Thermoelectric and water combined system and production process applicable to large-scale pressurized water reactor nuclear power units

Abstract

The present invention belongs to the technical field of pressurized water reactor nuclear power plants, and particularly relates to a combined thermal, electric and water system and a production process applicable to large-scale pressurized water reactor nuclear power units. In the present invention, nuclear power unit one and nuclear power unit two form a nuclear steam supply system; a superheater, a steam generator, a deaerator, a secondary feed water heater, a primary feed water heater, and a secondary feed water pump form an industrial steam production system; a demineralized water feed pump, a feed water tank, demineralized water facilities, seawater desalination facilities, heaters, regulating valve two, regulating valve two, a seawater intake, a seawater drain, a standby fresh water intake, and production water users constitute a seawater desalination and demineralized water supply system; a drain pipeline returns to the condenser of the pressurized water reactor nuclear power unit through regulating valve three and regulating valve four to form a steam condensate system. On the premise of ensuring nuclear safety, the present invention enables the nuclear power unit to have the ability to produce industrial steam and produce fresh water through seawater desalination technology.

Description

Technical Field

[0001] The present invention belongs to the technical field of pressurized water reactor nuclear power plants, and particularly relates to a combined thermal, electric and water system and production process applicable to large-scale pressurized water reactor nuclear power units. Background Art

[0002] The technical safety and reliability of pressurized water reactor nuclear power units have been fully verified. At present, domestic pressurized water reactor nuclear power units are mainly for power generation, and additionally supply a small amount of hot water to urban hot water pipe networks for residents' heating. Due to the low steam parameters of pressurized water reactor nuclear power units, there is no precedent in the field of industrial steam supply by nuclear power units. Therefore, it is necessary to explore a technical solution for technical transformation of pressurized water reactor nuclear power units to produce industrial steam.

[0003] Conventional combined heat and power generation has been successful in thermal power units. However, considering the particularity of nuclear power units, nuclear power units cannot directly use secondary loop steam as industrial steam. It is necessary to carry out technological innovation considering key factors such as unit safety and radioactive control to ensure the operation and maintenance safety of nuclear power units and industrial steam users.

[0004] Seawater desalination technology has been maturely applied in China. Small-scale seawater desalination facilities have also been built in some nuclear power units. However, there is no coupling scheme for producing fresh water using nuclear energy steam. Summary of the Invention

[0005] The purpose of the present invention is to provide a nuclear energy comprehensive utilization process of "nuclear power + industrial steam + seawater desalination" applicable to pressurized water reactor nuclear power units, enabling nuclear power units to have the ability to produce industrial steam and produce fresh water through seawater desalination technology on the premise of ensuring nuclear safety. The present invention provides a technical solution for nuclear energy comprehensive utilization, and can solve the environmental protection pressure of the petrochemical industry, and help to achieve regional carbon peak earlier.

[0006] The technical solution adopted by the present invention is as follows:

[0007] A combined thermal, electric and water system applicable to large-scale pressurized water reactor nuclear power units includes four parts: a nuclear steam supply system, an industrial steam production system, a seawater desalination and demineralized water supply system, and a steam condensate system. Nuclear power unit 1, nuclear power unit 2, regulating valve 1, regulating valve 5, stop valve 1, and stop valve 2 constitute the nuclear steam supply system; a superheater, a steam generator, a deaerator, a secondary feed water heater, a primary feed water heater, and a secondary feed water pump constitute the industrial steam production system; a demineralized water feed pump, a feed water tank, demineralized water facilities, seawater desalination facilities, a heater, regulating valve 2, regulating valve 6, a seawater intake, a seawater discharge, a standby fresh water intake, and a production water user constitute the seawater desalination and demineralized water supply system; a drain pipeline returns to the condenser of the pressurized water reactor nuclear power unit through regulating valve 3 and regulating valve 4 to form the steam condensate system;

[0008] For the described nuclear steam supply system, Nuclear Power Unit 1 is connected to Nuclear Power Unit 2 through a pipeline. A regulating valve 1, a stop valve 1, a stop valve 2, and a regulating valve 5 are successively arranged on the pipeline.

[0009] For the described industrial steam production system, on the connecting pipeline between the stop valve 1 and the stop valve 2, it is connected to a superheater through a pipeline. The superheater is connected to a steam generator to form a loop, the steam generator is connected to a secondary feedwater heater to form a loop, the secondary feedwater heater is respectively connected to a primary feedwater heater, the superheater transports steam to steam users, a deaerator is respectively connected to the superheater, the secondary feedwater heater, and the primary feedwater heater, and a secondary feedwater pump is arranged between the deaerator and the secondary feedwater heater.

