阅读说明：本技术 采用多级换热功率屏蔽换热器的空间核电系统及循环方法 (Space nuclear power system adopting multistage heat exchange power shielding heat exchanger and circulation method ) 是由 鹿鹏 杨沁山 闫晓蝶 魏剑 叶启航 黄护林 于 2021-09-29 设计创作，主要内容包括：本发明公开一种采用多级换热功率屏蔽换热器的空间核电系统及循环方法,在该发明的核反应堆发电系统中采用了多级换热功率屏蔽换热器。该换热器由两部分组成,第一部分为低功率管壳换热,第二部分为高功率板式换热。高温液态金属锂从核反应堆流出进入换热器,在低功率管壳换热阶段,通过屏蔽金属换热管与低温氦气进行换热。若不进行第二阶段的高功率板式换热,氦气则直接进入涡轮机做功。反之,则通过控制系统,使氦气进入第二阶段的高功率板式换热,通过屏蔽金属换热板片与高温液态锂进行第二阶段换热,满足了不同工况,如出舱作业、空间站休眠的使用需要,实现了换热器低功率和高功率的调节,从而提高了能源利用率和空间站适居性。(The invention discloses a space nuclear power system adopting a multistage heat exchange power shielding heat exchanger and a circulation method. The heat exchanger consists of two parts, wherein the first part is low-power tube shell heat exchange, and the second part is high-power plate heat exchange. High-temperature liquid metal lithium flows out of the nuclear reactor and enters the heat exchanger, and in the low-power shell-and-tube heat exchange stage, heat exchange is carried out between the high-temperature liquid metal lithium and the low-temperature helium through the shielding metal heat exchange tube. If the high-power plate type heat exchange of the second stage is not carried out, the helium directly enters the turbine to do work. Otherwise, helium enters the high-power plate type heat exchange of the second stage through the control system, and the heat exchange of the second stage is carried out through the shielding metal heat exchange plate and the high-temperature liquid lithium, so that the requirements of different working conditions such as cabin outlet operation and space station dormancy are met, the low-power and high-power adjustment of the heat exchanger is realized, and the energy utilization rate and the space station suitability are improved.)

1. A space nuclear power system adopting a multistage heat exchange power shielding heat exchanger comprises a first loop and a second loop, liquid metal lithium circularly operates through the first loop, helium circularly operates through the second loop, the space nuclear power system is characterized by further comprising a multistage heat exchange power shielding heat exchanger (4), a hot fluid channel of the multistage heat exchange power shielding heat exchanger belongs to the first loop, a cold fluid channel of the multistage heat exchange power shielding heat exchanger belongs to the second loop, and heat exchange is carried out between the liquid metal in the first loop and the helium in the second loop in the multistage heat exchange power shielding heat exchanger (4).

2. The space nuclear power system adopting the multistage heat exchange power shielding heat exchanger as claimed in claim 1, wherein the multistage heat exchange power shielding heat exchanger (4) comprises front and rear two-stage heat exchange, a hot fluid channel of the multistage heat exchange power shielding heat exchanger penetrates through two-stage heat exchange, two-stage heat exchange is respectively provided with a cold fluid channel, a cold fluid channel outlet (f) of the front-stage heat exchange, a cold fluid channel inlet (e) of the rear-stage heat exchange and inlets of the two loops are connected through a three-way plug valve (13), a first isolation valve (12) is arranged between the three-way plug valve (13) and the inlets of the two loops, and a second isolation valve (11) is arranged between a cold fluid channel outlet (c) of the rear-stage heat exchange and the inlets of the two loops.

3. The space nuclear power system adopting the multistage heat exchange power shielding heat exchanger as recited in claim 2, wherein the previous stage heat exchange is shell-and-tube heat exchange and comprises a plurality of shielding metal heat exchange tubes (19), and the shielding metal heat exchange tubes (19) are made of tungsten-rhenium alloy with shielding performance.

4. A space nuclear power system adopting a multistage heat exchange power shielding heat exchanger as recited in claim 3, characterized in that a plurality of baffle plates (18) are arranged along the outer side of the shielding metal heat exchange tube (19).

5. The space nuclear power system adopting the multistage heat exchange power shielding heat exchanger as recited in claim 3, wherein the latter stage of heat exchange is plate type heat exchange, and comprises a plurality of shielding metal heat exchange plate sheets (20), and the shielding metal heat exchange plate sheets (20) are made of tungsten-rhenium alloy with shielding performance; the shielding metal heat exchange plate (20) comprises a liquid metal lithium channel (26) and a helium channel (27), the liquid metal lithium channel (26) is communicated with the shielding metal heat exchange tube (19), and the helium channel (27) is a cold fluid channel for the heat exchange of the next stage.

