A core-sheath photoelectric-thermal composite yarn, its preparation method, and its application.

Abstract

This invention discloses a core-sheath photoelectric-thermal composite yarn, its preparation method, and its applications. This invention relates to the field of photoelectric thermal fabric technology. The core-sheath photoelectric-thermal composite yarn comprises a composite core yarn, a heating wire spirally wound around the composite core yarn, and a sheath structure Tencel-polypyrrole composite braided layer woven around the composite core yarn. The composite core yarn comprises a Tencel-polypyrrole composite yarn formed by in-situ polymerization of multiple strands of Tencel yarn and polypyrrole. This invention uses a unidirectional spiral heating wire wound around the surface of the composite core yarn. The spiral heating wire serves as an electrothermal auxiliary evaporation component. When the photothermal evaporation performance of the surface sheath structure is insufficient, the auxiliary electrothermal evaporation of the internal core structure provides a certain amount of evaporation heat, ensuring that the yarn and evaporation fabric maintain a high level of evaporation performance.

Description

Technical Field

[0001] This invention relates to the field of optoelectronic thermal fabric technology, and in particular to a core-sheath optoelectronic-thermal composite yarn, as well as the preparation method and application of the composite yarn. Background Technology

[0002] A light-driven interfacial water evaporation system typically consists of an absorber, a float, and a collection device. To achieve efficient light-to-vapor conversion, the following requirements must be met: the absorber must have excellent photothermal conversion performance and must not be in direct contact with water; the float must be able to transport water to the evaporation interface, so that the evaporation rate at the interface is balanced with the amount of water transported to the absorber, and it must have excellent thermal management capabilities; the collection device must be lightweight and have high light transmittance.

[0003] In the prior art, Chinese patent CN115976851A discloses the formation of a carbon-based polymer porous membrane by coating a carbon-based nanoparticle / polymer mixture onto a hydrophilic fabric and then using a water droplet template method. The pore size of the composite photothermal fabric surface provides an escape channel for water vapor generated during photo-vapor conversion, increasing the photo-vapor conversion efficiency and facilitating subsequent water vapor condensation and recovery. The water droplet template method allows for effective control of the pore size and hydrophilic / hydrophobic properties of the composite photothermal fabric surface through changes in materials and process parameters, offering high design flexibility. The method is simple to prepare, uses inexpensive materials, and has high practicality.

[0004] Chinese patent CN108221133A discloses a three-dimensional filled structure electrothermal evaporation fabric, which designs a composite electrothermal evaporation layer, a floating heat insulation layer, and a water-absorbing layer, all bound together by binding yarns. The fabric contains internal floating embedding materials, allowing it to float on water. The electrothermal evaporation layer uses materials such as carbon fiber, graphene fiber, metal-coated fiber, or nano-conductive particle coated fiber, or any combination thereof. These fibers possess light-absorbing or conductive heat-generating properties, enabling the fabric to easily achieve a photothermal-electrothermal evaporation effect. This three-dimensional filled structure features high strength, fast evaporation speed, short process flow, and suitability for industrial production.

[0005] However, the following technical problems still exist in the aforementioned existing technologies:

[0006] In patent CN115976851A, the porous film structure formed by the water droplet template method cannot maintain its transport performance for long. Specifically, the microporous structure is easily blocked by the crystallization of evaporated salt, and overall, the self-cleaning ability of the fabric is insufficient to ensure the continuity of evaporation performance. In addition, the film structure is easily affected by external forces, and the overall fabric strength is insufficient.

[0007] In patent CN108221133A, the heating material used in the electrothermal evaporation layer consists of both electrothermal and photothermal components. When only electrothermal material is used as the evaporation layer, the economic efficiency is low, the risk factor is high, and the overall heating effect is poor. When only photothermal material is used as the evaporation layer, it cannot meet the requirements for all-weather evaporation. Furthermore, when the daytime light intensity is insufficient for evaporation, the daily evaporation volume is poor. It is greatly affected by the duration and intensity of sunlight, failing to meet current expectations for evaporation performance. Summary of the Invention

[0008] The purpose of this invention is to address the aforementioned shortcomings of the prior art by proposing a core-sheath photothermal-electrical-thermal composite yarn, along with its preparation method and application, which is based on photothermal energy and supplemented by electrothermal energy. This solves the technical problem that existing interfacial evaporation fabrics cannot achieve efficient and sustained all-weather seawater evaporation.

