CN203882630U - Liquid water recovering and cooling device of passive heat exporting system of safety shell - Google Patents

Abstract

The utility model relates to a design technology of a reactor safety system and particularly relates to a liquid water recovering and cooling device of a passive heat exporting system of a safety shell. The liquid water recovering and cooling device structurally comprises a wind power enhancing device, a liquid water collecting and evaporating filter device and an air channel, wherein the wind power enhancing device is arranged at the top end of the air channel; the liquid water collecting and evaporating filter device is arranged in the air channel; an air guiding opening is formed in the bottom part of the air channel; the liquid water collecting and evaporating filter device is positioned between a hot water discharging opening of the heat exporting system of the safety shell and a water filling opening of a water tank. The liquid water recovering and cooling device has the advantages that due to the adoption of the passive scheme, the evaporating and cooling effects in the recovering process of high-temperature water are enhanced, and the heat discharging capability of the passive heat exporting system of the safety shell is improved; the liquid water can be furthest recovered, and long-time maintenance and full utilization of a cooling water source can be ensured, so that long-time heat discharge of the safety shell under the conditions of design basis accident and super-design basis accident is guaranteed, and the safety of a nuclear power plant is guaranteed.

Description

A liquid water recovery and cooling device for passive containment heat export system

technical field

The utility model relates to the design technology of a reactor safety system, in particular to a liquid water recovery and cooling device for a passive containment heat export system.

Background technique

Since the 1980s, the United States, Japan, France, Germany, Russia and other countries have carried out passive technology research, and the research and development of passive containment heat export system has become an important research hotspot.

A passive containment heat export system can passively dissipate the heat in the containment to the final heat sink—the atmosphere. The applicant submitted a paper titled "A Passive Containment Heat Export System" at the same time. Patent application, the structure of the containment heat export system is shown in Figure 1, including a heat exchanger 9 arranged inside the containment vessel 8 and a water tank 5 arranged outside the containment vessel 8, and the arrangement of the water tank 5 is higher than the The heat exchanger 9, the heat exchanger 9 is provided with an ascending pipe section 7 and a descending pipe section 17, the bottom of the water tank 5 is connected to the inlet of the heat exchanger 9 through the descending pipe section 17, and the ascending pipe section 7 passes through the Water tank 5, the uppermost outlet 3 of the ascending pipe section is connected with the liquid water recovery and cooling device 10 above the water tank 5, and several ascending sections are arranged at different liquid level heights on the pipe body of the ascending pipe section 7 located in the water tank 5 Outlets 13, 14, 15 and valve arrangement. Under operating conditions, the passive containment heat export system is set in the heat exchanger 9 inside the containment, which can take out the heat of the high-temperature and humid air in the containment through wall condensation and convective heat transfer, with the help of natural circulation driving force (the density difference between the downcomer section 17 and the riser section 7), the heated cooling water in the tube is discharged to the outside of the containment vessel. A part of the generated high-temperature cooling water is discharged to the atmosphere in the form of steam, and the other part is collected again in the form of liquid water and poured into the water tank.

In order to ensure that the passive containment heat export system can maintain the safety function for a long time, it is necessary to ensure the full utilization and recovery of cooling water, in order to maximize the heat removal capacity of the passive containment heat export system and significantly reduce the failure of the containment Therefore, it is necessary to strengthen the cooling effect of cooling water in the collection process as much as possible.

Utility model content

The purpose of this utility model is to provide a liquid water recovery and cooling device for the passive containment heat export system in response to the needs of the safety design of nuclear power plants. accidents and severe accidents), provide as much return water as possible with low temperature for the passive containment heat export system to ensure the long-term maintenance and high-efficiency performance of its safety functions, and then reduce the containment pressure and temperature to acceptable levels, to maintain the integrity of the containment shell.

The technical scheme of the utility model is as follows: a liquid water recovery and cooling device of the passive containment heat export system is arranged above the cooling water tank outside the containment, including a wind strengthening device, a liquid water collection and evaporation filtering device and an air duct , the wind strengthening device is arranged at the top of the air duct, the liquid water collection and evaporation filtering device is arranged inside the air duct, and the air inlet is arranged at the bottom of the air duct, and the liquid water collection and evaporation filtering device is located at the heat of the containment Between the hot water discharge outlet of the export system and the water filling port of the water tank.

