WO2022111371A1

WO2022111371A1 - Passive cold storage heat exchanger

Info

Publication number: WO2022111371A1
Application number: PCT/CN2021/131392
Authority: WO
Inventors: 胡北; 刘婧; 陆松; 温华; 张丽丽; 李百利; 康健; 邱珊珊; 韩金权; 张凤霖; 朱芸芸; 陈浩南; 刘新
Original assignee: 中国核电工程有限公司
Priority date: 2020-11-26
Filing date: 2021-11-18
Publication date: 2022-06-02
Also published as: GB2615269A; GB202306661D0; CN112611244B; CN112611244A; SA523440733B1; ZA202305604B

Abstract

A passive cold storage heat exchanger, comprising: a cooling room (1) to be cooled, a heat pipe assembly (4), a cold storage water tank (3), and a ventilation room (2). The ventilation room (2) is adjacent to the cooling room (1) and is separated therefrom by a floor slab (22); the ventilation room (2) is disposed above the cooling room (1); the heat pipe assembly (4) comprises at least two heat pipes (8) used for heat transfer; the heat pipes (8) are used for containing a liquid working medium (19); each heat pipe (8) comprises an evaporation section (5), a heat insulation section (6), and a condensation section (7) which are connected in sequence; the heat pipes (8) run through the floor slab (22) between the ventilation room (2) and the cooling room (1); the heat insulation sections (6) are disposed in the floor slab (22); the evaporation sections (5) are disposed in the cooling room (1); the condensation sections (7) are disposed in the cold storage water tank (3); the cold storage water tank (3) is used for introducing cooling water for cold storage of the liquid working medium (19) in the heat pipes (8); the cold storage water tank (3) is disposed in the ventilation room (2). By means of the passive cold storage heat exchanger, after losing all the power supplies inside and outside the nuclear power plant, the temperature of the cooling room can be maintained not to exceed a design value within a certain period of time only by means of water cold storage and passive heat transfer of the heat pipes.

Description

Passive Cool Storage Heat Exchanger

This disclosure claims the priority of a Chinese patent application with an application date of November 26, 2020, application number CN 202011346554.9, and titled "Passive Cool Storage Heat Exchanger", the entire contents of which are incorporated in this disclosure by reference .

technical field

The invention belongs to the technical field of heat exchange, and in particular relates to a passive cold storage type heat exchange device.

Background technique

After the main control room of a nuclear power plant loses normal power, it is still necessary to ensure the design temperature in the room. In the existing design, diesel generators are mostly used to supply power to the active ventilation and cooling equipment when the power is lost. The design is complex, the investment is large, and there is still a certain risk of failure, and the noise generated by the active equipment will affect the operation of the main control room operator. work efficiency.

In addition, there is a cold storage scheme using concrete and metal fins for the envelope structure, which releases a certain amount of cold energy to reduce the room temperature in the event of an accident. It is difficult to bear all the cooling loads of the room in the project.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to aim at the above-mentioned deficiencies in the prior art, and to provide a passive cold storage type heat exchange device. Maintain the cooling room temperature within a certain period of time not to exceed the design value.

The technical solution adopted to solve the technical problem of the present invention is to provide a passive cold storage type heat exchange device, which includes: a cooling room to be cooled, a heat pipe assembly, a cold storage tank, and a ventilation room. The ventilation room is adjacent to the cooling room and is separated by a floor plate. The ventilation room is set above the heat dissipation room. The heat pipe assembly includes: at least two heat pipes for heat transfer. The heat pipes are used to hold the liquid working medium. The floor between the ventilation room and the heat dissipation room. The adiabatic section is set in the floor, the evaporation section is set in the heat dissipation room, and the condensation section is set in the cold storage tank. The cold storage tank is used for cooling water to store the liquid working medium in the heat pipe. , the cold storage tank is arranged in a ventilated room.

Preferably, the heat pipe includes: an inner layer copper pipe and an outer layer steel pipe disposed outside the inner layer copper pipe.

Preferably, the cold water storage tank includes: a water tank body, a water inlet provided on the water tank body for water intake, a ventilation port for ventilation, an overflow port for overflow, and a water discharge port for draining water.

