Passive heat export system and method for coping with crevasse accident based on ocean heat trap

Abstract

The invention discloses a passive heat export system and method for coping with a crevasse accident based on an ocean heat trap. As the floating energy source is far away from the land, no standard processing structure and method for coping with crevasse accidents exist at present. A seawater cooling box is arranged above a heat source structure body, a one-way non-return device is arranged at the top of the seawater cooling box, seawater is injected into the seawater cooling box, a working medium is injected into the heat source structure body, a seawater filtering device is arranged in the seawater cooling box, and the seawater filtering device is arranged at the bottom of the seawater cooling box. The heat exchanger is vertically arranged in the heat source structure body, the connecting heat pipe and the connecting cold pipe are sequentially arranged between the seawater cooling box and the heat source structure body from top to bottom, the first isolation valve is arranged on the connecting heat pipe, and the second isolation valve is arranged on the connecting cold pipe; according to the passive heat exporting method for coping with the crevasse accident, the heat dissipation and pressure relief treatment process of the multiple circulating water paths for coping with the crevasse accident is completed through the passive heat exporting system for coping with the crevasse accident.

Description

TECHNICAL FIELD

[0001] The application is particularly a non-active heat removal system and method for coping with break accidents based on ocean heat sink. BACKGROUND

[0002] The offshore floating power generation platform refers to all platforms deployed in offshore, offshore and other sea areas for converting certain energy into electric energy, covering various power generation forms; it can be used for power supply for offshore oil and gas development, island power supply, marine resource development and other scenarios. As a new type of energy facility deployed in complex marine environment, the emergency coordination measures of the energy source safety system of the offshore floating power generation platform face a completely different processing method from the traditional land-based power station. The thermal hydraulic characteristics of the floating energy source system and the operation characteristics of its safety system such as natural circulation characteristics may be affected by the marine operating conditions. At the same time, the marine environment can also provide the final heat sink for the offshore floating power generation platform.

[0003] The energy source cabin is surrounded by a circle of water storage protection tank for passive cooling and radiation shielding. The design is still based on the safety facilities of conventional land-based facilities, and passive, non-active design is the dominant. The floating energy source is far away from the land, and the design of its accident response measures needs to achieve passive driving as much as possible. In addition, the reasonable compactness of the structure of the floating energy source system needs to be improved. Since the floating energy source is far away from the land, there is no standard processing structure and method for coping with break accidents at present. When different break accidents occur, the offshore floating power generation platform currently lacks active response processing structures and methods that can regulate and respond to different magnitude break accidents. SUMMARY

[0004] The application provides a non-active heat removal system and method for coping with break accidents based on ocean heat sink to solve the above problems.

[0005] The application discloses a non-active heat removal system based on a marine heat sink and coping with a break accident, which comprises a seawater cooling box, a seawater filtering device, a one-way check device, a connecting hot pipe, a connecting cold pipe, a first isolation valve, a second isolation valve, a heat exchanger and a heat source structure body, the seawater cooling box is arranged above the heat source structure body, the one-way check device is arranged on the top of the seawater cooling box, seawater is injected into the seawater cooling box, a working medium is injected into the heat source structure body, the seawater filtering device is arranged in the seawater cooling box and at the bottom of the seawater cooling box, the heat source structure body is a structure body with an inner cavity, the heat exchanger is vertically arranged in the heat source structure body, the connecting hot pipe and the connecting cold pipe are sequentially arranged between the seawater cooling box and the heat source structure body from top to bottom, one end of the connecting hot pipe is connected with the seawater cooling box, the other end of the connecting hot pipe passes through the heat source structure body and is connected with the top of the heat exchanger, the first isolation valve is arranged on the connecting hot pipe, one end of the connecting cold pipe is connected with the seawater cooling box, the other end of the connecting cold pipe passes through the heat source structure body and is connected with the bottom of the heat exchanger, and the second isolation valve is arranged on the connecting cold pipe.

[0006] As a preferred scheme: the seawater cooling box is a rectangular box body, the heat source structure body is a rectangular box body, the seawater cooling box is arranged obliquely above the heat source structure body, and the distance between the rear outer wall of the seawater cooling box and the front outer wall of the heat source structure body is less than one third of the length of the seawater cooling box.

[0007] As a preferred scheme: the connecting hot pipe and the connecting cold pipe are both L-shaped pipe bodies.

[0008] As a preferred scheme: the inner diameters of the connecting hot pipe and the connecting cold pipe are equal, and the diameter of the connecting hot pipe ranges from 200 mm to 300 mm.