[0010] For the described seawater desalination and demineralized water supply system, the demineralized water facility is respectively connected to a feedwater tank, a seawater desalination facility, a heater, a fresh water intake, and a production water user. Among them, the feedwater tank is connected to the primary feedwater heater through a demineralized water feed pump, the seawater desalination facility is respectively connected to the heater, a seawater intake, and a seawater drain, the demineralized water facility introduces seawater through the fresh water intake, and transports production water to the production water user.

[0011] For the described steam condensate system, the primary feedwater heater is respectively connected to Nuclear Power Unit 1 and Nuclear Power Unit 2 through pipelines, and regulating valves 3 and 4 are respectively arranged on the two pipelines.

[0012] The high-pressure cylinder exhaust pipelines of Nuclear Power Unit 1 and Nuclear Power Unit 2 are connected through a pipeline, and regulating valves 2 and 6 are arranged on the pipeline. The downstream pipeline of the valve is connected to the heater and is connected to the downstream pipe section of the regulating valve 3 in the steam condensate system.

[0013] The heater is connected to the connecting pipeline between the primary feedwater heater and Nuclear Power Unit 1 to heat it.

[0014] A combined thermoelectric and water production process applicable to large-scale pressurized water reactor nuclear power units, specifically including the following steps: Step 1: Normally put into operation Pressurized Water Reactor Nuclear Power Unit 1 and Pressurized Water Reactor Nuclear Power Unit 2; close regulating valve 1, regulating valve 5, stop valve 1, stop valve 2, regulating valve 2, regulating valve 6, regulating valve 3, and regulating valve 4; check and confirm the status of the pipeline for interface modification with the nuclear power unit, and confirm that the nuclear steam supply is not connected; according to the unit startup process, make Pressurized Water Reactor Nuclear Power Unit 1 and Pressurized Water Reactor Nuclear Power Unit 2 operate at full power; Step 2: Put into operation the seawater desalination facility and the demineralized water facility: Check the status of the drain pipeline and the pipeline of the conventional island unit to ensure that the pipelines are connected; draw the water supply from the standby fresh water intake to the heater through the self-provided water plant pipeline; introduce seawater into the seawater desalination facility through the seawater desalination intake; determine the steam source of the seawater desalination facility according to the steam operation scale, open regulating valve 6, and close regulating valve 2; monitor the parameters at the outlet of the heater, and when the quality meets the seawater desalination requirements, put into operation the seawater desalination facility; Step 3: Put into operation the nuclear steam supply system and the industrial steam production system. Check that the status of regulating valve 1, stop valve 1, regulating valve 5, and stop valve 2 is closed; according to the operation decision, determine the unit relying on for industrial load, and determine the opening requirements of regulating valve 1 and regulating valve 5; monitor and confirm that the pipelines of the nuclear steam supply system and the industrial steam production system are unobstructed; according to the feed water situation of the demineralized water system, when the demineralized water feed pump is started, open regulating valve 1, regulating valve 5, stop valve 1, and stop valve 2 to monitor the nuclear steam parameters; monitor the inlet and outlet parameters of the superheater, steam generator, deaerator, secondary feed water heater, and primary feed water heater to ensure that the outlet of the superheater meets the requirements of industrial steam users, and realize the operation of the unit with the seawater desalination system and the industrial steam system at the same time.

[0015] The second step further includes monitoring the fresh water quality of the seawater desalination facility: Introduce the fresh water produced by the seawater desalination facility into the demineralized water facility, monitor the water quality at the outlet of the demineralized water facility and introduce the demineralized water into the feed water tank; monitor the water level and capacity of the feed water tank, closely monitor the water level of the tank, and when the water storage capacity meets the requirement for starting the industrial steam production system, open the demineralized water feed pump.

[0016] The third step further includes monitoring the operation parameters of the unit and adjusting and removing the operating units according to the unit operation status: Monitor the inlet and outlet parameters of the superheater, steam generator, deaerator, secondary feed water heater, and primary feed water heater to ensure that the outlet of the superheater meets the requirements of industrial steam users, and realize the operation of the unit with the seawater desalination system and the industrial steam system at the same time; when the industrial steam load is adjusted, according to the operation decision, determine the unit relying on for industrial load, and determine the opening requirements of regulating valve 1 and regulating valve 5; adjust the opening of the regulating valve to make the steam load match the reactor power and power generation power of the unit; when the load demand can be met by one unit, gradually close stop valve 1 to remove one nuclear power unit.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] (1) The present invention provides a combined thermoelectric - water system and production process applicable to large - scale pressurized water reactor nuclear power units, which is the first in China to couple and design a pressurized water reactor nuclear power unit, a thermal seawater desalination facility, and an industrial steam production system.

