Continuous flow polyethylene glycol phase change microcapsule preparation device and method

Abstract

The invention relates to the technical field of PEG packaging, in particular to a continuous flow polyethylene glycol phase change microcapsule preparation device and method. The technical problems are as follows: the existing PEG packaging technology has the problems of complex process, large particle size and discontinuous production; according to the technical scheme, the continuous flow polyethylene glycol phase change microcapsule preparation device comprises a microreactor, a dispersed phase solution tank, a first valve, a dispersed phase plunger pump, a back pressure valve, a constant-temperature cooling circulating water pump, a continuous phase solution tank, a continuous phase plunger pump, a first coil pipe, a second coil pipe, a second valve and a microcapsule solution tank; the continuous production and preparation of the PEG microcapsules are realized in a manner of connecting the disc pipe behind the microreactor, and compared with intermittent preparation, the production efficiency is high, large-scale output can be realized, process parameters are more easily and stably controlled, automatic integration is more facilitated, and the continuous production and preparation of the PEG microcapsules are realized. Continuous preparation of the PEG microcapsules has obvious advantages in the aspects of efficiency, cost, quality control and the like compared with intermittent preparation.

Description

Technical Field

[0001] This invention relates to the field of PEG encapsulation technology, and more particularly to a continuous flow polyethylene glycol phase change microcapsule preparation apparatus and method. Background Technology

[0002] Polyethylene glycol (PEG) is a multifunctional phase change material with excellent enthalpy, phase change range, and thermal stability. However, PEG leaks during solid-liquid phase transitions, hindering its direct use. To address this issue, some inorganic porous materials such as SiO2, halloysite, diatomaceous earth, and mannitol have been used as support materials for PEG. However, due to the semi-closed pore structure of inorganic porous materials, the leakage problem cannot be completely solved. Compared with the adsorption method of inorganic porous materials, the microencapsulation of phase change materials can reduce the volume change and reaction with the external environment during the phase transition process, helping to maintain stable performance. Due to the hydrophilic nature of PEG, its microencapsulation process faces several challenges. Patent CN108940147B describes the preparation of polyethylene glycol / cellulose triacetate phase change microcapsules using spray drying, but this method is energy-intensive and requires sophisticated equipment. CN108620005A describes the preparation of polyethylene glycol / amino resin capsules using in-situ polymerization, but this method is cumbersome, requires intermittent production, and has low efficiency. CN103230765A describes the preparation of polyethylene glycol / ethyl cellulose microcapsules using oil-phase separation, but the process is complex and the capsules have large particle sizes. The aforementioned existing technologies provide new material combinations and process directions for the preparation of PEG microcapsules, but they have problems such as complex processes, large particle sizes, and discontinuous production. Therefore, a preparation process technology for the continuous production of PEG microcapsules is needed to overcome the shortcomings of the existing technologies. Summary of the Invention

[0003] In order to overcome the problem that existing PEG encapsulation technologies mostly use porous inorganic materials for encapsulation, although there are methods that use triacetate cellulose, ethyl cellulose and amino resins as wall materials to encapsulate PEG, these methods have problems such as complex processes, large particle size and discontinuous production.

[0004] The technical solution of this invention is as follows: a continuous flow polyethylene glycol phase change microcapsule preparation device, comprising a microreactor, a dispersed phase solution tank, a first valve, a dispersed phase plunger pump, a back pressure valve, a constant temperature cooling circulating water pump, a continuous phase solution tank, a continuous phase plunger pump, a first coil, a second coil, a second valve, and a microcapsule collection tank. The microreactor is a 3D-printed one-piece stainless steel structure. The microreactor contains reaction pipeline channels and heat exchange pipeline channels. The microreactor has two inlet channels, one for the continuous phase and one for the dispersed phase. A continuous phase plunger pump is installed at one end of the continuous phase channel, and a dispersed phase plunger pump is installed at one end of the dispersed phase channel. The input end of the dispersed phase plunger pump is connected to the dispersed phase solution tank. The plunger pump and the microreactor are connected by a pipeline structure. The continuous phase plunger pump and the microreactor are connected by a pipeline structure. The input end of the continuous phase plunger pump is connected to a continuous phase solution tank. A back pressure valve is installed on the dispersed phase channel of the microreactor. A constant temperature cooling circulating water pump is installed at one end of the heat exchange pipeline of the microreactor. The inlet and outlet of the heat exchange pipeline of the microreactor are connected to the constant temperature cooling circulating water pump. A first coil is installed at the output end of the microreactor. A second coil is installed at one end of the first coil. The first coil and the second coil are connected in a multi-segment structure. The first coil and the second coil are connected by a two-way valve. A microcapsule collection tank is installed at one end of the second coil. A first valve is installed on the output pipeline of the dispersed phase solution tank. A second valve is installed on the input pipeline of the microcapsule collection tank.