[0009] As a preferred scheme: the ratio of the minimum volume of the seawater cooling box to the minimum volume of the heat source structure body is 1:10.

[0010] As a preferred scheme: the inner cavity of the seawater cooling box is a first chamber, the inner cavity of the heat source structure body is a second chamber, the centroid horizontal height of the first chamber is higher than the centroid horizontal height of the heat source structure body, and the height difference between the centroid horizontal height of the first chamber and the centroid horizontal height of the heat source structure body ranges from 2 m to 10 m.

[0011] As a preferred scheme: the heat exchanger is a C-shaped heat exchanger.

[0012] As a preferred scheme: the end, connected with the seawater cooling box, of the connecting cold pipe is an upstream inlet end, the end, connected with the heat source structure body, of the connecting hot pipe is a downstream outlet end, and the vertical distance between the upstream inlet end and the downstream outlet end ranges from 0.8 m to 1.2 m.

[0013] As a preferred solution: the seawater cooling box is matched with a lifting device below, and the seawater cooling box is driven by the lifting device to make vertical reciprocating lifting movement.

[0014] A non-active heat removal method for coping with a break accident based on a marine heat sink, which is realized by using the non-active heat removal system for coping with a break accident based on a marine heat sink, The non-active heat removal method for coping with a break accident is completed by the non-active heat removal system for coping with a break accident to perform the heat dissipation and pressure relief process of the multi-cycle waterway for coping with a break accident, and the specific process is as follows: When the energy source is in a normal operation condition, the first isolation valve and the second isolation valve are in a closed state, the heat source structure is in a non-operation state, the seawater cooling box is in an operation state, the seawater filtering device and the one-way check device are in an open working state, a seawater circulation loop is formed between the seawater cooling box, the seawater filtering device and the one-way check device, the seawater circulation loop is in an open circuit state for a long time, seawater enters the seawater cooling box from the seawater filtering device, seawater in the seawater cooling box is discharged to a natural water area from the one-way check device, and the seawater circulation loop does not have a circulation driving force; when the energy source is in a normal operation condition, the seawater circulation loop has a flow size of zero; When a break accident occurs on the offshore floating power generation platform, the pressure of the large special pressure container rapidly rises due to the rapid injection of high-pressure cooling water in the pressure container into the space of the large special pressure container and the flash evaporation phenomenon, and the working medium in the heat source structure is heated and pressurized; when the pressure in the heat source structure reaches 0.42 MPa, a natural circulation loop is formed between the seawater cooling box, the connecting cold pipe, the connecting hot pipe, the heat exchanger and the heat source structure, and the first isolation valve and the second isolation valve are opened; the seawater in the natural circulation loop is heated by the working medium in the heat source structure through the heat exchanger, and the circulating seawater is cooled by stirring and heat exchange in the seawater cooling box after being heated, so that the water temperature in the seawater cooling box is increased to drive the formation of the natural circulation loop; the seawater filtering device inputs the filtered seawater into the seawater cooling box, and at the same time, the seawater circulation loop is superimposed and matched; the seawater enters the seawater cooling box from the seawater filtering device, and the one-way check device which is always in an open state discharges the seawater in the seawater cooling box to the natural water area; when the non-active heat removal system continuously works for 72 hours and the pressure value in the heat source structure continuously is lower than 0.4 MPa, it is indicated that the break accident is effectively handled in an emergency, and the crisis is resolved; at this time, the first isolation valve and the second isolation valve are closed, and the natural circulation loop stops running.

[0015] Compared with the prior art, the application provides a non-active heat removal system and method for coping with a break accident based on a marine heat sink, which has the following beneficial effects: The seawater cooling tank, the seawater filtering device, the one-way check device, the connecting hot pipe, the connecting cold pipe, the first isolation valve, the second isolation valve, the heat exchanger and the heat source structure in the marine heat sink based non-active heat lead-out system for coping with a break accident in the application can realize a compact structure and a multi-water circuit circulation heat lead-out process, realize a passive driving non-active heat lead-out structure form, improve the active processing performance for coping with a sudden break accident, and provide a safe operation standard guarantee structure when used with a marine floating power generation platform.

