Prefabricated cabin type transformer substation cabin suitable for extremely cold temperature

Abstract

The technical problem to be solved by the utility model is to provide the prefabricated cabin type transformer substation cabin under the extremely cold temperature, the temperature in the cabin can still be maintained above-5 DEG C when the extreme environment temperature is-50 DEG C by selecting a heat preservation and insulation material with a proper thickness, and the normal working temperature of secondary combination equipment is met. The prefabricated cabin type transformer substation cabin comprises a cabin body, a cabin top and a cabin bottom, gap areas inside two layers of sandwich structures of the cabin body are filled with rock wool boards, the thickness of each rock wool board is 80 mm, gap areas inside two layers of sandwich structures of the cabin top are filled with rock wool boards, and the thickness of each rock wool board is larger than or equal to 80 mm; a rock wool board is filled in a gap area of the support frame at the cabin bottom, and the thickness of the rock wool board is 80mm; a first broken bridge heat insulation structure is arranged between the middle stand column and the inner side plate of the cabin body framework structure, and a second broken bridge heat insulation structure is arranged between each corner stand column and the inner side plate of the cabin body framework structure, so that the prefabricated cabin type transformer substation cabin can be popularized and applied in extreme environment temperature.

Description

Technical Field

[0001] The utility model relates to the technical field of transformer substations, and in particular to a prefabricated substation cabin suitable for use in extremely cold temperatures. Background Art

[0002] Prefabricated cabin substation adopts the concept of "standardized design, factory processing, and prefabricated construction", forming a new type of fast-delivery and fast-assembly substation construction model. It has many advantages such as low energy consumption, light environmental pollution, fast construction speed, small footprint, low construction investment, flexible layout, long service life, safety and reliability, green environmental protection, and beautiful appearance. The widespread use of prefabricated cabin substation has become an inevitable trend.

[0003] The normal operating temperature of the monitoring server is -5℃~+45℃. Extremely cold environments below -40℃ will have a serious impact on the safe operation of electrical equipment. The prefabricated cabin must ensure that at an extreme temperature of -50℃, no industrial air conditioners, heaters or other heating facilities and equipment are used. Only by relying on the heat generated by its own operation, the ambient temperature in the prefabricated cabin can be kept above -5℃, so that the secondary assembly equipment can operate normally in the prefabricated cabin. In order to ensure the promotion and application of prefabricated cabin substations in extremely cold areas, the prefabricated cabin of the secondary assembly equipment in the prefabricated cabin substation should be able to work normally in an extremely low temperature environment of -50℃. This puts forward higher requirements on the thermal insulation performance of the prefabricated cabin of the substation. It is necessary to select suitable thermal insulation materials during the production process of the prefabricated cabin, and the thickness should be determined according to thermodynamic calculations. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a prefabricated cabin-type substation cabin for extremely cold temperatures. By selecting thermal insulation materials of appropriate thickness, the temperature inside the cabin can still be maintained above -5°C at an extreme ambient temperature of -50°C, thereby meeting the normal operating temperature of secondary combination equipment.

[0005] The technical solution adopted by the utility model to solve its technical problems is: the prefabricated cabin-type substation cabin suitable for extremely cold temperatures includes a cabin body, a cabin roof, and a cabin bottom, wherein the lower end of the cabin body is arranged on the cabin bottom, and the cabin roof is arranged at the upper end of the cabin body; the cabin body includes an inner side panel, an outer side panel, and a cabin body skeleton structure, and the upper and lower ends of the cabin body skeleton structure are respectively connected to the cabin roof and the cabin bottom, and the cabin body skeleton structure is composed of a plurality of columns and a plurality of light steel keels; the inner side panel and the outer side panel are respectively arranged inside and outside the cabin body skeleton structure to form a two-layer sandwich structure A together; the cabin roof includes a front side panel, a rear side panel, a left side panel, a right side panel, a top panel, a bottom panel, and a cabin roof skeleton structure. The front side plate, rear side plate, left side plate, right side plate, top plate and bottom plate are respectively arranged on the outside of the cabin top skeleton structure and wrapped inside to form a two-layer sandwich structure B; the cabin bottom includes a support plate and a cabin bottom support frame, the support plate is arranged above the cabin bottom support frame, and the lower end of the cabin body skeleton structure is arranged on the support plate, and the internal gap area of ​​the two-layer sandwich structure A is filled with rock wool board and the thickness of the rock wool board is 80mm; the internal gap area of ​​the two-layer sandwich structure B is filled with rock wool board and the thickness of the rock wool board is greater than or equal to 80mm; the gap area of ​​the support frame of the cabin bottom is filled with rock wool board and the thickness of the rock wool board is 80mm;

