Cold chain carriage composite insulation board structure
By using PP honeycomb boards, PP matrix composite skins and PP foaming materials in the refrigerated car insulation boards, and introducing a phase change energy storage material layer, the energy consumption problem caused by the large thermal conductivity of the traditional heat insulation boards is solved, and more efficient insulation performance and energy consumption reduction are achieved.
Patent Information
- Application Number
- CN202422038003.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-22
- Publication Date
- 2025-06-24
- Estimated Expiration
- 2034-08-22
AI Technical Summary
The thermal conductivity of traditional refrigerated carriage insulation boards is large, resulting in the need of a thicker foam layer to achieve the ideal thermal insulation effect, which increases the reduction of container content and cold loss, and thus increases energy consumption.
Using PP honeycomb boards, PP matrix composite skins and PP foaming materials, I-shaped PP honeycomb boards are designed to increase the strength and stiffness of the core layer, and a phase change energy storage material layer is introduced into the heat insulation board to absorb and release heat and reduce heat exchange.
It significantly reduces the energy consumption of refrigerated cars during transportation, improves thermal insulation performance, reduces temperature fluctuations, extends the service life of the refrigeration device, and saves operating costs.
Smart Images
Figure CN223014750U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of thermal insulation boards, and specifically to a composite thermal insulation board structure for a cold chain carriage. Background Art
[0002] With the continuous deepening of global economic integration, cold chain logistics, as an important part of modern logistics, is developing at an increasingly rapid pace. As one of the largest agricultural product producers in the world, China's output of vegetables, fruits, meats, poultry eggs, and aquatic products occupies a crucial position globally. Hundreds of millions of tons of agricultural products need to enter the market through cold chain logistics every year to ensure the freshness and safety of food. In this context, refrigerated carriages, as the main tool for refrigerated transportation, are of self-evident importance.
[0003] Refrigerated carriages play an increasingly important role in refrigerated transportation with their unique heat insulation structure, reliable refrigeration and heat preservation functions, perfect automatic control system, and good applicability and flexibility. However, with the continuous increase in the demand for refrigerated carriages, the energy consumption problem during transportation has gradually become prominent. Especially when transporting frozen foods, in order to maintain the required low-temperature environment inside the box, refrigeration devices with large refrigeration capacity and better heat insulation materials need to be used, which undoubtedly increases the processing cost, operating expenses, and energy consumption of refrigerated carriages.
[0004] Mechanical refrigerated carriages are the most widely used type at present. They can maintain the temperature inside the box between -25°C and +25°C according to different cargo requirements. The box body structure of this kind of container usually consists of main components such as a chassis, side panels, top panel, front frame, rear frame, and door.
[0005] Each component of the box body is mainly composed of an inner panel, an outer panel, and an intermediate foaming layer. The outer panel usually uses non-magnetic iron or stainless steel material, which is spliced by pressing corrugations to enhance the structural strength and reduce the influence of the external environment on the temperature inside the box. The inner side panel is spliced after being pressed into waves with stainless steel, ensuring good sealing performance and durability. The intermediate foaming layer is formed by foaming in the cavity between the outer panel and the inner panel. Usually, rigid polyurethane foam plastic is used, and because of its extremely low thermal conductivity (about 0.027 W / (m·K)), it plays a decisive role in heat insulation. The thickness of the heat insulation layer is one of the key factors affecting the heat preservation performance of refrigerated carriages. According to the parameters shown in Table 1, the heat preservation layer thickness and heat transfer coefficient of the side panels, top panel, floor, front panel, and door panel are different, and these parameters together determine the heat insulation effect of the box body.
[0006] Table 1
[0007]
[0008]
[0009] The thickness of the heat insulation layer is one of the key factors affecting the heat preservation performance of the refrigerated carriage. According to the parameters shown in Table 1, the thicknesses and heat transfer coefficients of the insulation layers of the side panel, top panel, floor panel, front panel, and door panel are different, and these parameters jointly determine the heat insulation effect of the box. The cold consumption of the refrigerated carriage mainly includes cold consumption due to heat transfer, cold consumption due to heat leakage, cold consumption due to ventilation, etc. Among them, the cold consumption due to heat transfer accounts for the main proportion, which is mainly caused by the heat transfer of the box wall. According to Fourier's law of heat conduction, the heat flux of the box wall can be calculated, and then the heat transfer amount within a certain operating time can be estimated.
