A device and method for measuring single droplet evaporation and heat transfer rate

Abstract

The application discloses a single-droplet evaporation and heat transfer rate measuring device and method, and relates to the technical field of micro-nanoparticle measurement. The device comprises an environment bin for generating a temperature and humidity environment meeting preset conditions; an aerosol droplet generating assembly for conveying a particle size aerosol airflow to the environment bin; a laser emitting assembly for respectively emitting first laser and second laser to the environment bin, so that the first laser and the second laser converge in the environment bin and generate an optical trap; the optical trap captures droplet particles so that the droplet particles are in a suspended state in the environment bin; a droplet evaporation observation assembly for observing particle size and droplet internal temperature distribution data of the droplet particles in the environment bin at different time points; and an evaporation rate and heat transfer efficiency calculating component for calculating the evaporation rate of the droplet particles according to the multiple particle sizes, and calculating the heat transfer efficiency of the droplet particles according to the multiple droplet internal temperature distribution data. The application realizes accurate measurement and calculation of the single-droplet evaporation rate and heat transfer efficiency.

Description

Technical Field

[0001] This invention relates to the field of micro-nano particle measurement technology, and in particular to a device and method for measuring the evaporation and heat transfer rate of a single droplet. Background Technology

[0002] Droplet evaporation is widespread in natural and industrial production and daily life, such as in natural rainfall cycles, pesticide spraying, and server phase change enhanced heat dissipation. However, droplet evaporation containing particles mostly occurs in a suspended state without contact with a surface. Furthermore, the theoretical model of particle evaporation is based on suspended particles; water vapor around the particles diffuses from the particle surface to the environment under the influence of vapor pressure, achieving droplet phase change evaporation under the vapor pressure difference.

[0003] Traditional methods for measuring the evaporation rate of single-droplet evaporation involve placing the particle on a substrate of a specific material and observing its three-phase lines and morphological changes under a microscope in a temperature- and humidity-controlled environment. The evaporation rate is then indirectly calculated by determining the volume change gradient. In this method, the particle is in direct contact with the substrate, and the surface properties of the substrate significantly influence the condensation site and evaporation rate. However, in real-world industrial applications, particles are suspended in airflow, and the theoretical models of particle evaporation kinetics are based on the dynamic movement of suspended particles. Therefore, traditional methods for measuring particle condensation and growth rates differ significantly from actual industrial evaporation processes. Furthermore, temperature sensors used in traditional temperature measurement methods are prone to capillary action on the droplet surface, affecting droplet morphology and leading to inaccuracies in the evaporation rate measurement. Summary of the Invention

[0004] The purpose of this invention is to provide a device and method for measuring the evaporation and heat transfer rate of a single droplet, thereby enabling accurate measurement and calculation of the evaporation rate and heat transfer efficiency of a single droplet.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] This invention provides a device for measuring the evaporation and heat transfer rate of a single droplet, comprising:

[0007] An environmental chamber is used to generate a temperature and humidity environment that meets preset conditions; the preset conditions include preset temperature and preset humidity.

[0008] An aerosol droplet generation component, connected to the environmental chamber, is used to generate a particle size aerosol gas stream and deliver the particle size aerosol gas stream to the environmental chamber; the particle size aerosol gas stream includes multiple droplet particles.

[0009] A laser emitting component is used to emit a first laser and a second laser into the environmental chamber, respectively, so that the first laser and the second laser converge in the environmental chamber and generate an optical trap; the optical trap is used to capture the droplet particles, so that the droplet particles are suspended in the environmental chamber.

[0010] The droplet evaporation observation component is used to observe the particle size and internal temperature distribution of the droplets at different times within the environmental chamber.

[0011] An evaporation rate and heat transfer efficiency calculation component is used to calculate the evaporation rate of the droplet particles based on multiple particle size data, and to calculate the heat transfer efficiency of the droplet particles based on multiple internal temperature distribution data of the droplets.