[0009] The present invention discloses a core-sheath photoelectric-thermal composite yarn, comprising a composite core yarn, a heating wire spirally wound around the composite core yarn, and a sheath structure Tencel polypyrrole composite braided layer woven around the composite core yarn; the composite core yarn comprises a Tencel polypyrrole composite yarn formed by in-situ polymerization of multiple strands of Tencel yarn and polypyrrole.

[0010] Furthermore, the parameters for unidirectional spiral winding of the heating wire are: winding pitch controlled at 2-5T / cm, winding eccentricity controlled at 1.3-1.6mm; and heating wire diameter at 0.3-0.5mm.

[0011] Furthermore, the composite core yarn comprises 8-16 strands of Tencel polypyrrole composite yarn; the Tencel yarn is 10 tex, and the diameter of the composite core yarn is 0.5-1 mm.

[0012] Furthermore, the diameter of the yarn obtained after unidirectional wrapping of the heating wire is 1-1.5 mm.

[0013] Furthermore, the diameter of the core-sheath photoelectric-thermal composite yarn is 2.5-3mm.

[0014] A method for preparing a core-sheath photoelectric-thermal composite yarn as described above includes the following steps:

[0015] S1. Use multi-strand Tencel polypyrrole composite yarn as the composite core yarn;

[0016] S2. The heating wire is spirally wound in one direction around the composite core yarn to form the core;

[0017] S3. The multi-strand Tencel polypyrrole composite yarns are arranged symmetrically. The yarn carrier moves along an approximately "8" track under the action of the angle guide wheel. The movement of the yarn carrier causes the yarns to interweave with each other, forming a tubular fabric with a sheath structure.

[0018] Furthermore, the specific preparation method of Tencel polypyrrole composite yarn is as follows: the Tencel yarn is ultrasonically cleaned and dried in anhydrous ethanol for later use; 1000 ml of 0.2-0.8 mol / L pyrrole solution is prepared, and the above Tencel yarn is immersed in the pyrrole solution and reacted in an ice bath for 1-3 hours; 300 ml of 5-15 g / L FeCl3 is gradually added dropwise to the pyrrole solution, and the mixture is stirred and reacted for 2-4 hours; then the above Tencel yarn is taken out and washed and dried.

[0019] Furthermore, it consists of 8-16 strands of 80-120tex Tencel polypyrrole composite yarn arranged symmetrically.

[0020] A photoelectric thermal interface evaporator fabric is woven using the aforementioned core-sheath photoelectric-thermal composite yarn as the weft yarn and black nylon as the warp yarn, with the entire weft yarn running through the warp yarns.

[0021] Furthermore, the weft density is 30-50 threads / 10cm.

[0022] A photoelectric thermal interface water evaporation system includes the aforementioned fabric, with heating wire interfaces exposed at the front and rear ends of the fabric, which are respectively connected to the positive and negative terminals of an external power source, which is a battery or a solar panel.

[0023] This invention uses a heating wire wound in a unidirectional spiral on the surface of a composite core yarn. The spiral heating wire serves as an electrothermal auxiliary evaporation part. When the photothermal evaporation performance of the surface sheath structure is insufficient, the auxiliary electrothermal evaporation of the internal core structure provides a certain amount of evaporation heat, which can ensure that the yarn and evaporation fabric maintain a high level of evaporation performance.

[0024] This invention uses multi-strand Tencel polypyrrole composite yarn woven into the outermost layer in a sheath structure, so that the entire yarn forms a tight core-sheath structure; the outer sheath structure is woven entirely from Tencel polypyrrole composite yarn, which can achieve the maximum light absorption rate, and the heat radiated to the inner yarn is more concentrated, and the process of the inner heating wire radiating heat outward is slowed down to a certain extent, resulting in a better overall heat utilization rate.