[0016] The marine heat sink based non-active heat lead-out method for coping with a break accident in the application realizes a simple and easy to standardize process, and reduces the space occupied by related facilities. In the process of the method, the active and static state combined multi-water circuit circulation mode is used to complete the active remediation process, realizes the external heat sink of the heat exchange system, fully utilizes the natural state of seawater cooling, can be used continuously and durably, the processing method is energy-saving and stable in continuity, the strain is fast, the emergency ability of the floating power generation platform for actively processing a sudden accident is improved, the space burden of the marine floating power generation platform is reduced, and a safe operation standard guarantee method is provided. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is the working principle schematic diagram of the marine heat sink based non-active heat lead-out system for coping with a break accident in the application, the arrow direction in the figure represents the seawater flow direction, and only a part of the heat source structure is shown in the figure in order to clearly show the position and structure of the heat exchanger; Figure 2 is a schematic diagram of the formation position area of the seawater circulation loop and the natural circulation loop; Figure 3 is the front view structural schematic diagram of the marine heat sink based non-active heat lead-out system for coping with a break accident in the application; Figure 4 is the front view structural schematic diagram of the marine heat sink based non-active heat lead-out system for coping with a break accident in the application with a lifting device.

[0018] In the figure: 100-seawater cooling tank; 101-seawater filtering device; 102-one-way check device; 103-connecting hot pipe; 104-connecting cold pipe; 105-first isolation valve; 106-second isolation valve; 107-heat exchanger; 108-heat source structure; 109-lifting device. DETAILED DESCRIPTION

[0019] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0020] Specific implementation manner one: in combination with Figure 1 、 Figure 2 and Figure 3 The present embodiment is described. In the present embodiment, the passive heat lead-out system comprises a seawater cooling tank 100, a seawater filtering device 101, a one-way check device 102, a connecting hot pipe 103, a connecting cold pipe 104, a first isolation valve 105, a second isolation valve 106, a heat exchanger 107, and a heat source structure 108. The seawater cooling tank 100 is arranged above the heat source structure 108. The one-way check device 102 is arranged at the top of the seawater cooling tank 100. The seawater cooling tank 100 is filled with seawater. The heat source structure 108 is filled with a working medium. The seawater filtering device 101 is arranged in the seawater cooling tank 100. The seawater filtering device 101 is arranged at the bottom of the seawater cooling tank 100. The heat source structure 108 is a structure with an inner cavity. The heat exchanger 107 is vertically arranged in the heat source structure 108. The connecting hot pipe 103 and the connecting cold pipe 104 are sequentially arranged between the seawater cooling tank 100 and the heat source structure 108 from top to bottom. One end of the connecting hot pipe 103 is connected with the seawater cooling tank 100. The other end of the connecting hot pipe 103 penetrates through the heat source structure 108 and is connected with the top of the heat exchanger 107. The first isolation valve 105 is arranged on the connecting hot pipe 103. One end of the connecting cold pipe 104 is connected with the seawater cooling tank 100. The other end of the connecting cold pipe 104 penetrates through the heat source structure 108 and is connected with the bottom of the heat exchanger 107. The second isolation valve 106 is arranged on the connecting cold pipe 104.

[0021] The connecting hot pipe 103 and the connecting cold pipe 104 in the present embodiment are existing pipes. According to the use of the working condition, a hard pipe or a flexible pipe body is selected. The connection mode between the connecting hot pipe 103 and the connecting cold pipe 104 and the seawater cooling tank 100 and the heat source structure 108 is consistent with the connection mode of the existing pipe body in underwater tank penetration.

[0022] The first isolation valve 105 and the second isolation valve 106 in the present embodiment are electromagnetic drive general standard gate valves for cutting off or connecting a flow path used underwater, for example, Z41H series gate valves. The working principle is the same as that of the existing general standard gate valve used underwater.

[0023] The one-way check device 102 in the embodiment is a product of the prior art, mainly comprising a micro-resistance slow-closing check valve, such as the H42X series, and necessary components matched with the micro-resistance slow-closing check valve, and can deliver heated purified seawater to the outside and prevent backflow. The working principle of the micro-resistance slow-closing check valve is the same as that of the prior art one-way check valve.

[0024] The first isolation valve 105 and the second isolation valve 106 in the embodiment are respectively used to control the cutting and connecting of the pipelines in which the valves are respectively arranged.

[0025] The system is matched with an electric control system for controlling the opening and closing of the seawater filtering device 101, the one-way check device 102, the first isolation valve 105, the second isolation valve 106 and the heat exchanger 107. The electric control program matched with the electric control system is a program of the prior art.

[0026] The heat source structure 108 in the embodiment is a floating power platform containment system, which has a containment pool with a volume of 150.0m 3 The containment pool is connected to the space of a large special pressure container of the floating power platform through a communication pipe. After a break accident, high-temperature water vapor and non-condensable gas are injected into the containment pool, and the coolant in the containment pool is heated due to the direct contact heat exchange phenomenon.

