阅读说明：本技术 一种气封自循环加热装置 (Air seal self-circulation heating device ) 是由 唐娟 毕文剑 余志勇 周楷 高越 孙峰 于 2019-09-24 设计创作，主要内容包括：本发明公开了一种气封自循环加热装置,包括第一高温熔盐储罐、第二高温熔盐储罐、低温熔盐储罐、补气罐；其中,第一高温熔盐储罐、第二高温熔盐储罐的上部均设置第一气体输入管路和气体输出管路,第一气体输入管路和气体输出管路均与补气罐的上部连接,低温熔盐储罐的上部设有第二气体输入管路,第二气体输入管路与第一气体输入管路连接；第一高温熔盐储罐的底部设置第一加热管,第二高温熔盐储罐的底部设置第二加热管,低温熔盐储罐的底部设置第三加热管；第一加热管、第二加热管、第三加热管的气体进口与补气罐底部气体出口通过管道连接,第一加热管、第二加热管、第三加热管的气体出口与补气罐底部气体进口通过管道连接。(The invention discloses a gas seal self-circulation heating device which comprises a first high-temperature molten salt storage tank, a second high-temperature molten salt storage tank, a low-temperature molten salt storage tank and a gas supplementing tank, wherein the first high-temperature molten salt storage tank is connected with the second high-temperature molten salt storage tank; the upper parts of the first high-temperature molten salt storage tank and the second high-temperature molten salt storage tank are respectively provided with a first gas input pipeline and a gas output pipeline, the first gas input pipeline and the gas output pipeline are respectively connected with the upper part of the gas supplementing tank, the upper part of the low-temperature molten salt storage tank is provided with a second gas input pipeline, and the second gas input pipeline is connected with the first gas input pipeline; the bottom of the first high-temperature molten salt storage tank is provided with a first heating pipe, the bottom of the second high-temperature molten salt storage tank is provided with a second heating pipe, and the bottom of the low-temperature molten salt storage tank is provided with a third heating pipe; the gas inlets of the first heating pipe, the second heating pipe and the third heating pipe are connected with the gas outlet at the bottom of the gas supplementing tank through pipelines, and the gas outlets of the first heating pipe, the second heating pipe and the third heating pipe are connected with the gas inlet at the bottom of the gas supplementing tank through pipelines.)

1. The gas seal self-circulation heating device is characterized by comprising a first high-temperature molten salt storage tank, a second high-temperature molten salt storage tank, a low-temperature molten salt storage tank and a gas supplementing tank;

the upper parts of the first high-temperature molten salt storage tank and the second high-temperature molten salt storage tank are respectively provided with a first gas input pipeline and a gas output pipeline, the first gas input pipeline and the gas output pipeline are respectively connected with the upper part of the gas supplementing tank, the upper part of the low-temperature molten salt storage tank is provided with a second gas input pipeline, and the second gas input pipeline is connected with the first gas input pipeline;

the first gas input pipeline and the second gas input pipeline are both provided with gas inlet valves, and the gas output pipeline is provided with a gas outlet valve;

a first heating pipe is arranged at the bottom of the first high-temperature molten salt storage tank, a second heating pipe is arranged at the bottom of the second high-temperature molten salt storage tank, and a third heating pipe is arranged at the bottom of the low-temperature molten salt storage tank;

the first heating pipe the second heating pipe the third heating pipe all is provided with gaseous business turn over, exit tube and valve, the bottom of gas supply tank is equipped with gaseous business turn over, exit tube and valve, first heating pipe the second heating pipe the gaseous business turn over of third heating pipe manage all with the gaseous exit tube of gas supply tank bottom is connected, first heating pipe the second heating pipe the gaseous exit tube of third heating pipe all with the gaseous business turn over union coupling of gas supply tank bottom.

2. The gas seal self-circulation heating device according to claim 1, wherein the gas supply tank is provided between the first high-temperature molten salt storage tank and the second high-temperature molten salt storage tank, the first high-temperature molten salt storage tank and the second high-temperature molten salt storage tank are communicated by a high-temperature tank communicating pipe, and the high-temperature tank communicating pipe passes through the gas supply tank;

the high-temperature tank communicating pipe comprises a first straight pipe, a second straight pipe, a first corrugated pipe, a first bent pipe and a second bent pipe, wherein one end of the first straight pipe is connected with one end of the first corrugated pipe, the other end of the first corrugated pipe is connected with one end of the second straight pipe, the other end of the first straight pipe penetrates out of the gas supplementing tank and stretches into the interior of the first high-temperature molten salt storage tank, the other end of the second straight pipe penetrates out of the gas supplementing tank and stretches into the interior of the second high-temperature molten salt storage tank, the first straight pipe is connected with one end of the interior of the first high-temperature molten salt storage tank, and the second straight pipe is connected with one end of the interior of the second high-temperature molten salt storage tank.