6. The space nuclear power system adopting the multistage heat exchange power shielding heat exchanger is characterized in that the primary circuit comprises a nuclear reactor (1), a pressure buffer device (2), a gas-liquid separator (3), the multistage heat exchange power shielding heat exchanger (4) and an electromagnetic pump (14); the liquid metal flows through an outlet of the nuclear reactor (1), the pressure buffer device (2), the gas-liquid separator (3), a hot fluid channel of the multi-stage heat exchange power shielding heat exchanger (4), the electromagnetic pump (14) and an inlet of the nuclear reactor (1) in sequence.

7. The space nuclear power system adopting the multistage heat exchange power shielding heat exchanger is characterized in that the two loops comprise the multistage heat exchange power shielding heat exchanger (4), a heat regenerator (5), a cooler (6), a radiation radiator (7), a compressor (8), a generator (9), a turbine (10), a first isolation valve (12), a second isolation valve (11) and a three-way plug valve (13); helium sequentially passes through a cold fluid channel outlet (f) or a cold fluid channel outlet (c) of the multi-stage heat exchange power shielding heat exchanger (4), a first isolation valve (12) or a second isolation valve (11), a turbine (10), a hot fluid channel of the heat regenerator (5), a cooler (6), a compressor (8), a cold medium channel of the heat regenerator (5) and an inlet (b) of the cold fluid channel of the multi-stage heat exchange power shielding heat exchanger (4).

8. A circulation method of a nuclear power system in space based on claim 3, characterized by comprising the following steps:

the heat exchange of the previous stage: liquid metal lithium enters from a liquid metal lithium inlet (a) of the multi-stage heat exchange power shielding heat exchanger (4) to exchange heat with helium, then flows out from a hot fluid outlet (d) of the multi-stage heat exchange power shielding heat exchanger (4), and helium enters from a helium inlet (b) of the multi-stage heat exchange power shielding heat exchanger (4) to exchange heat with liquid lithium in the shielding metal heat exchange tube (19); helium flows out from a cold fluid channel outlet (f) of the multistage heat exchange power shielding heat exchanger, a three-way plug valve (13) is adjusted to prevent the helium from flowing back to the multistage heat exchange power shielding heat exchanger (4), a first isolation valve (12) is opened, and a second isolation valve (11) is closed.

The next stage of heat exchange: if the heat exchange is carried out in the second stage, the liquid flows out from a cold fluid channel outlet (f) of the multi-stage heat exchange power shielding heat exchanger (4), at the moment, the first isolating valve (12) is closed, the second isolating valve (11) is opened, the liquid flows into a cold fluid channel inlet (e) of the multi-stage heat exchange power shielding heat exchanger (4) through the three-way plug valve (13), heat exchange is carried out on the liquid lithium and the liquid lithium through the shielding metal heat exchange plate sheets, and then the liquid flows out from a cold fluid channel outlet (c) of the multi-stage heat exchange power shielding heat exchanger (4).

Technical Field

The invention relates to a space nuclear power system adopting a multistage heat exchange power shielding heat exchanger and a circulating method, and belongs to the field of comprehensive utilization of energy.

Background

Large-scale spacecrafts for important space missions such as deep space exploration and high-resolution earth observation have become an important development trend. Compared with a solar power supply and a chemical power supply, the space nuclear power supply has obvious technical advantages in a deep space exploration task with difficult solar energy application and a near-earth orbit aerospace task requiring a high-power supply. The nuclear power generation utilizes the heat energy released by nuclear fission to generate power, the energy density of the nuclear fuel is one order of magnitude greater than that of other fossil fuels, and carbon dioxide cannot be generated in the nuclear power generation process, so that the volume occupied by fuel storage is small, the transportation is convenient, and the strategic requirements of national space development are met.

Compared with a common power system, the space nuclear power system based on nuclear power generation has the advantages of light weight, small size, high output power and the like, and plays a significant role in space exploration tasks. The space nuclear power supply converts nuclear energy into electric energy to supply power for the high-power electric propulsion system. The combination of the high energy density of nuclear power and the high specific impulse advantage of electric propulsion is considered as a preferred scheme for future large space tasks. The development of the space nuclear power system represents the military capability and high and new technology level of a country, and the research of the space nuclear power system has important significance for occupying the high point of space strategic control in China, so that higher requirements are put forward for the system, nuclear energy needs to be utilized more fully, the energy utilization rate is improved, the lasting, efficient and clean power supply in the space detection process is ensured, the safety of the space nuclear power system is ensured, and the construction and development of the space cause in China are promoted.