[0012] Optionally, the laser emitting assembly includes a first laser emitting sub-component and a second laser emitting sub-component;

[0013] The first laser emitting sub-component is disposed on the first side of the environmental chamber, and the first laser emitting sub-component is used to emit a first laser into the environmental chamber;

[0014] The second laser emitting sub-component is disposed on the second side of the environmental chamber, and the second laser emitting sub-component is used to emit a second laser from the environmental chamber;

[0015] Furthermore, the first side of the environmental chamber and the second side of the environmental chamber are opposite each other in the horizontal direction.

[0016] Optionally, the first laser emitting sub-component includes a first laser controller, a first laser, a first planar reflector, and a first movable convex lens;

[0017] The first laser controller is connected to the first laser, and the first laser controller is used for:

[0018] Control the first laser to generate the first laser;

[0019] After the droplet particles are captured by the optical trap in the environmental chamber, the laser power of the first laser is adjusted so that the droplet particles remain captured by the optical trap.

[0020] The first laser, the first planar reflector, and the first movable convex lens are arranged in sequence so that the first laser passes through the first planar reflector and the first movable convex lens in sequence before entering the environmental chamber.

[0021] Optionally, the first movable convex lens is used to focus the first laser, after being adjusted by the first planar reflector, to the center of the environmental chamber.

[0022] Optionally, the droplet evaporation observation assembly includes an optical microscope and a macro infrared camera;

[0023] The optical microscope is used to observe the particle size of the droplets at different times within the environmental chamber;

[0024] The macro-lens infrared camera is used to observe the internal temperature distribution data of the droplets at different times within the environmental chamber.

[0025] Optionally, the aerosol droplet generating assembly includes an aerosol generator and a droplet delivery pipeline;

[0026] The aerosol generator is used to generate a flow of aerosol particles consisting of single-component droplet particles.

[0027] One end of the droplet delivery pipe is connected to the aerosol generator, and the other end of the droplet delivery pipe is connected to the environmental chamber. The droplet delivery pipe is used to deliver the particle size aerosol gas stream into the environmental chamber.

[0028] Optionally, the measuring device further includes:

[0029] A temperature-controlled water bath is connected to the environmental chamber and is used to regulate the temperature in the environmental chamber so that the temperature in the environmental chamber reaches a preset temperature.

[0030] A humidity controller is installed in the environmental chamber to detect humidity data in the environmental chamber and increase or decrease the humidity in the environmental chamber according to the humidity data so that the humidity in the environmental chamber reaches a preset humidity.

[0031] Optionally, the second laser emitting sub-component includes a second laser controller, a second laser, a second planar reflector, and a second movable convex lens;

[0032] The second laser controller is connected to the second laser, and the second laser controller is used for:

[0033] Control the second laser to generate a second laser;

[0034] After the droplet particles are captured by the optical trap in the environmental chamber, the laser power of the second laser is adjusted so that the droplet particles remain captured by the optical trap.

[0035] The second laser, the second planar reflector, and the second movable convex lens are arranged in sequence so that the second laser passes through the second planar reflector and the second movable convex lens in sequence before entering the environmental chamber.

[0036] To achieve the above objectives, the present invention also provides the following technical solutions:

[0037] A method for measuring the evaporation and heat transfer rate of a single droplet, applied to a device for measuring the evaporation and heat transfer rate of a single droplet, the method comprising:

[0038] An environmental environment with preset temperature and humidity conditions is created in the environmental chamber; the preset conditions include preset temperature and preset humidity.

[0039] A particle size aerosol gas stream is generated by an aerosol droplet generation component and delivered to the environmental chamber; the particle size aerosol gas stream comprises multiple droplet particles.

[0040] A first laser and a second laser are emitted into the environmental chamber via a laser emitting component, so that the first laser and the second laser converge in the environmental chamber to generate an optical trap; the optical trap is used to capture the droplet particles, so that the droplet particles are suspended in the environmental chamber.

[0041] The droplet evaporation observation component was used to observe the particle size and internal temperature distribution of the droplets at different times within the environmental chamber.