[0027] The large special pressure container in the above process is a large volume pressure container of the prior art, which is a product of the prior art, and its working principle is consistent with that of the prior art large special pressure container.

[0028] In the specific use of the system, the seawater cooling tank 100 is arranged in seawater, seawater flows into the seawater cooling tank 100 through the seawater filtering device 101, the heat source structure 108 is a structure tank capable of generating heat, the heat exchanger 107 is arranged in the heat source structure 108, the coolant in the heat exchange pipe in the heat exchanger 107 is heated to form a density difference to cause natural circulation, and flows to the seawater cooling tank 100 through the connecting heat pipe 103, and then is stirred and mixed with the filtered seawater in the seawater cooling tank 100 to achieve cooling.

[0029] At the same time, in the specific use of the system, the initial temperature of seawater in the seawater cooling tank 100, the natural circulation loop and the external environment is 23℃, and the seawater temperature in the external environment is always kept in this range. The fluid in the heat source simulation body can be air, water, water vapor and mixed working medium, and the heat source temperature is between 15℃ and 300℃.

[0030] The system cools the heat source by natural circulation using seawater, and has compact structure and reasonable design, which can provide safe operation guarantee measures for the floating power platform.

[0031] The seawater cooling tank 100 in the embodiment has a cavity formed inside, the volume of which is greater than 10.0 m3, the cavity is filled with seawater, there can be an atmospheric space at the upper part of the cavity, and the initial temperature of the seawater is between -1.7℃ and 30℃.

[0032] The working principle of the system is as follows: The system mainly realizes natural circulation flow caused by the density difference of cold and hot sources, and the working mode is as shown in the figure. Figure 1 The system has the advantages of passive operation without external driving intervention and long-term cooling of the ocean as the final heat sink, and the working mode depends on the structure: the seawater cooling tank 100 and the heat source structure 108 are used as cold and hot sources, respectively, and the height difference and temperature difference of the loop are direct influencing factors of the size of the natural circulation driving force; the heat exchanger 107 is a key equipment for heat exchange between the heat source simulation body and the natural circulation loop, which can ensure that the natural circulation working medium is isolated outside the large special pressure container while heat exchange is carried out, avoiding leakage of harmful substances; the corresponding flow channel, i.e., the cold and hot pipe sections, is needed to form the natural circulation flow loop; the isolation valve provides a way to start and stop the system from the outside, and can avoid large leakage of harmful substances when the heat transfer pipe is damaged; the natural circulation loop in the seawater cooling tank 100 is in an open form, and heat is exchanged in the form of thermal mixing, so that the seawater in the seawater cooling tank 100 can be heated and the density is reduced, forming a density difference with the seawater outside the tank, thereby driving the cooling seawater into the seawater cooling tank 100; the seawater filtering device 101 and the one-way check device 102 in the seawater cooling tank 100 not only provide a natural flow channel, but also play a role in filtering seawater to avoid impurities damaging the system structure and controlling the flow direction.

[0033] Specific implementation method two: the seawater cooling tank 100 is a rectangular box, the heat source structure 108 is a rectangular box, the seawater cooling tank 100 is arranged obliquely above the heat source structure 108, and the distance between the rear side outer wall of the seawater cooling tank 100 and the front side outer wall of the heat source structure 108 is less than one third of the length of the seawater cooling tank 100. The above positional relationship and size relationship can improve the compactness of the system.

[0034] Specific implementation method three: the connecting hot pipe 103 and the connecting cold pipe 104 are both L-shaped pipe bodies when they are both hard pipe bodies. When the connecting hot pipe 103 and the connecting cold pipe 104 are both soft pipe bodies, the arrangement of the connecting hot pipe 103 and the connecting cold pipe 104 is more reasonable in the area L-shaped arrangement.

[0035] Specific embodiment four: the inner diameter of the connecting hot pipe 103 and the connecting cold pipe 104 is equal, and the diameter of the connecting hot pipe 103 is 200-300 mm.

[0036] Specific embodiment five: the volume ratio of the seawater cooling tank 100 to the heat source structure 108 is 1:10.

[0037] Specific embodiment six: the inner cavity of the seawater cooling tank 100 is a first chamber, and the inner cavity of the heat source structure 108 is a second chamber. The centroid horizontal height of the first chamber is higher than that of the heat source structure 108, and the height difference between the centroid horizontal height of the first chamber and the centroid horizontal height of the heat source structure 108 is 2-10 m.

