Heat preservation structure of high-temperature valve of sodium-cooled fast reactor and mounting method of heat preservation structure

Abstract

The invention provides a sodium-cooled fast reactor high-temperature valve thermal insulation structure and an installation method thereof, and belongs to the technical field of sodium-cooled fast neutron reactor high-temperature valve thermal insulation. The heat preservation structure comprises a valve body, and the valve body is sequentially wrapped with a spliced inner-layer heat preservation assembly, a spliced middle-layer heat preservation assembly and a spliced outer-layer heat preservation assembly. The splicing gap of the inner-layer heat preservation assembly and the splicing gap of the middle-layer heat preservation assembly are staggered by 90 degrees, and the splicing gap of the middle-layer heat preservation assembly and the splicing gap of the outer-layer heat preservation assembly are staggered by 90 degrees. The top gaps of the inner-layer heat preservation assembly, the middle-layer heat preservation assembly and the outer-layer heat preservation assembly are covered with the top-layer heat preservation assembly. The technical means that the joints of all the layers of the heat preservation body are staggered by 90 degrees is adopted, and the technical effects that the heat dissipating capacity is about 1 / 3 of the heat dissipating capacity of a double-wall detachable heat preservation structure, heat loss is small, the heat efficiency of a system is improved, and the heat preservation effect is good are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of sodium-cooled fast neutron reactor high-temperature valve insulation, and in particular to a sodium-cooled fast reactor high-temperature valve insulation structure and an installation method thereof. Background Art

[0002] After installing insulation on high-temperature valves, it can prevent scalding, improve working conditions, reduce heat loss in pipelines, and improve economic efficiency. The selection and thickness calculation of insulation materials in the design stage mainly consider the thermal conductivity, bulk density, allowable temperature, compressive strength, moisture content, linear expansion coefficient and other parameters of the insulation materials, and often ignore the influence of insulation structure on insulation performance.

[0003] The operating temperature of some high-temperature valves of the sodium-cooled fast neutron reactor is about 485℃. It adopts a double-wall detachable insulation structure. The outer shell of the insulation metal shell is a stainless steel plate with a thickness of 0.4mm; the side plate is a stainless steel plate with a thickness of 0.5mm; the outer wall is a stainless steel plate with a thickness of 0.6mm. The metal shell is manually filled with bulk glass wool or aluminum silicate fiber until all free space is filled.

[0004] It was found in engineering practice that the existing insulation structure had insulation performance that did not meet the requirements, the insulation outer surface temperature far exceeded the national standard requirements, and at the same time led to a series of problems such as excessive room temperature.

[0005] An inspection of the high-temperature valve insulation on site revealed that the temperature at the joints of the double-wall detachable insulation was much higher than that of other parts. Considering that the insulation was filled with insulation cotton by hand, it was not easy to fill the joints and other corners. It was determined that the fundamental reason why the performance of the double-wall detachable insulation did not meet the requirements was that there were obvious through gaps in the insulation structure, and the insulation in the gaps could not be filled, resulting in excessive heat dissipation in the gaps, and thus a significant increase in the overall heat dissipation. Summary of the invention

[0006] The purpose of the present invention is to provide a sodium-cooled fast reactor high-temperature valve insulation structure and an installation method thereof, so as to solve the problems that the insulation performance of the double-wall detachable insulation structure of some high-temperature valves of the current sodium-cooled fast neutron reactor does not meet the requirements, the temperature of the insulation outer surface far exceeds the national standard requirements, and the room temperature is too high.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A sodium-cooled fast reactor high-temperature valve insulation structure comprises a valve body, wherein the valve body is sequentially wrapped with a spliced ​​inner insulation component, a spliced ​​middle insulation component, and a spliced ​​outer insulation component; the splicing gap of the inner insulation component is staggered by 90° with the splicing gap of the middle insulation component, and the splicing gap of the middle insulation component is staggered by 90° with the splicing gap of the outer insulation component; the top gaps of the inner insulation component, the middle insulation component, and the outer insulation component are covered by a top insulation component.

[0009] In some embodiments, the inner layer thermal insulation component includes two inner layer thermal insulation components 1 and 2 that are symmetrical in structure.

[0010] In some embodiments, the splicing gaps of the inner thermal insulation component 1 and the inner thermal insulation component 2 are arranged vertically.

