Method and device for dewatering and heat recycling of nuclear energy steam supply system

Abstract

The invention relates to the field of nuclear energy steam supply, in particular to a method and device for dewatering and heat recycling of a nuclear energy steam supply system. The method comprises the steps that a second-loop drain pipeline and a third-loop drain pipeline of an energy station are arranged respectively, and drain water enters different expansion devices respectively; during normal operation, drain water of the main steam drain pipeline is cooled and then discharged to the drain water flash tank; drain water in the pressure water discharge main pipe is discharged to a drain water flash tank; demineralized water is added into the drain flash tank, and after the drain temperature is reduced, the drain is discharged to a condenser; during the start-stop period of the energy station, the overhaul drainage of a system pipeline and equipment on the secondary loop side enters a drainage flash tank to be cooled and then is directly collected to a hot wastewater pit; during normal operation, drain water of an industrial steam drain pipeline is discharged to a blow-down flash tank, sewage discharged by an evaporator is cooled and then enters the blow-down flash tank, domestic water is added into the blow-down flash tank, and after the drain water temperature is reduced, the drain water is discharged to a seawater desalination and recovery system; in the starting and stopping period of the energy station, the overhaul drainage of the system pipeline and equipment on the industrial steam side enters the blowdown flash tank to be cooled and then is directly collected to the hot waste water pit. According to the invention, radioactive pollution can be avoided, and the purposes of energy conservation and emission reduction can be achieved.

Description

Technical Field

[0001] The invention relates to the field of nuclear energy steam supply, and in particular to a method and device for draining water and recovering heat from a nuclear energy steam supply system. Background Art

[0002] During the operation of the energy station, the main steam is heated by the steam conversion equipment to heat the industrial steam side feed water, and qualified industrial steam is produced to supply to heat users. The wastewater generated during the entire production process mainly includes: drain water generated by the normal operation of the secondary circuit side system and equipment; drain water generated by the normal operation of the industrial steam side system and equipment; waste water from the evaporator; and drainage water during the startup and shutdown of the system pipelines and equipment on the secondary circuit side and the industrial steam side. Among them, the secondary circuit drain water includes the drain water generated by the normal operation of the secondary circuit side system and equipment, and the drainage water during the startup and shutdown of the system pipelines and equipment on the secondary circuit side. The tertiary circuit drain water includes the drain water generated by the normal operation of the industrial steam side system and equipment, the waste water from the evaporator, and the drainage water during the startup and shutdown of the system pipelines and equipment on the industrial steam side. In order to make full use of the above-mentioned wastewater, it is necessary to carry out research on the recycling and utilization of wastewater to achieve the goal of zero drainage. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a method and device for draining water and recovering heat from a nuclear energy steam supply system, which can avoid radioactive pollution and achieve the purpose of energy saving and emission reduction.

[0004] The present invention provides a method for draining water and recovering heat from a nuclear energy steam supply system, comprising the following steps:

[0005] The secondary and tertiary drain pipes of the energy station are arranged separately, and the drain enters different expansion devices respectively;

[0006] The secondary circuit draining includes draining from the pressure discharge main pipe, draining from the main steam drain pipe, and draining for maintenance of the system pipes and equipment on the secondary circuit side during the start-up and shutdown of the energy station;

[0007] During normal operation, the main steam drain pipe drains are discharged to the drain expansion tank after being cooled;

[0008] The drain in the pressurized drain pipe is discharged to the drain expansion tank;

[0009] Add deionized water into the drain expansion tank to lower the drain temperature, and then discharge the drain to the condenser;

[0010] During the start-up and shutdown of the energy station, the system pipelines and equipment on the secondary circuit side are drained during maintenance, enter the drain expansion tank for cooling, and then are directly collected in the hot wastewater pit;

[0011] The three-circuit drain includes the drain of industrial steam drain pipes, the drainage of evaporator sewage, and the maintenance and draining of system pipes and equipment on the industrial steam side during the start-up and shutdown of the energy station;

[0012] During normal operation, the industrial steam drain pipe drains into the blowdown expansion tank.

[0013] The evaporator wastewater is cooled and then enters the wastewater expansion tank.

