CN217866105U - A high temperature molten salt storage tank with thermal barrier coating - Google Patents

Abstract

The utility model relates to the field of energy storage type solar photothermal devices, in particular to a high-temperature molten salt storage tank with a thermal barrier coating, which comprises a tank top, a tank wall and a tank bottom, wherein the tank wall sequentially comprises a first ceramic layer, a first binder layer, a first carbon steel layer and a heat preservation layer from inside to outside; the tank bottom includes second ceramic layer, second binder layer, second carbon steel layer, gravel layer, first firebrick layer, foam glass layer and heat-resisting concrete layer from top to bottom in proper order, the foam glass layer is located tank bottom middle part, is located foam glass layer periphery and encircles to being provided with second firebrick layer, the second firebrick layer is located between first firebrick layer and the heat-resisting concrete layer. The utility model discloses utilize the binder layer to bond the ceramic layer to first carbon steel layer and second carbon steel internal surface, the fused salt can not make the jar wall produce higher temperature gradient storing-exothermic in-process, and then weakens the degree that high temperature creep and peak stress caused the damage, promotes the in service life-span of storage tank.

Description

A high temperature molten salt storage tank with thermal barrier coating

technical field

The utility model relates to the field of energy storage solar photothermal devices, in particular to a high-temperature molten salt storage tank with a thermal barrier coating.

Background technique

Concentrating solar power (CSP) technology is an energy utilization method with broad application prospects. By the end of 2021, 142 solar thermal projects around the world have been connected to the grid for power generation, with a cumulative installed capacity of about 6.8GW. At present, 8 commercial solar thermal power stations in my country have been successfully connected to the grid for power generation, and the proposed molten salt energy storage CSP projects have exceeded 2.16GW. It is worth noting that due to the intermittent instability of solar radiation energy caused by cloud cover and the mismatch between power generation and power consumption cycle caused by day and night cycles, the CSP system urgently needs to solve the heat storage problem to improve the stability and continuity of the entire system. , so that the power station can continue to meet the demand for power generation even when it cannot receive solar energy resources.

At present, energy storage-type photothermal power stations all adopt double-tank (high-temperature tank, low-temperature tank) molten salt heat storage method. Taking the tower-type CSP system with the most promising application prospects as an example, when heat is stored, it comes from the heat absorber. The 565°C hot molten salt is pumped into the high temperature tank. When the heat is released, the hot molten salt enters the steam generator to release heat, which drives the steam turbine to do work and generate electricity. Then, the cold molten salt whose temperature is lowered to 290°C returns to the low-temperature tank, and then enters the heat absorber to be heated to a high-temperature state when there is sufficient light. This cycle goes on and on, which can meet the demand for 24-hour uninterrupted power generation.

However, for high-temperature molten salt storage tanks, they still face the following problems during long-period, multi-cycle, and high-temperature operation: (1) High-temperature storage tanks with an operating temperature of 565 °C often use expensive 347H stainless steel as The tank material has a creep temperature of 538°C. During heat storage, under the long-term action of 565°C high-temperature molten salt, the wall surface of the stainless steel tank is prone to irreversible creep damage caused by slow plastic deformation, which poses a safety hazard to the operation of the tank. (2) During the heat storage and release process, high-temperature molten salt with a liquid level of not less than 1m will remain in the tank, making the bottom plate of the tank body and the bottom wall plate always in a high-temperature creep state, further increasing the failure of the storage tank. risk. (3) The storage tanks in the CSP power station are all vertical cylindrical steel welded structures, and the position of the large fillet weld connecting the wall plate and the bottom plate is prone to stress concentration. In particular, a higher wall temperature gradient will further increase the stress level at the fillet weld, causing stress-plastic damage to the weld structure; in the long-term heat storage-discharge cycle, the dynamic stress-plastic damage accumulation is likely to cause the tank to Low-cycle or high-cycle fatigue failure occurs on the wall surface. (4) The synergistic effect of high temperature creep and stress fatigue will accelerate the fracture failure rate of high temperature molten salt storage tanks, which can easily cause molten salt leakage. For example, in 2016 and 2017, the high-temperature storage tanks of Crescent Dunes in the United States and the GemaSolar tower power station in Spain had molten salt leakage accidents caused by creep and fatigue, and caused economic losses of millions of dollars. In particular, with the continuous development of the fourth-generation CSP technology coupled with supercritical carbon dioxide Brayton cycle with low cost and high efficiency, the working temperature of the molten salt medium will reach about 700 °C. Based on this, in the face of high-cost tank materials and rising molten salt operating temperature, how to effectively reduce the temperature level of the storage tank wall under the premise of satisfying the heat storage and release capacity, so as to improve the wall caused by high temperature Creep and fatigue damage phenomenon, so as to improve the safety performance of the whole system operation, has become one of the problems to be solved urgently in the CSP system.