[0011] In some embodiments, the middle layer insulation component includes a middle layer insulation component one, a middle layer insulation component two and a middle layer insulation component three. The middle layer insulation component one and the middle layer insulation component three are structurally symmetrical and the spliced ​​gap is perpendicular to the axial direction of the insulation component. The middle layer insulation component two is spliced ​​below the middle layer insulation component one and the middle layer insulation component three and the splicing gap and the splicing gap of the inner layer insulation component are staggered by 90° in the radial direction of the inner layer insulation component.

[0012] In some embodiments, the gap between the middle-layer thermal insulation component 2 and the spliced ​​middle-layer thermal insulation component 1 and the middle-layer thermal insulation component 3 is arranged horizontally.

[0013] In some embodiments, the outer thermal insulation component includes two symmetrically structured outer thermal insulation components, one and two.

[0014] In some embodiments, the splicing gap between the outer thermal insulation component 1 and the outer thermal insulation component 2 is in the same direction as the splicing gap of the inner thermal insulation component.

[0015] In some embodiments, the top layer insulation component includes a top layer insulation component 1, a top layer insulation component 2, and a top layer insulation component 3 which are arranged in sequence from bottom to top.

[0016] In some embodiments, in the axial direction of the insulation component, the length dimension of the inner insulation component is greater than that of the middle insulation component, and the length dimension of the middle insulation component is greater than that of the outer insulation component to form a stepped connection portion.

[0017] In some embodiments, in the axial direction of the valve body, the height dimension of the inner insulation component is smaller than that of the middle insulation component, and the height dimension of the middle insulation component is smaller than that of the outer insulation component, so as to form a stepped covering portion.

[0018] In some embodiments, the inner layer insulation component, the middle layer insulation component and the outer layer insulation component are all three-way pipe structures.

[0019] On the other hand, the present invention also provides a method for installing the sodium-cooled fast reactor high-temperature valve insulation structure, comprising:

[0020] Step 1: Install the inner thermal insulation component 1 and the inner thermal insulation component 2 on the valve body;

[0021] Step 2: Install the middle-layer insulation component 1, the middle-layer insulation component 2 and the middle-layer insulation component 3 on the valve body, and stagger the middle-layer insulation penetration gap with the inner-layer insulation by 90° to achieve complete coverage;

[0022] Step 3: Install the outer insulation component 1 and the outer insulation component 2 on the valve body, with the outer insulation penetration gap staggered 90° from the middle insulation to achieve complete coverage;

[0023] Step 4: Install the top insulation member 1 on the valve body, wherein the top insulation member 1 covers the through gap of the inner insulation layer;

[0024] Step 5: Install the second top insulation layer on the valve body, wherein the second top insulation layer covers the through gaps of the first top insulation layer and the middle insulation layer;

[0025] Step 6: Install the top insulation member 3 on the valve body, wherein the top insulation member 3 covers the through gaps of the top insulation member 2 and the outer insulation member;

[0026] Step 7: Cover the outer insulation layer with high temperature resistant silicon cloth.

[0027] Compared with the prior art, the sodium-cooled fast reactor high-temperature valve insulation structure and the installation method thereof provided by the present invention have the following beneficial effects:

[0028] The present invention adopts the technical means of staggering the joints of each layer of the insulation body by 90 degrees, which achieves technical effects such as heat dissipation of about 1 / 3 of the heat dissipation of the double-wall detachable insulation structure, small heat loss, improved system thermal efficiency, and good insulation effect.

[0029] The high-temperature valve has low heat dissipation due to thermal insulation, achieving the technical effect of reducing the temperature tolerance required by the valve electric drive mechanism and related instruments.

[0030] The high-temperature valve insulation is installed in multiple layers and overlapped, which enables different temperature valves to continue to add insulation layers as needed, achieving a technical effect with strong applicability.

[0031] The high-temperature valve insulation is installed in multiple layers and overlapped to achieve a technical effect of lower construction cost.

[0032] Furthermore, the high-temperature valve body insulation at the connection between the valve and the pipeline adopts a stepped installation technology, which achieves technical effects such as heat dissipation of about 1 / 3 of the heat dissipation of the double-wall detachable insulation structure, small heat loss, improved system thermal efficiency, and good insulation effect.