[0006] The multiple columns of the cabin skeleton structure include four L-shaped corner columns and multiple U-shaped center columns. A first thermal insulation structure is arranged between each center column of the cabin skeleton structure and the inner plate, and a second thermal insulation structure is arranged between each corner column of the cabin skeleton structure and the inner plate.

[0007] Furthermore, the thickness of the rock wool board filled inside the two-layer sandwich structure of the cabin roof is 90-100 mm.

[0008] Furthermore, the first thermal insulation structure includes a first connecting plate A, and second connecting plates A are arranged on both sides of the first connecting plate A and the two connecting plates A are perpendicular to each other. The first connecting plate A and the two second connecting plates A together form a U-shaped structure and are fixedly arranged in the corresponding middle column;

[0009] A third connecting plate A is disposed at one end of the second connecting plate A away from the first connecting plate A and the two are perpendicular to each other, and two sides of the third connecting plate A are respectively fixedly connected to the corresponding central column and inner side plate;

[0010] A fourth connecting plate A is provided at one end of the third connecting plate A away from the second connecting plate A and is parallel to the second connecting plate A. An O-shaped sealing strip is provided at one end of the fourth connecting plate away from the third connecting plate A. The two side walls of the center column are respectively located between the second connecting plate A and the fourth connecting plate A on the corresponding sides and are in sealing contact with the sealing strips on the corresponding sides.

[0011] The U-shaped structure formed by the first connecting plate A and the two second connecting plates A is filled with a rock wool board adapted thereto;

[0012] The first connecting plate A to the fourth connecting plate A are all made of non-metallic materials with low thermal conductivity.

[0013] Furthermore, the first thermal insulation structure includes a first connecting plate B and a second connecting plate B, one end of the first connecting plate B is connected to one end of the second connecting plate B and the two are perpendicular to each other, and the first connecting plate B and the second connecting plate B are respectively fixedly arranged on the inner side walls of the corresponding corner columns;

[0014] A third connecting plate B is disposed at one end of the first connecting plate B away from the second connecting plate B and the two are perpendicular to each other, and a fourth connecting plate B is disposed at one end of the third connecting plate B away from the first connecting plate B and is parallel to the first connecting plate B;

[0015] A fifth connecting plate B is disposed at one end of the second connecting plate B away from the first connecting plate B and the two are perpendicular to each other, and a sixth connecting plate B is disposed at one end of the fifth connecting plate B away from the second connecting plate B and is parallel to the second connecting plate B;

[0016] One end of the fourth connecting plate B is fixedly connected to one end of the sixth connecting plate B and the two are perpendicular to each other, and the fourth connecting plate B and the sixth connecting plate B are both fixedly connected to the inner plate;

[0017] A seventh connecting plate B is disposed at one end of the fourth connecting plate B away from the sixth connecting plate B and the two are perpendicular to each other, and an O-shaped sealing strip is disposed at one end of the seventh connecting plate B away from the fourth connecting plate B and the sealing strip is in sealing contact with the outer plate and the rock wool board on the corresponding side respectively;

[0018] An eighth connecting plate B is disposed at one end of the sixth connecting plate B away from the fourth connecting plate B and the two are perpendicular to each other, and an O-shaped sealing strip is disposed at one end of the eighth connecting plate B away from the sixth connecting plate B and the sealing strip is in sealing contact with the outer plate and the rock wool board on the corresponding side respectively;

[0019] The first connecting plate B to the eighth connecting plate B are all made of non-metallic materials with low thermal conductivity.

[0020] Furthermore, the inner surface of the support plate is paved with an anti-static floor.

[0021] Furthermore, the front side plate, rear side plate, left side plate, right side plate, top plate, bottom plate and support plate are all made of steel plates.