[0042] The evaporation rate and heat transfer efficiency calculation component calculates the evaporation rate of the droplet particles based on multiple particle size data, and calculates the heat transfer efficiency of the droplet particles based on multiple internal temperature distribution data of the droplets.

[0043] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0044] This invention provides a device and method for measuring the evaporation and heat transfer rate of a single droplet. An environmental chamber is formed with preset temperature and humidity. An aerosol droplet generation component generates a particle-size aerosol gas flow, which is then delivered to the environmental chamber. A laser emission component emits a first laser and a second laser into the environmental chamber, causing them to converge and form an optical trap. The optical trap captures the droplet particles, keeping them suspended within the chamber. This overcomes the influence of substrate surface characteristics on the evaporation rate when particles are placed directly on a substrate, as in traditional methods. A droplet evaporation observation component observes the particle size and internal temperature distribution of the droplets at different times within the environmental chamber, enabling non-contact tracking and recording. An evaporation rate and heat transfer efficiency calculation component calculates the evaporation rate of the droplets based on multiple particle sizes and the heat transfer efficiency based on the internal temperature distribution data. This overcomes the drawback of traditional temperature sensors, which are prone to capillary flow affecting droplet morphology. In summary, this invention makes the measurement of single droplet evaporation and heat transfer efficiency consistent with actual industrial applications, and has a wider range of applications and higher measurement accuracy compared to traditional measurement methods. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 This is a schematic diagram of the structure of the single-droplet evaporation and heat transfer rate measuring device of the present invention;

[0047] Figure 2 This is a schematic flowchart of the method for measuring the evaporation and heat transfer rate of a single droplet according to the present invention.

[0048] Symbol explanation:

[0049] 101-Aerosol generator, 201-Droplet particle conveying pipeline, 301-Environmental chamber, 401-Droplet particles, 501-First laser controller, 502-Second laser controller, 601-First laser, 602-Second laser, 701-First plane mirror, 702-Second plane mirror, 801-First movable convex lens, 802-Second movable convex lens, 901-Macro infrared camera, 1001-Optical microscope, 1002-Temperature-controlled water bath, 1003-Humidity controller. Detailed Implementation

[0050] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] This invention proposes a device and method for measuring the evaporation and heat transfer rate of a single droplet. Based on optical tweezers technology, a single droplet is stably suspended in an environmental chamber. The morphology and size of the droplet during the evaporation process are observed using an optical microscope, and the dynamic temperature distribution of the droplet is observed using a macro lens infrared camera. This allows for the dynamic measurement of the heat transfer efficiency and evaporation rate.

[0052] To make the objectives, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0053] Example 1

[0054] like Figure 1 As shown, this embodiment provides a device for measuring the evaporation and heat transfer rate of a single droplet, including an environmental chamber, an aerosol droplet generation component, a laser emission component, a droplet evaporation observation component, and an evaporation rate and heat transfer efficiency calculation component.

[0055] Specifically, the environmental chamber 301 is used to generate a temperature and humidity environment that meets preset conditions; the preset conditions include preset temperature and preset humidity.

[0056] The aerosol droplet generation component is connected to the environmental chamber 301. The aerosol droplet generation component generates a particle-size aerosol gas stream and delivers the particle-size aerosol gas stream to the environmental chamber 301. The particle-size aerosol gas stream includes multiple droplet particles 401. Each droplet particle 401 is a single component, and the droplet particles 401 in the same particle-size aerosol gas stream have the same composition. Furthermore, each droplet particle 401 is a micro-nano sized particle.

[0057] Preferably, the aerosol droplet generating assembly includes an aerosol generator 101 and a droplet delivery conduit 201; the aerosol generator 101 is used to generate a particle aerosol gas stream composed of single-component droplet particles 401; one end of the droplet delivery conduit 201 is connected to the aerosol generator 101, and the other end of the droplet delivery conduit 201 is connected to the environmental chamber 301, the droplet delivery conduit 201 being used to deliver the particle aerosol gas stream into the environmental chamber. The droplet delivery conduit 201 is a conduit designed to prevent particle adhesion.