[0005] Preferably, the microreactor employs a one-piece stainless steel structure printed by 3D metal, with internal reaction and heat exchange pipelines to ensure effective heat transfer and precise temperature control during the reaction. The reaction pipelines are used for the mixing of the continuous and dispersed phases. The heat exchange tubes are connected to a constant-temperature circulating water pump to maintain a stable reaction temperature. Heating wires are wound around the outside of the coils to further heat and mature the mixture after the reaction. The multi-segment connection of the coils and the two-way valve connection structure facilitate the adjustment and control of the residence time of the liquid in the coils. Thus, by connecting the coils after the microreactor, continuous production of PEG microcapsules can be achieved. Compared with batch preparation, it has higher production efficiency, can be mass-produced, process parameters are easier to stabilize and control, and is more conducive to automation integration. Continuous preparation of PEG microcapsules has significant advantages over batch preparation in terms of efficiency, cost, and quality control.

[0006] Preferably, the junction of the continuous phase channel and the dispersed phase channel on the microreactor is a liquid-liquid mixing reinforcement structure, the junction of the continuous phase channel and the dispersed phase channel is a T-shaped structure, and the reinforcement structure is a micro-channel composed of multi-component flow and confluence structure.

[0007] Preferably, the dispersed phase plunger pump is a conventional plunger pump, and the continuous phase plunger pump is a high-temperature plunger pump. The outer sides of the first and second coils are wound with heated winding wire.

[0008] A method for preparing continuous flow polyethylene glycol phase change microcapsules includes the following steps: S1: Prepare the dispersed phase solution: Mix the wall material monomer, initiator and solvent in the oil phase to form a dispersed phase solution; S2: Preparation of continuous phase solution: Mix phase change material, emulsifier and pH adjustment solution in aqueous phase to form continuous phase solution; S3: Setting up a microreactor: The microreactor is equipped with reaction pipeline channels and heat exchange pipeline channels. The microreactor has two inlet channels, namely a continuous phase channel and a dispersed phase channel. The continuous phase channel is connected to a continuous phase plunger pump, and the dispersed phase channel is connected to a dispersed phase plunger pump. A back pressure valve is connected between the dispersed phase plunger pump and the dispersed phase channel of the microreactor. The inlet and outlet of the heat exchange pipeline of the microreactor are connected to a constant temperature cooling circulating water pump. The outlet of the microreactor is connected to the first coil, and the second coil is connected after the first coil. The outlet of the second coil is connected to the microcapsule collection tank. S4: Pumping in dispersed and continuous phase solutions: The dispersed phase solution is pumped into the dispersed phase channel of the microreactor at a flow rate of 0.1~1 mL / min using a dispersed phase plunger pump, and the continuous phase solution is pumped into the continuous phase channel of the microreactor at a flow rate of 0.01~0.5 mL / min using a continuous phase plunger pump. The continuous phase plunger pump is a high-temperature plunger pump with a temperature control range of 30~50℃. S5: Mixing and Reaction: The continuous phase and the dispersed phase form W / O droplets at the junction of the microreactor. The junction has a T-shaped structure, followed by a liquid-liquid mixing enhancement structure. The microchannels composed of multiple splitting and merging structures promote the mixing and reaction of the two phases. S6: Heat exchange and temperature control: The temperature of the heat exchange pipeline is controlled at 30~50℃ by a constant temperature cooling circulating water pump to maintain a suitable reaction temperature in the microreactor; S7: Coil heating and residence: The reaction mixture enters the first and second coils. Heating windings are wrapped around the outside of the coils. The temperature control range is 70~90℃. The total length of the coils is 4~16m, and they are connected in 2m sections by a two-way valve. The residence time of the liquid in the coils is 1~3h. S8: Collection and post-processing: Connect the coil outlet to the microcapsule collection tank to collect the microcapsule solution after the reaction. After centrifugation, washing, and drying in a 60°C oven for 24 hours, PEG microcapsules are obtained.