[0019] (2) The present invention provides a combined thermoelectric - water system and production process applicable to large - scale pressurized water reactor nuclear power units. At the same time, technical transformations are carried out on two pressurized water reactor nuclear power plants, namely Pressurized Water Reactor Nuclear Power Plant 1 and Pressurized Water Reactor Nuclear Power Plant 2, so that a single unit has the ability to independently undertake the continuous supply of industrial steam scale. According to the single - unit layout characteristics of nuclear power units, in order to reduce the mutual influence between the two units during heat supply and make the system operation control flexible, the main steam circuit and its condensate circuit from the two units to the industrial steam production system adopt the unit system and can be used as spares for each other to ensure the reliability requirements of heat supply.

[0020] (4) The present invention provides a combined thermoelectric - water system and production process applicable to large - scale pressurized water reactor nuclear power units. A connecting circuit is provided between Pressurized Water Reactor Nuclear Power Plant 1 and Pressurized Water Reactor Nuclear Power Plant 2, and stop valves 3 and 4 are installed. By adjusting the states of stop valves 3 and 4 according to the steam supply scale, the operation states of Pressurized Water Reactor Nuclear Power Unit 1 and Pressurized Water Reactor Nuclear Power Unit 2 can be controlled, and the states of non - supply of industrial steam by the pressurized water reactor nuclear power unit, single - reactor supply of industrial steam, and dual - reactor combined supply of industrial steam can be achieved.

[0021] (4) The present invention provides a combined thermoelectric - water system and production process applicable to large - scale pressurized water reactor nuclear power units. Control valves 1 and 2 are provided. When dual - reactor combined supply of industrial steam is carried out, the steam scale can be distributed by adjusting the opening degrees of control valves 1 and 2, optimizing the relationship between steam supply and power generation between Pressurized Water Reactor Nuclear Power Unit 1 and Unit 2, and achieving the optimal matching among the reactor, power generation, and steam supply.

[0022] (5) The present invention provides a combined thermoelectric - water system and production process applicable to large - scale pressurized water reactor nuclear power units. An industrial steam production system composed of a superheater 5, a steam generator 6, a deaerator 7, a secondary feed - water heater 8, a primary feed - water heater 9, and a secondary feed - water pump 15 is provided. Through the way of step - by - step heating, series heating of four - stage heat exchangers is realized, and the steam heat energy is fully utilized.

[0023] (6) The present invention provides a combined thermoelectric - water system and production process applicable to large - scale pressurized water reactor nuclear power units. The main steam heats saturated steam into superheated industrial steam with a certain degree of superheat in the superheater 5 and is transported to the steam - using enterprises through a long - distance pipeline network. Part of the main steam is connected to the deaerator through a branch to heat the feed water and remove oxygen. In the heat exchanger 5, a phase change will occur on the high - temperature steam side.

[0024] (7) The present invention provides a combined thermal, electric and water system and production process applicable to large-scale pressurized water reactor nuclear power units, which are provided with a steam generator 6, a deaerator 7, a secondary feed water heater 8, a primary feed water heater 9, and a secondary feed water pump 15. The main steam heated by the superheater 5 becomes high-temperature saturated water and then gradually heats the feed water in the steam generator 6, the secondary feed water heater 8, and the primary feed water heater 9, making full use of the energy of the main steam. In the evaporator 6, the feed water is heated into saturated steam, and a phase change occurs on the low-temperature side of the evaporator.

[0025] (8) The present invention provides a combined thermal, electric and water system and production process applicable to large-scale pressurized water reactor nuclear power units, which are provided with a steam condensate system. The main steam condensate after being gradually heated returns to the secondary circuit conventional island condensate systems of the pressurized water reactor nuclear power unit 1 and the pressurized water reactor nuclear power unit 2 through a drain pipeline. Valves 22 and 23 can also be provided on the pipeline, and the opening and closing states of the valves 22 and 23 can be adjusted according to the operating state of the unit to regulate the amount of condensate returning to the unit, ensuring that the nuclear power unit 1 and the nuclear power unit 2 operate in a favorable steam-water balance state.

[0026] (9) The present invention provides a combined thermal, electric and water system and production process applicable to large-scale pressurized water reactor nuclear power units, which are provided with valves 16 and 17. By technically transforming the high-pressure cylinder exhaust pipelines of the pressurized water reactor nuclear power unit 1 and the pressurized water reactor nuclear power unit 2, two control valves, namely valves 16 and 17, are added. Through controlling the opening and closing states of the control valves, the operation states of the pressurized water reactor nuclear power unit 1 and the pressurized water reactor nuclear power unit 2 can be controlled, ensuring that the seawater desalination facility always has a steam source supply.