Preferably, the cold water storage tank further includes: a fire water interface provided on the water tank body with a preset water level. The cold water storage tank in the present invention can provide fire fighting water for the iodine adsorber in the emergency filtration system of the heat dissipation room nearby, so as to ensure the water demand in the event of fire and simplify the fire fighting system of the workshop.

Preferably, the passive cold storage type heat exchange device further comprises: a temperature detector arranged in the water tank body, a water inlet pipe connected to the water inlet, an electric regulating valve arranged on the water inlet pipe, and the temperature detector is connected to the water inlet pipe. The electric regulating valve is electrically connected. When the water temperature detected by the temperature detector is higher than the upper limit of the design value, the electric regulating valve is opened by interlocking; when the water temperature detected by the temperature detector is higher than the lower limit of the design value, the electric regulating valve is interlocked and closed.

Preferably, the heat pipe assembly further comprises: an upper support plate and a pre-embedded channel steel, the upper support plate is arranged on the bottom plate of the cold water storage tank, the heat pipe is connected with the upper support plate, the pre-embedded channel steel is pre-buried in the floor plate, and the upper support plate is connected to the upper support plate. Pre-embedded channel steel fixed connection.

Preferably, the heat pipe assembly further comprises: a lower support plate, the lower support plate is fixedly connected with the embedded channel steel, and the heat pipe and the lower support plate are only connected in contact.

Preferably, the heat pipe assembly further comprises: a flange, the heat pipe is connected with the flange, and the heat pipe is fixed on the upper support plate through the flange.

Preferably, the heat dissipation room is any one or more of the main control room, the electrical equipment room, the instrument control equipment room, the reactor containment, the diesel generator hall, and the air duct.

Preferably, the heat pipes are arranged in an array.

The cold storage function of the heat exchange device in the present invention is realized by the cold storage tank, and the cold storage can be carried out in three ways: by injecting frozen water into the cold storage tank; the metal part of the heat pipe assembly guides the excess cold energy in the ventilation room into the cold storage tank; outside the cold storage tank Surfaces are naturally ventilated. Among them, the injection of chilled water can be controlled by a temperature detector and an electric regulating valve in the cold storage tank. Through the above methods, the water temperature in the cold storage tank is kept lower than the design temperature all the year round, so that the cold storage capacity of the cold storage tank is greater than the room cooling load within a certain period of time after power failure.

The passive heat exchange function in the present invention is realized by the heat pipe assembly. During the normal operation of the nuclear power plant, when the temperature of the cold storage tank is lower than the indoor temperature of the heat dissipation room, the heat pipe cycle starts, and the passive heat pipe heat exchange undertakes part of the cooling load of the heat dissipation room, saving the energy consumption of the active cooling equipment; After the temperature of the heat dissipation room rises to the temperature of the water tank, the heat pipe cycle starts, and the cold storage capacity of the water tank is released to the heat dissipation room through the passive heat exchange of the heat pipe, so as to maintain the maximum design temperature of the heat dissipation room for a certain period of time, and ensure that the personnel can stay in the room.

Description of drawings

1 is a schematic structural diagram of a passive cold storage type heat exchange device in Embodiment 2 of the present invention;

2 is a schematic structural diagram of a heat pipe assembly in Embodiment 2 of the present invention;

3 is a schematic structural diagram of a single heat pipe in Embodiment 2 of the present invention;

FIG. 4 is a schematic structural diagram of a cold water storage tank in Embodiment 2 of the present invention.

In the figure: 1- cooling room; 2- ventilation room; 3- cold storage tank; 4- heat pipe assembly; 5- evaporation section; 6- condensation section; 7- adiabatic section; 8- heat pipe; 9- upper support plate; 10- Lower support plate; 11-flange; 12-reinforcing plate; 13a, 13b-gasket; 14a, 14b, 14c-bolt; 15-bottom plate; 16-embedded channel steel; 17-inner copper pipe; Layer steel pipe; 19-liquid working medium; 20-flange hole; 21-weld; 22-floor; 23-water inlet; 24-water inlet pipe; 25-water outlet; 26-water outlet pipe; 27-overflow outlet; 28-overflow pipe; 29-fire water interface; 30-fire control pipe; 31-vent; 32-temperature detector; 33-electric regulating valve.