The multistage heat exchange power shielding heat exchanger is combined, and improvement is performed on the safety and the energy utilization rate of a nuclear power system. The material of the multistage heat exchange power shielding heat exchanger adopts the tungsten-rhenium alloy with the shielding function, and the heat exchanger has two modes of low power and high power, so that the dormant use requirement of the space station is met under the low power, and the use requirement of the operation of workers is met under the high power, thereby improving the habitability of the space station, preventing radiation leakage and lightening the heat dissipation pressure of a subsequent radiation heat dissipation system.

Disclosure of Invention

The purpose of the invention is as follows:

aiming at the defects in the current nuclear power technology, the invention provides a space nuclear power system adopting a multistage heat exchange power shielding heat exchanger and a circulating method, so that the energy utilization rate of the nuclear power system is improved, the safety and stability of the nuclear power system are also improved, the habitability of a space station is improved, and the actual use requirements are better met.

The technical scheme is as follows:

a space nuclear power system adopting a multistage heat exchange power shielding heat exchanger comprises two loops.

The primary loop comprises a nuclear reactor, a pressure buffer device, a gas-liquid separator, a heat medium channel of a multistage heat exchange power shielding heat exchanger and an electromagnetic pump. The liquid metal lithium absorbs nuclear heat, flows out from an outlet of the nuclear reactor, flows into auxiliary devices such as a pressure buffer device and a gas-liquid separator through pipelines, flows into an inlet of a heat medium channel of the multistage heat exchange power shielding heat exchanger from an outlet of the gas-liquid separator, and enters a first stage, namely a shell-and-tube heat exchange stage, and at the stage, the liquid metal lithium performs heat exchange with helium through a shielding metal heat exchange tube. After the heat exchange is finished, in the second stage, namely the plate type heat exchange stage, the liquid metal lithium exchanges heat with helium through the shielding metal heat exchange plate, flows out of the outlet of the hot fluid channel, flows into the electromagnetic pump through the pipeline to be accelerated, and returns to the nuclear reactor.

The main heat exchange element of the multistage heat exchange power shielding heat exchanger is a shielding metal heat exchange tube and a shielding metal heat exchange plate, the heat exchanger is composed of two parts, the first part is a shell-and-tube part, the second part is a plate-type part, aiming at the structure, the heat exchange is also divided into a low-power stage and a high-power stage, helium only exchanges heat through the shell-and-tube part of the heat exchanger in the low-power stage, helium exchanges heat through the shell-and-tube part in the high-power stage, and the heat exchange is also carried out through the plate-type part, so that the effect of power regulation is achieved, the energy utilization rate is improved, and the use requirements of different conditions are met.

The second loop comprises an isolation valve, a turbine, a generator, a compressor, a cooler, a radiation radiator and a heat regenerator. High-temperature and high-pressure helium flows out from the outlet of a cold fluid channel of the multistage heat exchange power shielding heat exchanger, enters a turbine to do work for power generation, flows into a heat regenerator from a pipeline, exchanges heat with low-temperature helium, flows into a cooler, transfers waste heat to a radiation radiator through the cooler, flows out from the cooler, flows into a compressor, increases pressure, flows out from the compressor, flows into the heat regenerator to exchange heat with the high-temperature helium, and flows into the multistage heat exchange power shielding heat exchanger again to exchange heat with liquid metal lithium in a convection mode after heat exchange.

The invention has the following beneficial effects:

(1) the invention realizes the heat exchange power regulation of the heat exchanger, sets the heat exchange power into two gears, thereby achieving the effect of power regulation, improving the energy utilization rate, and meeting the use requirements of different conditions such as the working of workers out of the cabin, the dormancy of a space station and the like.

(2) According to the invention, the safety stability of the nuclear power system is improved, the risk of radiation leakage is prevented, liquid metal lithium flows in the shielding metal heat exchange pipeline and the shielding metal heat exchange plate and exchanges heat with helium through the shielding metal heat exchange pipe and the shielding metal heat exchange plate, the process is a first shielding, the shielding metal shell of the heat exchanger is a second shielding, the leakage is prevented through the mode, and the safety stability and the habitability of the space nuclear power system are improved.