[0010] Traditional heat insulation boards for refrigerated carriages have some limitations. First, due to the relatively large thermal conductivity of the insulation layer, a thicker foaming layer is required to achieve an ideal heat insulation effect, which results in a reduction in the internal volume of the container; second, under extreme climatic conditions, the temperature inside the box fluctuates greatly, increasing the cold loss and thus increasing the energy consumption. On this basis, it is very important to further enhance the heat preservation effect while reducing the weight. Summary of the Invention
[0011] In order to solve the above technical problems, the present invention provides a composite heat insulation board structure for a cold chain carriage, which uses a PP honeycomb board, a PP-based composite material skin, and a PP foaming material, with a higher degree of lightweight. The box body of the same thickness can reduce the weight by 10-20%. The PP honeycomb board can be designed in an I-shaped structure, which increases the strength of the core layer and improves the stiffness. It not only gives play to the flexibility of the PP honeycomb board but also improves the strength. By adjusting the thickness, the heat preservation performance can meet the market needs.
[0012] The technical solution of the present utility model is: a composite heat insulation board structure for a cold chain carriage, wherein the middle of the heat insulation board is a PP honeycomb board, and the two outer layers on both sides are PP-based composite material skins. Between the PP-based composite material skin and the PP honeycomb board is a PP foaming material; between the skin on one side of the heat insulation board and the PP honeycomb board is a phase change energy storage material layer; in this technical solution, the phase change energy storage material layer is composed of a steel plate, a phase change energy storage material, and a steel plate from the outside to the inside.
[0013] The phase change energy storage material is Na2SO4·10H2O.
[0014] In this technical solution, the cross-section of the PP honeycomb board is in an I-shaped structure.
[0015] In this technical solution, the cell size of the PP foaming material is less than 100 μm.
[0016] In this technical solution, the density of the PP honeycomb board is 0.04-0.3 g / cm 3 .
[0017] In this technical solution, the thickness of the PP honeycomb board is 5 - 10 mm.
[0018] In this technical solution, the thickness of the PP-based composite material skin is 2 - 3 mm.
[0019] In this technical solution, the thickness of each side of the I-shaped structure is 5 - 10 mm.
[0020] Compared with the prior art, its beneficial effects are as follows:
[0021] (1) The composite thermal insulation board of the carriage of the present utility model adopts a PP honeycomb board, a PP-based composite material skin, and a PP foaming material, with a higher degree of lightweight. For a carriage body of the same thickness, the weight can be reduced by 10 - 20%.
[0022] (2) The PP honeycomb board can be designed into an I-shape, which increases the strength of the core layer and improves the stiffness, giving full play to both the flexibility and strength of the PP honeycomb board.
[0023] (3) By adjusting the thickness, the thermal insulation performance can meet the market requirements.
[0024] (4) By using the phase change energy storage material as the core component of the refrigerated carriage heat insulation board, the energy consumption during the transportation of the refrigerated carriage is significantly reduced. The phase change material absorbs and releases heat when the temperature changes, effectively reducing the heat exchange caused by the temperature difference between indoors and outdoors, thereby reducing the burden on the refrigeration system and energy consumption. In addition, the design of the heat insulation board enhances the thermal insulation performance of the refrigerated carriage, reduces temperature fluctuations, and improves the storage quality of goods. Economic analysis shows that adopting the refrigerated heat insulation board of the present invention can save significant operating costs for users, with significant economic and environmental benefits.
[0025] In summary, for the structure of the composite thermal insulation board of a cold chain carriage of the present utility model, which adopts a PP honeycomb board, a PP-based composite material skin, and a PP foaming material, with a higher degree of lightweight. For a carriage body of the same thickness, the weight can be reduced by 10 - 20%. The PP honeycomb board can be designed into an I-shape, which increases the strength of the core layer and improves the stiffness, giving full play to both the flexibility and strength of the PP honeycomb board. By adjusting the thickness, the thermal insulation performance can meet the market requirements. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 is a schematic diagram of the present utility model;
[0027] Figure 2 is the expanded view of each layer of the present utility model;
[0028] Figure 3 is the three-dimensional view of an embodiment of the present utility model;
[0029] Figure 4 isFigure 3 Partial enlarged view of location A;
[0030] Figure 5 is the structure of Embodiment 4 of the present utility model;
[0031] Figure 6 is the structure of the phase change energy storage material layer of the present utility model.