[0027] (10) The present invention provides a combined thermal, electric and water system and production process applicable to large-scale pressurized water reactor nuclear power units, which are provided with a heater 14. Since the seawater desalination facility cannot directly use the secondary circuit steam of the nuclear power unit as the steam source for thermal seawater desalination, the heater 14 is provided to generate low-quality saturated steam through steam conversion for the thermal seawater desalination facility.

[0028] (11) The present invention provides a combined thermal, electric and water system and production process applicable to large-scale pressurized water reactor nuclear power units, which are provided with a seawater desalination facility 13, a demineralized water feed pump 10, a water supply tank 11, a demineralized water facility 12, a seawater intake 18, a seawater discharge port 19, a standby fresh water intake 20, and a production water user 21. Among them, the seawater desalination facility adopts a thermal process to make full use of the waste heat of the steam of the pressurized water reactor nuclear power unit; the fresh water produced by the seawater desalination facility is desalted by the demineralized water facility and then produces demineralized water to supply the production water user 21 in the nuclear power plant area, the industrial steam production water, and the low-pressure steam source water for seawater desalination; the concentrated seawater is discharged through the seawater discharge port 19 after being treated by the concentrated seawater treatment system.

[0029] (12) The present invention provides a combined thermoelectric and water system and production process applicable to large pressurized water reactor nuclear power units, which is provided with a standby fresh water intake 20 that can be used as the water source for the demineralized water facility alone. It is used as a backup for the seawater desalination facility 13 to ensure the safe and reliable water supply to the demineralized water facility 12 and guarantee sufficient demineralized water supply for the entire system.

[0030] (13) The present invention provides a combined thermoelectric and water system and production process applicable to large pressurized water reactor nuclear power units. The seawater intake 18 is arranged in the nuclear power unit circulating water drainage tunnel, and the seawater taken is the warm drainage of the nuclear power unit, which can reduce the impact of warm drainage on the sea area, utilize part of the waste heat of the nuclear power unit, and improve the thermal utilization rate of the nuclear power unit. Brief Description of the Drawings

[0031] Figure 1 is a schematic structural diagram of a combined thermoelectric and water system applicable to large pressurized water reactor nuclear power units provided by the present invention;

[0032] In the figure: 1 - First regulating valve, 2 - Second regulating valve, 3 - First stop valve, 4 - Second stop valve, 5 - Superheater, 6 - Steam generator, 7 - Deaerator, 8 - Second feed water heater, 9 - First feed water heater, 10 - Demineralized water feed pump, 11 - Feed water tank, 12 - Demineralized water facility, 13 - Seawater desalination facility, 14 - Heater, 15 - Second feed water pump, 16 - Second regulating valve, 17 - Second regulating valve, 18 - Seawater intake, 19 - Seawater discharge port, 20 - Standby fresh water intake, 21 - Production water user, 22 - Third regulating valve, 23 - Fourth regulating valve, 24 - First nuclear power unit, 25 - Second nuclear power unit, 26 - Steam user. Detailed Embodiments

[0033] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0034] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0035] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "linkage" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] As Figure 1 shown, a combined thermoelectric and water system applicable to large-scale pressurized water reactor nuclear power units provided by the present invention includes four parts: a nuclear steam supply system, an industrial steam production system, a seawater desalination and demineralized water supply system, and a steam condensate system. Specifically, it includes nuclear power unit 1 24, nuclear power unit 2 25, regulating valve 1 1, regulating valve 5 2, stop valve 1 3, stop valve 2 4, superheater 5, steam generator 6, deaerator 7, secondary feedwater heater 8, primary feedwater heater 9, demineralized water feed pump 10, feedwater tank 11, demineralized water facility 12, seawater desalination facility 13, heater 14, secondary feed pump 15, regulating valve 2 16, regulating valve 6 17, seawater intake 18, seawater discharge 19, standby fresh water intake 20, production water user 21, regulating valve 3 22, regulating valve 4 23, and steam user 26.

[0037] Among them, nuclear power unit 1 24, nuclear power unit 2 25, regulating valve 1 1, regulating valve 5 2, stop valve 1 3, and stop valve 2 4 form the nuclear steam supply system;

[0038] Superheater 5, steam generator 6, deaerator 7, secondary feedwater heater 8, primary feedwater heater 9, and secondary feed pump 15 form the industrial steam production system;

[0039] Demineralized water feed pump 10, feedwater tank 11, demineralized water facility 12, seawater desalination facility 13, heater 14, regulating valve 2 16, regulating valve 6 17, seawater intake 18, seawater discharge 19, standby fresh water intake 20, and production water user 21 constitute the seawater desalination and demineralized water supply system;

[0040] The drain pipeline returns to the condenser of the pressurized water reactor nuclear power unit through regulating valve 3 22 and regulating valve 4 23 to form the steam condensate system.