[0022] Beneficial effects of the utility model:

[0023] By filling the sandwich structure on the cabin top with rock wool boards with a thickness greater than or equal to 80 mm, filling the sandwich structure of the cabin body with rock wool boards with a thickness of 80 mm, filling the gap area of ​​the support frame at the bottom of the cabin with rock wool boards with a thickness of 80 mm, and providing a first thermal insulation structure between each center column and the inner plate of the cabin body skeleton structure, and a second thermal insulation structure between each corner column and the inner plate, it is ensured that when the extreme ambient temperature outside the cabin of the prefabricated cabin-type substation is -50°C, the temperature inside the cabin can be maintained above -5°C, meeting the normal operating temperature of the secondary combination equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a structural schematic diagram of the prefabricated cabin-type substation cabin suitable for use in extremely cold temperatures described in the utility model;

[0025] Figure 2 It is a schematic diagram of the combined structure of the inner plate, the outer plate, the middle column and the first thermal insulation structure of the utility model;

[0026] Figure 3 It is a schematic diagram of the combined structure of the central column and the first thermal insulation structure of the utility model;

[0027] Figure 4 It is a schematic diagram of the combined structure of the inner side plate, the outer side plate, the corner column and the second thermal insulation structure of the utility model;

[0028] Figure 5 It is a schematic diagram of the combined structure of the corner column and the second thermal insulation structure of the utility model;

[0029] Figure 6 is the relationship diagram between temperature gradient and Fourier's law;

[0030] Figure 7 Schematic diagram of steady-state heat conduction of a single flat wall;

[0031] Figure 8 Schematic diagram of steady-state heat conduction of multi-layer flat walls;

[0032] Markings in the figure: cabin roof 1, cabin body 2, inner plate 201, outer plate 202, center column 203, corner column 204, cabin bottom 3, first thermal insulation structure 4, first connecting plate A401, second connecting plate A402, third connecting plate A403, fourth connecting plate A404, second thermal insulation structure 5, first connecting plate B501, second connecting plate B502, third connecting plate B503, fourth connecting plate B504, fifth connecting plate B505, sixth connecting plate B506, seventh connecting plate B507, eighth connecting plate B508, sealing strip 6, rock wool board 7. DETAILED DESCRIPTION

[0033] The specific implementation of the utility model is further described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0034] It should be noted that the directions or positional relationships indicated by all directional indication terms such as "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" in the embodiments of the present application are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention. They are only used to explain the relative positional relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0035] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0036] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0037] like Figure 1-5As shown, the prefabricated cabin-type substation cabin suitable for use in extremely cold temperatures includes a cabin body 2, a cabin roof 1, and a cabin bottom 3. The lower end of the cabin body 2 is arranged on the cabin bottom 3, and the cabin roof 1 is arranged at the upper end of the cabin body 2; the cabin body 2 includes an inner plate 201, an outer plate 202, and a cabin body skeleton structure. The inner plate 201 has four inner plates connected end to end in sequence to form a rectangular shell, and the outer plate 202 also has four outer plates connected end to end in sequence to form a rectangular shell. The upper and lower ends of the cabin body skeleton structure are respectively connected to the cabin roof 1 and the cabin bottom 3, and the cabin body skeleton structure is composed of a plurality of columns and a plurality of light steel keels; the inner plate 201 and the outer plate 202 are respectively arranged on the cabin The inside and outside of the cabin skeleton structure together form a two-layer sandwich structure A; the cabin roof 1 includes a front side panel, a rear side panel, a left side panel, a right side panel, a top panel, a bottom panel, and a cabin roof skeleton structure, and the front side panel, the rear side panel, the left side panel, the right side panel, the top panel, and the bottom panel are respectively arranged on the outside of the cabin roof skeleton structure and wrapped inside to form a two-layer sandwich structure B; the cabin bottom 3 includes a support plate and a cabin bottom support frame, the support plate is arranged above the cabin bottom support frame, and the lower end of the cabin skeleton structure is arranged on the support plate. It should be noted that the cabin 2, the cabin roof 1, and the cabin bottom 3 are all prior art, and only the related structures involved are listed here, not all;

[0038] When choosing insulation materials for filling, the thermal conductivity and combustion grade of the materials should be considered first. Selecting insulation materials with low thermal conductivity can reduce the thickness of the insulation layer and increase the usable area in the cabin; selecting insulation materials with high combustion grade can reduce the loss of equipment and property in case of fire. At present, there are many types of thermal insulation and flame retardant materials on the market, including foamed polyurethane, rock wool board, FC board, polystyrene board, graphite polystyrene board, extruded polystyrene board, phenolic foam board, ultra-thin vacuum insulation board, etc. They have different advantages in thermal conductivity and combustion performance.