[0025] This invention uses in-situ polymerization to composite polypyrrole on the surface of Tencel yarn. After the yarn surface has a rough microstructure, it provides excellent water circulation channels, realizing self-cleaning ability after evaporation and salt formation, as well as efficient water supply and evaporation ability. In addition, polypyrrole enhances the heat resistance of Tencel, and the surface temperature transfer of the entire water absorption and water supply yarn part is integrated, resulting in more uniform temperature transfer.

[0026] The yarns and fabrics of the present invention have the properties of high water absorption, self-cleaning, heat resistance, and uniform temperature transfer.

[0027] The yarns and fabrics prepared by this invention have excellent continuous water supply capacity, high heat utilization rate, high light absorption rate, high photoelectric thermal storage and conversion efficiency, continuous and efficient evaporation efficiency, and high strength performance. Attached Figure Description

[0028] Figure 1 Schematic diagrams of photoelectric-thermal composite yarns and their fabrics, and their applications;

[0029] Figure 2 CBEF-P3 under 3.5wt% saline, different voltages, and 1kW·m -2 Comparison of desalination rates under radiation;

[0030] Figure 3 Temperature variation and freshwater collection rate of the outdoor evaporator of the CBEF-P3, which supplies solar panels and 3V input voltage;

[0031] Figure 4 Recording of stable drying temperatures at different locations on a CBEF-P with a 3V DC input. Detailed Implementation

[0032] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0033] The present invention relates to the preparation process of fabrics woven using core-sheath photoelectric-thermal composite yarns as follows:

[0034] S1: Tencel yarn and polypyrrole are polymerized in situ to form Tencel-polypyrrole composite yarn; multi-strand Tencel-polypyrrole composite yarn is used as composite core yarn;

[0035] S2: Composite core yarn unidirectional spiral-wound heating wire;

[0036] S3: Braided sheath structure Tencel polypyrrole composite layer;

[0037] S4: Weaving of core-sheath composite yarn fabrics.

[0038] S1: In-situ polymerization of Tencel core yarn and polypyrrole. The Tencel yarn is ultrasonically cleaned in anhydrous ethanol for 30 minutes and then dried for later use. Prepare 1000 ml of a 0.2-0.8 mol / L pyrrole solution, immerse 20 g of the above Tencel yarn in the pyrrole solution, and react in an ice bath for 1-3 hours. Further, gradually add 300 ml of 5-15 g / L FeCl3 solution to the pyrrole solution, stirring and reacting for 2-4 hours. In-situ polymerization of polypyrrole into Tencel results in a rough fiber surface and excellent heat resistance and thermal conductivity. The Tencel yarn is then removed, washed, and dried to obtain the Tencel-polypyrrole composite yarn.

[0039] The above-mentioned Tencel yarn is 10 tex; the Tencel polypyrrole composite yarn has a diameter of 0.5-1 mm.

[0040] S2: The composite core yarn is unidirectionally spirally wrapped with heating wire. The composite core yarn prepared in S1 is unidirectionally spirally wrapped with heating wire. The winding pitch and winding eccentricity are controlled to optimize the electrothermal conversion performance. The winding pitch is controlled at 2-5 T / cm, and the winding eccentricity is controlled at 1.3-1.6 mm. The composite core yarn has 8-16 strands to control the diameter and winding eccentricity. The winding pitch affects the degree of twisting of the heating wire and the heat distribution, further affecting the degree of heating and the degree of heating of the composite yarn layer.

[0041] The diameter of the heating wire is 0.3-0.5mm. The diameter of the yarn obtained after unidirectional winding of the heating wire is 1-1.5mm.

[0042] S3: Braiding the Tencel polypyrrole composite layer with a sheath structure. The yarn obtained in S2 is used as the core to braid the Tencel polypyrrole composite yarn with a sheath structure. The sheath structure consists of 8-16 strands of 80-120tex Tencel polypyrrole composite yarn arranged symmetrically. The yarn carrier moves along an approximately "8" track under the action of the angle guide wheel. The movement of the yarn carrier causes the yarns to interweave with each other to form a tubular fabric with a sheath structure, thus obtaining a core-sheath optical-electrical-thermal composite yarn.