[0038] Specific embodiment seven: the heat exchanger 107 is a C-type heat exchanger. The heat exchanger 107 is a conventional heat exchanger, and its working principle is consistent with that of the conventional heat exchanger. The heat exchanger 107 is arranged in the heat source structure 108 and exchanges heat with the heat source working medium through the heat exchange wall surface. The wall surface temperature difference is not less than 5℃. When in use, the heat is transferred to the purified seawater coolant in the heat exchange pipe of the heat exchanger 107.

[0039] The optimal configuration parameters of the heat exchanger 107 in this embodiment are that the inner diameter of the heat exchange pipe is 15.7 mm, the outer diameter is 19.1 mm, the pipe wall thickness is 1.7 mm, and a single group of heat exchanger has 700 heat exchange pipes.

[0040] Specific embodiment eight: the upstream inlet end of the connecting cold pipe 104 is connected to the seawater cooling tank 100, and the downstream outlet end of the connecting hot pipe 103 is connected to the heat source structure 108. The vertical distance between the upstream inlet end and the downstream outlet end is 0.8-1.2 m.

[0041] Specific embodiment nine: in combination with Figures 1 to 3 the method for dealing with the passive heat removal method for the broken pipe accident is to complete the heat dissipation and pressure relief process of the multi-cycle waterway for dealing with the broken pipe accident through the passive heat removal system for dealing with the broken pipe accident. The specific process is as follows: When the energy source is in normal operation, the first isolation valve 105 and the second isolation valve 106 are in the closed state, the heat source structure 108 is in the non-operation state, the seawater cooling tank 100 is in the operation state, the seawater filtering device 101 and the one-way check device 102 are in the open working state, the seawater circulation loop is formed between the seawater cooling tank 100, the seawater filtering device 101 and the one-way check device 102, the seawater circulation loop is in the open circuit state for a long time, the seawater in the seawater filtering device 101 enters the seawater cooling tank 100, the seawater in the seawater cooling tank 100 is discharged to the natural water area from the one-way check device 102, and the seawater circulation loop does not have a circulating driving force. When the energy source is in normal operation, the seawater circulation loop has a flow size of zero. When the offshore floating power generation platform has a break accident, the pressure vessel inside high-pressure cooling water is rapidly sprayed into the space of the large special pressure vessel, and the flash evaporation phenomenon causes the pressure of the large special pressure vessel to rapidly rise, and the working medium in the heat source structure 108 is heated and pressurized. When the pressure in the heat source structure 108 reaches 0.42 MPa, a natural circulation loop is formed between the seawater cooling tank 100, the connecting cold pipe 104, the connecting hot pipe 103, the heat exchanger 107 and the heat source structure 108, and the first isolation valve 105 and the second isolation valve 106 are opened. The seawater in the natural circulation loop is heated by the working medium in the heat source structure 108 through the heat exchanger 107, and the wall surface temperature difference of the heat exchanger 107 is not less than 5℃. After heating, the circulating seawater is cooled by stirring and heat exchange in the seawater cooling tank 100, so that the water temperature in the seawater cooling tank 100 is increased, and the natural circulation loop is formed. The seawater filtering device 101 inputs the filtered seawater into the seawater cooling tank 100, and at the same time, the seawater circulation loop is superimposed and matched. The seawater from the seawater filtering device 101 enters the seawater cooling tank 100, and the one-way check device 102 which is always in the open state discharges the seawater in the seawater cooling tank 100 to the natural water area. When the passive heat extraction system continues to work for 72 hours and the pressure value in the heat source structure 108 is continuously lower than 0.4 MPa, it indicates that the break accident is effectively handled in an emergency, and the crisis is resolved. At this time, the first isolation valve 105 and the second isolation valve 106 are closed, and the natural circulation loop stops operating.

[0042] During the implementation of the method, the heat source structure 108 has a chamber with a volume greater than 100.0 m3, and a high-temperature working medium exists in the chamber. The working medium can be in a liquid state or a gaseous state, and the temperature of the heat source working medium is between 15℃ and 300℃. Heat exchange is realized by the contact between the working medium and the wall surface of the heat exchanger 107.

[0043] During the implementation of the method, the seawater cooling tank 100 is arranged in seawater, seawater flows into the seawater cooling tank 100 through the seawater filtering device 101, the heat source structure 108 is a structural box capable of generating heat, a heat exchanger 107 is arranged inside the heat source structure 108, the heat exchanger 107 heats the coolant in the heat transfer device through heat transfer, the coolant in the heat exchange pipe of the heat exchanger 107 is heated to form a density difference to cause natural circulation, and flows to the seawater cooling tank 100 through the connecting heat pipe 103, and then is stirred and mixed with filtered seawater in the seawater cooling tank 100 to achieve cooling.

