine treatment system is put into operation continuously under this situation, it will lead to unnecessary absorption saturation failure of the ion exchange resin for ammonium ions, and the resin must be regenerated by adding acid and alkali to restore the exchange capacity of the resin, which increases the operation volume, and also increases the energy consumption of chemicals such as acid and alkali, and increases the amount of wastewater discharged, which is not conducive to energy conservation and emission reduction.

[0005] In order to achieve energy conservation and emission reduction and improve the economy and environmental performance of the units, nuclear power units and thermal power units at home and abroad currently adopt the method of shutting down the fine treatment system after the secondary circuit water quality returns to normal, and restarting it when the water quality deteriorates or needs to be put into operation.

[0006] However, the existing technology has the following disadvantages: the condensate polishing system is designed with local PLC control and operates in cold standby mode. When the secondary circuit water quality deteriorates transiently such as condenser leakage, it takes a long time for the polishing system to recover to full-flow purification operation. During this period, unexpected corrosion and scaling problems of major equipment such as steam generators and turbine blades will inevitably occur due to the deterioration of water quality, seriously endangering the operating safety of important equipment such as steam generators and turbine blades. Summary of the invention

[0007] The purpose of the present application is to provide a method for quickly putting into operation a condensate polishing system in a nuclear power plant, so as to solve the problem in the prior art that the polishing system cannot be put into operation in time when the condensate quality deteriorates, and effectively ensure the safety of the feed water quality of the steam generator of the nuclear power unit; and realize less-staffed operation in the control room of the polishing system, thereby improving work efficiency.

[0008] In order to achieve the above objectives, the present application provides the following technical solutions, including a manual rapid commissioning method and an automatic rapid commissioning method:

[0009] The manual rapid commissioning method of the nuclear power plant condensate polishing system provided in this application includes:

[0010] Step 1: Set up dual control of local PLC and DCS in the main control room for the fine treatment system equipment;

[0011] Step 2: Set up the secondary circuit water quality early warning function. When the secondary circuit water quality shows a trend of deterioration, it will remind the main control room operators to intervene in advance.

[0012] Step 3: During the power operation of the unit, the stop valve of the main pipe valve at the inlet of the fine treatment system, the inlet valve of the pre-cation bed, the outlet valve of the pre-cation bed, the inlet valve of the high-speed mixed bed, and the outlet valve of the high-speed mixed bed are maintained in the open state;

[0013] Step 4: Adjust the opening of the regulating valve at the outlet of the condensate polishing system to a certain percentage of the rated flow rate corresponding to the start-up of a condensate pump to avoid overloading the condensate pump due to excessive opening of the regulating valve;

[0014] Step 5: Maintain the front cation bed and high-speed mixed bed required for the full-flow purification operation of condensate water in a hot standby state with pressure operation, and the condensate pump in a shutdown standby state;

[0015] Step 6: During the power operation of the unit, determine whether the water quality indicators such as the secondary circuit condensate, feed water positive conductivity, steam generator wastewater positive conductivity, etc. have reached the warning value;

[0016] Step 7: When any water quality index of the secondary circuit reaches the warning value and it is determined that there is indeed a trend of water quality deterioration, the DCS in the main control room remotely and manually starts the condensate pump to restore the full flow purification operation of the fine treatment system;

[0017] Step 8: When the cause of the secondary circuit water quality deterioration is identified and eliminated, the condensate pump is manually shut down remotely in the DCS of the main control room to restore the full bypass operation of the fine treatment system.

[0018] In some embodiments, dual control of the fine treatment system equipment is set up by local PLC and main control room DCS, the condensate pump, condensate pump outlet stop valve and regulating valve are operated by the main control room DCS, and a PLC / DCS switching function is set.