Utility model content

In order to reduce the high-temperature creep time of the tank material and further weaken the influence of high-temperature creep damage on the safety performance of the storage tank, the utility model provides a high-temperature molten salt storage tank with a thermal barrier coating attached.

The utility model is realized through the following technical solutions: a high-temperature molten salt storage tank with a thermal barrier coating, comprising a tank top, a tank wall and a tank bottom,

The tank wall sequentially includes a first ceramic layer, a first adhesive layer, a first carbon steel layer and an insulation layer from inside to outside;

The tank bottom includes a second ceramic layer, a second adhesive layer, a second carbon steel layer, a gravel layer, a first refractory brick layer, a foam glass layer and a heat-resistant concrete layer from top to bottom. The layer is located in the middle of the bottom of the tank, and a second layer of refractory bricks is arranged circumferentially on the periphery of the foam glass layer, and the second layer of refractory bricks is located between the first layer of refractory bricks and the heat-resistant concrete layer.

As a further improvement of the technical solution of the utility model, the outer edge of the second ceramic layer extends to the lower surface of the first ceramic layer.

As a further improvement of the technical solution of the utility model, the outer edge of the second carbon steel layer is flush with the outer wall of the thermal insulation layer, and the second carbon steel layer is welded to the first carbon steel layer.

As a further improvement of the technical solution of the utility model, the first carbon steel layer includes an upper ring plate and a lower ring plate arranged sequentially from top to bottom, the inner walls of the upper ring plate and the lower ring plate are flush, and the lower ring plate The thickness of the plate is greater than that of the upper ring plate.

As a further improvement of the technical solution of the present invention, the second carbon steel layer includes an inner ring plate and an outer ring plate arranged sequentially from the inside to the outside, the upper surfaces of the inner ring plate and the outer ring plate are flush, and the outer ring plate The thickness of the plate is greater than that of the inner ring plate.

As a further improvement of the technical solution of the utility model, a cooling air duct is arranged in the heat-resistant concrete layer.

As a further improvement of the technical solution of the utility model, the outer edges of the gravel layer, the first refractory brick layer, the second refractory brick layer and the heat-resistant concrete layer all extend to the periphery of the tank wall.

As a further improvement of the technical solution of the utility model, the upper ring plate and the lower ring plate are connected by welding.

As a further improvement of the technical solution of the utility model, the inner ring plate and the outer ring plate are connected by welding.

As a further improvement of the technical solution of the utility model, the tank roof includes a vault and a bracket, the vault is supported on the top of the tank wall through the bracket, and the bracket and the first carbon steel layer are connected by angle steel welding.

Compared with the prior art, the high-temperature molten salt storage tank with thermal barrier coating attached to the utility model has the following beneficial effects:

1. The utility model uses the adhesive layer to bond the ceramic layer to the inner surface of the first carbon steel layer and the second carbon steel layer, and the molten salt will not cause a large temperature gradient on the tank wall during the heat storage-release process , thereby weakening the degree of damage caused by high temperature creep and peak stress, and improving the service life of the storage tank.