[0041] In the nuclear steam supply system, nuclear power unit 1 24 is connected to nuclear power unit 2 25 through a pipeline, and regulating valve 1 1, stop valve 1 3, stop valve 2 4, and regulating valve 5 2 are successively arranged on the pipeline;

[0042] Industrial steam production system. On the connecting pipeline of stop valve 1 and stop valve 2, it is connected to the superheater 5 through a pipeline. The superheater 5 is connected to the steam generator 6 to form a loop. The steam generator 6 is connected to the secondary feed water heater 8 to form a loop. The secondary feed water heater 8 is respectively connected to the primary feed water heater 9. The superheater 5 transports steam to the steam user 26. The deaerator 7 is respectively connected to the superheater 5, the secondary feed water heater 8, and the primary feed water heater 9. A secondary feed water pump 15 is provided between the deaerator 7 and the secondary feed water heater 8;

[0043] Seawater desalination and demineralized water supply system. The demineralized water facility 12 is respectively connected to the water supply tank 11, the seawater desalination facility 13, the heater 14, the fresh water intake 20, and the production water user 21. Among them, the water supply tank 11 is connected to the primary feed water heater 9 through the demineralized water feed pump 10. The seawater desalination facility 13 is respectively connected to the heater 14, the seawater intake 18, and the seawater drain 19. The demineralized water facility 12 introduces seawater through the fresh water intake 20 and transports the production water to the production water user 21;

[0044] Steam condensate system. The primary feed water heater 9 is respectively connected to the nuclear power unit 1 and the nuclear power unit 2 through pipelines. Control valves 3 and control valves 4 are respectively provided on the two pipelines;

[0045] The heater 14 is connected to the connecting pipelines of the primary feed water heater 9 and the nuclear power unit 1 to heat them;

[0046] The high-pressure cylinder exhaust pipelines of the nuclear power unit 1 and the nuclear power unit 2 are connected through a pipeline. Control valves 2 and control valves 6 are provided on the pipeline. The downstream pipeline of the valve is connected to the heater 14 and is connected to the downstream pipe section of the control valve 3 in the steam condensate system.

[0047] The working principle of the present invention is:

[0048] After transformation, the nuclear power unit 1 is connected to the nuclear power unit 2 through the regulating valve 1 and the stop valve 3, and the nuclear power unit 2 is connected to the nuclear power unit 1 through the regulating valve 5 and the stop valve 4. The connecting pipeline successively passes through the superheater 5, the steam generator 6, the secondary feedwater preheater 8, the secondary feedwater pump 15, the deaerator 7, the primary feedwater heater 9, and is connected to the unit condensate system to establish a connecting loop. The nuclear power unit 1 is connected to the nuclear power unit 2 through the regulating valve 6 and the regulating valve 2, and the connecting pipeline passes through the heater 14 and is connected to the unit condensate system to establish a connecting loop. Seawater is transported from the seawater intake 18 to the seawater desalination facility 13 through a pipeline, and the generated concentrated seawater is sent to the seawater discharge port 19. The generated fresh water is sent to users in three ways after passing through the demineralized water facility 12: one way is gradually heated through the water supply tank 11, the demineralized water feed pump 10, the primary feedwater heater 9, the deaerator 7, the secondary feedwater pump 15, the secondary feedwater preheater 8, the steam generator 6, and the superheater 5 to produce industrial steam; one way passes through the heater 14 and the seawater desalination facility 13 as the steam source of the thermal seawater desalination facility; one way is sent to the production water user 21. To ensure the reliability of the demineralized water supply, the standby fresh water intake 20 is connected to the demineralized water facility 12 as the standby water source for the fresh water produced by the seawater desalination implementation 13.

[0049] The nuclear steam supply system includes the nuclear power unit 1, the nuclear power unit 2, the regulating valve 1, the regulating valve 5, the stop valve 1, and the stop valve 4. Through technical transformation, part of the main steam is extracted from the conventional island main steam system of the pressurized water reactor nuclear power unit 1 and transported to the steam header before the heat exchange equipment through the regulating valve 1 and the stop valve 1. Part of the main steam is extracted from the conventional island main steam system of the pressurized water reactor nuclear power unit 2 and transported to the steam header before the heat exchange equipment through the regulating valve 5 and the stop valve 4.