[0019] In some embodiments, the secondary circuit water quality indicator warning signal includes:

[0020] (1) Condensate positive conductivity ≥ 0.3us / cm;

[0021] (2) The positive conductivity of steam generator wastewater is ≥ 0.5us / cm;

[0022] (3) The sodium ion concentration of steam generator wastewater is ≥ 20 ppb;

[0023] (4) The positive conductivity of steam generator feed water is ≥ 0.125us / cm.

[0024] In some embodiments, during the power operation of the unit, the shut-off valve of the main pipe valve at the inlet of the polishing system, the inlet valves of the 4 rows of pre-cationic beds, the outlet valves of the 4 rows of pre-cationic beds, the inlet valves of the 4 rows of high-speed mixed beds, and the outlet valves of the 4 rows of high-speed mixed beds are maintained in an open state;

[0025] In some embodiments, during the full bypass operation of the secondary condensate circuit, 4 rows of front cation beds and 4 rows of high-speed mixed beds are kept in hot standby operation with pressure, and 3 clean condensate pumps are kept in shutdown standby state.

[0026] In some embodiments, the opening of the outlet regulating valve of the condensate polishing system condensate clean pump is adjusted to 15% to 22% of the opening corresponding to the rated flow rate of starting a condensate clean pump.

[0027] In some embodiments, during the power operation of the unit, when the secondary circuit water quality index reaches any of the following warning values:

[0028] (1) Condensate positive conductivity ≥ 0.3us / cm;

[0029] (2) The positive conductivity of steam generator wastewater is ≥ 0.5us / cm;

[0030] (3) The sodium ion concentration of steam generator wastewater is ≥20ppb.

[0031] (4) The positive conductivity of steam generator feed water is ≥ 0.125us / cm.

[0032] In some embodiments, the four rows of pre-cation beds and four rows of high-speed mixed beds required to continuously maintain full-flow purification operation of condensate are in hot standby state with pressure operation, and the three condensate purification pumps are in shutdown standby state.

[0033] In some embodiments, during the power operation of the unit, it is determined whether water quality indicators such as the secondary circuit condensate, feed water cation conductivity, and steam generator wastewater cation conductivity have reached warning values.

[0034] In some embodiments, when it is determined that there is indeed a trend of water quality deterioration, the first condensate polishing system purifying pump is remotely and manually started in the DCS in the main control room, and then the opening of the purifying pump outlet regulating valve is increased from 15% to 22% to between 23% and 25%. The second purifying pump is remotely and manually started in the DCS in the main control room, and the opening of the purifying pump outlet regulating valve is increased to between 33% and 35%, thereby restoring 100% full-flow purification of the polishing system.

[0035] In some embodiments, after the cause of the deterioration of the secondary circuit water quality is identified and eliminated, when the positive conductivity of the steam generator feed water is ≤0.08us / cm and the positive conductivity of the steam generator wastewater is ≤0.2us / cm, the opening of the condensate pump outlet regulating valve is closed to between 23% and 25%, and then one condensate pump is shut down; then the opening of the condensate pump outlet regulating valve is closed to between 15% and 22%, and then the second condensate pump is shut down, and the full bypass operation of the fine treatment system is restored.

[0036] In some embodiments, the rapid commissioning method of the condensate polishing system of a nuclear power plant includes the following steps:

[0037] Step 9: Set the interlock signal for the condensate polishing system to automatically start operation and restore the condensate full flow purification operation;

[0038] Step 10: During the power operation of the unit, the stop valve of the main pipe valve at the inlet of the fine treatment system, the pre-cation bed inlet valve, the pre-cation bed outlet valve, the high-speed mixed bed inlet valve, and the high-speed mixed bed outlet valve are maintained in an open state;

[0039] Step 11: Adjust the opening of the outlet regulating valve of the condensate polishing system condensate pump to a certain percentage opening corresponding to the rated flow rate of starting a condensate pump;

[0040] Step 12: Continuously maintain the pre-cation bed and high-speed mixed bed required for the full-flow purification operation of condensate in a hot standby state under pressure;

