阅读说明：本技术 一种改进的非能动余热排出系统 (A kind of improved passive residual heat removal system ) 是由 陆道纲 马翔凤 张钰浩 唐甲璇 夏子涵 梁江涛 于 2019-07-08 设计创作，主要内容包括：本发明公开了属于池式快堆热工安全技术领域的一种改进的非能动余热排出系统,该余热排出系统是一种贯穿堆芯上下腔的池式快堆燃料组件盒内自然循环系统；本余热排出系统由四套独立的冷却环路构成,每套冷却环路均含有位于冷钠池、热钠池之间的贯穿热交换器、止回阀等关键装置与部件。充分考虑运行成本、换热效率、安全性等综合因素,通过设计采用密度差、自身重力等固有特性工作,提高系统运行的可靠性,减少因电源故障而引起的系统失效,较大程度地降低堆芯熔化概率；更有效地提高余热排出的效率,对提高核电站的固有安全性具有重要意义。(The invention discloses a kind of improved passive residual heat removal system for belonging to pool fast reactor thermal technology's security technology area, which is natural cycle system in a kind of pool fast reactor fuel assembly box through reactor core upper and lower cavity；This residual heat removal system is made of four sets of independent cooling loops, and every set cooling loop, which contains, runs through key devices and the components such as heat exchanger, check-valves between cold sodium pond, hot sodium pond.Fully consider the composite factors such as operating cost, heat exchange efficiency, safety, by design using the work of the inherent characteristics such as density contrast, self gravity, raising system reliability of operation reduces the thrashing because of caused by power failure, largely reduces core melt probability；The efficiency for more effectively improving Residual heat removal, is of great significance to the inherent safety for improving nuclear power station.)

1. a kind of improved passive residual heat removal system, which is characterized in that the residual heat removal system is a kind of on reactor core Natural cycle system in the pool fast reactor fuel assembly box of cavity of resorption；Natural cycle system is by four in the pool fast reactor fuel assembly box Independent cooling loop is covered to constitute, every set cooling loop contains there are three circuit, three circuits contain through cold sodium pond (3), Run through heat exchanger (1) between hot sodium pond (2)；Wherein primary Ioops through heat exchanger (1), check-valves (4), big screen by joining Case (5), small grid plate header (6) and reactor core (7) constitute coolant circulation circuit；Secondary circuit is by running through heat exchanger (1), sodium-sky Gas-heat exchanger (10) and surge tank (11) are connected by return is linked to be a loop；Three circuits are open circuits, Air is entered by the inlet damper of sodium-air heat exchanger (10), by heat-transfer pipe gap, export the breeze door, is finally discharged to atmosphere.

2. a kind of improved passive residual heat removal system according to claim 1, which is characterized in that the Residual heat removal system Every set circuit, which is contained, in system runs through heat exchanger (1) between cold sodium pond (3), hot sodium pond (2).

3. a kind of improved passive residual heat removal system according to claim 1, which is characterized in that the check-valves difference Connection runs through heat exchanger outlet pipeline and grid plate header.

4. a kind of improved passive residual heat removal system according to claim 1, which is characterized in that described to run through heat exchange The outlet of device does not contact directly with cold sodium pond, but is connected to check-valves by pipeline.

5. a kind of Residual heat removal method of improved passive residual heat removal system according to claim 1, which is characterized in that The course of work of the improved passive residual heat removal system: primary Ioops are divided into four loops in parallel, are operating normally feelings Under condition, the sodium in hot sodium pond (2) from top to bottom flows into stand alone type heat via the entrance of four penetration type independent heat exchangers (1) Exchanger is full of in the outer tunnel of free-standing heat exchanger；(9 run well pump, and free-standing heat exchanger outlet pipeline pressure is small Pressure in big grid plate header (5), small grid plate header (6), closure of check ring, the coolant of free-standing heat exchanger outer tunnel It cannot be flowed into fuel assembly box by big grid plate header (5), small grid plate header (6), at this point, passive residual heat removal system one The not formed complete loop of the sodium in circuit, but since there are certain non-firm power, each circuits also to deposit for passive residual heat removal system In the temperature difference, to the sodium of primary Ioops, there are still certain cooling effects；Under accident conditions, power supply is lost, pump shuts down, at this time Pressure in big grid plate header (5), small grid plate header (6) is greater than the pressure in the outlet conduit of free-standing heat exchanger, valve Door is opened under the action of pressure at both sides difference, and hot sodium is flowed through through heat exchanger, is carried out heat with the sodium of secondary circuit and is exchanged, via The outlet conduit of penetration type heat exchanger continues to sink, after check-valves, by pipeline, into big grid plate header (5), small grid It in plate header (6), is flowed in fuel assembly box, coolant runs through reactor core upper and lower cavities, reactor core heat is taken out of, into heat Sodium pond (2), repeats the above process and just forms access.