[0050] The industrial steam production system includes a superheater 5, a steam generator 6, a deaerator 7, a secondary feedwater preheater 8, a primary feedwater heater 9, and a secondary feedwater pump 15. The demineralized water from the seawater desalination and demineralized water supply system is sent to the deaerator for deaeration by the feed pump 10 after being heated by the primary preheater, and then is boosted by the secondary feedwater pump and sent to the steam generator after passing through the secondary feedwater preheater, taking away the heat released by the main steam and turning into industrial steam with a certain degree of superheat. Such a continuous heat exchange process realizes the continuous supply of industrial steam.

[0051] The steam condensate system includes a drain pipeline and a unit condensate system, which turns the heat released by the main steam into condensate water in the steam conversion equipment. The condensate water returns to the secondary circuit conventional island condensate system of the pressurized water reactor nuclear power unit 1 and the pressurized water reactor nuclear power unit 2 through the pipeline via the regulating valve 3 and the regulating valve 4, and finally returns to the condenser.

[0052] The seawater desalination and demineralized water supply system includes a demineralized water feed pump 10, a feed water tank 11, a demineralized water facility 12, a seawater desalination facility 13, a heater 14, a second regulating valve 16, a sixth regulating valve 17, a seawater intake 18, a seawater discharge 19, a standby fresh water intake 20, and a production water user 21. By extracting the exhaust steam of the high-pressure cylinder of the unit, the demineralized water is heated in the heater 14 to generate low-pressure steam for the thermal seawater desalination facility 13. The condensate water generated by the heater 14 returns to the unit condensate water system through the drain pipeline and the third regulating valve 22 and the fourth regulating valve 23. The demineralized water generated by the demineralized water facility 12 is divided into three paths. One path is transported to the industrial steam production system through the feed pump 10, one path generates the steam source for seawater desalination through the heat exchanger 14, and one path is for the production water user 21. The seawater desalination facility 13 and the standby fresh water intake 20 are the standby water sources for each other of the demineralized water facility 12. The concentrated seawater generated by the seawater desalination facility is discharged into the sea through the seawater discharge 19.

[0053] The present invention provides a combined heat, electricity and water production process applicable to large pressurized water reactor nuclear power units, which includes 3 stages, mainly including the normal operation stage of the first pressurized water reactor nuclear power unit 24 and the first pressurized water reactor nuclear power unit 25. After the nuclear power unit operates stably, the seawater desalination facility and the demineralized water system are put into operation to operate with the seawater desalination facility. After the demineralized water system is stable, the nuclear steam supply system and the industrial steam production system are put into operation synchronously. The specific steps are as follows:

[0054] The first stage: Normally put the first pressurized water reactor nuclear power unit 24 and the second pressurized water reactor nuclear power unit 25 into operation;

[0055] (a) Close the first regulating valve 1, the fifth regulating valve 2, the first stop valve 3, the second stop valve 4, the second regulating valve 16, the sixth regulating valve 17, the third regulating valve 22, and the third regulating valve 23;

[0056] (b) Check and confirm the status of the pipeline connecting to the nuclear power unit, and confirm that the nuclear steam supply is not connected;

[0057] (c) According to the unit startup process, make the first pressurized water reactor nuclear power unit 24 and the second pressurized water reactor nuclear power unit 25 operate at full power.

[0058] The second stage: Put the seawater desalination facility and the demineralized water facility into operation:

[0059] (a) Check the status of the drain pipeline and the pipeline of the conventional island unit to ensure that the pipelines are connected;

[0060] (b) Lead the water supply from the standby fresh water intake 20 to the heater 14 through the pipeline of the nuclear power plant's own water treatment plant; Introduce seawater into the seawater desalination facility 13 through the seawater desalination intake 18;

[0061] (c) Determine the steam source of the seawater desalination facility according to the steam operation scale, open the sixth regulating valve 17 and close the second regulating valve 16 (taking the pressurized water reactor nuclear power unit 24 as an example, if the pressurized water reactor nuclear power unit 25 is used as the heat source, the states of the sixth regulating valve 17 and the second regulating valve 16 are opposite);

[0062] (d) Monitor the parameters at the outlet of the heater 14. When the quality meets the seawater desalination requirements, put the seawater desalination facility 13 into operation. Monitor the quality of the fresh water discharged from the seawater desalination facility;

[0063] (e) Introduce the fresh water produced by the seawater desalination facility 13 into the demineralized water facility 12, monitor the quality of the water discharged from the demineralized water facility and introduce the demineralized water into the feed water tank 11;