Detailed ways

In order to make those skilled in the art better understand the technical solutions of the present disclosure, the present disclosure will be further described in detail below with reference to the accompanying drawings and embodiments.

Embodiments of the present patent are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present patent, but should not be construed as a limitation on the present patent.

Example 1

This embodiment provides a passive cold storage type heat exchange device, including: a heat dissipation room to be cooled, a heat pipe assembly, a cold storage tank, and a ventilation room. The ventilation room is adjacent to the heat dissipation room and separated by a floor, and the ventilation room is arranged in the heat dissipation room. Above, the heat pipe assembly includes: at least two heat pipes for heat transfer, the heat pipes are used to hold the liquid working medium, the heat pipes include: an evaporation section, an adiabatic section, and a condensation section connected in sequence, and the heat pipes run through the ventilation room and the heat dissipation room. Floor, the adiabatic section is set in the floor, the evaporation section is set in the heat dissipation room, the condensation section is set in the cold storage tank, the cold storage tank is used for cooling water to store the liquid working medium in the heat pipe, and the cold storage tank is set in the ventilation room. . After losing all the power supply inside and outside the nuclear power plant, only by means of water cooling and passive heat conduction through heat pipes, the temperature of the cooling room can be maintained within a certain period of time to not exceed the design value. The liquid working medium in the evaporation section is heated and evaporated in the main control room, the adiabatic section is adiabatic in the floor, and the liquid working medium in the condensation section is cooled and condensed in the cold storage tank.

The cold storage function of the heat exchange device in this embodiment is realized by the cold storage tank, which can be stored in three ways: by injecting chilled water into the cold storage tank; the metal part of the heat pipe assembly guides the excess cooling capacity in the ventilated room into the cold storage tank; the cold storage tank External surfaces are naturally ventilated. Among them, the injection of chilled water can be controlled by a temperature detector and an electric regulating valve in the cold storage tank. Through the above methods, the water temperature in the cold storage tank is kept lower than the design temperature all the year round, so that the cold storage capacity of the cold storage tank is greater than the room cooling load within a certain period of time after power failure.

The passive heat exchange function in this embodiment is realized by the heat pipe assembly. During the normal operation of the nuclear power plant, when the temperature of the cold storage tank is lower than the indoor temperature of the heat dissipation room, the heat pipe cycle starts, and the passive heat pipe heat exchange undertakes part of the cooling load of the heat dissipation room, saving the energy consumption of the active cooling equipment; After the temperature of the heat dissipation room rises to the temperature of the water tank, the heat pipe cycle starts, and the cold storage capacity of the water tank is released to the heat dissipation room through the passive heat exchange of the heat pipe, so as to maintain the maximum design temperature of the heat dissipation room for a certain period of time, and ensure that the personnel can stay in the room.

Example 2

As shown in FIGS. 1 to 4 , this embodiment provides a passive cooling storage type heat exchange device, including: a cooling room 1 to be cooled, a heat pipe assembly 4 , a cold storage tank 3 , a ventilation room 2 , the ventilation room 2 and the cooling room 1 Adjacent and separated by the floor 22, the ventilation room 2 is arranged above the heat dissipation room 1, the heat pipe assembly 4 includes: at least two heat pipes 8 for heat transfer, the heat pipes 8 are used for holding the liquid working medium 19, and the heat pipes 8 include: The evaporation section 5, the adiabatic section 7, and the condensation section 6 are connected in sequence, and the heat pipe 8 runs through the floor 22 between the ventilation room 2 and the heat dissipation room 1. The condensing section 6 is arranged in the cold storage tank 3 , which is used for passing cooling water to store the liquid working medium 19 in the heat pipe 8 , and the cold storage tank 3 is arranged in the ventilation room 2 . Specifically, the heat dissipation room 1 to be cooled in this embodiment is the main control room, the heat pipe assembly 4 is a gravity heat pipe assembly, the heat pipe 8 is installed on the roof of the heat dissipation room 1, and the evaporation section 5 of the heat pipe 8 is located in the upper part of the heat dissipation room 1 Space, the condensation section 6 is located at the bottom of the cold storage tank 3, and the adiabatic section 7 is fixed in the floor 22 through a steel structure frame. After losing all the power supply inside and outside the nuclear power plant, the temperature of the cooling room 1 is maintained within a certain period of time not exceeding the design value only by means of water cooling and passive heat conduction of the heat pipe 8 .