[0009] Preferably, the phase change material in step S2 is polyethylene glycol with a number-average molecular weight of 600-8000.

[0010] Preferably, the wall material monomer in step S1 is one or more of styrene, methyl methacrylate and pentaerythritol tetraacrylate, and the mass ratio of the wall material monomer to the core material phase change material is 0.5~4:1.

[0011] Preferably, the emulsifier in step S2 is one or more of Span emulsifiers, Tween emulsifiers, polyvinyl alcohol emulsifiers, and sodium dodecyl sulfate, and the mass ratio of emulsifier to core phase change material is 0.02~0.1:1.

[0012] Preferably, the initiator in step S1 is azobisisobutyronitrile, and the mass ratio of the initiator to the wall material monomer is 0.005~0.02:1.

[0013] Preferably, the pH adjusting solution in step S2 is an acetic acid or triethanolamine solution, and the mass ratio of the pH adjusting solution to the core phase change material is 0.01~0.1:1.

[0014] Preferably, the solvent in step S1 is cyclohexane, n-hexane, or liquid paraffin, and the pressure control range of the back pressure valve is 0.5~3MPa.

[0015] The beneficial effects of this invention are: 1. The microcapsule preparation device used in this invention employs a 3D-printed, one-piece stainless steel structure for the microreactor, which contains internal reaction and heat exchange pipelines to ensure effective heat transfer and precise temperature control during the reaction. The reaction pipelines are used for the mixing reaction of the continuous and dispersed phases. The heat exchange tubes are connected to a constant-temperature circulating water pump to maintain a stable reaction temperature. Heating wires are wound around the outside of the coils to further heat and mature the mixture after the reaction. The multi-segment connection of the coils and the bidirectional valve connection structure facilitate the adjustment and control of the residence time of the liquid in the coils. Thus, by connecting the coils after the microreactor, continuous production of PEG microcapsules can be achieved. Compared with batch preparation, it has higher production efficiency, can be mass-produced, process parameters are easier to stabilize and control, and is more conducive to automation integration. Continuous preparation of PEG microcapsules has significant advantages over batch preparation in terms of efficiency, cost, and quality control. By using a reverse emulsion system and using organic polymers as wall materials to encapsulate PEG, it has the advantages of low cost, ease of processing, and excellent mechanical and protective properties. Attached Figure Description