6. the Residual heat removal method of improved passive residual heat removal system according to claim 5, which is characterized in that institute It states and sodium-air heat exchanger is set in residual heat removal system, carry out air Natural Circulation.

Technical field

The invention belongs to pool fast reactor thermal technology's security technology area, in particular to a kind of improved passive residual heat removal system System, specifically, the residual heat removal system are Natural Circulation systems in a kind of pool fast reactor fuel assembly box through reactor core upper and lower cavity System.

Background technique

Fast reactor is the typical heap-type in the 4th generation of technology such as nuclear energy system, mostly uses pool structure, pool fast reactor include a large amount of sodium, The coolants such as lead or lead bismuth have very big thermal capacity.In normal conditions, fast reactor passes through medium spacing heat exchanger for reactor core Heat transfer is to two, three circuits, and then cooling reactor core.The accidents work such as water depletion is given in station blackout, main steam line rupture, master Under condition, reactor core heat can not be discharged in fast shut-down system loss of heat sink by the main heat transfers equipment such as intermediate heat exchanger, steam generator Amount.In the case where the active security system failure of accident conditions, how waste heat in heap is rationally efficiently exported to out-pile, guarantees reactor Safety is to design the key point of reactor.According to the design principle of inherent safety, pool fast reactor uses residual heat removal system Equal engineered safeguards features prevent radioactive substance from leaking to limit or reduce damage sequence.

The design of residual heat removal system is more in the world at present, mainly includes intermediate loop residual heat removal system, master The diversified forms such as circuit residual heat removal system, independent residual heat removal system and reactor pit residual heat removal system.Part generation is shown below The design scheme of table:

APl000 advanced pressurized water reactor passive residual heat removal system, the system is by a passive residual heat removal heat exchanger It being formed with relevant valve, pipeline and instrument, built-in material-changing water tank provides hot trap, and heat exchanger is located in built-in material-changing water tank, Its position is higher than reactor coolant loop；When reactor coolant pump is unavailable, coolant flows through c-type by Natural Circulation Reactor core heat is discharged by the heat convection and boiling heat transfer of subcooled water in the heat exchange of heat exchanger and material-changing water tank in heat exchanger Amount.In this approach, the water in passive residual heat removal system is directly injected into reactor core, influences the coolant of primary Ioops.It needs simultaneously The material-changing water tank and containment cooling system of large capacity are configured above reactor core, structure is complex, and economy is not high.

Passive residual heat removal system for high temperature gas cooled reactor, the system by water-cooling wall, air cooler, hot water header, cold water header, The composition such as expansion tank, air cooling tower.The heat that water wall absorption pressure vessel and cabin are transmitted by radiation and natural convection air, It is then passed to cooling water, air cooler is taken to by free convection form caused by density contrast as cooling water.Air cooler is placed on sky In cold tower, cooled down by the free convection of surrounding air.This kind of mode heat removal capacity is relatively limited, only when cooling water and reactor core Good effect could be obtained when being closer, and need to be arranged three return-air Natural Circulations, higher cost.Water-cooling wall Closed interval need to be constituted with reactor core and pressure vessel, structure is complex.

Reactor vessel air cooling system, the system is using the air Natural Circulation outside reactor vessel, accident work Residual heat of nuclear core under condition is discharged to ultimate heat sink.Outside reactor vessel, simplifies structure in heap, avoid causing remaining system It influences, system reliability is high.But heat removal capacity is relatively poor, for large reactor, needs to add other cooling systems, simultaneously Lack practical with reference to experience.