3. The air-seal self-circulation heating device according to claim 2, wherein the parts of the first straight pipe and the second straight pipe, which are in contact with the gas supplementing tank, are of a second corrugated pipe structure and a third corrugated pipe structure, the first straight pipe penetrates through the second corrugated pipe, the second straight pipe penetrates through the third corrugated pipe, one end, close to the interior of the gas supplementing tank, of the second corrugated pipe is welded with the tank body of the gas supplementing tank, and the other end of the second corrugated pipe is welded with the annular cover plate; and one end of the third corrugated pipe, which is close to the inside of the air supplementing tank, is welded with the tank body of the air supplementing tank, and the other end of the third corrugated pipe is welded with the annular cover plate.

4. The atmoseal self-circulation heating device of claim 2, wherein a sight glass is provided on a tank wall of a lower middle portion of the make-up gas tank.

5. The hermetically sealed self-circulating heating apparatus of claim 4, wherein the material of the sight glass is a high temperature resistant high borosilicate glass.

6. The gas seal self-circulation heating device according to claim 2, wherein the first straight pipe is provided with a first shut-off valve at a pipeline between the first high-temperature molten salt storage tank and the gas supplementing tank, and the second straight pipe is provided with a second shut-off valve at a pipeline between the second high-temperature molten salt storage tank and the gas supplementing tank.

7. The gas seal self-circulation heating device of claim 1, wherein the first heating tube, the second heating tube, and the third heating tube are all spiral coil structures or distribution tube structures.

8. The gas seal self-circulation heating device according to claim 3, wherein the gas supplementing tank comprises an upper seal head, a lower seal head, a cylinder body and a support, the upper seal head is welded with the upper part of the cylinder body, the lower seal head is welded with the lower part of the cylinder body, and the support is arranged on the outer surface of the lower seal head.

9. The air-seal self-circulation heating device according to claims 1-8, wherein heat insulation layers are arranged outside the first high-temperature molten salt storage tank, the second high-temperature molten salt storage tank, the low-temperature molten salt storage tank and the gas supplementing tank, and heat insulation layers are arranged on the parts of the high-temperature tank communicating pipes exposed outside.

Technical Field

The invention belongs to the field of solar thermal power generation, and particularly relates to an air-seal self-circulation heating device.

Background

The solar energy has the advantages of inexhaustibility, safety and reliability, the solar thermal power generation is not impacted by energy crisis and instability of fuel market, no fuel is used, the operation cost is very low, pollution waste is not easy to generate in the power generation process, the solar thermal power generation is an ideal clean energy, and the solar thermal power generation can be added or reduced at will according to the increase and decrease of load, so that the waste is avoided.

In a solar thermal power station storage and heat exchange system, a flat-bottom vault single-layer tank external heat insulation structure is basically adopted in the design of a molten salt storage tank, and because the molten salt medium in the storage tank is normal pressure, the top of the storage tank adopts a direct emptying structural form, the temperature of molten salt in a high-temperature molten salt storage tank is up to 560 ℃, and after direct emptying, energy is wasted and economical efficiency is poor.

Disclosure of Invention

The invention provides an air seal self-circulation heating device, which adopts micro-pressure gas to carry out positive pressure sealing on the top of a molten salt storage tank, reduces the heat dissipation of the top of the storage tank, and simultaneously, a first high-temperature molten salt storage tank and a second high-temperature molten salt storage tank are both communicated with a gas supplementing tank to store high-temperature gas and circularly heat a bottom plate of the storage tank.