[0032] Figure 7 is the temperature curve in the heat preservation test.
[0033] Wherein: 1 - PP-based composite skin, 2 - PP honeycomb panel, 3 - PP foaming material, 4 - phase change energy storage material layer, 41 - steel plate, 42 - phase change energy storage material. Specific embodiments
[0034] The embodiments of the present utility model will be described in detail below. The examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present utility model and should not be construed as a limitation to the present utility model.
[0035] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the referred combination or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model. In addition, during the description of the embodiments of the present utility model, the positional relationships of "upper", "lower", "front", "rear", "left", "right", etc. of all the devices in the drawings are based on Figure 1 as the standard.
[0036] Embodiment 1
[0037] As Figure 1 , Figure 2 shown, the middle of the heat preservation board is the PP honeycomb panel 2, and the outer layers on both sides are the PP-based composite skin 1. Between the PP-based composite skin 1 and the PP honeycomb panel 2 is the PP foaming material 3.
[0038] The cell size of the PP foaming material 3 is less than 100 μm. The density of the PP honeycomb panel 2 is 0.04 - 0.3 g / cm 3 . The thickness of the PP honeycomb panel 2 is 5 - 10 mm. The thickness of the PP-based composite skin 1 is 2 - 3 mm.
[0039] The thickness of the foaming layer is adjusted according to product requirements, with a total thickness of 20 to 100 mm.
[0040] Example 2
[0041] The difference from Example 1 is that Figure 3 , Figure 4 As shown, the cross section of the PP honeycomb panel 2 is an I-shaped panel. The thickness of each side of the I-shaped PP honeycomb panel 2 is 5 mm. The I-shaped structure increases the rigidity of the material. The cell size of the PP foam material 3 is 100 μm. The density of the PP honeycomb panel 2 is 0.05 g / cm 3 The thickness of the PP-based composite material skin 1 is 2 mm. The total thickness is 50 mm.
[0042] Example 3
[0043] like Figure 7 As shown, the plate of test embodiment 2 is turned on to reduce the temperature to -22°C according to the manufacturing standard 4×2×2m compartment, and then the refrigeration is turned off and the temperature is naturally restored. During this process, the temperature is measured every 15 minutes until the temperature exceeds 8°C. The temperature curve is shown in the figure. After testing, it can be seen that the temperature can be maintained for up to 2 hours, while the ordinary polyurethane foam compartment with a thickness of 50mm can be maintained for about 1.5 hours. The thermal conductivity is 0.034W / m·K, which proves that the insulation board material has better insulation performance.
[0044] The tested PP honeycomb panel 2 is an I-shaped structure, the thickness of each side of the I-shaped structure is 5 mm, the height of the I-shaped structure is 15 mm, and the density of the PP honeycomb panel 2 is g / cm 3 The skin thickness is 2mm, and the composite material with a glass fiber content of 60% is used. The total thickness of the plate is 20mm, the compression strength is 1MPa, the tensile strength is 2MPa, and the shear strength is 0.6MPa. It can meet the use requirements of the cargo compartment.
[0045] Example 4
[0046] Different from Example 1, Figure 5 As shown, a phase change energy storage material layer 4 is provided between the skin 1 on one side of the insulation board and the PP honeycomb board 2. Figure 6 As shown. The phase change energy storage material layer is steel plate 41, phase change energy storage material 42, and steel plate 41 from outside to inside. The phase change material is Na2SO4·10H2O, which has a melting temperature of 32°C and a melting heat of 254J / g. The steel plate is made of stainless steel, and the thermal conductivity is 20-30W / (m·K). Compared with the insulation layer, the thermal resistance can be ignored.