It is to increase an independent waste heat row in primary tank using the passive residual heat removal system of independent heat exchanger Heat exchanger out, design principle are the waste heats by reactor core after free convection and Natural Circulation export reactor trip.By It is mounted on the independent heat exchanger in hot pond, the air heat exchanger outside containment, connecting pipe and corresponding auxiliary system Composition, can efficiently take away residual heat of nuclear core.

In the Residual heat removal design of most of pool fast reactor, the residual heat removal system of independent heat exchanger is generallyd use. The form of Residual heat removal, path are distributed with compared with more options, such as active, passive starting form, primary Ioops, secondary circuit cloth Set form etc..The country for developing fast reactor is designed research to fast reactor residual heat removal system, proposes relevant programme.

The KALIMA600 residual heat removal system of South Korea is made of the independent loop of 2-3 item, and each loop includes that independent heat is handed over Parallel operation, air heat exchanger and intermediate sodium loop, independent heat exchanger are arranged in the buffer area of cold and hot plenums, intermediate sodium loop It is upper that there is no arrangement active component-mechanical pump or electromagnetic pumps.Under nominal situation, residual heat removal system does not start, and ensure that fortune Capable economy.Under accident conditions, high-temperature sodium can flow through sodium partition in hot pond, the sodium perforation in cold and hot plenums, independent heat exchange Device plays a role.But the program was never run on reactor, and there is also many uncertainties.And in the BN- of Russia In 800 fast reactor residual heat removal systems, independent heat exchanger is replaced to realize its function by intermediate heat exchanger.Three coolings are set Loop, each loop include a residual heat removal loop and a steam generator.But the system is not complete passive, portion Electromagnetic pump is configured on point circuit to reinforce heat removal capacity, this is the major defect of the program.

There are four completely self-contained residual heat removal systems by the prototype fast reactor PFBR of India, and heat directly is discharged from hot pond.Packet Include the equipment such as independent heat exchanger, a sodium-air heat exchanger and corresponding pipeline.Free-standing heat exchanger assignment is in heat Heat is taken out of from reactor core by Natural Circulation and passes to atmosphere by pond, system.The design of the device is the same as the existing waste heat row of CEFR The arrangement of system is similar out, and under accidental conditions, the operation of the device can take away partial heat, to the economy of reactor It has a certain impact.Fail for coolant to be sent directly into reactor core simultaneously, on-way resistance is larger, and cooling is not direct enough.

In the ASTRID reactor of France's research and development, residual heat removal system is designed by the way of multiple combinations.Setting altogether Four loops, each loop include the equipment such as a free-standing heat exchanger, electromagnetic pump and a sodium-air heat exchanger.Two In four sodium-air heat exchangers, the surface of evaporator, heap vessel cooling system, primary Ioops pond on the bypass duct of circuit The safety of the independent multiple different mode common guarantee residual heat of nuclear core discharge of heat exchange, embodies the diversity of system design.So And the construction and operating cost of reactor can be also increase accordingly using the design of multiplicity.

The investment situation of residual heat removal system has great influence, association accident trend to core temperature development.This patent It is dedicated to the research of pool type natrium cold fast reactor passive residual heat removal system, proposes a kind of improved passive residual heat removal system side Case.There are four loops for program tool, close comprising four between cold sodium pond, hot sodium pond through heat exchanger, check-valves etc. Key apparatus and component.The efficiency for more effectively improving Residual heat removal, is of great significance to the inherent safety for improving nuclear power station. Fully consider the composite factors such as operating cost, heat exchange efficiency, safety, it is intrinsic using density contrast, self gravity etc. by design Characteristic work, improves system reliability of operation, reduces the thrashing because of caused by power failure, largely reduces heap Core melts probability.

Summary of the invention

The purpose of the present invention is to propose to a kind of improved passive residual heat removal system, which is characterized in that the Residual heat removal System is natural cycle system in a kind of pool fast reactor fuel assembly box through reactor core upper and lower cavity；The pool fast reactor fuel assembly Natural cycle system is made of four sets of independent cooling loops in box, and every set cooling loop contains there are three circuit, three circuits Contain and runs through heat exchanger 1 through between cold sodium pond 3, hot sodium pond 2.Wherein primary Ioops are by running through heat exchanger 1, check-valves 4, big grid plate header 5, small grid plate header 6 and reactor core 7 constitute coolant circulation circuit；Secondary circuit is by running through heat exchanger 1, sodium- Air heat exchanger 10 and surge tank 11 are connected by return is linked to be a loop；Three circuits are open circuits, empty Gas is entered by the inlet damper of sodium-air heat exchanger 10, by heat-transfer pipe gap, export the breeze door, is finally discharged to atmosphere.