[0016] Figure 1 The diagram shown is a three-dimensional structural schematic of the continuous flow polyethylene glycol phase change microcapsule preparation apparatus of the present invention. Figure 2 The diagram shown is a planar structural schematic of the continuous flow polyethylene glycol phase change microcapsule preparation apparatus of the present invention. Figure 3The diagram shown is a schematic flow chart of the continuous flow polyethylene glycol phase change microcapsule preparation method of the present invention. Explanation of reference numerals in the attached drawings: 1. Dispersed phase solution tank; 2. First valve; 3. Dispersed phase plunger pump; 4. Back pressure valve; 5. Constant temperature cooling circulating water pump; 6. Continuous phase solution tank; 7. Continuous phase plunger pump; 8. Microreactor; 9. First coil; 10. Second coil; 11. Second valve; 12. Microcapsule collection tank. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Please see Figures 1-3 This invention provides an embodiment: a continuous flow polyethylene glycol phase change microcapsule preparation device and method. The continuous flow polyethylene glycol phase change microcapsule preparation device includes a microreactor 8, a dispersed phase solution tank 1, a first valve 2, a dispersed phase plunger pump 3, a back pressure valve 4, a constant temperature cooling circulating water pump 5, a continuous phase solution tank 6, a continuous phase plunger pump 7, a first coil 9, a second coil 10, a second valve 11, and a microcapsule collection tank 12. The microreactor 8 is a 3D-printed one-piece stainless steel structure. The microreactor 8 has reaction pipeline channels and heat exchange pipeline channels. The microreactor 8 has two inlet channels, which are a continuous phase channel and a dispersed phase channel, respectively. A continuous phase plunger pump 7 is installed at one end of the continuous phase channel of the microreactor 8, and a dispersed phase plunger pump 3 is installed at one end of the dispersed phase channel of the microreactor 8. The input end of the dispersed phase plunger pump 3 is provided with dispersed phase solution. Solution tank 1, dispersed phase plunger pump 3, and microreactor 8 are connected by a pipeline structure. Continuous phase plunger pump 7 and microreactor 8 are also connected by a pipeline structure. The input end of continuous phase plunger pump 7 is connected to continuous phase solution tank 6. A back pressure valve 4 is installed on the dispersed phase channel of microreactor 8. A constant temperature cooling circulating water pump 5 is installed at one end of the heat exchange pipeline of microreactor 8. The inlet and outlet of the heat exchange pipeline of microreactor 8 are connected to the constant temperature cooling circulating water pump 5. A first coil 9 is installed at the output end of microreactor 8. A second coil 10 is installed at one end of the first coil 9. The first coil 9 and the second coil 10 are multi-segment connected structures. The first coil 9 and the second coil 10 are connected by a two-way valve. A microcapsule collection tank 12 is installed at one end of the second coil 10. A first valve 2 is installed on the output pipeline of dispersed phase solution tank 1. A second valve 11 is installed on the input pipeline of microcapsule collection tank 12.

[0019] The microreactor 8 is constructed using a 3D-printed, one-piece stainless steel structure, with internal reaction and heat exchange pipelines, ensuring effective heat transfer and precise temperature control during the reaction process.

[0020] The junction of the continuous phase channel and the dispersed phase channel on the microreactor 8 is a liquid-liquid mixing enhancement structure. The junction of the continuous phase channel and the dispersed phase channel is a T-shaped structure. The enhancement structure is a micro-channel composed of multi-component flow and confluence structure. It is used for the mixing reaction of the continuous phase and the dispersed phase through the reaction pipeline. The heat exchange tube is connected by a constant temperature circulating water pump to maintain the stability of the reaction temperature. The dispersed phase plunger pump 3 is a common plunger pump, and the continuous phase plunger pump 7 is a high temperature plunger pump. The outer side of the first coil 9 and the second coil 10 is wound with heating wire. The heating wire wound on the outer side of the coil is used to further heat and mature the mixture after the reaction. The multi-segment connection form of the coil and the two-way valve connection structure facilitate the adjustment and control of the residence time of the liquid in the coil.