[0044] During the implementation of the method, the initial temperature of seawater in the seawater cooling tank 100, the natural circulation loop and the external environment is 23°C, and the seawater temperature in the external environment is always kept in this range. The fluid in the heat source simulation body can be air, water, water vapor and mixed working medium, and the heat source temperature is between 15°C and 300°C.

[0045] Specific implementation ten: in combination Figures 1 to 4 As shown, the passive heat extraction system in the embodiment includes a seawater cooling tank 100, a seawater filtering device 101, a one-way check device 102, a connecting heat pipe 103, a connecting cold pipe 104, a first isolation valve 105, a second isolation valve 106, a heat exchanger 107 and a heat source structure 108. The seawater cooling tank 100 is arranged above the heat source structure 108, the one-way check device 102 is arranged at the top of the seawater cooling tank 100, seawater is injected into the seawater cooling tank 100, and working medium is injected into the heat source structure 108. The seawater filtering device 101 is arranged in the seawater cooling tank 100 and is arranged at the bottom of the seawater cooling tank 100. The heat source structure 108 is a structure with an inner cavity. The heat exchanger 107 is vertically arranged in the heat source structure 108. The connecting heat pipe 103 and the connecting cold pipe 104 are sequentially arranged from top to bottom between the seawater cooling tank 100 and the heat source structure 108. One end of the connecting heat pipe 103 is connected with the seawater cooling tank 100, the other end of the connecting heat pipe 103 passes through the heat source structure 108 and is connected with the top of the heat exchanger 107, the first isolation valve 105 is arranged on the connecting heat pipe 103, one end of the connecting cold pipe 104 is connected with the seawater cooling tank 100, the other end of the connecting cold pipe 104 passes through the heat source structure 108 and is connected with the bottom of the heat exchanger 107, the second isolation valve 106 is arranged on the connecting cold pipe 104, and a lifting device 109 is arranged below the seawater cooling tank 100. The seawater cooling tank 100 is driven by the lifting device 109 to make reciprocating vertical lifting movement. The lifting device 109 is a lifting platform used underwater, which drives the seawater cooling tank 100 to make synchronous movement through lifting movement.

[0046] Further, in order to improve the compactness of the overall structure, the lifting device 109 is machined with an inlet and outlet in communication with the seawater filtering device 101, so as to facilitate the seawater to enter the seawater filtering device 101 and then enter the seawater cooling box 100.

[0047] Further, the lifting device 109 is arranged at the bottom of the cooling box 100, and the lifting device 109 is machined with a through hole matched with the connecting heat pipe 103 and the connecting cold pipe 104, for respectively installing the connecting heat pipe 103 and the connecting cold pipe 104. The connecting heat pipe 103 and the connecting cold pipe 104 are connected to the cooling box 100 in a sealing manner and a communication manner, which is consistent with the existing pipe body.

[0048] Further, the seawater cooling box 100 is installed with a sensor, and the heat source structure 108 is matched with another sensor, which can be selected as a transmitting sensor and a receiving sensor, and the position is arranged in the existing arrangement manner, which is beneficial to the sensing signal to detect the distance between the heat source structure 108 and the seawater cooling box 100.