2. The utility model attaches a ceramic layer to the inner wall of the tank wall, which can effectively isolate the tank body from the molten salt fluid during operation, and achieve thermal insulation effect by reducing the temperature level of the wall surface, so that the thermal efficiency of operation is higher. The peak stress level of the large fillet weld is weakened by reducing the wall temperature, thereby reducing the influence of stress plastic damage on the safety performance of the storage tank.

3. The utility model attaches a ceramic layer to the inner wall of the tank wall, which can reduce the temperature of the tank wall, reduce the requirements of the high temperature creep resistance, stress damage resistance and molten salt corrosion resistance of the tank body, and increase the material selection range of the tank body , to reduce initial investment costs.

4. The ceramic layer described in this utility model has been widely used on the hot end parts of aero-engines, and has achieved good results in cooling and heat insulation. Therefore, the utility model has good application prospects and is a kind of A thermal protection technology to prolong the service life of tanks in complex and harsh environments.

5. The basic structure of the tank bottom provided by the utility model not only meets the load-bearing requirements of the storage tank, but also reduces the heat loss of the system.

Description of drawings

In order to more clearly illustrate the specific implementation of the utility model or the technical solutions in the prior art, the accompanying drawings that need to be used in the description of the specific implementation or the prior art will be briefly introduced below. Obviously, the following descriptions The accompanying drawings are some implementations of the utility model, and those skilled in the art can also obtain other drawings according to these drawings without any creative work.

Figure 1 is a schematic diagram of the connection between the tank roof and the tank wall of the high-temperature molten salt storage tank with a thermal barrier coating attached according to the utility model (the thermal insulation layer is not drawn in the figure).

Fig. 2 is a schematic diagram of the connection between the tank wall and the tank bottom.

In the figure: 1-tank roof, 101-vault, 102-bracket, 103-angle steel, 2-tank wall, 201-first ceramic layer, 202-first adhesive layer, 203-first carbon steel layer, 204-insulation layer, 213-upper ring plate, 223-lower ring plate, 3-tank bottom, 301-second ceramic layer, 302-second adhesive layer, 303-second carbon steel layer, 304-gravel layer , 305-first refractory brick layer, 306-foam glass layer, 307-heat-resistant concrete layer, 308-second refractory brick layer, 309-cooling air duct, 313-inner ring plate, 323-outer ring plate.

Detailed ways

The technical solution of the utility model is clearly and completely described below, obviously, the described embodiments are some embodiments of the utility model, but not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

In the description of the present utility model, it should be noted that the terms "first" and "second" are only used for description purposes, and should not be understood as indicating or implying relative importance.

In the description of the present utility model, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a flexible connection. Detachable connection, or integral connection; it can be mechanical connection; it can be direct connection or indirect connection through an intermediary, and it can be the internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present utility model according to specific situations.

The utility model provides a specific embodiment of a high-temperature molten salt storage tank with a thermal barrier coating, which includes a tank top 1, a tank wall 2 and a tank bottom 3,

The tank wall 2 sequentially includes a first ceramic layer 201, a first adhesive layer 202, a first carbon steel layer 203 and an insulation layer 204 from the inside to the outside;

The tank bottom 3 includes a second ceramic layer 301, a second adhesive layer 302, a second carbon steel layer 303, a gravel layer 304, a first refractory brick layer 305, a foam glass layer 306 and a heat-resistant layer from top to bottom. The concrete layer 307, the foam glass layer 306 is located in the middle of the tank bottom 3, and the second refractory brick layer 308 is arranged circumferentially on the periphery of the foam glass layer 306, and the second refractory brick layer 308 is located on the first refractory brick layer 305 and the Between layers 307 of hot concrete.