Through such an arrangement, the unidirectional heat conduction of the heat pipe 8 can be realized by gravity, that is, the heat of the cooling room 1 can be easily introduced into the cold storage tank 3, and the heat of the cold storage tank 3 is difficult to enter the cooling room 1. At the same time, the heat pipe 8 connects the cold storage tank 3 and the cooling room 1 as a whole heat transfer unit, which greatly increases the thermal inertia of the cooling room 1, and the temperature peak and fluctuation range of the cooling room 1 will be much smaller than that of the outdoor room, which improves the heat dissipation room 1. Passive safety against thermal influences.

Specifically, the liquid working medium 19 used for holding the heat pipe 8 is water or refrigerant. Floor 22 is a concrete floor.

As shown in FIG. 3 , preferably, the heat pipe 8 includes: an inner layer copper pipe 17 and an outer layer steel pipe 18 arranged outside the inner layer copper pipe 17 . The inner layer copper pipe 17 ensures the compatibility with the working medium. No matter whether water or refrigerant is used, non-condensable gas will not be generated during the working process, which improves the service life of the heat pipe 8 . The stainless steel outer steel tube 18 ensures the mechanical processing, corrosion resistance and shock resistance of the heat pipe 8 .

As shown in FIG. 4 , preferably, the cold storage tank 3 includes: a water tank body, a water inlet 23 provided on the water tank body for water intake, a ventilation port 31 for ventilation, and an overflow port 27 for overflow , The drain port 25 for draining water. Specifically, the water inlet 23 is arranged on the top of the water tank body, and is used to connect the chilled water system of the factory building. The air vent 31 is arranged at the highest part of the water tank body. The overflow port 27 and the water discharge port 25 are used to connect the plant drainage system. The water inlet 23 is connected to the chilled water inlet pipe 24 , the water outlet 25 is connected to the water outlet pipe 26 , and the overflow port 27 is connected to the overflow pipe 28 .

Preferably, the cold water storage tank 3 further includes: a fire water interface 29 provided on the water tank body with a preset water level. The fire-fighting water interface 29 is used to connect the iodine adsorber in the emergency filtration system of the heat-dissipating room 1. The cold storage tank 3 in this embodiment can provide fire-fighting water for the iodine adsorber in the emergency filtration system of the heat-dissipating room 1 to ensure that in the event of a fire water requirements to simplify the plant fire protection system. The fire water interface 29 is connected to the fire hose 30 . According to the single fault criterion, the simultaneous occurrence of fire and power loss is not considered, so part of the water in the cold storage tank 3 can be used as backup water for firefighting. 3. The height difference can realize passive water injection, extinguish fires efficiently and quickly, and because the pipeline distance is short, the investment is less than the centralized fire protection system of the workshop.

Preferably, the passive cold storage type heat exchange device further comprises: a temperature detector 32 arranged in the water tank body, a water inlet pipe 24 connected to the water inlet 23 , and an electric regulating valve 33 arranged on the water inlet pipe 24 , the temperature detector 32 is electrically connected to the electric regulating valve 33. When the water temperature detected by the temperature detector 32 is higher than the upper limit of the design value, the electric regulating valve 33 is interlocked to open; when the water temperature detected by the temperature detector 32 is higher than the design value If the lower limit is reached, the electric regulating valve 33 is interlocked to close. Specifically, the temperature detector 32 in this embodiment is a temperature sensor, the temperature sensor is also connected to an external instrument control system, and the temperature sensor adopts a continuous meter.