[0049] Specific implementation method eleven: Figures 1 to 4 As shown in the figure, the non-active heat removal method for coping with the break accident in this embodiment is to complete the heat dissipation and pressure relief process of the multi-cycle waterway for coping with the break accident through the non-active heat removal system for coping with the break accident. The specific process is: When the energy source is in normal operation condition, the first isolation valve 105 and the second isolation valve 106 are in closed state, the heat source structure 108 is in non-operation state, the seawater cooling box 100 is in operation state, the initial temperature of seawater is detected to be between-1.7℃ and 30℃, the seawater filtering device 101 and the one-way check device 102 are in open working state, the seawater cooling box 100, the seawater filtering device 101 and the one-way check device 102 form a seawater circulation loop N, the seawater circulation loop N is in open circuit state for a long time, seawater enters the seawater cooling box 100 from the seawater filtering device 101, seawater in the seawater cooling box 100 is discharged to the natural water area from the one-way check device 102, the seawater circulation loop N does not have a circulating driving force, and the flow of the seawater circulation loop N is zero when the energy source is in normal operation; When a break accident occurs in a floating power generation platform at sea, the pressure of the large special pressure vessel rapidly rises due to the rapid injection of high-pressure cooling water in the pressure vessel into the space of the large special pressure vessel and the flash evaporation phenomenon, the working medium in the heat source structure 108 is heated and pressurized, and the pressure rise rate of the heat source simulation body within 100.0 s after the accident is detected by the pressure anomaly detection system to determine the break accident level. The height difference between the seawater cooling tank 100 and the heat source structure 108 is adjusted correspondingly. When the pressure rise rate is less than 500.0 Pa / s, it is judged as a small break accident, and the height difference is adjusted to 2 m. When the pressure rise rate is greater than 500.0 Pa / s and less than 1000.0 Pa / s, it is judged as a medium break accident, and the height difference is adjusted to 5 m. When the pressure rise rate is greater than 1000.0 Pa / s, it is judged as a large break accident, and the height difference is adjusted to 10 m. The seawater cooling tank 100 is lifted and lowered to the predetermined position by the lifting device 109, and the height difference between the seawater cooling tank 100 and the heat source structure 108 is detected and ensured to meet the predetermined height difference value. When the pressure in the heat source structure 108 reaches 0.42 MPa, a natural circulation loop M corresponding to the break accident level is formed between the seawater cooling tank 100, the connecting cold pipe 104, the connecting hot pipe 103, the heat exchanger 107 and the heat source structure 108. At the same time, the first isolation valve 105 and the second isolation valve 106 are opened. The seawater in the natural circulation loop M is heated by the working medium in the heat source structure 108 through the heat exchanger 107. After heating, the circulating seawater is cooled by stirring and heat exchange in the seawater cooling tank 100, so that the water temperature in the seawater cooling tank 100 rises, and the corresponding natural circulation loop M is formed. The seawater filtering device 101 inputs the filtered seawater into the seawater cooling tank 100, and at the same time, the seawater circulation loop N is superimposed and cooperated. The seawater enters the seawater cooling tank 100 from the seawater filtering device 101. The one-way check valve 102 in the always open state discharges the seawater in the seawater cooling tank 100 to the natural water area. When the passive heat removal system continues to work for 72 hours and the pressure value in the heat source structure 108 is continuously lower than 0.4 MPa, it indicates that the break accident has been effectively handled in an emergency, and the crisis is resolved. At this time, the first isolation valve 105 and the second isolation valve 106 are closed, and the natural circulation loop M stops running.

Claims

1. A marine heat sink based passive heat removal system for coping with a LOCA, characterized in that: The application relates to a seawater cooling box (100), a seawater filtering device (101), a one-way check device (102), a connecting hot pipe (103), a connecting cold pipe (104), a first isolation valve (105), a second isolation valve (106), a heat exchanger (107) and a heat source structure (108), wherein the seawater cooling box (100) is arranged above the heat source structure (108), the one-way check device (102) is arranged on the top of the seawater cooling box (100), seawater is injected into the seawater cooling box (100), a working medium is injected into the heat source structure (108), the seawater filtering device (101) is arranged in the seawater cooling box (100), the seawater filtering device (101) is arranged at the bottom of the seawater cooling box (100), the heat source structure (108) is a structure with an inner cavity, the heat exchanger (107) is vertically arranged in the heat source structure (108), the connecting hot pipe (103) and the connecting cold pipe (104) are sequentially arranged between the seawater cooling box (100) and the heat source structure (108) from top to bottom, one end of the connecting hot pipe (103) is connected with the seawater cooling box (100), the other end of the connecting hot pipe (103) penetrates through the heat source structure (108) and is connected with the top of the heat exchanger (107), the first isolation valve (105) is arranged on the connecting hot pipe (103), one end of the connecting cold pipe (104) is connected with the seawater cooling box (100), the other end of the connecting cold pipe (104) penetrates through the heat source structure (108) and is connected with the bottom of the heat exchanger (107), and the second isolation valve (106) is arranged on the connecting cold pipe (104).

2. A passive heat removal system based on the oceanic heat sink to cope with a LOCA according to claim 1, characterized in that: The seawater cooling box (100) is a rectangular box, the heat source structure (108) is a rectangular box, the seawater cooling box (100) is arranged obliquely above the heat source structure (108), and the distance between the rear outer wall of the seawater cooling box (100) and the front outer wall of the heat source structure (108) is less than one third of the length of the seawater cooling box (100).

3. A passive heat removal system based on the oceanic heat sink to cope with a LOCA according to claim 1, characterized in that: The connecting hot pipe (103) and the connecting cold pipe (104) are both L-shaped pipe bodies.