[0058] The laser emitting component emits a first laser and a second laser into the environmental chamber 301, respectively, so that the first laser and the second laser converge in the environmental chamber 301 to form an optical trap; the optical trap is used to capture the droplet particles 401, so that the droplet particles 401 are suspended in the environmental chamber 301. Both the first laser and the second laser have specific wavelengths and powers, which are set by the operator as needed.

[0059] The laser emitting assembly includes a first laser emitting sub-component and a second laser emitting sub-component.

[0060] The first laser emitting sub-component is disposed on the first side of the environmental chamber 301 and is used to emit a first laser into the environmental chamber 301; the second laser emitting sub-component is disposed on the second side of the environmental chamber 301 and is used to emit a second laser into the environmental chamber 301; and the first side and the second side of the environmental chamber 301 are opposite each other in the horizontal direction.

[0061] Preferably, the first laser emitting sub-component includes a first laser controller 501, a first laser 601, a first planar reflector 701, and a first movable convex lens 801. The first laser controller 501 is connected to the first laser 601 and is used to: 1) control the first laser 601 to generate a first laser; 2) adjust the laser power of the first laser after the droplet particle 401 is captured by the optical trap in the environmental chamber 301, so that the droplet particle remains captured by the optical trap during the evaporation process. The first laser 601, the first planar reflector 701, and the first movable convex lens 801 are arranged sequentially so that the first laser passes through the first planar reflector 701 and the first movable convex lens 801 sequentially before entering the environmental chamber.

[0062] Specifically, the first planar reflector 701 is used to adjust the laser direction of the first laser, so that the first laser enters the first movable convex lens 801; the first movable convex lens 801 is used to focus the first laser, after being adjusted by the first planar reflector 701, to the center of the environmental chamber 301, and at the center of the environmental chamber 301, it converges with the second laser to generate a light trap of a certain intensity. Here, the first planar reflector 701 is a controllable and precisely movable planar reflector, and the first movable convex lens 801 is a controllable and precisely movable convex lens.

[0063] The second laser emitting sub-component includes a second laser controller 502, a second laser 602, a second planar reflector 702, and a second movable convex lens 802. The second laser controller 502 is connected to the second laser 602 and is used to: 1) control the second laser 602 to generate a second laser; 2) adjust the laser power of the second laser after the droplet particles are captured by the optical trap in the environmental chamber 301, so that the droplet particles remain captured by the optical trap during evaporation. The second laser 602, the second planar reflector 702, and the second movable convex lens 802 are arranged sequentially so that the second laser passes through the second planar reflector 702 and the second movable convex lens 802 sequentially before entering the environmental chamber 301.

[0064] Specifically, the working principle of the second plane mirror 702 and the second movable convex lens 802 is the same as that of the first plane mirror 701 and the first movable convex lens 801, and will not be repeated here. Among them, the second plane mirror 702 is a controllable and precisely movable plane mirror, and the second movable convex lens 802 is a controllable and precisely movable convex lens.

[0065] The droplet evaporation observation component is used to observe the particle size and internal temperature distribution of the droplets at different times within the environmental chamber.

[0066] Preferably, the droplet evaporation observation assembly includes an optical microscope 1001 and a macro infrared camera 901; the optical microscope 1001 is used to observe the particle size of the droplet particles 401 in the environmental chamber 301 at different times; the macro infrared camera 901 is used to observe the internal temperature distribution data of the droplet particles 401 in the environmental chamber 301 at different times.

[0067] The evaporation rate and heat transfer efficiency calculation unit is used to calculate the evaporation rate of the droplet particles based on multiple particle size data, and to calculate the heat transfer efficiency of the droplet particles based on multiple internal temperature distribution data of the droplets.