In this embodiment, the first adhesive layer 202 is used to attach the first ceramic layer 201 to the surface of the first carbon steel layer 203, and the second adhesive layer 302 is used to attach the second ceramic layer 301 to the surface of the second carbon steel layer 303. , the carbon steel layer used is heat-resistant, molten salt corrosion-resistant, and low-cost carbon steel material (the creep temperature of A516Gr.70 material is 343°C). The ceramic layer is zirconia ceramics as an example, and the zirconia ceramics with a thickness of 150 μm can achieve a cooling effect of about 170K. At the same time, the zirconia ceramic layer occupies a small space, does not affect the heat storage and release capacity of the tank, and has stable chemical properties, has good high-temperature corrosion resistance, and is not easy to react with high-temperature molten salt. In this embodiment, taking zirconia ceramics as an example, the thickness of the first ceramic layer 201 and the second ceramic layer 301 is 250-350 μm.

During specific implementation, the binder used in the binder layer may be NiCrAlY material, FeCrAlY material, CoCrAlY material, NiCoCrAlY material or PtAl material.

During specific application, the first adhesive layer 202 is applied to the inner surface of the first carbon steel layer 203, the second adhesive layer 302 is applied to the inner surface of the second carbon steel layer 303, and then the low thermal conductivity, resistant The high-temperature, corrosion-resistant first ceramic layer 201 is sprayed on the inner surface of the first adhesive layer 202, and the second ceramic layer 301 is sprayed on the inner surface of the second adhesive layer 302, and the adhesive layer and the ceramic layer together form a tank Body thermal barrier coating. The tank wall 2 and the tank bottom 3 are isolated from the high-temperature molten salt, effectively reducing the temperature of the tank body, improving the high-temperature creep damage resistance and stress-plastic damage resistance of the tank body, so as to increase the service life of the molten salt storage tank. The insulation layer 204 is the outermost layer, covering the first carbon steel layer 203 to reduce the heat loss of the tank body. The thermal barrier coating should cover the entire tank wall 2 and the inner surface of the tank bottom 3, and the thickness of the thermal barrier coating at the joint of the fillet weld can also be increased to further reduce the higher peak stress caused by high temperature.

As shown in FIG. 2 , the outer edge of the second ceramic layer 301 extends to the lower surface of the first ceramic layer 201 .

In this embodiment, the outer edge of the second carbon steel layer 303 is flush with the outer wall of the thermal insulation layer 204 , and the second carbon steel layer 303 is welded to the first carbon steel layer 203 .

As shown in FIG. 2 , the first carbon steel layer 203 includes an upper ring plate 213 and a lower ring plate 223 arranged sequentially from top to bottom, the inner walls of the upper ring plate 213 and the lower ring plate 223 are flush, and the lower ring plate The thickness of the ring plate 223 is greater than that of the upper ring plate 213 . The thickness of the lower ring plate 223 is greater than that of the upper ring plate 213 , which can improve the supporting strength of the first carbon steel layer 203 . Preferably, the upper ring plate 213 and the lower ring plate 223 are connected by welding.

As shown in FIG. 2, the second carbon steel layer 303 includes an inner ring plate 313 and an outer ring plate 323 arranged sequentially from the inside to the outside. The upper surfaces of the inner ring plate 313 and the outer ring plate 323 are flush, and the outer The thickness of the ring plate 323 is greater than the thickness of the inner ring plate 313 . The thickness of the outer ring plate 323 is greater than that of the inner ring plate 313 , which can increase the support strength of the second carbon steel layer 303 to the tank wall 2 . Further, in order to facilitate the construction and installation of the second carbon steel layer 303, the inner ring plate 313 and the outer ring plate 323 are connected by welding.

During specific implementation, a cooling air duct 309 is arranged in the heat-resistant concrete layer 307 . The purpose of setting the cooling air duct 309 is to ensure that the temperature of the foundation is controlled at about 75°C.

In specific applications, in order to improve the supporting strength of the tank bottom 3, the outer edges of the gravel layer 304, the first refractory brick layer 305, the second refractory brick layer 308 and the heat-resistant concrete layer 307 all extend to the periphery of the tank wall 2.

In addition to the zirconia ceramic layer, the first ceramic layer 201 and/or the second ceramic layer 301 may also use a perovskite ceramic layer, a pyrochlore ceramic layer, a fluorite ceramic layer or a magnetoplumbite ceramic layer.