[0021] A method for preparing continuous flow polyethylene glycol phase change microcapsules includes the following steps: S1: Prepare the dispersed phase solution: Mix the wall material monomer, initiator and solvent in the oil phase to form a dispersed phase solution; S2: Preparation of continuous phase solution: Mix phase change material, emulsifier and pH adjustment solution in aqueous phase to form continuous phase solution; S3: Setting up microreactor 8: Microreactor 8 is equipped with reaction pipeline channels and heat exchange pipeline channels. Microreactor 8 has two inlet channels, namely a continuous phase channel and a dispersed phase channel. The continuous phase channel is connected to the continuous phase plunger pump 7, and the dispersed phase channel is connected to the dispersed phase plunger pump 3. A back pressure valve 4 is connected between the dispersed phase plunger pump 3 and the dispersed phase channel of microreactor 8. The inlet and outlet of the heat exchange pipeline of microreactor 8 are connected to the constant temperature cooling circulating water pump 5. The outlet of microreactor 8 is connected to the first coil 9, and the first coil 9 is connected to the second coil 10. The outlet of the second coil 10 is connected to the microcapsule collection tank 12. S4: Pumping in dispersed and continuous phase solutions: The dispersed phase solution is pumped into the dispersed phase channel of the microreactor 8 at a flow rate of 0.1~1 mL / min using the dispersed phase plunger pump 3, and the continuous phase solution is pumped into the continuous phase channel of the microreactor 8 at a flow rate of 0.01~0.5 mL / min using the continuous phase plunger pump 7. The continuous phase plunger pump 7 is a high-temperature plunger pump with a temperature control range of 30~50℃. S5: Mixing and Reaction: The continuous phase and the dispersed phase form W / O droplets at the junction of the microreactor 8. The junction has a T-shaped structure, followed by a liquid-liquid mixing enhancement structure. The microchannels composed of multiple splitting and merging structures promote the mixing and reaction of the two phases. S6: Heat exchange and temperature control: The temperature of the heat exchange pipeline is controlled at 30~50℃ by the constant temperature cooling circulating water pump 5 to maintain a suitable reaction temperature in the microreactor 8. S7: Coil heating and residence: The reaction mixture enters the first coil 9 and the second coil 10. The outer side of the coil is wound with heating wire. The temperature control range is 70~90℃. The total length of the coil is 4~16m, and it is connected in 2m sections by a two-way valve. The residence time of the liquid in the coil is 1~3h. S8: Collection and post-processing: Connect the coil outlet to the microcapsule collection pool 12 to collect the microcapsule solution after the reaction. After centrifugation, washing, and drying in a 60℃ oven for 24 hours, PEG microcapsules are obtained.

[0022] Preferably, the phase change material in step S2 is polyethylene glycol with a number-average molecular weight of 600-8000.

[0023] Preferably, the wall material monomer in step S1 is one or more of styrene, methyl methacrylate and pentaerythritol tetraacrylate, and the mass ratio of the wall material monomer to the core material phase change material is 0.5~4:1.

[0024] Preferably, the emulsifier in step S2 is one or more of Span emulsifiers, Tween emulsifiers, polyvinyl alcohol emulsifiers, and sodium dodecyl sulfate, and the mass ratio of emulsifier to core phase change material is 0.02~0.1:1.

[0025] Preferably, the initiator in step S1 is azobisisobutyronitrile, and the mass ratio of the initiator to the wall material monomer is 0.005~0.02:1.

[0026] Preferably, the pH adjusting solution in step S2 is an acetic acid or triethanolamine solution, and the mass ratio of the pH adjusting solution to the core phase change material is 0.01~0.1:1.

[0027] Preferably, the solvent in step S1 is cyclohexane, n-hexane, or liquid paraffin, and the pressure control range of the back pressure valve 4 is 0.5~3MPa.

[0028] Example Optionally, the specific steps for preparing polyethylene glycol (PEG) phase change microcapsules using the formulation and process parameters of the present invention are as follows: Preparation of continuous phase: Wall material monomers: 4g styrene + 1g pentaerythritol tetraacrylate; Emulsifier: 0.2g Span80; Initiator: 0.1g azobisisobutyronitrile; Solvent: Appropriate amount of cyclohexane; Mix the above ingredients ultrasonically for 10 minutes and set aside. b. Preparation of the dispersed phase: Phase change material: 5g polyethylene glycol 1500; pH adjustment solution: 5 mL 1% triethanolamine solution; After heating and melting polyethylene glycol, add triethanolamine solution and continue stirring. The temperature is set to 50℃ and the stirring speed is 300 rpm. c. Microreactor operating conditions: Continuous phase flow rate: 1 mL / min; Dispersed phase flow rate: 0.1 mL / min; Back pressure valve pressure: 1 MPa; High-temperature plunger pump temperature: 35℃; Circulating water pump temperature: 50℃; Coil hot winding wire temperature: 70℃; Total coil length: 8m; Post-processing: Collect the reaction liquid at the outlet and wash it by centrifugation; PEG microcapsules were obtained by drying in an oven at 60°C for 24 hours.