[0014] Domestic water is added to the blowdown expansion tank to reduce the drain temperature, and then the drain is discharged to the seawater desalination recovery system;

[0015] During the start-up and shutdown of the energy station, the water from the system pipes and equipment on the industrial steam side is discharged into the sewage expansion tank for cooling and then directly collected in the hot wastewater pit.

[0016] In a specific embodiment of the present invention, desalted water is used to cool the evaporator wastewater and drain the main steam drain pipe through a cooler. The heated desalted water enters the feed water tank and then enters the steam generator from the feed water tank. The desalted water serves as the medium on the feed water side of the steam generator.

[0017] In a specific embodiment of the present invention, desalted water is added into the hydrophobic expansion vessel, the amount of desalted water added is controlled, the hydrophobic temperature is adjusted, and when the hydrophobic temperature is not higher than 60° C., the hydrophobic water is discharged to the condenser.

[0018] In a specific embodiment of the present invention, domestic water is added to the sewage expansion tank, the amount of domestic water added is controlled, the drain temperature is adjusted, and when the drain temperature is not higher than 60°C, the drain is discharged to the seawater desalination recovery system.

[0019] In a specific embodiment of the present invention, the hydrophobic expansion tank is equipped with two drainage pumps for hydrophobic recovery.

[0020] In a specific embodiment of the present invention, the sewage expansion tank is equipped with two drainage pumps for drain recovery.

[0021] The present invention provides a device for draining and heat recovery of a nuclear energy steam supply system, comprising: a secondary circuit drain recovery unit and a tertiary circuit drain recovery unit;

[0022] The secondary circuit drain recovery unit includes: a drain expansion tank, a main steam drain pipeline, a desalted water pipeline, a pressurized water discharge main pipe, a condenser and a hot wastewater pit;

[0023] There are pressure discharge main pipe, main steam drain pipe and desalted water pipe connected to the drain expansion tank respectively.

[0024] The system pipes and equipment on the secondary circuit side are also connected to the drain expansion tank;

[0025] The main steam drain pipe is provided with a first cooler;

[0026] The drain expansion tank is connected to the condenser and the hot wastewater pit respectively;

[0027] The three-circuit drain recovery unit includes: a blowdown expansion tank, an industrial steam drain pipeline, an evaporator blowdown pipeline, a domestic water pipeline, a seawater desalination recovery system and a hot wastewater pit;

[0028] The industrial steam drain pipe, evaporator sewage pipe, and domestic water pipe are connected to the sewage expansion tank respectively.

[0029] The system pipes and equipment on the industrial steam side are also connected to the blowdown expansion tank;

[0030] A second cooler is provided on the evaporator sewage pipe;

[0031] The sewage expansion tank is connected to the seawater desalination recovery system and the hot wastewater pit respectively.

[0032] In a specific embodiment of the present invention, the first cooler is connected to the water supply tank, and industrial desalted water is used for open cooling. The desalted water after passing through the first cooler is heated and enters the water supply tank, and then enters the steam generator from the water supply tank;

[0033] The second cooler is connected to the water feed tank and uses industrial desalted water for open cooling. The desalted water after passing through the second cooler is heated up and enters the water feed tank, and then enters the steam generator from the water feed tank.

[0034] In a specific embodiment of the present invention, two recovery pumps are arranged in parallel on the pipeline connecting the blowdown expansion tank to the seawater desalination recovery system; and two recovery pumps are arranged in parallel on the pipeline connecting the hydrophobic expansion tank to the condenser.

[0035] In a specific embodiment of the present invention, electric regulating valves are respectively provided on the domestic water pipeline and the demineralized water pipeline.