In order to solve the problems, the technical scheme of the invention is as follows:

a gas seal self-circulation heating device comprises a first high-temperature molten salt storage tank, a second high-temperature molten salt storage tank, a low-temperature molten salt storage tank and a gas supplementing tank;

the upper parts of the first high-temperature molten salt storage tank and the second high-temperature molten salt storage tank are respectively provided with a first gas input pipeline and a gas output pipeline, the first gas input pipeline and the gas output pipeline are respectively connected with the upper part of the gas supplementing tank, the upper part of the low-temperature molten salt storage tank is provided with a second gas input pipeline, and the second gas input pipeline is connected with the first gas input pipeline;

the first gas input pipeline and the second gas input pipeline are both provided with gas inlet valves, and the gas output pipeline is provided with a gas outlet valve;

a first heating pipe is arranged at the bottom of the first high-temperature molten salt storage tank, a second heating pipe is arranged at the bottom of the second high-temperature molten salt storage tank, and a third heating pipe is arranged at the bottom of the low-temperature molten salt storage tank;

the first heating pipe the second heating pipe the third heating pipe all is provided with gaseous business turn over, exit tube and valve, the bottom of gas supply tank is equipped with gaseous business turn over, exit tube and valve, first heating pipe the second heating pipe the gaseous business turn over of third heating pipe manage all with the gaseous exit tube of gas supply tank bottom is connected, first heating pipe the second heating pipe the gaseous exit tube of third heating pipe all with the gaseous business turn over union coupling of gas supply tank bottom.

In a preferred embodiment, the air supply tank is arranged between the first high-temperature molten salt storage tank and the second high-temperature molten salt storage tank, the first high-temperature molten salt storage tank and the second high-temperature molten salt storage tank are communicated through a high-temperature tank communicating pipe, and the high-temperature tank communicating pipe penetrates through the air supply tank;

the high-temperature tank communicating pipe comprises a first straight pipe, a second straight pipe, a first corrugated pipe, a first bent pipe and a second bent pipe, wherein one end of the first straight pipe is connected with one end of the first corrugated pipe, the other end of the first corrugated pipe is connected with one end of the second straight pipe, the other end of the first straight pipe penetrates out of the gas supplementing tank and stretches into the interior of the first high-temperature molten salt storage tank, the other end of the second straight pipe penetrates out of the gas supplementing tank and stretches into the interior of the second high-temperature molten salt storage tank, the first straight pipe is connected with one end of the interior of the first high-temperature molten salt storage tank, and the second straight pipe is connected with one end of the interior of the second high-temperature molten salt storage tank. First high temperature fused salt storage tank and second high temperature fused salt storage tank adopt high temperature jar communicating pipe intercommunication can reduce cost, practice thrift the use quantity of fused salt pump, because first high temperature fused salt storage tank, the temperature of second high temperature fused salt storage tank is high, the inflation volume is big, so high temperature jar communicating pipe adopts bellows and straight tube connection structure, the compensation storage tank is because the flexible volume that the inflation produced, the bellows can be along with the change of salt temperature and periodic compression and extension, and there is the fused salt to pass through bellows inside, so the bellows is very important with the connection quality of straight tube section department.

In the preferred embodiment, in order to reduce molten salt leakage caused by leakage of the high-temperature tank communicating pipe, the high-temperature tank communicating pipe is fixed inside the gas supplementing tank, the parts of the first straight pipe and the second straight pipe, which are in contact with the gas supplementing tank, are of a second corrugated pipe and a third corrugated pipe structure, the first straight pipe penetrates through the second corrugated pipe, the second straight pipe penetrates through the third corrugated pipe, one end, close to the inside of the gas supplementing tank, of the second corrugated pipe is welded with the tank body of the gas supplementing tank, and the other end of the second corrugated pipe is welded with the annular cover plate; the third bellows is close to the inside one end of tonifying qi jar with the welding of the tonifying qi jar body, the other end and the annular cover plate welding of third bellows, when normal operating, the high-temperature gas in the tonifying qi jar can carry out the heat preservation effect to the intraduct fused salt of high-temperature tank intercommunication.

In a preferred embodiment, the tank wall at the middle lower part of the air supply tank is provided with a sight glass, and if the fused salt in the high-temperature tank communicating pipe leaks, the fused salt can be observed through the sight glass on the tank wall of the air supply tank, so that measures can be taken and remedied as soon as possible.

In a preferred embodiment, the material of the sight glass is high-temperature-resistant high borosilicate glass.

In a preferred embodiment, the first straight pipe is provided with a first shut-off valve at a pipeline between the first high-temperature molten salt storage tank and the gas supplementing tank, and the second straight pipe is provided with a second shut-off valve at a pipeline between the second high-temperature molten salt storage tank and the gas supplementing tank.

In a preferred embodiment, the first heating pipe, the second heating pipe and the third heating pipe are all in a spiral coil pipe structure or a distribution pipe structure.

In a preferred embodiment, the air supply tank comprises an upper seal head, a lower seal head, a cylinder body and a support, wherein the upper seal head is welded with the upper part of the cylinder body, the lower seal head is welded with the lower part of the cylinder body, and the support is arranged on the outer surface of the lower seal head.