4. A non-energized heat extraction system based on the oceanic heat sink to cope with a break- loss accident according to claim 1 or 3, characterized in that: The inner diameters of the connecting hot pipe (103) and the connecting cold pipe (104) are equal, and the diameter of the connecting hot pipe (103) ranges from 200 mm to 300 mm.

5. A passive heat removal system based on oceanic heat sink to cope with a break- loss-of-coolant accident according to claim 2, characterized in that: The ratio of the minimum volume of the seawater cooling box (100) to the minimum volume of the heat source structure (108) is 1:

10.

6. A passive heat removal system based on the oceanic heat sink to cope with a LOCA according to claim 5, characterized in that: The inner cavity of the seawater cooling box (100) is a first chamber, the inner cavity of the heat source structure (108) is a second chamber, the centroid horizontal height of the first chamber is higher than the centroid horizontal height of the heat source structure (108), and the height difference between the centroid horizontal height of the first chamber and the centroid horizontal height of the heat source structure (108) ranges from 2 m to 10 m.

7. A passive heat removal system based on the oceanic heat sink to cope with a LOCA according to claim 1, characterized in that: The heat exchanger (107) is a C-shaped heat exchanger.

8. A passive heat removal system based on oceanic heat sink to cope with a LOCA according to claim 4, characterized in that: The end of the connecting cold pipe (104) connected with the seawater cooling box (100) is an upstream inlet end, the end of the connecting hot pipe (103) connected with the heat source structure (108) is a downstream outlet end, and the vertical distance between the upstream inlet end and the downstream outlet end ranges from 0.8 m to 1.2 m.

9. A marine heat sink based passive heat removal system for coping with a loss of coolant accident according to any one of claims 1 to 8, characterized in that: The seawater cooling box (100) is matched with a lifting device (109) below, and the seawater cooling box (100) is driven by the lifting device (109) to make vertical reciprocating lifting movement.

10. A non-active heat removal method for coping with a break accident based on a marine heat sink, which is implemented by using the non-active heat removal system for coping with a break accident based on a marine heat sink according to any one of claims 1 to 9, characterized in that: The non-active heat removal method for coping with a break accident is used to complete the heat dissipation and pressure relief process of the multi-cycle waterway for coping with a break accident by the non-active heat removal system for coping with a break accident, and the specific process is: When the energy source is in a normal operation condition, the first isolation valve (105) and the second isolation valve (106) are in a closed state, the heat source structure (108) is in a non-operation state, the seawater cooling box (100) is in an operation state, the seawater filtering device (101) and the one-way check device (102) are in an open working state, a seawater circulation loop is formed between the seawater cooling box (100), the seawater filtering device (101) and the one-way check device (102), the seawater circulation loop is in an open circuit state for a long time, seawater enters the seawater cooling box (100) from the seawater filtering device (101), seawater in the seawater cooling box (100) is discharged to a natural water area from the one-way check device (102), the seawater circulation loop does not have a circulation driving force, and the seawater circulation loop flow size is zero when the energy source is in a normal operation condition. When a break accident occurs in a floating power generation platform at sea, the pressure in a large special pressure vessel rapidly rises due to the rapid injection of high-pressure cooling water in the pressure vessel into the space of the large special pressure vessel and the flash evaporation phenomenon, and the working medium in a heat source structure (108) is heated and pressurized, when the pressure in the heat source structure (108) reaches 0.42 MPa, a natural circulation loop is formed between a seawater cooling tank (100), a connecting cold pipe (104), a connecting hot pipe (103), a heat exchanger (107) and the heat source structure (108), and the first isolation valve (105) and the second isolation valve (106) are opened, the seawater in the natural circulation loop is heated by the working medium in the heat source structure (108) through the heat exchanger (107), and after being heated, the circulating seawater is cooled by stirring and heat exchange in the seawater cooling tank (100), so that the water temperature in the seawater cooling tank (100) is increased, the natural circulation loop is formed, the seawater filtering device (101) inputs the filtered seawater into the seawater cooling tank (100), and at the same time, the seawater circulation loop is superimposed and matched, the seawater enters the seawater cooling tank (100) from the seawater filtering device (101), the one-way check device (102) which is always in an open state discharges the seawater in the seawater cooling tank (100) to the natural water area, when the non-active heat extraction system continuously works for 72 hours and the pressure value in the heat source structure (108) continuously is lower than 0.4 MPa, it is indicated that the break accident is effectively treated in an emergency, and the crisis is resolved, at this time, the first isolation valve (105) and the second isolation valve (106) are closed, and the natural circulation loop stops running.

Images