The position through heat exchanger is between cold sodium pond 3 and hot sodium pond 2.

The course of work of the improved passive residual heat removal system: primary Ioops are divided into four loops in parallel, just Under normal operating condition, the sodium in hot sodium pond runs through the entrance of heat exchanger via four, from top to bottom flows into and runs through heat exchanger, It is full of in the outer tunnel of penetration type heat exchanger；Pump 9 runs well, and joins through heat exchanger outlet pipeline pressure less than big screen Pressure in case 5, small grid plate header 6, closure of check ring, the coolant through heat exchanger outer tunnel cannot be joined by big screen Case 5, small grid plate header 6 flow into fuel assembly box, at this point, the not formed unbroken loop of the sodium of passive residual heat removal system primary Ioops Road, but since there are certain non-firm power, each circuits there is also the temperature difference for passive residual heat removal system, still to the sodium of primary Ioops There are certain cooling effects；Under accident conditions, power supply is lost, pump shuts down, at this time big grid plate header 5, small screen connection Pressure in case 6 is greater than the pressure in the outlet conduit of free-standing heat exchanger 1, and valve is beaten under the action of pressure at both sides difference Open, hot sodium is flowed through through heat exchanger, carry out heat with the sodium of secondary circuit and exchange, via the outlet conduit through heat exchanger after Continuous sinking, after check-valves, is carried out in fuel assembly box by pipeline into big grid plate header 5, small grid plate header 6 Flowing, coolant run through reactor core upper and lower cavities, take reactor core heat out of, into hot sodium pond 2, repeat the above process and just form access.

It is provided with four in the residual heat removal system and runs through heat exchanger,

The check-valves is separately connected through heat exchanger outlet pipeline and grid plate header.

The outlet through heat exchanger does not contact directly with cold sodium pond 3, but is connected to check-valves 4 by pipeline.

It is described that sodium-air heat exchanger is set in residual heat removal system, carry out the cooling Natural Circulation of air.

The beneficial effects of the invention are as follows passive function can be achieved, exchange capability of heat is improved, increases heat exchange efficiency, takes into account fortune Row cost, the design for fast reactor residual heat removal system provide support and foundation；It improves pool and piles up the non-energy under accident conditions fastly Dynamic safety, residual heat removal system of the present invention as pool fast reactor realize residual heat removal system by setting check-valves etc. Automatic shutter, using communication type independent heat exchanger realize reactor core passive residual heat removal, improve heat transfer effect, alleviate accident into Journey realizes reactor safety shutdown.

Compared with prior art, the invention has the characteristics that

1. running through reactor core upper and lower cavities, runs through reactor core upper and lower cavity using stream between box, realize cooling reactor core target, take away reactor core Heat, heat exchange efficiency are high；

2. Natural Circulation distance is shorter, smaller along journey flow resistance, mobility is stronger；

3. primary Ioops difference in height is larger, the Natural Circulation power generated by gravity is larger；

4. further increasing Residual heat removal efficiency, good cooling results；

5. in normal conditions, the system is relatively independent, the operation of other systems, high reliablity will not influence；

6. rationally setting valve opens and closes, the safety that triggering equipment manually effectively improves pool fast reactor is not needed to provide；

7. reducing the probability of system failure, prevent radioactivity from leaking.

8. system is in close state under nominal situation, the thermal efficiency of reactor is improved, economy is high.

Detailed description of the invention

Fig. 1 is System planes schematic diagram.

Fig. 2 is non-return valve closing state schematic diagram.

Fig. 3 is check-valves open state schematic diagram.

Specific embodiment

The present invention proposes that a kind of improved passive residual heat removal system, the residual heat removal system are a kind of on reactor core Natural cycle system in the pool fast reactor fuel assembly box of cavity of resorption；Natural cycle system in the pool fast reactor fuel assembly box, should Residual heat removal system is made of four sets of independent cooling loops.The present invention is further described with reference to the accompanying drawing.