[0041] Step 13: The condensate polishing system condensate pumps are all in standby mode;

[0042] Step 14: During the power operation of the unit, the DCS instrumentation and control system automatically monitors whether the water quality indicators of the secondary circuit condensate, the positive conductivity of the steam generator feed water, and the positive conductivity of the steam generator wastewater reach the instrumentation and control interlocking set values;

[0043] Step 15: When the water quality of the secondary circuit deteriorates and the interlocking signal set in step 9 is met at the same time, the two condensate purification pumps of the condensate polishing system are automatically started to restore the full flow purification operation of the condensate polishing system;

[0044] Step 16: When the cause of the secondary circuit water quality deterioration is identified and eliminated, the condensate pump is manually shut down remotely in the DCS of the main control room to restore the full bypass operation of the fine treatment system.

[0045] In some embodiments, an interlock signal is set for the condensate polishing system to automatically resume operation to purify condensate at full flow rate:

[0046] (1) Unit power ≥ 50%;

[0047] (2) Condensate positive conductivity ≥ 0.5us / cm;

[0048] (3) Steam generator feed water cation conductivity ≥ 0.125us / cm;

[0049] (4) The positive conductivity of steam generator wastewater is ≥1us / cm;

[0050] (5) The sodium ion concentration of steam generator wastewater is ≥50ppb;

[0051] (6) The condensate polishing system maintains 4 cation beds and 4 mixed beds in pressurized hot standby operation;

[0052] (7) The condensate polishing system condensate pumps are in standby status;

[0053] (8) The opening of the outlet regulating valve of the condensate polishing system net condensate pump is maintained between 15% and 22%.

[0054] In some embodiments, during the power operation of the unit, the shut-off valve of the main pipe valve at the inlet of the polishing system, the inlet valves of the 4 rows of pre-cationic beds, the outlet valves of the 4 rows of pre-cationic beds, the inlet valves of the 4 rows of high-speed mixed beds, and the outlet valves of the 4 rows of high-speed mixed beds are maintained in an open state;

[0055] In some embodiments, during the full bypass operation of the secondary condensate circuit, 4 cation beds and 4 mixed beds are kept in hot standby operation with pressure, and 3 condensate pumps are kept in standby state.

[0056] In some embodiments, the opening of the outlet regulating valve of the condensate polishing system condensate clean pump is adjusted to 15% to 22% of the opening corresponding to the rated flow rate of starting a condensate clean pump.

[0057] In some embodiments, during the power operation of the unit, the DCS instrumentation and control system automatically monitors whether the water quality indicators of the secondary circuit condensate, the positive conductivity of the steam generator feed water, and the positive conductivity of the steam generator wastewater reach the instrumentation and control interlocking setting values:

[0058] (1) Unit power ≥ 50%;

[0059] (2) Condensate positive conductivity ≥ 0.5us / cm;

[0060] (3) Steam generator feed water cation conductivity ≥ 0.125us / cm;

[0061] (4) The positive conductivity of steam generator wastewater is ≥1us / cm;

[0062] (5) The sodium ion concentration of steam generator wastewater is ≥50ppb;

[0063] (6) The condensate polishing system maintains 4 cation beds and 4 mixed beds in pressurized hot standby operation;

[0064] (7) The condensate polishing system condensate pumps are in standby status;

[0065] (8) The opening of the outlet regulating valve of the condensate polishing system net condensate pump is maintained between 15% and 22%.

[0066] In some embodiments, when the water quality of the secondary circuit deteriorates and the eight interlocking signals set above are met at the same time, the first condensate polishing system purifying pump is automatically started, and then the opening of the purifying pump outlet regulating valve is automatically opened from 15% to 22% to between 23% and 25%, and then the second condensate polishing system purifying pump is automatically started, and the opening of the purifying pump outlet regulating valve is automatically opened to between 33% and 35%, thereby restoring the condensate polishing system to 100% full-flow purification operation.