In a preferred embodiment, the first high-temperature molten salt storage tank, the second high-temperature molten salt storage tank, the low-temperature molten salt storage tank and the gas supplementing tank are all provided with heat preservation layers, and the parts of the high-temperature tank communicating pipes exposed outside are provided with heat preservation layers.

Due to the adoption of the technical scheme, compared with the prior art, the invention has the following advantages and positive effects:

the gas supplementing tank is arranged and connected with a first gas input pipeline and a gas output pipeline of a first high-temperature molten salt storage tank and a second high-temperature molten salt storage tank, the heat values of the upper parts of the first high-temperature molten salt storage tank and the second high-temperature molten salt storage tank are utilized, the gas supplementing tank is filled with gas, the first gas input pipeline is used for filling gas into the first high-temperature molten salt storage tank and the second high-temperature molten salt storage tank, the internal molten salt is sealed and stored in a positive pressure mode, the gas is heated through the high-temperature molten salt, the heated gas enters the gas supplementing tank through the gas output pipeline, the circulation is carried out until the pressure in the first high-temperature molten salt storage tank and the second high-temperature molten salt storage tank is balanced with the pressure in the gas supplementing tank, and the high-temperature gas is filled in the gas supplementing;

after the photo-thermal power generation system is shut down, because the molten salt temperature in the first high-temperature molten salt storage tank, the second high-temperature molten salt storage tank and the low-temperature molten salt storage tank can be slowly reduced, the density of the molten salt is inversely proportional to the temperature, the lower density of the molten salt is higher, the low-temperature molten salt can be deposited at the bottom of the storage tank to gradually form layering, if the photo-thermal power generation system is not operated in rainy days for a long time, the bottom molten salt has solidification risk due to the lengthening of time, a first heating pipe, a second heating pipe and a third heating pipe are designed at the bottom of the first high-temperature molten salt storage tank, the second high-temperature molten salt storage tank and the low-temperature molten salt storage tank, inlet pipes of the three heating pipes are communicated with outlet pipes of the gas supplementing tank, so that the high-temperature gas in the gas supplementing tank can be circularly conveyed into each heating pipe, and then, gaseous rethread first gas input pipeline of low temperature gets into first high temperature fused salt storage tank and second high temperature fused salt storage tank and heats, and the gas after the heating gets back to the tonifying qi jar in through gas output pipeline, and setting through circulation heating heats first high temperature fused salt storage tank, second high temperature fused salt storage tank, low temperature fused salt storage tank, prevents that the fused salt from forming the layering, and the bottom fused salt solidifies. Therefore, the heat of the tops of the first high-temperature molten salt storage tank and the second high-temperature molten salt storage tank is stored in the air supply tank, and the bottom of the storage tank and the air supply tank are subjected to cyclic heating and heat preservation through pipelines, so that the heat dissipation capacity of the storage tank is reduced, and the energy consumption is reduced.

Drawings

FIG. 1 is a schematic view of a nitrogen-sealed self-circulation heating apparatus according to an embodiment of the present invention;

FIG. 2 is a first structural schematic diagram of a bottom heating pipe of a molten salt storage tank according to an embodiment of the invention;

FIG. 3 is a schematic diagram II of a bottom heating pipe structure of a molten salt storage tank according to an embodiment of the invention;

FIG. 4 is a third schematic structural diagram of a bottom heating pipe of a molten salt storage tank in an embodiment of the invention.

Description of reference numerals: 1-low temperature molten salt storage tank; 2-a first high temperature molten salt storage tank; 3-a second high-temperature molten salt storage tank; 4-sight glass; 5-a second heating pipe; 6-high temperature tank communicating pipe; 7-a third bellows; 8-a first bellows; 9-nitrogen supplement tank; 10-an annular cover plate; 11-a first shut-off valve; 12-a second shut-off valve; 13-upper end enclosure; 14-a cylinder body; 15-lower end enclosure; 16-a support; 17-a first heating tube; 18-a third heating tube; 19-second bellows.

Detailed Description

The present invention provides a gas seal self-circulation heating device, which is further described in detail with reference to the accompanying drawings and specific embodiments. Advantages and features of the present invention will become apparent from the following description and from the claims.

The gas sealed molten salt storage tank and the gas participating in self-circulation can be inert gas or gas with stable chemical properties, such as nitrogen.