(3) The invention overcomes the defects of low heat exchange efficiency of a single shell-and-tube heat exchanger and limited use temperature of a single plate heat exchanger, reasonably utilizes the advantages of two heat exchangers, enlarges the use range of the heat exchanger, ensures the safety and stability in use and improves the heat exchange efficiency of the heat exchanger.

(4) According to the multi-stage heat exchange power shielding heat exchanger, when the heat exchanger works at low power, the temperature of helium entering a thermal radiation heat dissipation system is low, and the pressure of subsequent heat dissipation of the radiation heat dissipation system is reduced.

Drawings

FIG. 1 is a schematic structural diagram of a nuclear power system employing a multistage heat exchange power shield heat exchanger according to the present invention;

wherein: 1-nuclear reactor, 2-pressure buffer device, 3-gas-liquid separator, 4-nuclear radiation shielding heat exchanger for regulating heat exchange power, 5-heat regenerator, 6-cooler, 7-radiation radiator, 8-compressor, 9-generator, 10-turbine, 11-second isolating valve, 12-first isolating valve, 13-three-way plug valve and 14-electromagnetic pump.

FIG. 2 is a schematic structural diagram of a multi-stage heat exchange power shielding heat exchanger according to the present invention;

wherein: 15-liquid metal inlet, 16-tube plate, 17-helium tube shell type inlet, 18-baffle plate, 19-shielding metal heat exchange tube, 20-shielding metal heat exchange plate, 21-helium plate type outlet, 22-liquid metal outlet, 23-helium plate type inlet, 24-liquid metal plate type inlet and 25-helium tube shell type outlet.

FIG. 3 is a schematic three-dimensional structure diagram of a multi-stage heat exchange power shielding heat exchanger according to the present invention;

fig. 4 is a schematic structural view of the shielding metal heat exchange plate of the present invention;

wherein: 26-liquid metal lithium channel, 27-helium channel.

Detailed Description

The invention is further explained below with reference to the drawings.

A space nuclear power system (shown in figure 1) adopting a multistage heat exchange power shielding heat exchanger comprises a nuclear reactor 1, a pressure buffer device 2, a gas-liquid separator 3, a multistage heat exchange power shielding heat exchanger 4, a heat regenerator 5, a cooler 6, a radiation radiator 7, a compressor 8, a generator 9, a turbine 10, a second isolation valve 11, a first isolation valve 12, a three-way plug valve 13 and an electromagnetic pump 14. The system comprises two loops, wherein one loop comprises a nuclear reactor 1, a pressure buffer device 2, a gas-liquid separator 3, a multi-stage heat exchange power shielding heat exchanger 4 and an electromagnetic pump 14, and liquid metal lithium circularly operates through the loop. The second loop comprises a multistage heat exchange power shielding heat exchanger 4, a heat regenerator 5, a cooler 6, a radiation radiator 7, a compressor 8, a generator 9, a turbine 10, a second isolation valve 11, a first isolation valve 12 and a three-way plug valve 13, and helium gas circularly works through the second loop.

A multi-stage heat exchange power shielding heat exchanger (as shown in figure 2) comprises a 15-liquid metal inlet, a 16-tube plate, a 17-helium tube shell type inlet, 18-baffle plates, 19-shielding metal heat exchange tubes, 20-shielding metal heat exchange plate sheets, 21-helium plate type outlets, 22-liquid metal outlets, 23-helium plate type inlets, 24-liquid metal plate type inlets and 25-helium tube shell type outlets. Liquid lithium enters a liquid metal lithium inlet of the multistage heat exchange power shielding heat exchanger, heat exchange is carried out on the liquid lithium and helium through the shielding metal heat exchange tube, then the liquid lithium enters the plate type liquid metal lithium inlet and flows into a liquid metal channel, and the first stage of heat exchange is a shell-and-tube heat exchange stage. If the second stage, namely the plate type heat exchange stage, is carried out, the three-way plug valve is controlled to enable helium to enter the plate type cold fluid inlet, the helium flows into the helium channel, heat exchange is carried out between the helium and liquid lithium through the shielding metal heat exchange plate, then the helium flows out from the plate type cold fluid outlet, and the liquid lithium flows out from the plate type hot fluid outlet.

A shielding metal heat exchange plate (as shown in figure 4) comprises 26-liquid metal lithium channels and 27-helium channels. The liquid metal lithium and helium exchange heat through the shielding metal heat exchange plate.