[0067] In some embodiments, after the cause of the deterioration of the secondary circuit water quality is identified and eliminated, when the positive conductivity of the steam generator feed water is ≤0.08us / cm and the positive conductivity of the steam generator wastewater is ≤0.2us / cm, the opening of the condensate pump outlet regulating valve is closed to between 23% and 25%, and then one condensate pump is shut down; then the opening of the condensate pump outlet regulating valve is closed to between 15% and 22%, and then the second condensate pump is shut down, and the full bypass operation of the fine treatment system is restored.

[0068] Compared with the prior art, the rapid commissioning method for the condensate polishing system of a nuclear power plant provided by the present application has the following beneficial effects:

[0069] This application realizes dual control of DCS remote control in the main control room and PLC local control of fine treatment. When transient deterioration of secondary circuit water quality occurs, such as condenser leakage, the fine treatment system can be quickly restored to a full-flow purification state, effectively ensuring the safety of feed water quality of steam generators of nuclear power units; and the fine treatment system control room can be operated with fewer people, thereby improving work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for the technical description.

[0071] Figure 1 Schematic diagram of condensate polishing system for nuclear power plant provided by existing technology;

[0072] Figure 2 A flow chart of a manual rapid commissioning method for a condensate polishing system of a nuclear power plant provided for this application;

[0073] Figure 3 A flow chart of a method for automatically and rapidly commissioning a condensate polishing system in a nuclear power plant provided in this application.

[0074] Description of reference numerals:

[0075] 1. Stop valve of the main pipe valve at the inlet of the fine treatment system; 2. Inlet valve of the pre-cation bed; 3. Pre-cation bed; 4. Outlet valve of the pre-cation bed; 5. Inlet valve of the high-speed mixed bed; 6. High-speed mixed bed; 7. Outlet valve of the high-speed mixed bed; 8. Clean condensate pump; 9. Outlet valve of the clean condensate pump; 10. Adjustment valve of the main pipe of the fine treatment outlet. DETAILED DESCRIPTION

[0076] The following is further explained in detail through specific implementation methods.

[0077] For ease of understanding, the condensate polishing system of a nuclear power plant is briefly described first. Figure 1 As shown, the condensate polishing system of the nuclear power plant includes a shut-off valve 1 at the inlet main pipe valve of the polishing system, a pre-cation bed inlet valve 2, a pre-cation bed 3, a pre-cation bed outlet valve 4, a high-speed mixed bed inlet valve 5, a high-speed mixed bed 6, a high-speed mixed bed outlet valve 7, a clean condensate pump 8, a clean condensate pump outlet valve 9, and a polishing outlet main pipe regulating valve 10. The system is provided with an inlet for condensate before purification and an outlet for condensate after purification.

[0078] The present application provides a rapid commissioning method for a condensate polishing system of a nuclear power plant, including a manual rapid commissioning method and an automatic rapid commissioning method.

[0079] like Figure 2 As shown, the manual rapid commissioning method of the nuclear power plant condensate polishing system provided in this application includes:

[0080] Step 1: The original design, which could only restore the full flow purification operation of the fine treatment system on the local PLC, was changed to a design that could also be implemented remotely on the DCS in the main control room, so as to realize the dual control of the local PLC for fine treatment and the DCS in the main control room. The local PLC realizes the operation of all equipment, and the DCS in the main control room only needs to operate the condensate pump, the outlet stop valve of the condensate pump, and the regulating valve, and set the PLC / DCS switching function.

[0081] Step 2: Maintain the shut-off valve 1 of the main inlet valve of the fine treatment system, the pre-cation bed inlet valve 2, the pre-cation bed outlet valve 4, the high-speed mixed bed inlet valve 5, and the high-speed mixed bed outlet valve 7 in the open state.