[0036] Compared with the prior art, the method and device for draining water and recovering heat from a nuclear energy steam supply system of the present invention has the following beneficial effects:

[0037] (1) By recycling the drain water separately, the water quality returned to the secondary condenser can be prevented from being unqualified;

[0038] (2) Achieve zero external discharge of drainage water;

[0039] (3) Adding coolers to the steam generator wastewater pipes and main steam drain pipes, which account for the majority of daily hot water discharge, reduces the amount of hot water entering the expansion tank, further reduces the amount of domestic water used and the amount of desalted water added, reduces the amount of drain recovery, and greatly reduces the burden on the downstream receiving drain system;

[0040] (4) The cooling water used in the steam generator wastewater cooler and the main steam drain pipe drain cooler is demineralized water. After heat exchange, the temperature rises and enters the feed water tank, which can increase the water temperature in the feed water tank as a whole. The feed water tank provides water to the steam generator of the energy station. The increase in feed water temperature can improve the thermal efficiency of the steam generator.

[0041] (5) The high-temperature drain water in the expansion vessel is discharged after cooling, which will not affect the downstream recovery system;

[0042] (6) Different cooling water sources are used for draining water from different systems. Draining water from the secondary circuit is recycled to the unit condenser and cooled with demineralized water. Draining water from the industrial steam side is recycled to the seawater desalination recovery system and uses domestic water to ensure economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It represents the flow chart of drain recovery;

[0044] In the figure, 1-drain expansion tank, 2-main steam drain pipe, 3-desalted water pipe, 4-pressurized water discharge main pipe, 5-condenser, 6-hot wastewater pit, 7-first cooler, 8-blowdown expansion tank, 9-industrial steam drain pipe, 10-evaporator blowdown pipe, 11-domestic water pipe, 12-seawater desalination recovery system, 13-second cooler, 14-feedwater tank, 15 steam generator. DETAILED DESCRIPTION

[0045] In order to further understand the present invention, the embodiments of the present invention are described below in conjunction with examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the present invention.

[0046] The embodiment of the present invention discloses a method for draining water and recovering heat from a nuclear energy steam supply system, comprising the following steps:

[0047] The secondary and tertiary drain pipes of the energy station are arranged separately, and the drain enters different expansion devices respectively;

[0048] The secondary circuit draining includes draining from the pressure discharge main pipe, draining from the main steam drain pipe, and draining for maintenance of the system pipes and equipment on the secondary circuit side during the start-up and shutdown of the energy station;

[0049] During normal operation, the main steam drain pipe is drained into the drain expansion tank after being cooled; specifically, desalted water is used to cool the main steam drain pipe through a cooler, and the heated desalted water enters the feed water tank, and then enters the steam generator from the feed water tank. The desalted water serves as the medium on the feed water side of the steam generator.

[0050] The drain in the pressurized drain pipe is discharged to the drain expansion tank;

[0051] Add deionized water into the drain expansion tank to lower the drain temperature, and then discharge the drain to the condenser;

[0052] Specifically, desalted water is added to the drain expansion tank, the amount of desalted water added is automatically controlled, the drain temperature is adjusted, and when the drain temperature is not higher than 60° C., the drain is discharged to the condenser. Desalted water is used as the cooling water in the drain expansion tank to ensure that the drain water quality recovered to the condenser is qualified.

[0053] The drain expansion tank is equipped with two drainage pumps for drain recovery, one for use and one for standby under normal circumstances.

[0054] During the start-up and shutdown of the energy station, the system pipelines and equipment on the secondary circuit side are inspected and drained. The water quality is poor and enters the drain expansion tank for cooling before being directly collected in the hot wastewater pit.

[0055] The three-circuit drain includes the drain of industrial steam drain pipes, the drainage of evaporator sewage, and the maintenance and draining of system pipes and equipment on the industrial steam side during the start-up and shutdown of the energy station;

[0056] During normal operation, the industrial steam drain pipe drains into the blowdown expansion tank.

[0057] The evaporator wastewater is cooled and then enters the wastewater expansion tank. Specifically, desalted water is used to cool the evaporator wastewater through a cooler. The heated desalted water enters the feed water tank, and then enters the steam generator from the feed water tank. The desalted water serves as the medium on the feed water side of the steam generator.

[0058] Domestic water is added into the blowdown expansion tank, and after the drain temperature is lowered, the drain is discharged into the seawater desalination recovery system; specifically, domestic water is added into the blowdown expansion tank, the amount of domestic water added is controlled, the drain temperature is adjusted, and when the drain temperature is not higher than 60°C, the drain is discharged into the seawater desalination recovery system.