A working process of a space nuclear power system adopting a multistage heat exchange power shielding heat exchanger comprises the following steps:

the method comprises the following steps: in a loop, liquid metal lithium absorbs nuclear heat, flows out of a nuclear reactor 1, flows into auxiliary devices such as a pressure buffer device 2 and a gas-liquid separator 3 through a pipeline, flows into an inlet of a liquid lithium channel of a multistage heat exchange power shielding heat exchanger 4 from an outlet of the gas-liquid separator 3, enters a first stage, namely a shell-and-tube heat exchange stage, exchanges heat with helium through a shielding metal heat exchange tube, exchanges heat with helium in a second stage, namely a plate heat exchange stage, after the heat exchange is finished, flows out of an outlet of a hot fluid channel, flows into an electromagnetic pump through a pipeline, accelerates 14, and returns to the nuclear reactor 1.

Step two: in the second loop, helium enters from a helium inlet b of the multistage heat exchange power shielding heat exchanger, heat exchange is carried out between the helium and liquid lithium through a heat exchange metal pipe, if plate type heat exchange is not carried out in the second stage, the helium flows out from a cold fluid outlet f of the multistage heat exchange power shielding heat exchanger, the helium does not flow back to the heat exchanger by adjusting a three-way plug valve 13, the first isolation valve 12 is opened, and the second isolation valve 11 is opened. If the heat exchange of the second stage is carried out, the heat flows out from a cold fluid outlet f of the multistage heat exchange power shielding heat exchanger, at the moment, the first isolation valve 12 is closed, the second isolation valve 11 is opened, the heat flows into a helium plate type inlet e of the multistage heat exchange power shielding heat exchanger through the three-way plug valve 13, the heat is exchanged with liquid lithium through the shielding metal heat exchange plate, and then the heat flows out from a cold fluid plate type outlet c of the multistage heat exchange power shielding heat exchanger. Flows into a turbine 10 to do work for power generation, flows into a heat regenerator 5 to perform heat convection with low-temperature helium after doing work, flows into a cooler 6 after heat exchange is finished, and transfers waste heat to a radiation radiator 7 through the cooler 6. And the compressed gas flows into the compressor 8, flows into the heat regenerator 5 to perform heat convection with the high-temperature helium gas, flows into the multistage heat exchange power shielding heat exchanger 4 after heat exchange is finished, and performs heat exchange with the high-temperature liquid metal lithium again to form circulation.

The invention discloses a space nuclear power system adopting a multistage heat exchange power shielding heat exchanger, and belongs to the field of comprehensive utilization of energy. The nuclear reactor power generation system adopts a multi-stage heat exchange power shielding heat exchanger. The heat exchanger consists of two parts, wherein the first part is low-power tube shell heat exchange, and the second part is high-power plate heat exchange. High-temperature liquid metal lithium flows out of the nuclear reactor and enters the heat exchanger, and in the low-power shell-and-tube heat exchange stage, heat exchange is carried out between the high-temperature liquid metal lithium and the low-temperature helium through the shielding metal heat exchange tube. If the high-power plate type heat exchange of the second stage is not carried out, the helium directly flows out. Otherwise, the helium enters the high-power plate type heat exchange of the second stage through valve control, and carries out the second-stage heat exchange with the high-temperature liquid lithium, so that the use requirements under different conditions are met, the low-power and high-power regulation is realized, and the utilization rate of energy is reasonably improved. The liquid metal lithium flows in the plates and the pipeline and exchanges heat with helium through the shielding metal heat exchange tubes and the shielding metal heat exchange plates, the process is a first shielding, and the shielding metal shell of the heat exchanger is a second shielding, so that leakage is prevented, and the safety of a space nuclear power system is improved. And the heat exchanger overcomes the defects that the heat exchange efficiency of a single shell-and-tube heat exchanger is low and the service temperature of a single plate heat exchanger is limited, reasonably utilizes the advantages of two heat exchangers, enlarges the application range of the heat exchanger, ensures the safety and stability in use, and simultaneously improves the heat exchange efficiency.

The above description is only a preferred embodiment of the present invention, and it will be obvious to those skilled in the art that various modifications may be made without departing from the principle of the present invention, such as using water cooling instead of a radiator on the ground; when the device is used in the ocean, the seawater is utilized for heat dissipation; other shielding metals are adopted as the materials of the heat exchange tube and the heat exchange plate, and the improvement is also considered to be the protection scope of the invention.