[0039] From the relevant data in Table 1, it can be found that the thermal conductivity of foamed polyurethane is better than that of rock wool board and FC board, but the difference is not very large. The combustion performance of foamed polyurethane is only Class B (flammable), and the combustion performance of the latter two materials is Class A (non-combustible). The fire resistance is better than that of foamed polyurethane. Fire resistance is one of the key factors in the design and production of prefabricated cabins. Considering the processing technology and construction cost, rock wool board is suitable for filling the prefabricated cabin as the insulation material.

[0040]

[0041] Table 1 Comparison of some properties of different thermal insulation and flame retardant materials

[0042] When choosing the insulation material to be filled, the thickness of the insulation material should also be considered. The thickness should be determined based on thermodynamic calculations to avoid insufficient thickness that reduces the insulation effect or excessive thickness that causes waste of material costs.

[0043] According to the heat conduction model formula of prefabricated cabin engineering: The thickness of rock wool insulation material can be calculated:

[0044] Take the lowest extreme temperature value t2 = -50 °C, the target temperature in the prefabricated cabin t1 = -5 °C, and the maximum thermal conductivity of the rock wool board λ = 0.046, which is the worst thermal insulation performance;

[0045] Take the external dimensions of the prefabricated cabin as an example: length L = 12.2m, height H = 3.2m, width D = 2.8m, and the heat dissipation area is calculated as the maximum, which is A = 164㎡. In order to increase the capacity of the prefabricated cabin and improve the space utilization rate in the cabin, the secondary equipment cabinets in the cabin are arranged in double rows against the wall with a width of 800mm. The maximum number of cabinets that can be accommodated is 24. The heat dissipation power of each cabinet is calculated as 200W / face. The heat dissipation of the prefabricated cabin equipment is Q1 = 200×24 = 4800W.

[0046] The compensation heat power in the prefabricated cabin is mainly the heat emitted by the secondary equipment in the cabin during operation and the compensation heat power of the air conditioner (or heater). Without considering the compensation heat power of the air conditioner (or heater) and the solar radiation heat, the compensation heat in the cabin is completely the heat emitted by the secondary equipment during operation.

[0047] According to the above heat conduction model formula, the thickness of the rock wool board insulation material can be calculated:

[0048]

[0049] According to the calculation results, if no other heating measures are adopted and only the heat generated by the secondary equipment itself is used, the thickness of the rock wool insulation layer should be at least 71mm. After the above calculation and considering a certain margin, the use of rock wool boards of not less than 80mm in the prefabricated cabin can ensure that after the secondary equipment in the prefabricated cabin is put into operation, when the extreme ambient temperature outside the cabin is -50℃, the cabin temperature can be maintained above -5℃;

[0050] The thickness of the rock wool board insulation material calculated by the above heat conduction model is not less than 80 mm. Therefore, the gap area inside the two-layer sandwich structure A is filled with rock wool board 7, and the thickness of the rock wool board 7 is 80 mm; the gap area inside the two-layer sandwich structure B is filled with rock wool board 7, and the thickness of the rock wool board 7 is greater than or equal to 80 mm; the gap area of ​​the support frame of the bilge 3 is filled with rock wool board 7, and the thickness of the rock wool board 7 is 80 mm;

[0051] The multiple columns of the cabin skeleton structure include four L-shaped corner columns 204 and multiple U-shaped center columns 203. A first thermal insulation structure 4 is arranged between each center column 203 of the cabin skeleton structure and the inner plate 201. A second thermal insulation structure 5 is arranged between each corner column 204 of the cabin skeleton structure and the inner plate 201. The thermal insulation structure reduces the heat conduction between the cabin skeleton structure and the inner plate 201, thereby further improving the thermal insulation effect of the prefabricated cabin.