[0033] Furthermore, the top of the high-temperature valve insulation is installed with a multi-layer stepped covering, which achieves technical effects such as heat dissipation of about 1 / 3 of the heat dissipation of the double-wall detachable insulation structure, small heat loss, improved system thermal efficiency, and good insulation effect;

[0034] Furthermore, the high-temperature valve insulation has no overall penetration (the insulation covers the seam of the previous layer of insulation, that is, the seam between the two layers of insulation is staggered, which will not cause the insulation seam to penetrate) and the heat dissipation gap technical means achieves a technical effect of no risk of scalding of high-temperature personnel.

[0035] Furthermore, the heat-insulating outer layer is coated with silicon cloth instead of the stainless steel metal shell, which is convenient to implement and easy to maintain. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for the technical description.

[0037] Figure 1 A three-dimensional diagram of the thermal insulation structure of a high-temperature valve of a sodium-cooled fast reactor provided by the present invention;

[0038] Figure 2 An exploded diagram of the thermal insulation structure of a high-temperature valve of a sodium-cooled fast reactor provided by the present invention;

[0039] Figure 3 A schematic diagram of the inner layer thermal insulation installation provided by the present invention;

[0040] Figure 4 A schematic diagram of the middle layer thermal insulation installation provided by the present invention;

[0041] Figure 5 A schematic diagram of the outer thermal insulation installation provided by the present invention;

[0042] Figure 6 A schematic diagram of the top floor insulation installation provided by the present invention;

[0043] Figure 7 A schematic diagram of the second installation of the top layer thermal insulation provided by the present invention;

[0044] Figure 8 The present invention provides a flowchart of the method for installing the high-temperature valve insulation structure.

[0045] Description of reference numerals:

[0046] 1. Inner insulation component; 2. Middle insulation component; 3. Outer insulation component; 4. Top insulation component; 5. Valve body;

[0047] 11. Inner insulation component one; 12. Inner insulation component two; 21. Middle insulation component one; 22. Middle insulation component two; 23. Middle insulation component three; 31. Outer insulation component one; 32. Outer insulation component two; 41. Top insulation component one; 42. Top insulation component two; 43. Top insulation component three. DETAILED DESCRIPTION

[0048] The following is further explained in detail through specific implementation methods.

[0049] like Figures 1 to 7 As shown, the present invention provides a sodium-cooled fast reactor high-temperature valve insulation structure, including a valve body 5, an inner insulation component 1, a middle insulation component 2, an outer insulation component 3, and a top insulation component 4.

[0050] The insulation structure adopts multi-layer overlapping installation, and the insulation of the superimposed layer can completely cover the splicing gap of the bottom insulation. At the same time, the splicing gap of the superimposed layer is staggered at an angle of 90° with the bottom layer, that is, the splicing gap of the middle insulation component 2 is staggered at 90° with the splicing gap of the inner insulation component 1, and the splicing gap of the outer insulation component 3 is staggered at 90° with the splicing gap of the middle insulation component 2, thereby avoiding the occurrence of through gaps in the main body.

[0051] like Figure 5 As shown, the dimension of the insulation component of the inner insulation component 1 in the axial direction (i.e., the direction perpendicular to the axis of the valve body 5, with the axis of the valve body 5 pointing vertically downward) is larger than that of the middle insulation component 2, and the axial dimension of the middle insulation component 2 is larger than that of the outer insulation component 3, so that after the inner insulation component 1, the middle insulation component 2, and the outer insulation component 3 are installed on the valve body 5 in sequence, a stepped connection portion is formed, and the body insulation at the connection between the valve and the pipeline is installed in a stepped manner, and the bottom insulation extends 100mm longer than the covering layer, that is, the axial dimension of the inner insulation component 1 is 100mm larger than the axial dimension of the middle insulation component 2. It should be noted that the above-mentioned bottom layer can be the inner insulation component 1 or the middle insulation component 2. When the bottom insulation is the inner insulation component 1, the covering layer is the middle insulation component 2; when the bottom insulation is the middle insulation component 2, the covering layer is the outer insulation component 3.

[0052] Preferably, the step width at each location is 100 mm.