[0082] Step 3: Adjust the opening of the fine treatment outlet main pipe regulating valve 10 to 15% to 22% of the rated flow rate for starting a condensate pump 8.

[0083] Step 4: Continue to maintain the 4 rows of front cation beds 3 and the 4 rows of high-speed mixed beds 6 in a hot standby state under pressure.

[0084] Step 5: The three condensate pumps 8 are in a shutdown standby state.

[0085] Step 6: When the secondary circuit water quality triggers one or more of the following warning signals, after analysis and confirmation, decide whether to manually start the condensate pump 8, as follows:

[0086] (1) Condensate positive conductivity ≥ 0.3us / cm;

[0087] (2) The positive conductivity of steam generator wastewater is ≥ 0.5us / cm;

[0088] (3) The sodium ion concentration of steam generator wastewater is ≥20ppb.

[0089] Step 7: When the water quality of the secondary circuit does show a trend of deterioration, the first condensate polishing system purifying pump 8 is manually started remotely in the DCS in the main control room, and then the outlet regulating valve 10 of the purifying pump is opened to the minimum regulating valve opening corresponding to the operation of the two purifying pumps 8 (for example, between 23% and 25%), and the second purifying pump 8 is manually started remotely in the DCS in the main control room, and the outlet regulating valve 10 of the purifying pump is opened to the regulating valve opening corresponding to the rated flow operation of the two purifying pumps 8 (for example, between 33% and 23%), and the full flow purification operation of the polishing system is restored.

[0090] Step 8: After the cause of the deterioration of the water quality in the secondary circuit is identified and eliminated, when the positive conductivity of the steam generator feed water reaches the set value (for example, ≤0.08us / cm) and the positive conductivity of the steam generator wastewater reaches the set value (for example, ≤0.2us / cm), the opening of the condensate pump outlet regulating valve 10 is closed to the minimum regulating valve opening corresponding to the operation of the two condensate pumps 8 (for example, between 23% and 25%), and then one condensate pump 8 is shut down; then the opening of the condensate pump outlet regulating valve 10 is closed to the regulating valve opening corresponding to the operation of one condensate pump (for example, between 15% and 22%), and then the second condensate pump 8 is shut down, and the full bypass operation of the fine treatment system is restored.

[0091] The present application can realize two rapid commissioning methods, one of which is manual early intervention commissioning; if the system needs manual intervention commissioning and the system is not put into operation in time due to human factors, once the water quality continues to deteriorate and reaches the water quality index for automatic commissioning, the system will automatically be put into operation to ensure effective protection of the secondary circuit water quality.

[0092] Furthermore, when the manual intervention commissioning system fails to be commissioned in time, the system will be automatically commissioned, including the following steps:

[0093] Step 9: Set the interlock signal for the condensate polishing system to automatically resume operation and restore the condensate full flow purification operation:

[0094] (1) Unit power ≥ 50%;

[0095] (2) Condensate positive conductivity ≥ 0.5us / cm;

[0096] (3) Steam generator feed water cation conductivity ≥ 0.125us / cm;

[0097] (4) The positive conductivity of steam generator wastewater is ≥1us / cm;

[0098] (5) The sodium ion concentration of steam generator wastewater is ≥50ppb;

[0099] (6) The condensate polishing system maintains 4 cation beds and 4 mixed beds in pressurized hot standby operation;

[0100] (7) The condensate polishing system condensate pumps are in standby status;

[0101] (8) The opening of the outlet regulating valve of the condensate polishing system net condensate pump is maintained between 15% and 22%.

[0102] Step 10: During the power operation of the unit, maintain the shut-off valve 1 of the inlet main pipe valve of the fine treatment system, the 4th row of pre-cationic bed inlet valve 2, the 4th row of pre-cationic bed outlet valve 4, the 4th row of high-speed mixed bed inlet valve 5, and the 4th row of high-speed mixed bed outlet valve 7 in the open state.