Fig. 1 is System planes schematic diagram.It is natural in the provided pool fast reactor fuel assembly box through reactor core upper and lower cavity The circulatory system is constituted by natural cycle system in the pool fast reactor fuel assembly box by four sets of independent cooling loops, and every set is cooling Loop contains there are three circuit, containing running through heat exchanger 1 through between cold sodium pond 3, hot sodium pond 2.Wherein primary Ioops by Coolant circulation circuit is constituted through heat exchanger 1, check-valves 4, big grid plate header 5, small grid plate header 6 and reactor core 7；Secondary circuit By being linked to be a loop by return series connection through heat exchanger 1, sodium-air heat exchanger 10 and surge tank 11； Three circuits are open circuits, and air is entered by the inlet damper of sodium-air heat exchanger 10, by heat-transfer pipe gap, go out one's intention as revealed in what one says Door, is finally discharged to atmosphere.

Above-mentioned circuit relies on natural circulation, and residual heat of nuclear core is discharged in atmospheric environment.As shown in Figure 1, penetration type is only The sodium-air heat exchanger 10 of out-of-pile, sodium-air heat exchanger is arranged in vertical heat exchanger 1 by pipeline connection respectively 10 outside is equipped with chimney.

Under accidental conditions, the entry design through heat exchanger 1 in hot sodium pond 2 is open in usual, hot sodium pond There is the sodium of part to enter through heat exchanger 1, since reactor core pressure is greater than the pressure of penetration type heat exchanger 1, check-valves 4 is closed (as shown in Figure 2).Due to the action of thermal difference inside and outside non-firm power and heap, still there are some flows in intermediate loop, ensure that sodium pond Interior major heat is used for the power generation of reactor, embodies the economy of normal operation.

Under accident conditions, since pressure difference changes, check-valves 4 is automatically turned on, which will realize 7 heat of reactor core to heat The transmitting in sodium pond 2, hot sodium pond 2 is by carrying out hot transmitting through air heat exchanger 8 of the heat exchanger 1 to outside reactor, most It distributes heat in atmosphere eventually.Carry out sodium-sodium heat exchange respectively in heat exchanger 1, the sodium being heated in heat exchanger tube passes through Pipeline enters sodium-air heat exchanger 10, and sodium-air heat exchange is carried out in sodium-air heat exchanger 10.This residual heat removal system The setting of device will automatically switch to carry out under accident conditions, by flowing discharge residual heat of nuclear core in the box of reactor fuel component, Accident process is effectively relieved, guarantees the safety of reactor.

The flow path of the primary Ioops sodium of this residual heat removal system are as follows: enter the sodium for running through heat exchanger 1, arrive after cooling Enter in the fuel assembly box of reactor core 7 up to cold sodium pond 3, and by check-valves 4, big grid plate header 5, small grid plate header 6.Through in box After cooling, hot sodium pond 2 finally is entered through fuel assembly head outlet；Sodium of accident afterheat discharge system in this way constitutes The circulation route for parallel branch that there are four open types, tool.

This residual heat removal system secondary circuit is a loop, it is by running through heat exchanger 1, sodium-air heat exchanger 10, surge tank 11 and connect they return composition.From the secondary sodium (hot sodium) exported through heat exchanger 1 through hot pipe section To sodium-air heat exchanger 10 carry out heat exchange, into cold tube section return to through heat exchanger 1 constitute one closed time Road.

Three circuit of this residual heat removal system is open circuit, and air is entered by the inlet damper of sodium-air heat exchanger 10, By heat-transfer pipe gap, export the breeze door, it is finally discharged to atmosphere.

The core of the system is the designing points such as penetration type heat exchanger, the check-valves being mounted in reator body.Occurring When accident, coolant temperature is increased with the sharply decline of flow, and forced circulation is converted to Natural Circulation, and check-valves is opened (as shown in Figure 3), hot sodium carry out heat exchange in passive heat exchanger.Flow through between cold and hot plenums through sodium in heat exchanger It is directly fed at reactor core, forms access in the box of fuel assembly, form flowing in box.It is effectively discharged out residual heat of nuclear core, is protected Protect reactor safety.Four relatively independent loops have preferable working performance, when one of loop failure, non-energy Dynamic residual heat removal system can continue to discharge residual heat of nuclear core.