[0053] The top of the insulation is installed with multiple layers of stepped covering, the first layer (i.e., the top insulation piece 1 41) covers the gap between the valve body 5 and the bottom insulation (inner insulation component 1), the second layer (i.e., the top insulation piece 2 42) covers the gap between the bottom insulation (inner insulation component 1) and the superimposed layer (middle insulation component 2), and so on. This ensures that the insulation structure has no overall penetrating heat dissipation gaps.

[0054] Preferably, the thermal insulation top is installed with multiple layers of stepped covering, and each layer covers an annular heat dissipation gap.

[0055] Preferably, the outer insulation layer (outer insulation component 3 + top insulation component 43) is covered with silicon cloth.

[0056] The thermal insulation structure of the present invention and the double-wall detachable thermal insulation structure were tested and compared using a test bench. It was found from the test data that the heat dissipation of the thermal insulation structure of the present invention is approximately 1 / 3 of the heat dissipation of the double-wall detachable thermal insulation structure, and the thermal insulation effect is good.

[0057] Example

[0058] Determine the sizes of the inner insulation component 1, the middle insulation component 2, the outer insulation component 3, and the top insulation component 4 according to the size of the high-temperature valve, wrap the inner insulation component 1, the middle insulation component 2, the outer insulation component 3 in sequence on the valve body 5, and install the top insulation component 4 on the top of the three-layer insulation component (insulation top) to cover the gap at the top between the three-layer insulation component and the valve body 5.

[0059] like Figure 3 As shown, the inner insulation component 1 is a T-shaped three-way pipe structure as a whole, and the inner insulation component 1 includes two symmetrical inner insulation parts 11 and 12. The inner insulation parts 11 and 12 are installed on the valve body 5, and the splicing gaps of the inner insulation parts 11 and 12 are arranged up and down.

[0060] like Figure 4 As shown, the middle-layer insulation component 2 is a T-shaped three-way pipe structure as a whole, and its radial dimension is larger than that of the inner-layer insulation component 1, and the middle-layer insulation component 2 is wrapped outside the inner-layer insulation component 1. In the axial direction of the insulation component, the inner diameter of the middle-layer insulation component 2 is equal to the outer diameter of the inner-layer insulation component 1, so that the middle-layer insulation component 2 is just wrapped outside the inner-layer insulation component 1, or the inner diameter of the middle-layer insulation component 2 is slightly smaller than that of the inner-layer insulation component 1, so that the middle-layer insulation component 2 and the inner-layer insulation component 1 are interference-fitted.

[0061] The middle layer insulation assembly 2 includes a middle layer insulation component 1 21, a middle layer insulation component 22, and a middle layer insulation component 3 23. The middle layer insulation component 21 and the middle layer insulation component 3 23 are symmetrical in structure, and the gap between the splicing and the gap between the inner layer insulation component 1 11 and the inner layer insulation component 2 12 are staggered by 90°. Figure 4 The middle insulation component 1 21 and the middle insulation component 3 23 are located at the top, and the middle insulation component 2 22 is located at the bottom, so that the gap between the middle insulation component 2 22 and the middle insulation component 1 21 and the middle insulation component 3 23 is arranged horizontally, and the gap between the middle insulation component 2 22 and the inner insulation component 1 11 and the inner insulation component 2 12 is also staggered by 90 degrees.

[0062] Install the middle insulation component 1 21 , the middle insulation component 2 22 , and the middle insulation component 3 23 on the valve body 5 , and ensure that the middle insulation component 2 is staggered 90° from the inner insulation component 1 through the gap to achieve complete coverage.

[0063] The dimension of the middle-layer insulation component 2 in the axial direction of the insulation component is about 100 mm smaller than that of the inner-layer insulation component 1 , that is, the insulation portion with the pipeline is 100 mm shorter than the inner-layer insulation portion.

[0064] The dimension of the middle insulation component 2 in the axial direction of the valve body 5 is higher than that of the inner insulation component 1 , so that a step (a step-shaped covering portion) is formed on the insulation top.

[0065] like Figure 5 As shown, the outer insulation component 3 is a T-shaped three-way pipe structure as a whole, and its radial size is larger than the middle insulation component 2. The outer insulation component 3 is wrapped around the outside of the middle insulation component 2. In the axial direction of the insulation component, the inner diameter of the outer insulation component 3 is equal to the outer diameter of the middle insulation component 2, so that the outer insulation component 3 is just wrapped around the outside of the middle insulation component 2, or the inner diameter of the outer insulation component 3 is slightly smaller than the middle insulation component 2, so that the outer insulation component 3 and the middle insulation component 2 are interference fit.