[0043] By controlling the denier and ply count of the Tencel polypyrrole composite yarn, the tightness of the sheath structure Tencel polypyrrole composite braided layer wrapped around the outside and the crossing angle of the Tencel polypyrrole composite yarn are further controlled, as well as the water supply channel and heat exchange channel.

[0044] The diameter of the sheath-structured Tencel polypyrrole composite yarn, i.e., the core-sheath photoelectric-thermal composite yarn, is 2.5-3mm.

[0045] S4: Weaving of the core-sheath optical-electrical-thermal composite yarn fabric, wherein the core-sheath optical-electrical-thermal composite yarn in S3 above is used as the weft yarn for weaving, specifically weaving in plain weave, twill weave or satin weave, etc.

[0046] The weft yarn runs through the warp yarns, which are made of black nylon.

[0047] The heating wire interfaces exposed at the front and rear ends of the fabric are connected to the positive and negative terminals of an external power source, which can be a battery or a solar panel.

[0048] The specific weft density can be 30-50 threads / 10cm.

[0049] External power sources can be either solar panels or batteries. When sunlight intensity is high, choose a healthy and environmentally friendly solar panel; when sunlight intensity is low, choose a battery for greater economic efficiency.

[0050] Combination Figure 1 Several specific embodiments of the present invention are given.

[0051] Example 1:

[0052] Its preparation method is as follows:

[0053] S1: Ultrasonically clean the Tencel yarn in anhydrous ethanol for 30 minutes, then dry it for later use. Prepare 1000 ml of 0.2 mol / L pyrrole solution, immerse 10 g of the above Tencel yarn in the pyrrole solution, and react in an ice bath for 2 hours. Then, gradually add 300 ml of 10 g / L FeCl3 solution dropwise to the pyrrole solution, stirring and reacting for another 2 hours. Remove the yarn, wash it with water, and dry it.

[0054] S2: The S1 yarn is unidirectionally spirally wound with heating wire, wherein the diameter of the heating wire is 0.3mm, the winding pitch is controlled at 3T / cm, the number of Tencel strands is 8, and the winding eccentricity is controlled at 1.50-1.55mm.

[0055] S3: The above-mentioned S2 yarn is used as the core and wrapped with a sheath structure Tencel polypyrrole composite yarn, wherein the Tencel polypyrrole composite yarn has eight strands and a specification of 95tex.

[0056] S4: The S3 yarn is used as the weft yarn for weaving the fabric. The warp yarn is black nylon with a warp density of 50 threads / 10cm and a weft density of 35 threads / 10cm. The weave structure is plain weave. The entire weft yarn runs through the fabric, and the heating wires at both ends are connected to a 3V battery.

[0057] The evaporator fabric is 5.53 mm thick and 40 cm wide.

[0058] The evaporator obtained above was then tested for its evaporation performance and other properties:

[0059] At 3V voltage and 1kW·m -2 Under radiation, the evaporation rate in a pure water environment is 5.57 kg·m³. -2 ·h -1 In a simulated seawater (3.5 wt% brine) environment, the evaporation rate is 4.89 kg·m³. -2 ·h -1 The all-weather water absorption capacity reaches 46 kg·m³. -2 ·d -1 After five days of continuous operation, no obvious salt buildup was observed on the surface, and the fabric showed an increase of 2.5 g / m². -2 .

[0060] In a simulated seawater (3.5 wt% brine) environment, the average energy consumption is 1.29 kW·h·m. -3 In a highly concentrated simulated seawater (10 wt% brine) environment, the average energy consumption is 1.61 kW·h·m. -3 .

[0061] Example 2:

[0062] Its preparation method is as follows:

[0063] This embodiment is similar to the previous one, except that the pyrrole solution is 0.3 mol / L and the FeCl3 is 15 g / L. This change will affect the degree of pyrrole polymerization on the Tencel surface, and further affect the water absorption capacity, heat resistance and thermal conductivity of the composite core yarn.