[0052] In this embodiment, the insulation process of the cabin roof 1 is consistent with the insulation process of the cabin body 2, but because the cabin roof 1 is greatly affected by direct sunlight, the insulation effect of the cabin roof 1 is smaller than that of the cabin body 2 with the same thickness of insulation material. Therefore, the thickness of the rock wool board 7 of the cabin roof 1 is 1.1-1.2 times the thickness of the rock wool board 7 of the cabin body 2, and the thickness of the rock wool board 7 filled inside the two-layer sandwich structure of the cabin roof 1 is 90-100mm.

[0053] like Figure 2 , Figure 3 As shown, in this embodiment, as a preference, the first thermal insulation structure 4 includes a first connecting plate A401, and second connecting plates A402 are arranged on both sides of the first connecting plate A401 and the two are perpendicular to each other, and the first connecting plate A401 and the two second connecting plates A402 together form a U-shaped structure and are fixedly arranged in the corresponding middle column 203;

[0054] A third connecting plate A403 is disposed at one end of the second connecting plate A402 away from the first connecting plate A401 and the two are perpendicular to each other, and two sides of the third connecting plate A403 are fixedly connected to the corresponding middle column 203 and the inner side plate 201 respectively;

[0055] A fourth connecting plate A404 is provided at one end of the third connecting plate A403 away from the second connecting plate A402 and is parallel to the second connecting plate A402. An O-shaped sealing strip 6 is provided at one end of the fourth connecting plate away from the third connecting plate A403. The two side walls of the center column 203 are respectively located between the second connecting plate A402 and the fourth connecting plate A404 on the corresponding sides and are in sealing contact with the sealing strip 6 on the corresponding sides.

[0056] The U-shaped structure formed by the first connecting plate A401 and the two second connecting plates A402 is filled with a rock wool board 7 adapted thereto;

[0057] The first connecting plate A401 to the fourth connecting plate A404 are all made of non-metallic materials with low thermal conductivity, that is, the first connecting plate A401, the two second connecting plates A402, the two third connecting plates A403, and the two fourth connecting plates A404 are all made of non-metallic materials with low thermal conductivity, such as plastic, etc. The center column 203 is separated from the inner panel 201 by the first thermal insulation structure 4, which reduces the heat conduction between the inner panel 201 and the center column 203, thereby further improving the insulation effect of the prefabricated cabin.

[0058] like Figure 4 , Figure 5 As shown, in this embodiment, as a preference, the second thermal insulation structure 5 includes a first connecting plate B501 and a second connecting plate B502, one end of the first connecting plate B501 is connected to one end of the second connecting plate B502 and the two are perpendicular to each other, and the first connecting plate B501 and the second connecting plate B502 are respectively fixedly arranged on the inner side walls of the corresponding corner columns 204;

[0059] A third connecting plate B503 is disposed at one end of the first connecting plate B501 away from the second connecting plate B502 and the two are perpendicular to each other, a fourth connecting plate B504 is disposed at one end of the third connecting plate B503 away from the first connecting plate B501 and is parallel to the first connecting plate B501, and the fourth connecting plate B504 is fixedly connected to the corresponding inner side plate 201 area;

[0060] A fifth connecting plate B505 is disposed at one end of the second connecting plate B502 away from the first connecting plate B501 and the two are perpendicular to each other, a sixth connecting plate B506 is disposed at one end of the fifth connecting plate B505 away from the second connecting plate B502 and is parallel to the second connecting plate B502, and the sixth connecting plate B506 is fixedly connected to the corresponding inner side plate 201 area;

[0061] One end of the fourth connecting plate B504 is fixedly connected to one end of the sixth connecting plate B506 and the two are perpendicular to each other. The fourth connecting plate B504 and the sixth connecting plate B506 are both fixedly connected to the inner plate 201;

[0062] A seventh connecting plate B507 is disposed at one end of the fourth connecting plate B504 away from the sixth connecting plate B506 and the two are perpendicular to each other, and an O-shaped sealing strip 6 is disposed at one end of the seventh connecting plate B507 away from the fourth connecting plate B504 and the sealing strip 6 is in sealing contact with the outer plate 202 and the rock wool plate 7 on the corresponding side respectively;