[0064] (f) Monitor the water level and capacity of the feed water tank 11, closely monitor the water level in the tank. When the water storage capacity meets the requirement for starting the industrial steam production system, open the demineralized water feed pump 10;

[0065] The third stage: Put the nuclear steam supply system and the industrial steam production system into operation

[0066] (a) Check that the states of the first regulating valve 1, the first stop valve 3, the fifth regulating valve 2, and the second stop valve 4 are closed;

[0067] (b) According to the operation decision, determine the industrial load-dependent unit and determine the opening requirements of the first regulating valve 1 and the fifth regulating valve 2;

[0068] (c) Monitor and confirm that the pipelines of the nuclear steam supply system and the industrial steam production system are unobstructed;

[0069] (d) According to the feed water situation of the demineralized water system, when the demineralized water feed pump 10 is opened, open the first regulating valve 1, the fifth regulating valve 2, the first stop valve 3, and the second stop valve 4 to monitor the nuclear steam parameters (taking the case where both units are put into operation and bear the industrial steam load as an example);

[0070] (e) Monitor the inlet and outlet parameters of the superheater 5, the steam generator 6, the deaerator 7, the secondary feed water heater 8, and the primary feed water heater 9 to ensure that the outlet of the superheater 5 meets the requirements of industrial steam users and realize the operation of the unit with the seawater desalination system and the industrial steam system simultaneously.

[0071] (4) Monitor the operation parameters of the unit and adjust and cut off the operating units according to the operation state of the unit

[0072] (a) Monitor the inlet and outlet parameters of the superheater 5, the steam generator 6, the deaerator 7, the secondary feed water heater 8, and the primary feed water heater 9 to ensure that the outlet of the superheater 5 meets the requirements of industrial steam users and realize the operation of the unit with the seawater desalination system and the industrial steam system simultaneously;

[0073] (b) When the industrial steam load is adjusted, the industrial load is determined based on the operation decision, and the opening requirements of the regulating valve 1 and regulating valve 5 are determined;

[0074] (c) Adjust the opening of the regulating valve to match the steam load with the reactor power and power generation capacity of the unit;

[0075] (d) When the load demand can be met by one unit (or one of the nuclear power units is about to enter overhaul), gradually close the stop valve 1 3 (or stop valve 2 4) to cut off one nuclear power unit;

[0076] Taking the technical transformation of VVER type pressurized water reactor nuclear power unit as an example, according to this scheme, the main steam header of the VVER pressurized water reactor unit is technically transformed to lead out the main steam, and low-pressure superheated industrial steam is produced through the steam conversion system, and then transported to the user enterprises of the petrochemical industry base through long-distance pipelines. The present invention realizes the coupling of nuclear power + seawater desalination + industrial steam process schemes, provides new ideas and demonstration projects for the comprehensive utilization of nuclear energy, and provides reference for the technical transformation of pressurized water reactor nuclear power units.

[0077] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0078] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A combined thermal, electric and water system applicable to large-scale pressurized water reactor nuclear power units, Characterized in that: It includes four parts: a nuclear steam supply system, an industrial steam production system, a seawater desalination and demineralized water supply system, and a steam condensate system. For the nuclear steam supply system, the nuclear power unit one (24) is connected to the nuclear power unit two (25) through a pipeline, and a regulating valve one (1), a stop valve one (3), a stop valve two (4), and a regulating valve five (2) are successively arranged on the pipeline. For the industrial steam production system, on the connecting pipeline between the stop valve one (3) and the stop valve two (4), it is connected to a superheater (5) through a pipeline. The superheater (5) is connected to a steam generator (6) to form a loop. The steam generator (6) is connected to a secondary feedwater heater (8) to form a loop. The secondary feedwater heater (8) is connected to a primary feedwater heater (9). The superheater (5) transports steam to a steam user (26). A deaerator (7) is respectively connected to the superheater (5), the secondary feedwater heater (8), and the primary feedwater heater (9). A secondary feedwater pump (15) is arranged between the deaerator (7) and the secondary feedwater heater (8). For the seawater desalination and demineralized water supply system, the demineralized water facility (12) is respectively connected to a feedwater tank (11), a seawater desalination facility (13), a heater (14), a fresh water intake (20), and a production water user (21). Among them, the feedwater tank (11) is connected to the primary feedwater heater (9) through a demineralized water feed pump (10). The seawater desalination facility (13) is respectively connected to the heater (14), a seawater intake (18), and a seawater drain (19). The demineralized water facility (12) introduces fresh water through the fresh water intake (20) and transports production water to the production water user (21). The high-pressure cylinder exhaust pipelines of the nuclear power unit one (24) and the nuclear power unit two (25) are connected through a pipeline, and a regulating valve two (16) and a regulating valve six (17) are arranged on the pipeline. The downstream pipelines of the regulating valve two (16) and the regulating valve six (17) are connected to the heater (14) and are connected to the downstream pipe section of the regulating valve three (22) of the steam condensate system. For the steam condensate system, the primary feedwater heater (9) is respectively connected to the nuclear power unit one (24) and the nuclear power unit two (25) through pipelines, and a regulating valve three (22) and a regulating valve four (23) are respectively arranged on the two pipelines. The drain pipeline returns to the condenser of the pressurized water reactor nuclear power unit after passing through the regulating valve three (22) and the regulating valve four (23) to form a steam condensate system.