Referring to fig. 1, in one embodiment, a nitrogen-sealed self-circulation heating device comprises a first high-temperature molten salt storage tank 2, a second high-temperature molten salt storage tank 3, a low-temperature molten salt storage tank 1 and a nitrogen supplement tank 9; the nitrogen supplementing tank 9 can be of a flat-bottom vault structure similar to a molten salt storage tank, can also be of a cylindrical structure, and can also be of a structure with an upper end enclosure 13, a lower end enclosure 15, a cylinder 14 and a support 16 as shown in fig. 1, wherein the upper end enclosure 13 is connected with the cylinder 14 in a welding manner, the lower end enclosure 15 is connected with the cylinder 14 in a welding manner, and the support 16 is arranged on the outer surface of the lower end enclosure 15 and used for supporting the whole nitrogen supplementing tank 9; the top parts of the first high-temperature molten salt storage tank 2, the second high-temperature molten salt storage tank 3 and the low-temperature molten salt storage tank 1 are also provided with emptying valves for detecting whether the gas at the top part of the storage tanks is nitrogen or not; the temperature of the molten salt in the high-temperature molten salt storage tank is generally up to 560 ℃, and the temperature of the molten salt in the low-temperature molten salt storage tank is generally 290-400 ℃;

the upper parts of the first high-temperature molten salt storage tank 2 and the second high-temperature molten salt storage tank 3 are respectively provided with a first nitrogen input pipeline and a nitrogen output pipeline, the first nitrogen input pipeline and the nitrogen output pipeline are respectively connected with the upper part of the nitrogen supplementing tank 9, the upper part of the low-temperature molten salt storage tank 1 is provided with a second nitrogen input pipeline, and the second nitrogen input pipeline is connected with the first nitrogen input pipeline; the first nitrogen input pipeline and the second nitrogen input pipeline are both provided with air inlet valves, and the nitrogen output pipeline is provided with an air outlet valve; as shown in fig. 1, an upper seal head of a nitrogen supplement tank 9 is provided with a nitrogen inlet and a nitrogen outlet, the nitrogen outlet of the nitrogen supplement tank 9 is connected with a first nitrogen input pipeline, the first nitrogen input pipeline is respectively connected with an upper nitrogen inlet of a first high-temperature molten salt storage tank 2 and an upper nitrogen inlet of a second high-temperature molten salt storage tank 3, the nitrogen outlet of the nitrogen supplement tank 9 is provided with a valve V3, the nitrogen inlet of the first high-temperature molten salt storage tank 2 is provided with a valve V14, the nitrogen inlet of the second high-temperature molten salt storage tank 3 is provided with a valve V4, the second nitrogen input pipeline is connected with the first nitrogen input pipeline, and the second nitrogen input pipeline is provided with a valve V13; a nitrogen inlet of the nitrogen supplement tank 9 is connected with a nitrogen output pipeline, a valve V1 is arranged near a nitrogen outlet of the first high-temperature molten salt storage tank 2 on the nitrogen output pipeline, and a valve V2 is arranged near a nitrogen outlet of the second high-temperature molten salt storage tank 3;

the nitrogen pressure in the nitrogen supplementing tank 9 is preferably not more than 0.01MPa, the purpose of limiting the nitrogen pressure in the nitrogen supplementing tank 9 is to consider the tank body cost of the nitrogen supplementing tank 9, the larger the nitrogen pressure is, the thicker the tank body of the nitrogen supplementing tank 9 is, the higher the cost is, and the nitrogen supplementing tank 9 is set to be proper in thickness under the condition of ensuring the subsequent heat preservation of high-temperature nitrogen as much as possible, so that the nitrogen pressure is limited to be 0.01 MPa;

the bottom of the first high-temperature molten salt storage tank 2 is provided with a first heating pipe 17, the bottom of the second high-temperature molten salt storage tank 3 is provided with a second heating pipe 5, the bottom of the low-temperature molten salt storage tank 1 is provided with a third heating pipe 18, and the first heating pipe 17, the second heating pipe 5 and the third heating pipe 18 are filled with high-temperature nitrogen for heating the corresponding molten salt storage tanks;