[0066] The outer thermal insulation component 3 includes a spliced ​​outer thermal insulation component 1 31 and an outer thermal insulation component 2 32. The outer thermal insulation component 1 31 and the outer thermal insulation component 2 32 are symmetrical in structure, and the spliced ​​gap is staggered by 90° from the gaps of the middle thermal insulation component 1 21, the middle thermal insulation component 2 22, and the middle thermal insulation component 3 23. The gap of the outer thermal insulation component 3 is in the same direction as the gap of the inner thermal insulation component 1.

[0067] The dimension of the outer layer heat-insulating component 3 in the axial direction of the heat-insulating component is about 100 mm smaller than the dimension of the middle layer heat-insulating component 2 , that is, 100 mm shorter.

[0068] An outer insulation component 1 31 and an outer insulation component 2 32 are installed on the valve body 5 to ensure that the outer insulation component 3 penetrates the gap and is staggered by 90° with the middle insulation component 2 to achieve complete coverage.

[0069] like Figure 6 As shown, the top layer insulation component 4 includes top layer insulation component 1 41, top layer insulation component 2 42, and top layer insulation component 3 43 arranged in sequence from bottom to top. The inner layer insulation component 1, the middle layer insulation component 2, and the outer layer insulation component 3 are covered by three layers, so that their top gaps are covered by the top layer insulation component 4.

[0070] A top insulation member 41 is installed on the valve body 5, and the top insulation member 41 covers the through gap of the inner insulation (inner insulation component 1). The top of the top insulation member 41 and the top of the middle insulation component 2 are basically in the same height.

[0071] The second top insulation member 42 is installed on the valve body 5, and the second top insulation member 42 covers the through gap of the first top insulation member 41 and the middle insulation (middle insulation assembly 2). The top of the second top insulation member 42 and the top of the outer insulation assembly 3 are basically guaranteed to be in the same height.

[0072] The top insulation member 3 43 is installed on the valve body 5 , and the top insulation member 3 43 covers the through gap of the top insulation member 2 42 and the outer insulation (outer insulation assembly 3 ). The top insulation member 3 43 is arranged above the outer insulation assembly 3 .

[0073] The outer insulation layer (referring to the outer surface of the outer insulation component 3 + the top insulation component 3 43, that is, the outer surface after all the insulation is installed) is covered with high temperature resistant silicon cloth. The silicon cloth replaces the stainless steel metal shell, which is convenient to implement and easy to maintain.

[0074] In addition, if Figure 8 As shown, the present invention also provides a method for installing a sodium-cooled fast reactor high-temperature valve insulation structure, comprising the following steps:

[0075] Step 1: Install the inner thermal insulation 11 and the inner thermal insulation 12 on the valve body 5;

[0076] Step 2: Install middle insulation 21, middle insulation 22, and middle insulation 23 on the valve body 5. The middle insulation penetration gap is staggered by 90° with the inner insulation to achieve complete coverage; the middle insulation is 100mm shorter than the inner insulation at the pipe insulation.

[0077] Step 3: Install outer insulation 31 and outer insulation 32 on the valve body 5. The outer insulation penetrates the gap and is staggered by 90° with the middle insulation to achieve complete coverage. The outer insulation is 100mm shorter than the middle insulation at the pipe insulation.

[0078] Step 4: Install the top insulation layer 41 on the valve body 5, and the top insulation layer 41 covers the through gap of the inner insulation layer;

[0079] Step 5: Install the top insulation layer 42 on the valve body 5, the top insulation layer 42 covers the through gaps of the top insulation layer 41 and the middle insulation layer;

[0080] Step 6: Install the top insulation layer 43 on the valve body 5, the top insulation layer 43 covers the through gaps of the top insulation layer 42 and the outer insulation layer;

[0081] Step 7: Cover the outer insulation layer with high temperature resistant silicon cloth.