[0103] Step 11: During the full bypass operation of the secondary condensate circuit, the four rows of pre-cation beds 3 and the four rows of high-speed mixed beds 6 are kept in pressurized hot standby operation.

[0104] Step 12: The three condensate pumps 8 are in a shutdown standby state.

[0105] Step 13: Adjust the opening of the outlet regulating valve 10 of the condensate polishing system condensate pump to 15% to 22% of the opening corresponding to the rated flow rate of starting a condensate pump 8.

[0106] Step 14: During the power operation of the unit, the DCS instrumentation and control system automatically monitors whether the water quality indicators of the secondary circuit condensate, steam generator feed water positive conductivity, and steam generator wastewater positive conductivity reach the instrumentation and control interlocking set values:

[0107] (1) Unit power ≥ 50%;

[0108] (2) Condensate positive conductivity ≥ 0.5us / cm;

[0109] (3) Steam generator feed water cation conductivity ≥ 0.125us / cm;

[0110] (4) The positive conductivity of steam generator wastewater is ≥1us / cm;

[0111] (5) The sodium ion concentration of steam generator wastewater is ≥50ppb;

[0112] (6) The condensate polishing system maintains 4 cation beds and 4 mixed beds in pressurized hot standby operation;

[0113] (7) The condensate polishing system condensate pumps are in standby status;

[0114] (8) The opening of the outlet regulating valve of the condensate polishing system net condensate pump is maintained between 15% and 22%.

[0115] Step 15: When the water quality of the secondary circuit deteriorates and the above-set 8 interlocking signals are met at the same time, the first condensate polishing system purifying pump 8 is automatically started, and then the opening of the condensate polishing pump outlet regulating valve 10 is automatically opened from 15% to 22% to between 23% and 25%, and then the second condensate polishing system purifying pump 8 is automatically started, and the opening of the condensate polishing pump outlet regulating valve 10 is automatically opened to between 33% and 35%, and the condensate polishing system is restored to 100% full-flow purification operation.

[0116] Step 16: After the cause of the deterioration of the secondary circuit water quality is identified and eliminated, when the positive conductivity of the steam generator feed water is ≤0.08us / cm and the positive conductivity of the steam generator wastewater is ≤0.2us / cm, close the opening of the condensate pump outlet regulating valve 10 to between 23% and 25%, and then shut down one condensate pump 8; then close the opening of the condensate pump outlet regulating valve 10 to between 15% and 22%, and then shut down the second condensate pump 8, and restore the full bypass operation of the fine treatment system.

[0117] This application realizes dual control of DCS remote control in the main control room and PLC local control for fine treatment. When the water quality of the secondary circuit deteriorates, such as transient conditions such as condenser leakage, the Tianwan fine treatment system can be restored to the full flow purification state in about 1 minute under full bypass operation, while domestic power plants need about 15-25 minutes, which greatly shortens the protection time and makes up for the shortcomings of existing technologies. While achieving energy conservation and emission reduction, it effectively guarantees the safety of steam generator feed water quality; and realizes less people on duty in the control room of the fine treatment system, reducing staffing and daily workload.

[0118] After the implementation of this application, while ensuring the safe and stable operation of the unit, the economy and environmental protection of the unit are improved, and key technical problems affecting energy conservation and emission reduction such as large desalted water consumption, high plant electricity consumption, large wastewater discharge, and large consumption of chemicals such as acids and alkalis in the unit are solved, which significantly improves the synergistic efficiency of the unit in energy saving, carbon reduction, and pollution reduction.

[0119] The following table compares the production energy consumption data before and after the implementation of the project in 2022:

[0120]

[0121] It can be seen that the statistical comparison data of production energy consumption before and after the implementation of the project shows that the energy saving rate of each item exceeds 80%.

[0122] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed in the present application should be covered within the protection scope of the present application.