[0068] In one specific application, the measuring device of this embodiment further includes a temperature-controlled water bath 1002 and a humidity controller 1003. The temperature-controlled water bath 1002 is connected to the environmental chamber 301 and is used to regulate the temperature in the environmental chamber 301 to achieve a preset temperature. The humidity controller 1003 is disposed in the environmental chamber 301 and is used to detect humidity data in the environmental chamber 301 and increase or decrease the humidity in the environmental chamber 301 according to the humidity data to achieve a preset humidity level.

[0069] The specific process of the device in this embodiment in practical application is as follows:

[0070] The principle of optical tweezers technology is that two laser beams converge to create an optical trap. Dust-laden particles entering the vicinity of the optical trap are bound under the action of light pressure, achieving non-contact free evaporation while suspended within the environmental chamber. Based on this, the first and second laser emitting sub-components control the movement direction and speed of the two laser beams, respectively, so that the first and second lasers converge at the center of the environmental chamber to create an optical trap. When droplet particles pass through the optical trap, they are captured and suspended at the center of the environmental chamber 301. The suspended single droplet undergoes phase change evaporation in the saturated environment within the environmental chamber. As the size of the droplet particles continuously decreases during the phase change evaporation process, the power of the first laser needs to be adjusted by the first laser controller 501, and the power of the second laser needs to be adjusted by the second laser controller 502 to ensure that the droplet remains stably suspended within the environmental chamber throughout the evaporation cycle. During the dynamic evaporation of the droplet particles, the temperature of the droplet particles is collected in real time by a macro-mirror infrared camera 901, while the particle size of the droplet is recorded by an optical microscope 1001, thereby calculating its heat flux density and dynamic evaporation rate.

[0071] In summary, this invention employs optical tweezers technology to focus two laser beams to create an optical trap. When a single particle of a specific size passes near the optical trap within the environmental chamber along with the carrier fluid, it is bound to the trap by the light pressure, thus transforming the particle's motion into a stationary state and suspending it in the environmental chamber under specific temperature and humidity conditions. At this point, a microscope is used to observe the particle size changes within the environmental chamber over a distance, and a macro infrared imager is used to record transient temperature changes, thereby obtaining the evaporation rate of the single particle under specific time and temperature / humidity conditions.

[0072] Example 2

[0073] like Figure 2 As shown, this embodiment provides a method for measuring the evaporation and heat transfer rate of a single droplet, applied to the measuring device for the evaporation and heat transfer rate of a single droplet in Embodiment 1. The measurement method includes:

[0074] Step 100: Create a temperature and humidity environment in the environmental chamber that meets preset conditions; the preset conditions include preset temperature and preset humidity. Specifically, the temperature in the environmental chamber is adjusted by a temperature-controlled water bath, and the humidity in the environmental chamber is adjusted by a humidity controller, thereby obtaining an environment with preset temperature and preset humidity (generally, higher temperature and lower humidity, relatively dry).

[0075] Step 200: A particle size aerosol airflow is generated by an aerosol droplet generating component and the particle size aerosol airflow is delivered to the environmental chamber; the particle size aerosol airflow includes multiple droplet particles; specifically, a certain flow rate concentration is set to ensure smooth flow of the particle size aerosol airflow.

[0076] Step 300: A first laser and a second laser are emitted into the environmental chamber via a laser emitting component, so that the first laser and the second laser converge in the environmental chamber to generate an optical trap; the optical trap is used to capture the droplet particles so that the droplet particles are suspended in the environmental chamber.

[0077] Specifically, a first laser, under the control of a first laser controller, generates a first laser with a specific wavelength and power, which passes sequentially through a first planar reflector and a first movable convex lens to reach the environmental chamber. A second laser, under the control of a second laser controller, generates a second laser with a specific wavelength and power, which passes sequentially through a second planar reflector and a second movable convex lens to reach the environmental chamber. The first and second lasers converge at the center of the environmental chamber to create an optical trap of a certain intensity to capture and fix individual droplet particles.