[0082] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A sodium-cooled fast reactor high temperature valve insulation structure, comprising a valve body (5), characterized in that: The valve body (5) is wrapped with a spliced ​​inner insulation component (1), a spliced ​​middle insulation component (2), and a spliced ​​outer insulation component (3) in sequence; the splicing gap of the inner insulation component (1) and the splicing gap of the middle insulation component (2) are staggered by 90°, and the splicing gap of the middle insulation component (2) and the splicing gap of the outer insulation component (3) are staggered by 90°; the top gaps of the inner insulation component (1), the middle insulation component (2), and the outer insulation component (3) are covered by the top insulation component (4).

2. The sodium-cooled fast reactor high temperature valve insulation structure according to claim 1, characterized in that: The inner layer thermal insulation component (1) comprises two inner layer thermal insulation components, a first component (11) and a second component (12) with symmetrical structures.

3. The sodium-cooled fast reactor high temperature valve insulation structure according to claim 2, characterized in that: The splicing gaps of the inner thermal insulation component 1 (11) and the inner thermal insulation component 2 (12) are arranged up and down.

4. The sodium-cooled fast reactor high temperature valve insulation structure according to claim 1, characterized in that: The middle layer thermal insulation component (2) comprises a middle layer thermal insulation component one (21), a middle layer thermal insulation component two (22) and a middle layer thermal insulation component three (23); the middle layer thermal insulation component one (21) and the middle layer thermal insulation component three (23) are symmetrical in structure and the splicing gap is perpendicular to the axial direction of the thermal insulation component; the middle layer thermal insulation component two (22) is spliced ​​below the middle layer thermal insulation component one (21) and the middle layer thermal insulation component three (23) and the splicing gap is staggered by 90° with the splicing gap of the inner layer thermal insulation component (1) in the radial direction of the inner layer thermal insulation component (1).

5. The sodium-cooled fast reactor high temperature valve insulation structure according to claim 1, characterized in that: The outer layer thermal insulation component (3) comprises two outer layer thermal insulation components (1) (31) and (2) (32) with symmetrical structures.

6. The sodium-cooled fast reactor high temperature valve insulation structure according to claim 1, characterized in that: The top layer thermal insulation component (4) comprises a top layer thermal insulation component 1 (41), a top layer thermal insulation component 2 (42) and a top layer thermal insulation component 3 (43) which are arranged in sequence from bottom to top.

7. The sodium-cooled fast reactor high temperature valve insulation structure according to claim 1, characterized in that: In the axial direction of the insulation component, the length dimension of the inner insulation component (1) is greater than that of the middle insulation component (2), and the length dimension of the middle insulation component (2) is greater than that of the outer insulation component (3), so as to form a stepped connection portion.

8. The sodium-cooled fast reactor high temperature valve insulation structure according to claim 1, characterized in that: In the axial direction of the valve body, the height dimension of the inner insulation component (1) is smaller than that of the middle insulation component (2), and the height dimension of the middle insulation component (2) is smaller than that of the outer insulation component (3), so as to form a stepped covering portion.

9. The sodium-cooled fast reactor high temperature valve insulation structure according to claim 1, characterized in that: The inner layer thermal insulation component (1), the middle layer thermal insulation component (2) and the outer layer thermal insulation component (3) are all three-way pipe structures.

10. A method for installing a sodium-cooled fast reactor high temperature valve insulation structure according to any one of claims 1 to 9, characterized in that: include: Step 1: Installing the inner thermal insulation component 1 (11) and the inner thermal insulation component 2 (12) on the valve body (5); Step 2: Install the middle-layer insulation component 1 (21), the middle-layer insulation component 2 (22) and the middle-layer insulation component 3 (23) on the valve body (5), with the middle-layer insulation penetration gap being staggered by 90° from the inner-layer insulation to achieve complete coverage; Step 3: Install the outer insulation component 1 (31) and the outer insulation component 2 (32) on the valve body (5), with the outer insulation penetration gap staggered by 90° from the middle insulation to achieve complete coverage; Step 4: Install the top insulation member 1 (41) on the valve body (5), wherein the top insulation member 1 (41) covers the through gap of the inner insulation layer; Step 5: Install the second top insulation layer (42) on the valve body (5), wherein the second top insulation layer (42) covers the through gaps of the first top insulation layer (41) and the middle insulation layer; Step 6: Install the third top-layer insulation member (43) on the valve body (5), wherein the third top-layer insulation member (43) covers the second top-layer insulation member (42) and the through-slit of the outer insulation member; Step 7: Cover the outer insulation layer with high temperature resistant silicon cloth.

Images