[0059] During the start-up and shutdown of the energy station, the water from the system pipes and equipment on the industrial steam side is discharged into the sewage expansion tank for cooling and then directly collected in the hot wastewater pit.

[0060] The sewage expansion tank is equipped with two drainage pumps for drainage recovery, one for use and one for standby under normal circumstances.

[0061] The embodiment of the present invention discloses a device for draining water and recovering heat from a nuclear energy steam supply system, such as Figure 1 As shown, it includes: a secondary drain recovery unit and a tertiary drain recovery unit;

[0062] The secondary circuit drain recovery unit comprises: a drain expansion tank 1, a main steam drain pipe 2, a desalted water pipe 3, a pressurized water discharge main pipe 4, a condenser 5 and a hot wastewater pit 6;

[0063] The pressure discharge pipe 4, the main steam drain pipe 2 and the desalted water pipe 3 are connected to the drain expansion tank 1 respectively.

[0064] The desalted water pipelines 3 are respectively provided with electric regulating valves for automatically adjusting the amount of desalted water added, thereby controlling the water temperature of the desalted water in the desalted water expansion tank 1 .

[0065] The system pipes and equipment on the secondary circuit side are also connected to the drain expansion tank 1;

[0066] The main steam drain pipe 2 is provided with a first cooler 7;

[0067] The first cooler 7 is connected to the water supply tank 14 and uses industrial desalted water for open cooling. The desalted water after passing through the first cooler 7 is heated and enters the water supply tank 14, and then enters the steam generator 15 from the first water supply tank 14;

[0068] The drain expansion tank 1 is connected to the condenser 5 and the hot wastewater pit 6 respectively;

[0069] Two recovery pumps are arranged in parallel on the pipeline connecting the hydrophobic expansion tank 1 to the condenser 5 .

[0070] The three-circuit drain recovery unit includes: a blowdown expansion tank 8, an industrial steam drain pipeline 9, an evaporator blowdown pipeline 10, a domestic water pipeline 11, a seawater desalination recovery system 12 and a hot wastewater pit 7;

[0071] The industrial steam drain pipe 9, the evaporator sewage pipe 10, and the domestic water pipe 11 are respectively connected to the sewage expansion tank 8,

[0072] The domestic water pipelines 11 are respectively provided with electric regulating valves for automatically adjusting the amount of domestic water added, thereby controlling the drainage temperature in the sewage expansion tank 8.

[0073] The system pipes and equipment on the industrial steam side are also connected to the blowdown expansion tank 8;

[0074] The evaporator sewage pipe 11 is provided with a second cooler 13; the second cooler 13 is connected to the water supply tank 14, and uses industrial desalted water for open cooling. The desalted water after passing through the second cold cooler 13 is heated and enters the cold water supply tank 14, and then enters the steam generator 15 from the cold water supply tank 14.

[0075] The sewage expansion tank 8 is connected to the seawater desalination recovery system 12 and the hot wastewater pit 7 respectively.

[0076] Two recovery pumps are arranged in parallel on the pipeline connecting the sewage expansion tank 8 to the seawater desalination recovery system 12 .

[0077] The above embodiments are only used to help understand the method and core idea of ​​the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0078] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for draining water and recovering heat from a nuclear energy steam supply system, characterized in that: The following steps are involved: The secondary and tertiary drain pipes of the energy station are arranged separately, and the drain enters different expansion devices respectively; The secondary circuit draining includes draining from the pressure discharge main pipe, draining from the main steam drain pipe, and draining for maintenance of the system pipes and equipment on the secondary circuit side during the start-up and shutdown of the energy station; During normal operation, the main steam drain pipe drains are discharged to the drain expansion tank after being cooled; The drain in the pressurized drain pipe is discharged to the drain expansion tank; Add deionized water into the drain expansion tank to lower the drain temperature, and then discharge the drain to the condenser; During the start-up and shutdown of the energy station, the system pipelines and equipment on the secondary circuit side are drained during maintenance, enter the drain expansion tank for cooling, and then are directly collected in the hot wastewater pit; The three-circuit drain includes the drain of industrial steam drain pipes, the drainage of evaporator sewage, and the maintenance and draining of system pipes and equipment on the industrial steam side during the start-up and shutdown of the energy station; During normal operation, the industrial steam drain pipe drains into the blowdown expansion tank. The evaporator wastewater is cooled and then enters the wastewater expansion tank. Domestic water is added to the blowdown expansion tank to reduce the drain temperature, and then the drain is discharged to the seawater desalination recovery system; During the start-up and shutdown of the energy station, the water from the system pipes and equipment on the industrial steam side is discharged into the sewage expansion tank for cooling and then directly collected in the hot wastewater pit.