As shown in FIG. 2 , preferably, the heat pipe assembly 4 further comprises: an upper support plate 9 and a pre-embedded channel steel 16 , the upper support plate 9 is arranged on the bottom plate 15 of the cold water storage tank 3 , and the heat pipe 8 is bolted to the upper support plate 9 . For connection, the pre-embedded channel steel 16 is pre-embedded in the floor slab 22 , and the upper support plate 9 is fixedly connected with the pre-embedded channel steel 16 .

Preferably, the heat pipe assembly 4 further includes: a lower support plate 10 , and the lower support plate 10 is fixedly connected with the embedded channel steel 16 . The lower support plate 10 is only in contact with the heat pipe 8 to limit the horizontal displacement of the end of the heat pipe 8 , so that the heat pipe 8 can be repaired and replaced on the side of the cold water storage tank 3 .

Preferably, the heat pipe assembly 4 further includes a flange 11 , the heat pipe 8 is connected to the flange 11 , and the heat pipe 8 is fixed on the upper support plate 9 through the flange 11 . Specifically, a welding seam 21 is left between the flange 11 and the heat pipe 8, and the flange 11 is welded and fixed on the heat pipe 8 through the welding seam 21. The flange 11 is provided with a flange hole 20, and the upper support plate 9 is provided with a Bolt holes, the bolts 14a pass through the flange holes 20 and the bolt holes, a gasket 13 is also provided between the flange 11 and the upper support plate 9, the nuts are locked, and the flange 11 is screwed with the upper support plate 9, through The heat pipe 8 is fixed on the upper support plate 9 by the bolts 14a and the gasket 13a, and the heat insulating section 7 of the heat pipe 8 is fixed in the hole of the floor plate 22 . The upper support plate 9 is fixed on the pre-embedded channel steel 16 by bolts 14b and washers 13b, and the upper support plate 9 is screwed to the pre-embedded channel steel 16. The lower support plate 10 is fixed on the embedded channel steel 16 by bolts 14c, and the lower support plate 10 is screwed to the embedded channel steel 16. Since the service life of the heat pipe 8 is shorter than the operating life of the nuclear power plant, the above structure uses as few welding methods as possible, and the convenience of installation, maintenance and replacement of the heat pipe assembly 4 and the single heat pipe 8 is ensured through the bolt connection between the components. Specifically, the gasket 13 in this embodiment is a watertight gasket.

Preferably, the heat pipe assembly 4 further includes a reinforcement plate 12 connected to the upper support plate 9. In order to meet the earthquake resistance requirements, the reinforcement plate 12 is welded on the upper support plate 9 to improve the bending resistance.

Preferably, the heat dissipation room 1 is any one or more of the main control room, the electrical equipment room, the instrument control equipment room, the reactor containment, the diesel generator hall, and the air duct.

Preferably, the heat pipes 8 are arranged in an array. The length of a single heat pipe 8 is less than 2m, which can ensure that it has a small start-up temperature difference and high heat transfer efficiency, and can work stably in transition seasons and power outages, while meeting energy-saving and safety requirements. Especially when the power outage accident just happened, the cooling load of the cooling room 1 is still at the peak value for a short time, and the heat transfer coefficient of the heat pipe 8 increases with the increase of the temperature difference. Compared with other passive cooling methods with fixed heat transfer coefficient, digestion Peak load capacity is stronger.

The cold storage function of the heat exchange device in this embodiment is realized by the cold storage tank 3, which can be stored in three ways: injecting chilled water into the cold storage tank 3 through the water inlet 23; The amount is introduced into the cold storage tank 3; the outer surface of the cold storage tank 3 is naturally ventilated. The injection of chilled water can be controlled by the temperature detector 32 and the electric regulating valve 33 in the cold storage tank 3 . Through the above methods, the water temperature in the cold storage tank 3 is maintained below the design temperature all the year round, so that the cold storage capacity of the cold storage tank 3 is greater than the room cooling load within a certain period of time after power failure.