[0078] Within a relatively dry and high-temperature environment chamber, a single droplet undergoes a non-contact evaporation process. As the droplet size continuously decreases during the evaporation phase change, the laser controller needs to make corresponding adjustments to change the laser power. Specifically, the steps are as follows: the laser power of the first laser is adjusted by the first laser controller in the first laser emitting sub-component, and the laser power of the second laser is adjusted by the second laser controller in the second laser emitting sub-component. This causes the first and second lasers, with adjusted power, to converge at the center of the environment chamber, creating an optical trap. The optical trap continues to capture the droplet particles, ensuring that the droplet particles remain trapped and stably suspended within the environment chamber throughout the entire evaporation cycle.

[0079] Step 400: Observe the particle size and internal temperature distribution of the droplets at different times within the environmental chamber using the droplet evaporation observation component.

[0080] Step 500: The evaporation rate of the droplet particles is calculated by the evaporation rate and heat transfer efficiency calculation component based on the multiple particle size data, and the heat transfer efficiency of the droplet particles is calculated based on the multiple internal temperature distribution data of the droplets.

[0081] Specifically, the particle size change of droplets during the evaporation process is observed using an optical microscope, and the droplet volume change is calculated based on the particle size change (the droplets are considered spherical and the influence of gravity is ignored); at the same time, the evaporation duration of the droplet particles is recorded, and the evaporation rate is obtained through the transient changes in the droplet volume during the evaporation process.

[0082] The temperature distribution data inside the droplets during the evaporation process were simultaneously observed using a macro-mirror infrared camera, and the transient change process of the droplets was determined based on the temperature distribution data inside multiple droplets. Furthermore, the transient heat flux density was calculated using Fourier's law, thereby obtaining the transient heat transfer efficiency of the droplets.

[0083] In practical applications, by changing the original size of the droplet particles generated by the aerosol generator and by changing the temperature and humidity conditions in the environmental chamber, the influence of the above parameters on the evaporation rate and heat transfer efficiency of the single droplet particles during the evaporation phase change process can be obtained, so as to facilitate further application in actual industry.

[0084] Compared with the prior art, the present invention also has the following advantages:

[0085] This invention uses an optical tweezers system to generate an optical trap of a certain intensity within an environmental chamber, causing particles to move within the chamber and ultimately be captured by the optical trap. The dynamic evaporation process is calculated by measuring movement time and particle size changes, avoiding the influence of substrate material on particle evaporation rates found in traditional methods. Furthermore, traditional temperature measurement methods often use temperature sensors that are prone to capillary action on droplet surfaces, affecting droplet morphology and causing inaccuracies in evaporation rate measurements. In contrast, the micro-mirror infrared sensing measurement employed in this invention enables real-time, dynamic, non-contact tracking and recording. The measured dynamic evaporation process aligns with industrial application requirements, significantly improving the approach to studying the evaporation rate of dust-laden droplets.

[0086] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0087] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A device for measuring the evaporation and heat transfer rate of a single droplet, characterized in that, The measuring device includes: An environmental chamber is used to generate a temperature and humidity environment that meets preset conditions; the preset conditions include preset temperature and preset humidity. An aerosol droplet generation component, connected to the environmental chamber, is used to generate a particle size aerosol gas stream and deliver the particle size aerosol gas stream to the environmental chamber; the particle size aerosol gas stream includes multiple droplet particles. A laser emitting component is used to emit a first laser and a second laser into the environmental chamber, respectively, so that the first laser and the second laser converge in the environmental chamber and generate an optical trap; the optical trap is used to capture the droplet particles, so that the droplet particles are suspended in the environmental chamber. The laser emitting assembly includes a first laser emitting sub-component and a second laser emitting sub-component; the first laser emitting sub-component is disposed on a first side of the environmental chamber and is used to emit a first laser into the environmental chamber; the second laser emitting sub-component is disposed on a second side of the environmental chamber and is used to emit a second laser into the environmental chamber; and the first side and the second side of the environmental chamber are opposite each other in the horizontal direction. The first laser emitting sub-component includes a first laser controller, a first laser, a first planar reflector, and a first movable convex lens; the first laser controller is connected to the first laser, and the first laser controller is used for: Control the first laser to generate the first laser; After the droplet particles are captured by the optical trap in the environmental chamber, the laser power of the first laser is adjusted so that the droplet particles remain captured by the optical trap. The first laser, the first planar reflector, and the first movable convex lens are arranged in sequence so that the first laser passes through the first planar reflector and the first movable convex lens in sequence before entering the environmental chamber; The droplet evaporation observation component is used to observe the particle size and internal temperature distribution of the droplets at different times within the environmental chamber. A temperature-controlled water bath is connected to the environmental chamber and is used to regulate the temperature in the environmental chamber so that the temperature in the environmental chamber reaches a preset temperature. An evaporation rate and heat transfer efficiency calculation component is used to calculate the evaporation rate of the droplet particles based on multiple particle size data, and to calculate the heat transfer efficiency of the droplet particles based on multiple internal temperature distribution data of the droplets.