[0063] An eighth connecting plate B508 is disposed at one end of the sixth connecting plate B506 away from the fourth connecting plate B504 and the two are perpendicular to each other, and an O-shaped sealing strip 6 is disposed at one end of the eighth connecting plate B508 away from the sixth connecting plate B506 and the sealing strip 6 is in sealing contact with the outer plate 202 and the rock wool plate 7 on the corresponding side respectively;

[0064] The first connecting plate B501 to the eighth connecting plate B508 are all made of non-metallic materials with low thermal conductivity, that is, the first connecting plate B501, the second connecting plate B502, the third connecting plate B503, the fourth connecting plate B504, the fifth connecting plate B505, the sixth connecting plate B506, the seventh connecting plate B507, and the eighth connecting plate B508 are all made of non-metallic materials with low thermal conductivity, such as plastic, etc. The corner column 204 is separated from the inner plate 201 by the second thermal insulation structure 5, thereby reducing the heat conduction between the inner plate 201 and the corner column 204, thereby further improving the insulation effect of the prefabricated cabin.

[0065] In this embodiment, in order to dissipate the electrostatic charge in the cabin 2, prevent electronic equipment failure caused by static electricity, and protect the equipment from damage and wear, the inner surface of the support plate is paved with an anti-static floor.

[0066] In this embodiment, preferably, the front side plate, rear side plate, left side plate, right side plate, top plate, bottom plate and support plate are all made of aluminum-zinc coated steel plates.

[0067] The above-mentioned prefabricated cabin engineering heat conduction model formula is obtained through the following steps:

[0068] 1) Heat conduction and Fourier's law

[0069] Heat conduction, also known as heat conduction, is a method of heat transfer in which there is a temperature difference inside an object or between two objects in direct contact, and heat is automatically transferred from the high-temperature part to the low-temperature part, or from the high-temperature object to the low-temperature object in contact with it.

[0070] The basic law of heat conduction is Fourier's law, which states that in a solid flat wall with uniform mass and stable chemical properties, when heat conduction is stable, the heat transfer rate Q through the isothermal surface is proportional to the heat conduction area A perpendicular to the heat flow direction and the temperature gradient.

[0071] Proportional [ ,Right now:

[0072] Where: Q is the heat transfer rate or heat flux, that is, the amount of heat passing through the entire heat transfer area of ​​the solid wall per unit time, W or J / s;

[0073] A is the heat conduction area, that is, the cross-sectional area perpendicular to the heat flow direction, m2;

[0074] λ is the thermal conductivity or thermal conductivity of the material, W / (m·K) or W / (m·℃).

[0075] is the temperature gradient along the x direction, that is, the ratio of the temperature difference Δt between the two isothermal surfaces to the vertical distance Δx between them, K / m or ℃ / m; the temperature gradient is a vector, its direction is perpendicular to the isothermal surface and its positive direction points to the direction of temperature increase. For a stable one-dimensional temperature field, the temperature only changes along the x direction, then the temperature gradient can be expressed as

[0076] like Figure 6 As shown, the negative sign in equation (1) means that the direction of heat flow is opposite to the direction of temperature gradient, that is, heat is transferred from high temperature to low temperature.

[0077] 2) Steady-state heat conduction of a single flat wall

[0078] like Figure 7 As shown, it is assumed that a flat wall is made of uniform material, with a thickness of b and an area of ​​A. The thermal conductivity λ does not change with temperature (or the average thermal conductivity is taken) and is considered a constant. The temperature inside the flat wall only changes along the x-axis direction perpendicular to the wall surface, so the isothermal surfaces are all parallel planes perpendicular to the x-axis. If the temperatures t1 and t2 on both sides of the flat wall are constant, then when x = 0, t = t1; when x = b, t = t2, so it is a steady-state one-dimensional heat conduction. According to Fourier's law, after separating the variables and integrating, we can get:

[0079]

[0080] The heat transfer rate equation is:

[0081]

[0082] Where: R is the thermal resistance, °C / W.