The passive heat exchange function in this embodiment is realized by the heat pipe assembly 4 . During the normal operation of the nuclear power plant, when the temperature of the cold storage tank 3 is lower than the indoor temperature of the cooling room 1, the heat pipe 8 is started in a cycle, and the passive heat pipe 8 is used for heat exchange to undertake part of the cooling load of the cooling room 1, thus saving the energy consumption of the active cooling equipment; the nuclear power plant When the power is lost, the heat pipe 8 starts to circulate as the room temperature of the cooling room 1 rises to the temperature of the water tank, and the cold storage capacity of the water tank is released to the cooling room 1 through the passive heat exchange of the heat pipe 8, so as to maintain the highest temperature in the cooling room 1 for a certain period of time. Design temperature to ensure that personnel can stay in the room.

It can be understood that the above embodiments are only exemplary embodiments adopted to illustrate the principle of the present invention, but the present invention is not limited thereto. For those skilled in the art, without departing from the spirit and essence of the present invention, various modifications and improvements can be made, and these modifications and improvements are also regarded as the protection scope of the present invention.

Claims

A passive cold storage type heat exchange device is characterized by comprising: a cooling room to be cooled, a heat pipe assembly, a cold storage tank, and a ventilation room for ventilation, the ventilation room is adjacent to the cooling room and separated by a floor, and the ventilation room Set above the heat dissipation room, the heat pipe assembly includes: at least two heat pipes for heat transfer, the heat pipes are used to hold the liquid working medium, the heat pipes include: an evaporation section, adiabatic section, and condensation section connected in sequence, and the heat pipe runs through the ventilation room and the heat dissipation section. The floor between rooms, the adiabatic section is set in the floor, the evaporation section is set in the heat dissipation room, the condensation section is set in the cold storage tank, the cold storage tank is used to pass the cooling water to the liquid working medium in the heat pipe to store cold, and the cold storage tank is set in a ventilated room.
The passive cold storage type heat exchange device according to claim 1, wherein the heat pipe comprises: an inner layer copper pipe and an outer layer steel pipe arranged outside the inner layer copper pipe.
The passive cold storage type heat exchange device according to claim 1, wherein the cold storage tank comprises: a water tank body, a water inlet provided on the water tank body for water intake, a ventilation port for ventilation, and an overflow port for overflow. The overflow port for the flow, the drain port for draining the water.
The passive cold storage type heat exchange device according to claim 3, characterized in that, the cold storage tank further comprises: a fire water interface provided on the water tank body with a preset water level.
The passive cold storage type heat exchange device according to claim 3, further comprising: a temperature detector arranged in the water tank body, a water inlet pipe connected to the water inlet, and an electric regulating valve arranged on the water inlet pipe, The temperature detector is electrically connected to the electric regulating valve. When the water temperature detected by the temperature detector is higher than the upper limit of the design value, the electric regulating valve is opened by interlock; when the water temperature detected by the temperature detector is higher than the lower limit of the design value, the interlock is closed. Electric regulating valve.
The passive cold storage type heat exchange device according to claim 1, wherein the heat pipe assembly further comprises: an upper support plate and a pre-embedded channel steel, the upper support plate is arranged on the bottom plate of the cold storage water tank, and the heat pipe is connected to the upper support plate , the pre-embedded channel steel is pre-buried in the floor slab, and the upper support plate is fixedly connected with the pre-embedded channel steel.
The passive cold storage type heat exchange device according to claim 6, wherein the heat pipe assembly further comprises: a lower support plate, the lower support plate is fixedly connected with the embedded channel steel, and the heat pipe and the lower support plate are only connected by contact.
The passive cold storage type heat exchange device according to claim 6, wherein the heat pipe assembly further comprises: a flange, the heat pipe is connected with the flange, and the heat pipe is fixed on the upper support plate through the flange.
The passive cold storage type heat exchange device according to any one of claims 1 to 8, characterized in that the heat dissipation room is a main control room, an electrical equipment room, an instrument control equipment room, a reactor containment, a diesel generator hall, and a ventilation room. Any one or several of the tubes.
The passive cold storage type heat exchange device according to any one of claims 1 to 8, wherein the heat pipes are arranged in an array.