2. The measuring device for single droplet evaporation and heat transfer rate according to claim 1, characterized in that, The first movable convex lens is used to focus the first laser, after being adjusted by the first planar reflector, onto the center of the environmental chamber.

3. The measuring device for single droplet evaporation and heat transfer rate according to claim 1, characterized in that, The droplet evaporation observation assembly includes an optical microscope and a macro infrared camera; The optical microscope is used to observe the particle size of the droplets at different times within the environmental chamber; The macro-lens infrared camera is used to observe the internal temperature distribution data of the droplets at different times within the environmental chamber.

4. The measuring device for single droplet evaporation and heat transfer rate according to claim 1, characterized in that, The aerosol droplet generating assembly includes an aerosol generator and a droplet delivery pipeline. The aerosol generator is used to generate a flow of aerosol particles consisting of single-component droplet particles. One end of the droplet delivery pipe is connected to the aerosol generator, and the other end of the droplet delivery pipe is connected to the environmental chamber. The droplet delivery pipe is used to deliver the particle size aerosol gas stream into the environmental chamber.

5. The measuring device for single droplet evaporation and heat transfer rate according to claim 1, characterized in that, The measuring device further includes: A humidity controller is installed in the environmental chamber to detect humidity data in the environmental chamber and increase or decrease the humidity in the environmental chamber according to the humidity data so that the humidity in the environmental chamber reaches a preset humidity.

6. The measuring device for single droplet evaporation and heat transfer rate according to claim 1, characterized in that, The second laser emitting sub-component includes a second laser controller, a second laser, a second planar reflector, and a second movable convex lens; The second laser controller is connected to the second laser, and the second laser controller is used for: Control the second laser to generate a second laser; After the droplet particles are captured by the optical trap in the environmental chamber, the laser power of the second laser is adjusted so that the droplet particles remain captured by the optical trap. The second laser, the second planar reflector, and the second movable convex lens are arranged in sequence so that the second laser passes through the second planar reflector and the second movable convex lens in sequence before entering the environmental chamber.

7. A method for measuring the evaporation and heat transfer rate of a single droplet, using the measuring device for the evaporation and heat transfer rate of a single droplet as described in any one of claims 1-6, characterized in that, The measurement method includes: An environmental environment with preset temperature and humidity conditions is created in the environmental chamber; the preset conditions include preset temperature and preset humidity. A particle size aerosol gas stream is generated by an aerosol droplet generation component and delivered to the environmental chamber; the particle size aerosol gas stream comprises multiple droplet particles. A first laser and a second laser are emitted into the environmental chamber via a laser emitting component, so that the first laser and the second laser converge in the environmental chamber to generate an optical trap; the optical trap is used to capture the droplet particles, so that the droplet particles are suspended in the environmental chamber. The droplet evaporation observation component was used to observe the particle size and internal temperature distribution of the droplets at different times within the environmental chamber. The evaporation rate and heat transfer efficiency calculation component calculates the evaporation rate of the droplet particles based on multiple particle size data, and calculates the heat transfer efficiency of the droplet particles based on multiple internal temperature distribution data of the droplets.

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