In addition, the thermal insulation layer 204 is made of aluminum silicate rock wool. In this embodiment, the heat-resistant concrete layer 307 is C30 concrete.

In this embodiment, the tank roof 1 includes a vault 101 and a bracket 102, the vault 101 is supported on the top of the tank wall 2 through the bracket 102, and the bracket 102 and the first carbon steel layer 203 are welded and connected by an angle steel 103 . Specifically, one side of the angle steel 103 is welded to the bracket 102 , and the other side of the angle steel 103 is welded to the first carbon steel layer 203 .

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present utility model, and are not intended to limit it; although the present utility model has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand : It is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements to some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions depart from the embodiments of the present utility model Scope of technical solutions.

Claims (10)

1. A high-temperature molten salt storage tank with a thermal barrier coating comprises a tank top (1), a tank wall (2) and a tank bottom (3),

the tank wall (2) sequentially comprises a first ceramic layer (201), a first adhesive layer (202), a first carbon steel layer (203) and a heat insulation layer (204) from inside to outside;

tank bottom (3) include second ceramic layer (301), second binder layer (302), second carbon steel layer (303), gravel layer (304), first firebrick layer (305), foam glass layer (306) and heat-resisting concrete layer (307) from top to bottom in proper order, foam glass layer (306) are located tank bottom (3) middle part, are located foam glass layer (306) peripheral hoop and are provided with second firebrick layer (308), second firebrick layer (308) are located between first firebrick layer (305) and heat-resisting concrete layer (307).

2. The high-temperature molten salt storage tank with thermal barrier coating attached as claimed in claim 1, wherein the outer edge of the second ceramic layer (301) extends to the lower surface of the first ceramic layer (201).

3. The high-temperature molten salt storage tank with the thermal barrier coating attached thereon as claimed in claim 1, wherein the outer edge of the second carbon steel layer (303) is flush with the outer wall of the thermal insulation layer (204), and the second carbon steel layer (303) is welded with the first carbon steel layer (203).

4. The high-temperature molten salt storage tank with thermal barrier coating attached as claimed in claim 1, wherein the first carbon steel layer (203) comprises an upper annular plate (213) and a lower annular plate (223) which are arranged from top to bottom in sequence, the inner walls of the upper annular plate (213) and the lower annular plate (223) are flush, and the thickness of the lower annular plate (223) is greater than that of the upper annular plate (213).

5. The high-temperature molten salt storage tank with thermal barrier coating attached as claimed in claim 1, wherein the second carbon steel layer (303) comprises an inner annular plate (313) and an outer annular plate (323) which are arranged from inside to outside in sequence, the upper surfaces of the inner annular plate (313) and the outer annular plate (323) are flush, and the thickness of the outer annular plate (323) is larger than that of the inner annular plate (313).

6. The high-temperature molten salt storage tank with thermal barrier coating attached as claimed in claim 1, wherein a cooling air pipe (309) is arranged in the heat-resistant concrete layer (307).

7. A high temperature molten salt storage tank with thermal barrier coating attached as claimed in claim 1, characterized in that the gravel layer (304), the first refractory brick layer (305), the second refractory brick layer (308) and the outer edges of the heat resistant concrete layer (307) all extend to the periphery of the tank wall (2).

8. The high-temperature molten salt storage tank with thermal barrier coating attached as claimed in claim 4, characterized in that the upper ring plate (213) and the lower ring plate (223) are welded together.

9. A high temperature molten salt storage tank with thermal barrier coating attached as claimed in claim 5, characterized in that the inner ring plate (313) and the outer ring plate (323) are welded together.

10. The high-temperature molten salt storage tank with the thermal barrier coating attached is characterized in that the tank roof (1) comprises a vault (101) and a bracket (102), the vault (101) is supported on the top of the tank wall (2) through the bracket (102), and the bracket (102) is connected with the first carbon steel layer (203) through angle steel (103) in a welding mode.

Images