the first heating pipe 17, the second heating pipe 5 and the third heating pipe 18 are all provided with a nitrogen inlet pipe, a nitrogen outlet pipe and a valve, the bottom of the nitrogen supplementing tank 9 is provided with the nitrogen inlet pipe, the nitrogen outlet pipe and the valve, the nitrogen inlet pipes of the first heating pipe 17, the second heating pipe 5 and the third heating pipe 18 are all connected with the nitrogen outlet pipe at the bottom of the nitrogen supplementing tank 9, and the nitrogen outlet pipes of the first heating pipe 17, the second heating pipe 5 and the third heating pipe 18 are all connected with the nitrogen inlet pipe at the bottom of the nitrogen supplementing tank 9; as shown in fig. 1, a valve V10 is arranged on the nitrogen outlet pipe of the first heating pipe 17, a valve V11 is arranged on the nitrogen outlet pipe of the second heating pipe 5, a valve V12 is arranged on the nitrogen outlet pipe of the third heating pipe 18, the nitrogen outlet pipes of the three heating pipes are communicated with the nitrogen inlet pipe of the nitrogen supplement tank 9 through a four-way joint, and a valve V9 is arranged on the nitrogen inlet pipe of the nitrogen supplement tank 9; the nitrogen inlet pipe of the first heating pipe 17 is provided with a valve V6, the nitrogen inlet pipe of the second heating pipe 5 is provided with a valve V7, the nitrogen inlet pipe of the third heating pipe 18 is provided with a valve V8, the nitrogen inlet pipes of the three heating pipes are communicated with the nitrogen outlet pipe of the nitrogen supplementing tank 9 through a four-way valve, and the nitrogen outlet pipe of the nitrogen supplementing tank 9 is provided with a valve V5.

In the embodiment, by arranging the nitrogen supplementing tank 9, the nitrogen supplementing tank 9 is connected with the first nitrogen input pipeline and the nitrogen output pipeline of the first high-temperature molten salt storage tank 2 and the second high-temperature molten salt storage tank 3, the heat values of the upper parts of the first high-temperature molten salt storage tank 2 and the second high-temperature molten salt storage tank 3 are utilized, the nitrogen supplementing tank 9 is filled with nitrogen, the nitrogen is filled into the first high-temperature molten salt storage tank 2 and the second high-temperature molten salt storage tank 3 through the first nitrogen input pipeline, the internal molten salt is sealed in a positive pressure manner, the nitrogen is heated through the high-temperature molten salt, the heated nitrogen enters the nitrogen supplementing tank 9 through the nitrogen output pipeline, the circulation is performed until the pressure in the first high-temperature molten salt storage tank 2 and the second high-temperature molten salt storage tank 3 is balanced with the pressure in the nitrogen supplementing tank 9, and the pressure in the nitrogen supplementing tank 9 is not higher than 0.01 Mpa;

the nitrogen supplementing tank 9 is filled with high-temperature nitrogen, after the photo-thermal power generation system is stopped, because the temperature of molten salt in the first high-temperature molten salt storage tank 2, the second high-temperature molten salt storage tank 3 and the low-temperature molten salt storage tank 1 can be slowly reduced, and the density of the molten salt is inversely proportional to the temperature, the lower density of the temperature is higher, the low-temperature molten salt can be deposited at the bottom of the storage tanks, and gradually forms layering, along with the lengthening of time, if the molten salt does not operate in rainy days for a long time, the risk of solidification exists in the bottom molten salt, a first heating pipe 17, a second heating pipe 5 and a third heating pipe 18 are designed at the bottom of the first high-temperature molten salt storage tank 2, the second high-temperature molten salt storage tank 3 and the low-temperature molten salt storage tank 1, nitrogen inlet pipes of the three heating pipes are communicated with nitrogen outlet pipes of the nitrogen supplementing tank 9, nitrogen outlet pipes of the three heating pipes, then the low temperature nitrogen gas that every heating pipe came out enters into and mends nitrogen tank 9, and low temperature nitrogen gas rethread first nitrogen gas input pipeline gets into first high temperature fused salt storage tank 2 and second high temperature fused salt storage tank 3 and heats, and the nitrogen gas after the heating gets back to through nitrogen gas output pipeline and mends in nitrogen tank 9, and setting through circulation heating heats first high temperature fused salt storage tank 2, second high temperature fused salt storage tank 3, low temperature fused salt storage tank 1 and heats, prevents that the fused salt from forming the layering, and the bottom fused salt takes place to solidify. Therefore, the embodiment stores the heat at the tops of the first high-temperature molten salt storage tank 2 and the second high-temperature molten salt storage tank 3 in the nitrogen supplement tank 9, and circularly heats the bottom of the storage tank and the nitrogen supplement tank 9 through pipelines to keep the temperature, so that the heat dissipation capacity of the storage tank is reduced, and the energy consumption is reduced.