2. The method for draining water and recovering heat from a nuclear energy steam supply system according to claim 1, characterized in that: Desalted water is used to cool the evaporator wastewater and drain the main steam drain pipe through the cooler. The heated desalted water enters the feed water tank, and then enters the steam generator from the feed water tank. The desalted water serves as the medium on the feed water side of the steam generator.

3. The method for draining water and recovering heat from a nuclear energy steam supply system according to claim 1, characterized in that: Desalted water is added into the drain expansion container, the amount of desalted water added is controlled, and the drain temperature is adjusted. When the drain temperature is not higher than 60° C., the drain is discharged to the condenser.

4. The method for draining water and recovering heat from a nuclear energy steam supply system according to claim 1, characterized in that: Domestic water is added into the sewage expansion container, the amount of domestic water added is controlled, and the drain temperature is adjusted. When the drain temperature is not higher than 60° C., the drain is discharged to the seawater desalination recovery system.

5. The method for draining water and recovering heat from a nuclear energy steam supply system according to claim 1, characterized in that: The drain expansion tank is equipped with two drainage pumps for drain recovery.

6. The method for draining water and recovering heat from a nuclear energy steam supply system according to claim 1, characterized in that: The sewage expansion tank is equipped with two drainage pumps for drainage recovery.

7. A device for draining water and recovering heat from a nuclear energy steam supply system, characterized in that: include: Secondary circuit drain recovery unit and tertiary circuit drain recovery unit; The secondary circuit drain recovery unit includes: a drain expansion tank, a main steam drain pipeline, a desalted water pipeline, a pressurized water discharge main pipe, a condenser and a hot wastewater pit; There are pressure discharge main pipe, main steam drain pipe and desalted water pipe connected to the drain expansion tank respectively. The system pipes and equipment on the secondary circuit side are also connected to the drain expansion tank; The main steam drain pipe is provided with a first cooler; The drain expansion tank is connected to the condenser and the hot wastewater pit respectively; The three-circuit drain recovery unit includes: a blowdown expansion tank, an industrial steam drain pipeline, an evaporator blowdown pipeline, a domestic water pipeline, a seawater desalination recovery system and a hot wastewater pit; The industrial steam drain pipe, evaporator sewage pipe, and domestic water pipe are connected to the sewage expansion tank respectively. The system pipes and equipment on the industrial steam side are also connected to the blowdown expansion tank; A second cooler is provided on the evaporator sewage pipe; The sewage expansion tank is connected to the seawater desalination recovery system and the hot wastewater pit respectively.

8. The device for draining water and recovering heat from a nuclear energy steam supply system according to claim 7, characterized in that: The first cooler is connected to the water supply tank and uses industrial desalted water for open cooling. The desalted water after passing through the first cooler is heated and enters the water supply tank, and then enters the steam generator from the water supply tank. The second cooler is connected to the water feed tank and uses industrial desalted water for open cooling. The desalted water after passing through the second cooler is heated up and enters the water feed tank, and then enters the steam generator from the water feed tank.

9. The device for draining water and recovering heat from a nuclear energy steam supply system according to claim 7, characterized in that: Two recovery pumps are arranged in parallel on the pipeline connecting the blowdown expansion tank to the seawater desalination recovery system; and two recovery pumps are arranged in parallel on the pipeline connecting the drain expansion tank to the condenser.

10. The device for draining water and recovering heat from a nuclear energy steam supply system according to claim 7, characterized in that: Electric regulating valves are respectively arranged on the domestic water pipeline and the desalted water pipeline.

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