Further, the liquid water recovery and cooling device of the passive containment heat export system described above, wherein the wind strengthening device includes a solar panel installed on the outer wall of the air duct and a fan installed in the air duct.

Further, the liquid water recovery and cooling device of the heat export system of the passive containment as described above, wherein, the air duct is a conical diversion cover, and several air ducts are arranged on the inner wall of the diversion cover to induce Secondary flow mixing wings for lateral flow.

Furthermore, in the above-mentioned liquid water recovery and cooling device of the passive containment heat export system, an annular space is formed between the draft cover and the liquid water collection and evaporation filtering device inside, and the thickness of the annular space is 10 -50cm; the several secondary flow mixing wings deviate clockwise from the axial section of the drainage cover at a certain angle, and the value of the deflection angle is 30-60 degrees.

Further, the above-mentioned liquid water recovery and cooling device of the passive containment heat export system, wherein the liquid water collection and evaporation filtration device includes a liquid water collection plate and a spiral liquid film evaporation and condensation plate, the spiral The liquid film evaporating and condensing plate has a spiral descending structure, and the bottom end of the spiral liquid film evaporating and condensing plate is connected with the porous filter water collecting plate, and the porous filtering water collecting plate is connected with the water inlet of the water tank.

Furthermore, the above-mentioned liquid water recovery and cooling device of the passive containment heat export system, wherein, the overall height of the liquid water collection and evaporation filtering device is between 0.2-0.8m, and the spiral The descending inclination angle of the liquid film evaporation and condensation plate is between 2 and 10 degrees.

The beneficial effects of the utility model are as follows: (1) The utility model adopts the passive scheme to strengthen the evaporative cooling effect in the high-temperature water recovery process, significantly reduce the return water temperature, and improve the heat discharge of the passive containment heat export system (2) It can recover liquid water to the greatest extent and return it to the water tank of the passive containment heat export system to ensure the long-term maintenance of the cooling water source, thereby ensuring the safety of the containment under design basis and beyond-design basis accidents. Long-term heat removal ensures the safety of the nuclear power plant; (3) It can fully utilize the coolant in the water tank, providing an equipment basis for winning a longer non-intervention time after an accident.

Description of drawings

Figure 1 is a schematic structural diagram of the passive containment heat export system;

Fig. 2 is a structural schematic diagram of the liquid water recovery and cooling device of the present invention.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is described in detail.

As shown in Figure 1, the design of the containment heat transfer system (PCS) adopts the passive design concept, including the heat exchanger 9 set inside the containment vessel 8 and the water tank 5 set outside the containment vessel 8, the heat exchanger 9 and the water tank 5 is connected through the ascending pipe section 7 and the descending pipe section 17, and the normally open containment isolation valves 16 and 18 are respectively set on the ascending pipe section 7 and the descending pipe section 17. Utilize the heat exchanger 9 arranged in the containment shell 8, through the condensation and convective heat transfer on the outer wall surface of the heat exchange tube of the heat exchanger 9, the heat of the high-temperature and humid air in the containment shell 8 is taken out, and the driving force of natural circulation ( Density difference between the descending pipe section 17 and the ascending pipe section 7), the heated cooling water in the pipe is discharged to the outside of the containment vessel 8, and part of the high-temperature cooling water generated is released into the atmosphere in the form of steam, and the other part is redistributed in the form of liquid water collect.