[0029] The technical solution of the present invention is compared with existing technologies such as spray drying, in-situ polymerization, and oil phase separation, as shown in the figure below:

[0030] As can be seen from the above comparison, the continuous flow polyethylene glycol phase change microcapsule preparation method and apparatus of the present invention have significant advantages. By employing a continuous flow microreactor and a coil heating system, continuous production of PEG microcapsules is achieved, greatly improving production efficiency and product quality stability. Simultaneously, this method also possesses excellent particle size control and process parameter control capabilities, resulting in superior product performance. Furthermore, the preparation method of the present invention has a high degree of automation and environmental friendliness, making it suitable for large-scale production and industrial applications. In summary, the continuous flow polyethylene glycol phase change microcapsule preparation method and apparatus of the present invention have significant technical advantages and application prospects, providing a new, efficient, and environmentally friendly solution for the preparation of PEG microcapsules.

[0031] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A continuous flow polyethylene glycol phase change microcapsule preparation apparatus comprising a microreactor (8); characterised in that: The micro-reactor (8) is a 3D-printed integrated stainless steel structure, and the micro-reactor (8) is provided with a reaction pipeline channel and a heat exchange pipeline channel, and the micro-reactor (8) is provided with two inlet channels, and the two inlet channels are a continuous phase channel and a dispersed phase channel respectively, one end of the continuous phase channel of the micro-reactor (8) is provided with the continuous phase piston pump (7), one end of the dispersed phase channel of the micro-reactor (8) is provided with the dispersed phase piston pump (3), the input end of the dispersed phase piston pump (3) is provided with the dispersed phase solution tank (1), the dispersed phase piston pump (3) and the micro-reactor (8) are connected through a pipeline structure, the continuous phase piston pump (7) and the micro-reactor (8) are connected through a pipeline structure, the input end of the continuous phase piston pump (7) is connected with the continuous phase solution tank (6), the dispersed phase channel of the micro-reactor (8) is provided with the back pressure valve (4), one end of the heat exchange pipeline of the micro-reactor (8) is provided with the constant temperature cooling circulating water pump (5), the heat exchange pipeline inlet and outlet of the micro-reactor (8) are connected with the constant temperature cooling circulating water pump (5), the output end of the micro-reactor (8) is provided with the first coil pipe (9), one end of the first coil pipe (9) is provided with the second coil pipe (10), the first coil pipe (9) and the second coil pipe (10) are a multi-section connection structure, the first coil pipe (9) and the second coil pipe (10) are connected through a two-way valve, one end of the second coil pipe (10) is provided with the microcapsule collection tank (12), the output pipeline of the dispersed phase solution tank (1) is provided with the first valve (2), and the input pipeline of the microcapsule collection tank (12) is provided with the second valve (11).

2. A continuous flow polyethylene glycol phase change microcapsule preparation device according to claim 1, wherein: The intersection of the continuous phase channel and the dispersed phase channel on the micro-reactor (8) is a liquid-liquid mixing reinforcement structure, the intersection of the continuous phase channel and the dispersed phase channel is a T-shaped structure, and the reinforcement structure is a micro channel composed of multiple diversion and combination structures.

3. The apparatus for preparing continuous-flow polyethylene glycol phase change microcapsules according to claim 1, characterized in that: The dispersed phase piston pump (3) is a common piston pump, the continuous phase piston pump (7) is a high-temperature piston pump, and the outer sides of the first coil pipe (9) and the second coil pipe (10) are wound with heating winding wires.