Claims

1. A method for rapidly commissioning a condensate polishing system in a nuclear power plant, characterized in that: include: Step 1: Set up dual control of local PLC and DCS in the main control room for the fine treatment system equipment; Step 2: Set up the secondary circuit water quality early warning function. When the secondary circuit water quality shows a trend of deterioration, it will remind the main control room operators to intervene in advance. Step 3: During the power operation of the unit, the stop valve of the main pipe valve at the inlet of the fine treatment system, the inlet valve of the pre-cation bed, the outlet valve of the pre-cation bed, the inlet valve of the high-speed mixed bed, and the outlet valve of the high-speed mixed bed are maintained in the open state; Step 4: Adjust the opening of the regulating valve at the outlet of the condensate polishing system to a certain percentage of the rated flow rate corresponding to the start-up of a condensate pump to avoid overloading the condensate pump due to excessive opening of the regulating valve; Step 5: Maintain the front cation bed and high-speed mixed bed required for the full-flow purification operation of condensate water in a hot standby state with pressure operation, and the condensate pump in a shutdown standby state; Step 6: During the power operation of the unit, determine whether the water quality indicators such as the secondary circuit condensate, feed water positive conductivity, steam generator wastewater positive conductivity, etc. have reached the warning value; Step 7: When any water quality index of the secondary circuit reaches the warning value and it is determined that there is indeed a trend of water quality deterioration, the DCS in the main control room remotely and manually starts the condensate pump to restore the full flow purification operation of the fine treatment system; Step 8: When the cause of the secondary circuit water quality deterioration is identified and eliminated, the condensate pump is manually shut down remotely in the DCS of the main control room to restore the full bypass operation of the fine treatment system.

2. The rapid commissioning method for a condensate polishing system of a nuclear power plant according to claim 1 is characterized in that: In step 1, the condensate pump, condensate pump outlet stop valve, and regulating valve are operated through the DCS in the main control room, and the PLC / DCS switching function is set.

3. The rapid commissioning method for a condensate polishing system of a nuclear power plant according to claim 1 is characterized in that: In step 2, a secondary circuit water quality warning signal is set to remind the operator in the main control room to intervene in advance when the secondary circuit water quality shows a trend of deterioration; The warning signals set include: (1) Condensate positive conductivity; (2) The positive conductivity of steam generator wastewater; (3) Sodium ion concentration of steam generator wastewater; (4) Steam generator feed water conductivity.

4. The rapid commissioning method for a condensate polishing system of a nuclear power plant according to claim 1 is characterized in that: In step 3, during the power operation of the unit, the shut-off valve of the inlet main pipe valve of the fine treatment system, the pre-cation bed inlet valve, the pre-cation bed outlet valve, the high-speed mixed bed inlet valve, and the high-speed mixed bed outlet valve are maintained in the open state.

5. The rapid commissioning method for a condensate polishing system of a nuclear power plant according to claim 1, characterized in that: In step 7, when the water quality of the secondary circuit does show a trend of deterioration, the first condensate polishing system purifier pump is manually started remotely in the DCS in the main control room, and then the outlet regulating valve opening of the purifier pump is opened to the regulating valve opening corresponding to the start of the second purifier pump. The second purifier pump is manually started remotely in the DCS in the main control room, and the outlet regulating valve opening of the purifier pump is opened to the regulating valve opening required for full-flow purification.

6. According to the rapid commissioning method of the nuclear power plant condensate polishing system as described in claim 1, in step 8, after the cause of the deterioration of the secondary circuit water quality is found and eliminated, when the positive conductivity of the steam generator feed water reaches the set value, and the positive conductivity of the steam generator wastewater reaches the set value, the outlet regulating valve opening of the condensate cleaning pump is closed to the minimum regulating valve opening corresponding to the operation of the two condensate cleaning pumps, and then one condensate cleaning pump is shut down; the outlet regulating valve opening of the condensate cleaning pump is closed to the regulating valve opening corresponding to the rated flow operation of one condensate cleaning pump, and then the second condensate cleaning pump is shut down to restore the full bypass operation of the polishing system.