The ascending pipe section 7 passes through the water tank 5 upwards, and a plurality of outlets are arranged on the ascending pipe section 7, wherein the hot water outlet at the uppermost end of the ascending pipe section 7 - the outlet A3 of the ascending section is higher than the water tank 5, Its position is arranged in the liquid water recovery and cooling device 10 of the utility model. The rising pipe section 7 is located at different liquid level heights on the pipe body in the water tank 5. Several ascending section outlets are respectively provided, such as the ascending section outlet B13 in Figure 1, the ascending section outlet C14 and the ascending section outlet D15, and in the height direction Arranged in sequence, each outlet is provided with a corresponding valve device. The valve device is a normally closed valve device, which is connected with a liquid level sensor and triggered to open by a low water level signal. As the water evaporates, the water level 12 in the water tank 5 gradually drops, so the ascending section outlet B13 is triggered step by step, and the valves of the ascending section outlet C14 and the ascending section outlet D15 are opened. On the one hand, the step-by-step opening of the valves ensures the maintenance of the circulation capacity of the system (the excessive height difference between the inlet and outlet of the natural circulation system may cause the circulation to fail to be established), on the other hand, after the outlet valves of the ascending section at lower positions are opened step by step, the steam It is still discharged from the outlet A3 of the ascending section, and the liquid water is directly imported into the water tank 5 by the outlet of the ascending section at a lower position.

Inside the water tank 5, between the ascending section outlet B13, the ascending section outlet C14, and the ascending section outlet D15, installations are installed to weaken the mixing of the water flow inside the water tank, but do not hinder the water layers of different heights. Connected porous fabric6.

During the recovery of liquid water and the collection process of the cooling device, the high-temperature cooling water will be significantly cooled (by 20-40 degrees), so that it flows into the water tank 5 at a lower temperature. The arrangement position of the water tank 5 is higher than the heat exchanger 9, and the bottom of the water tank 5 is connected to the inlet of the heat exchanger 9 through the down pipe section 17, and the coolant can be continuously injected into the heat exchanger under the action of gravity to complete the continuous heating of the system cycle. Since the system is driven by natural circulation, the higher the temperature inside the containment vessel 8, the greater the heat exchange intensity on the surface of the heat exchanger 9, and the higher the temperature of the water in the heat transfer tubes will be, which means that the riser section 7 has a higher temperature. Small density, thus causing a larger density difference between the riser section 7 and the downcomer section 17, so the system obtains a larger driving pressure head, resulting in a stronger circulation flow rate. vice versa. That is, the heat removal capacity of the system can automatically match and balance with the heat removal demand.

The utility model has designed liquid water recovery and cooling device above the water tank, and its structure is as shown in Figure 2. The liquid water recovery and cooling device includes a wind strengthening device 1, a liquid water collection and evaporation filtering device and an air duct. The air duct is a conical draft hood 2, the wind strengthening device 1 is arranged on the top of the draft hood 2, the liquid water collection and evaporation filter device is arranged inside the draft hood 2, and the air induction port 4 is arranged at the bottom of the draft hood 2 , 11.

The wind power strengthening device 1 can adopt a solar wind power strengthening device, including a solar panel installed on the outer wall of the draft cover 2 and a fan in the air duct. Through the design of the solar wind strengthening device 1, the diversion cover 2, the specially designed air inlet 4 and the liquid water collection and evaporation filtering device, the wind force on the water surface is increased, the evaporation area of the water surface is expanded, and the evaporation intensity of the high-temperature coolant is strengthened. In this way, the water tank 5 can finally collect the coolant at a lower temperature, thus indirectly promoting the heat removal capability of the system, and finally achieving a greater degree of temperature and pressure reduction in the containment vessel 8 .

The liquid water collection and evaporation filtering device is arranged between the hot water discharge port and the water tank water injection port, and includes a liquid water collection plate 19 and a spiral liquid film evaporation and condensation plate 20. The position of the liquid water collection plate 19 is in line with the hot water discharge Corresponding to the position of the outlet (the outlet A3 of the ascending section), the spiral liquid film evaporation and condensation plate 20 has a spiral downward structure, and the bottom end of the spiral liquid film evaporation and condensation plate 20 is connected with the porous filter water collecting plate 22. The filter water collecting plate 22 is connected to the water filling port 23 of the water tank. The heated high-temperature cooling water is sprayed to the liquid water collecting plate 19, which is designed in a circular arc shape, so that the liquid water flows to the top of the spiral liquid film evaporation and condensing plate 20 while realizing the effective steam-water separation function , with the slope of the condensation plate, the water flow spirals down and expands into a liquid film. In the wind field with reverse flow and strong disturbance, the evaporation effect is obvious, and at the same time, the temperature is significantly lowered. The low-temperature water flow evaporates and condenses in the spiral liquid film. The bottom of the plate 20 collects, passes through the porous filter collecting plate 22, and finally enters the tank water filling port 23. The typical value of the overall height of the liquid water collection and evaporative filtration device is between 0.2-0.8m, and the specific size is determined according to the needs of the design. The spiral liquid film evaporative cooling plate descends in a spiral manner to form a structure similar to a propeller. Typical values for the dip angle are between 2-10 degrees.