4. A method for the preparation of continuous-flow polyethylene glycol phase change microcapsules, characterized by: The method comprises the following steps: S1: preparing a dispersed phase solution: mixing wall material monomers, initiators and solvents in an oil phase to form a dispersed phase solution; S2: preparing a continuous phase solution: mixing phase change materials, emulsifiers and pH adjusting liquids in an aqueous phase to form a continuous phase solution; S3: setting up the micro-reactor (8): the micro-reactor (8) is provided with a reaction pipeline channel and a heat exchange pipeline channel, and the micro-reactor (8) is provided with two inlet channels, which are a continuous phase channel and a dispersed phase channel, respectively; the continuous phase channel is connected with the continuous phase piston pump (7), and the dispersed phase channel is connected with the dispersed phase piston pump (3); the dispersed phase piston pump (3) is connected with the dispersed phase channel of the micro-reactor (8) through a back pressure valve (4); the heat exchange pipeline inlet and outlet of the micro-reactor (8) are connected with the constant temperature cooling circulating water pump (5); the outlet of the micro-reactor (8) is connected with the first coil pipe (9); the first coil pipe (9) is connected with the second coil pipe (10); and the outlet of the second coil pipe (10) is connected with the microcapsule collection tank (12); S4: pumping the dispersed phase and the continuous phase solution: the dispersed phase solution is pumped into the dispersed phase channel of the micro-reactor (8) through the dispersed phase piston pump (3) at a flow rate of 0.1-1 mL / min; and the continuous phase solution is pumped into the continuous phase channel of the micro-reactor (8) through the continuous phase piston pump (7) at a flow rate of 0.01-0.5 mL / min; wherein the continuous phase piston pump (7) is a high-temperature piston pump, and the temperature control range is 30-50℃; S5: mixing and reaction: the continuous phase and the dispersed phase form W / O droplets at the intersection of the micro-reactor (8); the intersection is a T-shaped structure, followed by a liquid-liquid mixing enhancement structure composed of multiple branch and confluence structures, which promotes the mixing and reaction of the two phases; S6: heat exchange and temperature control: the temperature of the heat exchange pipeline is controlled at 30-50℃ through the constant temperature cooling circulating water pump (5) to maintain the appropriate reaction temperature in the micro-reactor (8); S7: coil heating and residence: the mixed liquid after reaction enters the first coil pipe (9) and the second coil pipe (10); the outer side of the coil pipe is wound with a heating winding wire, and the temperature control range is 70-90℃; the total length of the coil pipe is 4-16 m, and each 2 m is connected through a two-way valve; and the residence time of the liquid in the coil pipe is 1-3 h; S8: collection and post-treatment: the outlet of the coil pipe is connected with the microcapsule collection tank (12) to collect the microcapsule solution after reaction; and the microcapsule solution is subjected to centrifugal washing and drying in a 60℃ oven for 24 h to obtain the PEG microcapsule.

5. A process for the preparation of continuous-flow polyethylene glycol phase change microcapsules according to claim 4, characterized in that: The phase change material in the S2 step is polyethylene glycol with a number average molecular weight of 600-8000.

6. The process for the preparation of continuous-flow polyethylene glycol phase change microcapsules according to claim 4, characterized in that: The wall material monomer in the S1 step is one or more of styrene, methyl methacrylate and pentaerythritol tetraacrylate; and the mass ratio of the wall material monomer to the core material phase change material is 0.5-4:

1.

7. The process for the preparation of continuous-flow polyethylene glycol phase change microcapsules according to claim 4, characterized in that: The emulsifier in the S2 step is one or more of a Span emulsifier, a Tween emulsifier, polyvinyl alcohol and sodium dodecyl sulfate; and the mass ratio of the emulsifier to the core material phase change material is 0.02-0.1:

1.

8. The process for the preparation of continuous-flow polyethylene glycol phase change microcapsules according to claim 4, characterized in that: The initiator in the S1 step is azobisisobutyronitrile; and the mass ratio of the initiator to the wall material monomer is 0.005-0.02:

1.

9. The process for the preparation of continuous-flow polyethylene glycol microencapsulates according to claim 4, characterized in that: The pH adjusting solution in the S2 step is acetic acid or triethanolamine solution; and the mass ratio concentration of the pH adjusting solution to the core material phase change material is 0.01-0.1:

1.

10. The process for the preparation of continuous-flow polyethylene glycol phase change microcapsules according to claim 4, characterized in that: The solvent in the S1 step is cyclohexane, n-hexane or liquid paraffin, and the pressure control range of the back pressure valve (4) is 0.5-3 MPa.

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