In the preferred embodiment, the nitrogen supplement tank 9 is arranged between the first high-temperature molten salt storage tank 2 and the second high-temperature molten salt storage tank 3, the first high-temperature molten salt storage tank 2 and the second high-temperature molten salt storage tank 3 are communicated through the high-temperature tank communicating pipe 6, and the high-temperature tank communicating pipe 6 penetrates through the nitrogen supplement tank 9; the first high-temperature molten salt storage tank 2 is communicated with the second high-temperature molten salt storage tank 3, so that the cost is reduced, each high-temperature molten salt storage tank is provided with a molten salt pump, and the two high-temperature molten salt storage tanks are communicated in order to reduce the number of the used molten salt pumps and reduce the cost due to the fact that the adopted molten salt pumps are expensive;

high temperature jar communicating pipe 6 includes first straight tube, the second straight tube, first bellows 8, first return bend, the second return bend, the one end of first straight tube and the one end welding of first bellows 8, the one end of the other end welded connection second straight tube of first bellows 8, the other end of first straight tube is worn out and is mended nitrogen jar 9 and stretch into 2 insides of first high temperature fused salt storage tank, the other end of second straight tube is worn out and is mended nitrogen jar 9 and stretch into 3 insides of second high temperature fused salt storage tank, first return bend is connected at 2 inside one ends of first high temperature fused salt storage tank to first straight tube, the second return bend is connected at 3 inside one ends of second high temperature fused salt storage tank to the second straight tube. Because the temperature of first high temperature fused salt storage tank 2, second high temperature fused salt storage tank 3 is high, and the inflation volume is big, so high temperature tank communicating pipe 6 adopts bellows and straight tube connection structure, and the compensation storage tank is because the flexible volume that the inflation produced, and the bellows can be along with the change of salt temperature and periodic compression and extension, and there is the fused salt to pass through bellows inside, so the bellows is very important with the connected quality of straight tube section department.

In the preferred embodiment, in order to reduce molten salt leakage caused by leakage of the high-temperature tank communicating pipe 6, the high-temperature tank communicating pipe 6 is fixed inside the nitrogen supplement tank 9, the parts of the first straight pipe and the second straight pipe, which are in contact with the nitrogen supplement tank 9, are provided with a second corrugated pipe 19 and a third corrugated pipe 7, the first straight pipe penetrates through the second corrugated pipe 19, the second straight pipe penetrates through the third corrugated pipe 7, one end of the second corrugated pipe 19, which is close to the inside of the nitrogen supplement tank 9, is welded with the tank body of the nitrogen supplement tank 9, the other end of the second corrugated pipe 19 is welded with the annular cover plate 10, namely the first straight pipe penetrates through the annular cover plate 10, and the first corrugated pipe 8 is sleeved on the outer side surface of; third bellows 7 is close to the inside one end of benefit nitrogen jar 9 and fills the welding of nitrogen jar 9 jar body, and the other end and the annular cover plate 10 welding of third bellows 7 guarantee the flexible that first straight tube and second straight tube can be free, do not have the atress problem, and when normal operating, the high temperature nitrogen gas in the benefit nitrogen jar 9 can heat the fused salt of 6 inside communicating pipes of high temperature jar.

In the preferred embodiment, the viewing mirror 4 is arranged on the wall of the middle lower part of the nitrogen supplement tank 9, and if the molten salt in the high-temperature tank communicating pipe 6 leaks, the molten salt can be observed through the viewing mirror 4 on the wall of the nitrogen supplement tank 9, so that measures can be taken and remedied as soon as possible.

In the preferred embodiment, the material of the viewing mirror 4 is high temperature borosilicate glass.

In the preferred embodiment, the first straight pipe is provided with a first shut-off valve 11 at the pipeline between the first high-temperature molten salt storage tank and the nitrogen supplement tank 9, and the second straight pipe is provided with a second shut-off valve 12 at the pipeline between the second high-temperature molten salt storage tank and the nitrogen supplement tank 9.

In a preferred embodiment, as shown in fig. 2, 3 and 4, the first heating pipe 17, the second heating pipe 5 and the third heating pipe 18 are all of a spiral coil structure or a distribution pipe structure, but are not limited to these three structures.

In the preferred embodiment, the first high-temperature molten salt storage tank 2, the second high-temperature molten salt storage tank 3, the low-temperature molten salt storage tank 1 and the nitrogen supplement tank 9 are all externally provided with heat preservation layers, and the exposed part of the high-temperature tank communicating pipe 6 is provided with the heat preservation layers.