7. The method for rapid commissioning of a condensate polishing system in a nuclear power plant according to any one of claims 1 to 6, characterized in that: Including automatic commissioning steps: Step 9: Set the interlock signal for the condensate polishing system to automatically start operation and restore the condensate full flow purification operation; Step 10: During the power operation of the unit, the stop valve of the main pipe valve at the inlet of the fine treatment system, the pre-cation bed inlet valve, the pre-cation bed outlet valve, the high-speed mixed bed inlet valve, and the high-speed mixed bed outlet valve are maintained in an open state; Step 11: Adjust the opening of the outlet regulating valve of the condensate polishing system condensate pump to a certain percentage opening corresponding to the rated flow rate of starting a condensate pump; Step 12: Continuously maintain the pre-cation bed and high-speed mixed bed required for the full-flow purification operation of condensate in a hot standby state under pressure; Step 13: The condensate polishing system condensate pumps are all in standby mode; Step 14: During the power operation of the unit, the DCS instrumentation and control system automatically monitors whether the water quality indicators of the secondary circuit condensate, the positive conductivity of the steam generator feed water, and the positive conductivity of the steam generator wastewater reach the instrumentation and control interlocking set values; Step 15: When the water quality of the secondary circuit deteriorates and the interlocking signal set in step 9 is met at the same time, the two condensate purification pumps of the condensate polishing system are automatically started to restore the full flow purification operation of the condensate polishing system; Step 16: When the cause of the secondary circuit water quality deterioration is identified and eliminated, the condensate pump is manually shut down remotely in the DCS of the main control room to restore the full bypass operation of the fine treatment system.

8. The rapid commissioning method for a condensate polishing system of a nuclear power plant according to claim 7, characterized in that: In step 9, the interlocking signal includes: (1) The unit is in power operation state; (2) The positive conductivity of condensate reaches the interlock setting value; (3) The positive conductivity of the steam generator feed water reaches the interlock setting value; (4) The positive conductivity of the steam generator wastewater reaches the interlock setting value; (5) The sodium ion concentration of the steam generator wastewater reaches the interlock setting value; (6) Maintaining the pre-positive bed and high-speed mixed bed required for the full-flow purification operation of condensate in a hot standby state under pressure; (7) The condensate polishing system condensate pumps are in standby status; (8) The outlet regulating valve of the condensate polishing system is adjusted to a certain percentage opening corresponding to the rated flow rate of starting a condensate pump.

9. The rapid commissioning method for a condensate polishing system of a nuclear power plant according to claim 7, characterized in that: In step 15, when the water quality of the secondary circuit deteriorates and the set interlocking signal is met at the same time, the first condensate polishing system purifying pump is automatically started, and then the purifying pump outlet regulating valve opening is automatically opened to the minimum regulating valve opening corresponding to the operation of the two purifying pumps, and then the second condensate polishing system purifying pump is automatically started, and the purifying pump outlet regulating valve opening is automatically opened to the regulating valve opening corresponding to the rated flow operation of the two purifying pumps, and the condensate polishing system is restored to 100% full flow purification operation.

10. The method for rapid commissioning of a condensate polishing system of a nuclear power plant according to claim 7, characterized in that: In step 16, after the cause of the deterioration of the water quality in the secondary circuit is identified and eliminated, when the positive conductivity of the steam generator feed water reaches the set value and the positive conductivity of the steam generator wastewater reaches the set value, the outlet regulating valve opening of the condensate pump is closed to the minimum regulating valve opening corresponding to the operation of the two condensate pumps, and then one condensate pump is shut down; then the outlet regulating valve opening of the condensate pump is closed to the regulating valve opening corresponding to the rated flow operation of one condensate pump, and then the second condensate pump is shut down to restore the full bypass operation of the condensate polishing system.

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