[0083] 3) Steady-state heat conduction of multi-layer flat walls

[0084] like Figure 8 As shown, it is assumed that a flat wall has three layers with thicknesses of b1, b2, and b3, respectively. The thermal conductivity coefficients are λ1, λ2, and λ3, respectively. They do not change with temperature (or take the average thermal conductivity coefficient) and are regarded as constants. The contact between the layers is good, that is, the temperature on the surfaces in contact with each other is equal. All isothermal surfaces are parallel planes perpendicular to the x-axis. The area of ​​the flat wall is A. In the steady-state heat transfer process, the heat conduction rate passing through each layer per unit time is equal: Q = Q1 = Q2 = Q3. From formula (3), we can get:

[0085]

[0086] Because Δt=t1-t4＝ Δt1+Δt2+Δt3, according to the law of geometric proportions, we can get

[0087]

[0088] Depend on It can be seen that the total thermal resistance R of the steady-state heat conduction of the multi-layer flat wall is equal to the sum of the thermal resistances of each layer, that is,

[0089]

[0090] Heat transfer model for prefabricated cabin engineering

[0091] The cabin of the prefabricated cabin is a multi-layer flat wall structure. The outer and inner wall panels are generally made of aluminum-zinc coated steel plates, and the middle is filled with thermal insulation and flame retardant materials. The total thermal conductivity resistance of the prefabricated cabin is calculated as formula (6);

[0092] Since the thermal conductivity of the aluminum-zinc-clad steel plate is about 45W / (m·K), which is hundreds of times that of the insulation material, and the thickness is usually 2 to 3mm, the influence of the thermal resistance of the aluminum-zinc-clad steel plate on the total thermal resistance R can be ignored. Therefore, from the principle of heat conduction, the heat conduction of the prefabricated cabin project can be simplified to the steady-state heat conduction model calculation of a single-layer flat wall.

[0093] After the prefabricated cabin is put into operation, the ambient temperature t2 outside the prefabricated cabin will not change suddenly in a short period of time and can be set as a constant. According to Fourier's law, the dependent variable heat transfer rate Q and the independent variable cabin temperature t1 are in a one-to-one functional relationship, that is, Q = f(t1). When the cabin compensation heat power Q1 is equal to the cabin heat dissipation Q2, the cabin temperature t1 will be constant. Therefore, the heat conduction model of the prefabricated cabin project can be obtained from formula (3):

[0094]

[0095] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A prefabricated cabin-type substation cabin suitable for use in extremely cold temperatures, comprising a cabin body (2), a cabin roof (1), and a cabin bottom (3), wherein the lower end of the cabin body (2) is arranged on the cabin bottom (3), and the cabin roof (1) is arranged on the upper end of the cabin body (2); the cabin body (2) comprises an inner side plate (201), an outer side plate (202), and a cabin body skeleton structure, wherein the upper and lower ends of the cabin body skeleton structure are respectively connected to the cabin roof (1) and the cabin bottom (3), and the cabin body skeleton structure is composed of a plurality of columns and a plurality of light steel keels; the inner side plate (201) and the outer side plate (202) are They are respectively arranged inside and outside the cabin skeleton structure to form a two-layer sandwich structure A; the cabin top (1) includes a front side plate, a rear side plate, a left side plate, a right side plate, a top plate, a bottom plate, and a cabin top skeleton structure, and the front side plate, the rear side plate, the left side plate, the right side plate, the top plate, and the bottom plate are respectively arranged on the outside of the cabin top skeleton structure and wrapped inside to form a two-layer sandwich structure B; the cabin bottom (3) includes a support plate and a cabin bottom support frame, the support plate is arranged above the cabin bottom support frame, and the lower end of the cabin skeleton structure is arranged on the support plate, characterized in that: The gap areas inside the two-layer sandwich structure A are filled with rock wool boards (7) and the thickness of the rock wool boards (7) is 80 mm; the gap areas inside the two-layer sandwich structure B are filled with rock wool boards (7) and the thickness of the rock wool boards (7) is greater than or equal to 80 mm; the gap areas of the support frame of the bilge (3) are filled with rock wool boards (7) and the thickness of the rock wool boards (7) is 80 mm; The plurality of columns of the cabin skeleton structure include four L-shaped corner columns (204) and a plurality of U-shaped center columns (203); a first thermal insulation structure (4) is provided between each center column (203) of the cabin skeleton structure and the inner plate (201); and a second thermal insulation structure (5) is provided between each corner column (204) of the cabin skeleton structure and the inner plate (201).