[0064] The number of Tencel strands is 16. This change will affect the diameter of the composite core yarn, which in turn will affect the water absorption capacity of the composite core yarn and the eccentricity of the unidirectional winding.

[0065] The number of plies in the Tencel polypyrrole composite yarn is 16. This change will affect the precision structure of the sheath structure Tencel polypyrrole composite braided layer, further affecting the light absorption of the sheath structure Tencel polypyrrole composite braided layer, the water permeability of the outer layer, and the heating and heat preservation capabilities of the internal heating wire.

[0066] The evaporator fabric is 7.63 mm thick and 40 cm wide.

[0067] The evaporator obtained above was then tested for its evaporation performance and other properties:

[0068] At 3V voltage and 1kW·m -2 Under radiation, the evaporation rate in a pure water environment is 4.98 kg·m³. -2 ·h -1 In a simulated seawater (3.5 wt% brine) environment, the evaporation rate is 4.11 kg·m³. -2 ·h -1 The all-weather water absorption capacity reaches 40 kg·m³. -2 ·d -1 After five days of continuous operation, no obvious salt buildup was observed on the surface, and the fabric showed an increase of 3.5 g / m². -2 .

[0069] In a simulated seawater (3.5 wt% brine) environment, the average energy consumption is 1.11 kW·h·m. -3 In a highly concentrated simulated seawater (10 wt% brine) environment, the average energy consumption is 1.52 kW·h·m. -3 .

[0070] The data recording and analysis process is as follows: The experiment was conducted under standard indoor conditions (24℃, 50% humidity), with real-time mass changes monitored by an electronic balance. Solar radiation was provided by a solar simulation irradiance instrument. The evaporation rate was calculated using the following formula. (Δm represents the change in evaporating mass, S represents the evaporating area, and t represents the evaporation time); Numerical simulation of electrothermal conversion: The energy balance law is introduced to evaluate the saturation temperature of the heater. The saturation surface temperature depends on the applied voltage, material resistance, and heat transfer coefficient. The formula is as follows: U^2 / R=mcdT / dt+hA(〖TT〗_0), where U is the applied voltage, R is the sheet resistance, c is the specific heat capacity, m is the CTFF weight, T is the saturation surface temperature, T0 is the initial temperature, A is the electrothermal area, and h represents the heat transfer coefficient; the surface temperature is recorded by an infrared camera and an ion concentration tracker.

[0071] Figure 2 CBEF-P3 under 3.5wt% saline, different voltages, and 1kW·m -2 Comparison of desalination rates under radiation;

[0072] Figure 3 Temperature variation and freshwater collection rate of the outdoor evaporator of the CBEF-P3, which supplies solar panels and 3V input voltage;

[0073] Figure 4 Recording of stable drying temperatures for CBEF-P with different coating densities (eccentricity and eccentricity) for 3V DC input;

[0074] in: Figure 1 The process includes in-situ polymerization of polypyrrole with Tencel yarn followed by unidirectional wrapping of commercial heating wire. The sheath structure is woven into the composite yarn using a rope weaving method with Tencel polypyrrole composite yarn. The fabric is then further woven into a woven material, which is combined with foam and semi-suspended in the evaporating liquid, and connected to an external fixed power source.

[0075] Figure 2 CBEF-P3 is a composite yarn (different specifications of composite yarn) with an eccentricity of 1.53mm and a pitch of 3T / cm. The weaving specification is 20cm×20cm, and the weft density is 35 ends / 10cm. CBEF-P3 is tested under 3.5wt% saline solution, different voltages, and 1kW·m -2 The desalination rate under radiation can be compared to find that the higher the voltage input, the higher the evaporation rate.

[0076] Figure 3 The CBEF (abbreviation for composite yarn) supplied by the solar panel and 3V input voltage has a moderate overall evaporation rate, and the evaporator evaporation rate further depends on the CBEF and weaving specifications; the evaporator evaporation rate of the solar panel with external power supply further depends on the solar radiation intensity of the evaporation environment.