[0047] The phase change energy storage material is packaged into a plate shape using a steel plate, and then the phase change energy storage material layer is arranged on the inner side of the insulation board and below the skin.
[0048] The phase change energy storage refrigeration insulation board is an insulation board with encapsulated phase change materials added inside. Phase change materials are substances that use the absorption and release of heat during phase changes for latent heat energy storage, mainly including solid-gas phase change materials, liquid-gas phase change materials, and solid-liquid phase change materials. Solid-liquid phase change materials have little volume change during phase changes and large latent heat, making them the most promising in the phase change energy storage method. In the solid-liquid phase change of the phase change energy storage refrigeration insulation board, when the ambient temperature is higher than the phase change temperature of the material, the material undergoes a phase change, absorbs heat, and reduces the heat transfer from the outside into the refrigerator; when the ambient temperature is lower than the phase change temperature of the material, the environment will cool the material and store the cold energy, which will be released when needed. Phase change materials use the change in the form of the phase change material with temperature change to store and release latent heat, which can make full use of natural cold energy to save energy for the refrigerated carriage and has a good energy-saving effect. Solid-liquid phase change has a large energy storage density, a constant phase change temperature, an easy-to-control process, and can be reused multiple times. The use of phase change materials absorbs excess external heat, reduces the thickness of the insulation layer, increases the net volume inside the refrigerated carriage, and also buffers the temperature change inside the box, reduces the number of starts of the refrigeration compressor, and extends the service life of the refrigeration device.
[0049] Design parameters: The ambient temperature is 38 °C, the temperature inside the box is -18 °C. It is assumed that within 12 hours, the heat transfer Q from the environment in the cold chain box is 4×10 7 J, and the refrigeration capacity of the carriage is q0 = Q / t = 4×10 7 J / 12 / 3600 = 925.92 W.
[0050] If 10% of the heat transfer is stored in the phase change material, the mass of Na2SO4·10H2O required is calculated as m = Q / γ = 4×10 7 / 254 = 15.7 kg.
[0051] Assuming the price of Na2SO4·10H2O is 160 yuan / ton, its cost is 2.51 yuan.
[0052] Calculated at an electricity price of 0.5 yuan / kWh, the electricity saved in running for 12 hours is L = q0×t / ε = 925.92×12×3600 / 0.8 / 3600 / 1000 = 13.89 kWh.
[0053] Calculated based on the carriage being used for 150 days a year, the electricity saved is 150×13.89 kwh, and the electricity cost saved is 1041 yuan, while the cost of the phase change material is much less than the electricity cost saved.
[0054] The embodiments disclosed in the present utility model are preferred embodiments, but are not limited thereto. Those of ordinary skill in the art can easily understand the spirit of the present utility model based on the above embodiments and make different extensions and changes. However, as long as they do not depart from the spirit of the present utility model, they are within the protection scope of the present utility model.
Claims
1. A composite insulation board structure for a cold chain carriage, characterized in that: The middle of the insulation board is a PP honeycomb board, the outer layers on both sides are PP-based composite material skins, and between the PP-based composite material skins and the PP honeycomb board is a PP foam material; between the skin on one side of the insulation board and the PP honeycomb board is a phase change energy storage material layer; the phase change energy storage material layer is a steel plate, a phase change energy storage material and a steel plate from the outside to the inside, and the pore size of the PP foam material is less than 100μm.
2. The cold chain compartment composite insulation board structure according to claim 1 is characterized in that: The cross section of the PP honeycomb panel is an I-shape.
3. The cold chain compartment composite insulation board structure according to claim 1 is characterized in that: The phase change energy storage material is Na2SO4·10H2O.
4. The cold chain compartment composite insulation board structure according to claim 3 is characterized in that: The density of the PP honeycomb panel is 0.04-0.3 g / cm 3 .
5. The cold chain compartment composite insulation board structure according to claim 4 is characterized in that: The thickness of the PP honeycomb panel is 5-20 mm.
6. The cold chain compartment composite insulation board structure according to claim 5, characterized in that: The thickness of the PP-based composite material skin is 2-3 mm.
7. The cold chain compartment composite insulation board structure according to claim 2, characterized in that: The thickness of each side of the I-shape is 5-20 mm.