2. The prefabricated cabin-type substation cabin suitable for use in extremely cold temperatures according to claim 1 is characterized in that: The thickness of the rock wool board (7) filled inside the two-layer sandwich structure B of the cabin roof (1) is 90-100 mm.

3. The prefabricated cabin-type substation cabin suitable for use in extremely cold temperatures according to claim 2 is characterized in that: The first thermal insulation structure (4) comprises a first connecting plate A (401), and second connecting plates A (402) are arranged on both sides of the first connecting plate A (401) and the two connecting plates A (402) are perpendicular to each other. The first connecting plate A (401) and the two second connecting plates A (402) together form a U-shaped structure and are fixedly arranged in the corresponding middle column (203); A third connecting plate A (403) is provided at one end of the second connecting plate A (402) away from the first connecting plate A (401), and the two are perpendicular to each other, and two sides of the third connecting plate A (403) are respectively fixedly connected to the corresponding central column (203) and the inner side plate (201); A fourth connecting plate A (404) is provided at one end of the third connecting plate A (403) away from the second connecting plate A (402) and is parallel to the second connecting plate A (402); an O-shaped sealing strip (6) is provided at one end of the fourth connecting plate away from the third connecting plate A (403); two side walls of the center column (203) are respectively located between the second connecting plate A (402) and the fourth connecting plate A (404) on the corresponding side and are in sealing contact with the sealing strip (6) on the corresponding side; The U-shaped structure formed by the first connecting plate A (401) and the two second connecting plates A (402) is filled with a rock wool board (7) adapted thereto; The first connecting plate A (401) to the fourth connecting plate A (404) are all made of non-metallic materials with low thermal conductivity.

4. The prefabricated cabin-type substation cabin suitable for use in extremely cold temperatures according to claim 3 is characterized in that: The second thermal insulation structure (5) comprises a first connecting plate B (501) and a second connecting plate B (502), one end of the first connecting plate B (501) is connected to one end of the second connecting plate B (502) and the two are perpendicular to each other, and the first connecting plate B (501) and the second connecting plate B (502) are respectively fixedly arranged on the inner side walls of the corresponding corner columns (204); A third connecting plate B (503) is disposed at one end of the first connecting plate B (501) away from the second connecting plate B (502) and the two are perpendicular to each other; a fourth connecting plate B (504) is disposed at one end of the third connecting plate B (503) away from the first connecting plate B (501) and the fourth connecting plate B (504) is parallel to the first connecting plate B (501); A fifth connecting plate B (505) is disposed at one end of the second connecting plate B (502) away from the first connecting plate B (501) and the two are perpendicular to each other; a sixth connecting plate B (506) is disposed at one end of the fifth connecting plate B (505) away from the second connecting plate B (502) and is parallel to the second connecting plate B (502); One end of the fourth connecting plate B (504) is fixedly connected to one end of the sixth connecting plate B (506) and the two are perpendicular to each other, and the fourth connecting plate B (504) and the sixth connecting plate B (506) are both fixedly connected to the inner plate (201); A seventh connecting plate B (507) is provided at one end of the fourth connecting plate B (504) away from the sixth connecting plate B (506), and the two are perpendicular to each other; an O-shaped sealing strip (6) is provided at one end of the seventh connecting plate B (507) away from the fourth connecting plate B (504), and the sealing strip (6) is in sealing contact with the outer plate (202) and the rock wool plate (7) on the corresponding side respectively; An eighth connecting plate B (508) is provided at one end of the sixth connecting plate B (506) away from the fourth connecting plate B (504), and the two are perpendicular to each other; an O-shaped sealing strip (6) is provided at one end of the eighth connecting plate B (508) away from the sixth connecting plate B (506), and the sealing strip (6) is in sealing contact with the outer plate (202) and the rock wool plate (7) on the corresponding side, respectively; The first connecting plate B (501) to the eighth connecting plate B (508) are all made of non-metallic materials with low thermal conductivity.

5. The prefabricated cabin-type substation cabin suitable for use in extremely cold temperatures according to claim 4 is characterized in that: The inner surface of the support plate is paved with an antistatic floor.

6. The prefabricated cabin-type substation cabin suitable for use in extremely cold temperatures according to claim 5 is characterized in that: The front side plate, the rear side plate, the left side plate, the right side plate, the top plate, the bottom plate and the supporting plate are all made of steel plates.

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