2. A combined thermal, electric and water production method applicable to large-scale pressurized water reactor nuclear power units, based on the combined thermal, electric and water system applicable to large-scale pressurized water reactor nuclear power units described in claim 1, Characterized in that: Specifically, it includes the following steps: Step 1: Normally put into operation the first pressurized water reactor nuclear power unit (24) and the second pressurized water reactor nuclear power unit (25); close the first regulating valve (1), the fifth regulating valve (2), the first stop valve (3), the second stop valve (4), the second regulating valve (16), the sixth regulating valve (17), the third regulating valve (22), and the fourth regulating valve (23); check and confirm the status of the pipeline for the interface modification with the nuclear power unit, and confirm that the nuclear steam supply is not connected; according to the unit startup process, make the first pressurized water reactor nuclear power unit (24) and the second pressurized water reactor nuclear power unit (25) operate at full power; Step 2: Put into operation the seawater desalination facility and the demineralized water facility: Check the status of the drain pipeline and the pipeline of the conventional island unit to ensure that the pipelines are connected; draw the water supply from the standby fresh water intake (20) to the heater (14) through the self-provided water plant pipeline; introduce seawater into the seawater desalination facility (13) through the seawater desalination intake (18); determine the steam source of the seawater desalination facility according to the steam operation scale, open the sixth regulating valve (17), and close the second regulating valve (16); monitor the outlet parameters of the heater (14), and when the quality meets the seawater desalination demand, put into operation the seawater desalination facility (13); Step 3: Put into operation the nuclear steam supply system and the industrial steam production system. Check that the first regulating valve (1), the first stop valve (3), the fifth regulating valve (2), and the second stop valve (4) are in the closed state; according to the operation decision, determine the unit relying on for industrial load and determine the opening requirements of the first regulating valve (1) and the fifth regulating valve (2); monitor and confirm that the pipelines of the nuclear steam supply system and the industrial steam production system are unobstructed; according to the feed water situation of the demineralized water system, when the demineralized water feed pump (10) is started, open the first regulating valve (1), the fifth regulating valve (2), the first stop valve (3), and the second stop valve (4) to monitor the nuclear steam parameters; monitor the inlet and outlet parameters of the superheater (5), the steam generator (6), the deaerator (7), the second feed water heater (8), and the first feed water heater (9) to ensure that the outlet of the superheater (5) meets the requirements of industrial steam users, and realize the operation of the unit with the seawater desalination system and the industrial steam system simultaneously.

3. A combined heat, power and water production method applicable to a large pressurized water reactor nuclear power unit according to claim 2, characterized in that: Step 2 further includes monitoring the quality of the fresh water discharged from the seawater desalination facility: Introduce the fresh water produced by the seawater desalination facility (13) into the demineralized water facility (12), monitor the quality of the water discharged from the demineralized water facility and introduce the demineralized water into the feed water tank (11); monitor the water level and capacity of the feed water tank (11), closely monitor the water level of the tank, and when the water storage capacity meets the requirement for starting the industrial steam production system, open the demineralized water feed pump (10).

4. A combined heat, power and water production method applicable to a large pressurized water reactor nuclear power unit according to claim 3, characterized in that: Step 3 further includes monitoring the operating parameters of the unit and adjusting and removing the operating units according to the operating status of the unit: monitoring the inlet and outlet parameters of the superheater (5), steam generator (6), deaerator (7), secondary feedwater heater (8), and primary feedwater heater (9) to ensure that the outlet of the superheater (5) meets the requirements of industrial steam users, so as to realize the operation of the unit with the seawater desalination system and industrial steam system simultaneously; when the industrial steam load is adjusted, according to the operation decision, determine the unit relying on the industrial load, and determine the opening requirements of the first regulating valve (1) and the fifth regulating valve (2); adjust the opening of the regulating valve to make the steam load match the reactor power and generating power of the unit; when the load demand can be met by one unit, gradually close the first stop valve (3) to remove one nuclear power unit.

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