The drainage cover 2 is conical, and the flow channel formed between the drainage cover 2 and the outer contour of the liquid water collection and evaporation filter device is a tapered annular flow channel with a uniform width and smoothness. The typical thickness of the annular space is 10-50cm, and the specific size is determined according to the needs of the design. Several secondary flow agitating wings 21 may also be arranged on the inner side of the draft cover 2 along the circumferential direction to induce the lateral flow of the air flow in the air duct of the draft cover. The secondary flow mixing vane 21 deviates clockwise from the axial section of the shroud at a certain angle to induce lateral flow in the air duct. The typical value of the deflection angle is 30-60 degrees. With the help of conical hood design, several secondary flow mixing wings arranged side by side along the circumferential direction in the air duct, and the circular air inlet at the bottom of the air duct form a narrow annular channel, and make the internal wind field present violent three-dimensional mixing. feature. All the above wind field optimization and enhanced design provide a very favorable evaporation condition for the liquid film on the surface of the spiral liquid film evaporation condensing plate 20 .

Obviously, those skilled in the art can make various changes and modifications to the utility model without departing from the spirit and scope of the utility model. In this way, if these modifications and variations of the present utility model fall within the scope of the claims of the utility model and equivalent technologies, the utility model is also intended to include these modifications and variations.

Claims (6)

1. the aqueous water of a passive containment thermal conduction system reclaims and cooling device, be arranged on the top of the outer cooling water tank of containment, it is characterized in that: comprise wind force intensified device (1), liquid water collection and evaporation filtration unit and air channel (2), described wind force intensified device (1) is arranged on the top of air channel (2), liquid water collection and evaporation filtration unit are arranged on inside, air channel (2), in air channel, the bottom of (2) arranges air-vent (4, 11), described liquid water collection and evaporation filtration unit are positioned between the hot water escape hole (3) and water tank water filling port (23) of containment heat guiding system.

2. the aqueous water of passive containment thermal conduction system as claimed in claim 1 reclaims and cooling device, it is characterized in that: described wind force intensified device (1) comprises and is installed on the solar panel of air channel outside wall surface and is arranged on the blower fan in air channel.

3. the aqueous water of passive containment thermal conduction system as claimed in claim 1 or 2 reclaims and cooling device, it is characterized in that: described air channel (2), for being conical drainage hood, drainage hood internal face is provided with several and mixes the wing (21) in order to cause the Secondary Flow of cross flow in air channel.

4. the aqueous water of passive containment thermal conduction system as claimed in claim 3 reclaims and cooling device, it is characterized in that: between described drainage hood and its inner liquid water collection and evaporation filtration unit, form annular space, the thickness of annular space is 10-50cm; Several described Secondary Flows mix that the shaft section of the wing and drainage hood is angled to be departed to clockwise direction, and the value of drift angle is 30-60 degree.

5. the aqueous water of passive containment thermal conduction system as claimed in claim 1 reclaims and cooling device, it is characterized in that: described liquid water collection and evaporation filtration unit comprise liquid water collection plate (19) and spiral liquid film evaporation cold plate (20), described spiral liquid film evaporation cold plate (20) is spiral structure drop, the bottom of spiral liquid film evaporation cold plate (20) is connected with porous filtering water collection sheet (22), and described porous filtering water collection sheet (22) connects water tank water filling port (23).

6. the aqueous water of passive containment thermal conduction system as claimed in claim 5 reclaims and cooling device, it is characterized in that: the whole height of described liquid water collection and evaporation filtration unit is between 0.2-0.8m, and the decline inclination angle of described spiral liquid film evaporation cold plate is between 2-10 degree.