[0077] Figure 4 In this process, density adjustment is achieved by changing the radial wrapping density of the conductor on the core PPy@Tencel. The wrapping spacing of CBEF-P1, CBEF-P2, CBEF-P3, CBEF-P4, and CBEF-P5 are set to 1, 2, 3, 4, and 5 T / cm, respectively. Among them, the yarn of specification CBEF-P3 has the best overall performance. This is because of the dynamic balance of light and heat in the evaporator, that is, the water supply and the water consumed by electric and light heat are equal, and all the heat is used for water evaporation.

[0078] For any points not covered above, existing technologies shall apply.

[0079] Although specific embodiments of the present invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the invention. Those skilled in the art can make various modifications or additions to the described specific embodiments or use similar methods to replace them, without departing from the direction of the invention or exceeding the scope defined by the appended claims. Those skilled in the art should understand that any modifications, equivalent substitutions, improvements, etc., made to the above embodiments based on the technical essence of the present invention should be included within the protection scope of the present invention.

Claims

1. A core-sheath opto-electro-thermal interfacial evaporator composite yarn, characterized by: The composite core yarn, the electric heating wire spirally wrapped outside the composite core yarn, and the sheath structure viscose poly-pyrrole composite braided layer wrapped outside the composite core yarn; the composite core yarn comprises a plurality of viscose poly-pyrrole composite yarns obtained by in-situ polymerization of viscose yarn and poly-pyrrole; The parameter of the one-way spiral wrapping of the electric heating wire is that the winding pitch is controlled to be 2-5T / cm, and the winding eccentricity is controlled to be 1.3-1.6mm; the diameter of the electric heating wire is 0.3-0.5mm; The composite core yarn comprises 8-16 viscose poly-pyrrole composite yarns; the viscose yarn is 10tex, and the diameter of the composite core yarn is 0.5-1mm; The diameter of the yarn obtained after the one-way wrapping of the electric heating wire is 1-1.5mm; The diameter of the core-sheath light-electric-thermal interface evaporator composite yarn is 2.5-3mm.

2. A method of making a core-sheath photo-electro-thermal interfacial evaporator composite yarn as claimed in claim 1, characterized by: The method comprises the following steps: S1, a plurality of viscose poly-pyrrole composite yarns are used as a composite core yarn; S2, an electric heating wire is spirally wrapped outside the composite core yarn to form a core; S3, a plurality of viscose poly-pyrrole composite yarns are symmetrically arranged, a yarn carrier moves along a track approximately in the shape of "8" under the action of an angle guide wheel, the yarns are interwoven by the movement of the yarn carrier, and a tubular fabric with a sheath structure is formed.

3. The production method according to claim 2, characterized by: The specific preparation method of the viscose poly-pyrrole composite yarn is as follows: the viscose yarn is cleaned by ultrasonic wave in anhydrous ethanol and dried for standby use; a pyrrole solution with a concentration of 0.2-0.8mol / L is prepared, the viscose yarn is immersed in the pyrrole solution, and an ice bath reaction is performed for 1-3 hours; 5-15g / L FeCl3 is gradually added dropwise into the pyrrole solution, stirring is performed, and a reaction is performed for 2-4 hours; then the viscose yarn is taken out and washed and dried; and / or 8-16 viscose poly-pyrrole composite yarns with a fineness of 80-120tex are symmetrically arranged.

4. A photo electro thermal interface evaporator fabric characterized by: The core-sheath light-electric-thermal interface evaporator composite yarn according to any one of claims 1-3 is used as weft yarn, black nylon is used as warp yarn, and weaving is performed, and the whole weft yarn penetrates between the warp yarns.

5. A photo electro thermal interface evaporator fabric according to claim 4, wherein: The weft density is 30-50 per 10cm.

6. A photoelectrothermal interface water evaporation system, characterized in that: The fabric according to claim 4 or 5 is connected to the positive and negative poles of an external power source through the electric heating wires exposed at the front end and the rear end of the fabric, respectively, and the external power source is a storage battery or a solar panel.

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