The working process of the device provided by the embodiment is as follows:

during normal operation, firstly filling nitrogen into the nitrogen supplement tank 9, when the pressure of the nitrogen in the nitrogen supplement tank 9 reaches 0.01MPa, closing a nitrogen inlet valve, filling dry and pure nitrogen into the nitrogen supplement tank 9, then opening valves V3, V4, V14 and V13, enabling the nitrogen in the nitrogen supplement tank 9 to enter the tops of the first high-temperature molten salt storage tank 2, the second high-temperature molten salt storage tank 3 and the low-temperature molten salt storage tank 1, simultaneously opening vent valves of the first high-temperature molten salt storage tank 2, the second high-temperature molten salt storage tank 3 and the low-temperature molten salt storage tank 1, closing an air release valve until the gas at the top of the molten salt storage tank is completely nitrogen through gas sampling detection, closing the valve V13 at the moment, opening valves V1 and V2, enabling the high-temperature nitrogen of the first high-temperature molten salt storage tank 2 and the second high-temperature molten salt storage tank 3 to enter the nitrogen supplement tank 9, and filling the nitrogen into the top of the nitrogen supplement tank 9 again because the nitrogen in the nitrogen supplement, until the pressure of the high-temperature molten salt storage tank and the nitrogen supplement tank 9 is balanced but not higher than 0.01MPa, the nitrogen supplement tank 9 is filled with high-temperature nitrogen, the tops of the first high-temperature molten salt storage tank 2, the second high-temperature molten salt storage tank 3 and the low-temperature molten salt storage tank 1 are filled with low-pressure nitrogen, and the internal molten salt is sealed and stored under positive pressure;

the nitrogen supplement tank 9 is filled with high-temperature nitrogen, after the photo-thermal system is shut down, because the heat preservation of the molten salt storage tank can not absolutely ensure that the molten salt storage tank does not dissipate heat, the temperature of the molten salt in the tank can be slowly reduced, and the density of the molten salt is in direct proportion to the temperature, the lower the temperature is, the higher the density is, the lower the density is, the low-temperature molten salt can be deposited at the bottom of the storage tank to gradually form layering, and along with the lengthening of time, if the molten salt at the bottom is not operated in rainy days for a long time, therefore, after the shutdown at night, the nitrogen outlet valve V5 of the nitrogen supplement tank 9 is opened, the nitrogen inlet valves V6, V7 and V8 of the first heating pipe 17, the second heating pipe 5 and the third heating pipe 18 are opened, meanwhile, the nitrogen inlet valve V9 of the nitrogen supplement tank 9 is opened, the nitrogen outlet valves V10, V11 and V12 of the first heating pipe, and the nitrogen from the outlet of the heating pipe is changed into low temperature and returns to the nitrogen supplementing tank 9, and then the nitrogen is heated by utilizing the nitrogen supplementing tank 9 and the nitrogen circulation of the first high-temperature molten salt storage tank 2 and the second high-temperature molten salt storage tank 3. For the supplement of the nitrogen in the high-temperature molten salt tank and the nitrogen supplement tank 9, the opening and closing regulation is carried out according to the pressure in the nitrogen supplement tank 9, the flow, the gas velocity and the pressure of each path are controlled, and the stable circulating heating of the whole system is met.

The top of the low-temperature molten salt storage tank 1 is only provided with a nitrogen positive pressure sealing pipeline, and because the gas temperature at the top of the low-temperature molten salt storage tank 1 is not higher than that of a high-temperature tank, the internal molten salt is sealed by only adopting low-temperature nitrogen without heat extraction, and after the low-temperature molten salt storage tank 1 is filled with nitrogen, the valve V13 is closed, nitrogen sealing treatment of filling nitrogen is carried out on the low-temperature molten salt storage tank 1, nitrogen supplement cannot be carried out on the low-temperature molten salt storage tank 1 when the nitrogen supplement tank 9 is high-temperature nitrogen, and the tank body material of the low-temperature molten salt storage tank 1 cannot bear the pressure of the high; the bottom of the low-temperature molten salt storage tank 1 is provided with a third heating pipe 18, and the third heating pipe 18 is circularly heated by utilizing hot nitrogen in the nitrogen supplementing tank 9, so that the molten salt temperature at the bottom of the low-temperature molten salt storage tank 1 is increased.

It should be noted that when two or more gas lines in fig. 1 intersect, if the lines in the figure are broken, the two gas lines are not communicated, and if the lines are not broken, the intersecting gas lines are communicated.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, it is still within the scope of the present invention if they fall within the scope of the claims of the present invention and their equivalents.