Phase Evaporation Research Articles

Thermal-hydraulic transient performance and dynamic characterization analysis of direct steam generation for parabolic trough solar collectors

Parabolic trough solar direct-steam-generation (PTC-DSG) technology is a low-carbon technology by combining clean energy with green energy carriers. However, abrupt variations in solar radiation (I) due to weather changes can significantly affect the DSG performance and stable operation. In this work, PTC-DSG system's optical-thermal-flow-pattern transient coupling model is developed based on the Separated Flow model, Finite Volume method and Lagrangian method. The dynamic response of the loop's transient flow law and heat transfer performance under I step-variation are analyzed, and the correlation between the DSG system's transient flow characteristics and the multiple perturbation factors is discussed. The results reveal that adding (reducing) 12.5 % and 37.5 % of I shortens (lengthens) the evaporation phase by 7.2 % and 16.5 % (10.7 % and 16 %). The superheated zone has the greatest influence on the transient response characteristics and instability relative to the preheated and evaporated zones under various step-variations, and the heat transfer recovery still needs longer time after flow state is re-stabilized. Under I step-variation, adding mass flow can effectively shorten the superheat phase but not the response time, and the system instability range increases; Increasing inlet temperature (Tin) can augments the superheat zone, but effectively shorten the response time and regulate and improve the outlet steam quality; Raising inlet pressure not only reduces the evaporation phase, which is most favorable for heat transfer, but also requires longer re-stabilization time and increases the probability of stratified flow, which should be paid more attention.

Evaporation of stable microemulsion droplets

Emulsion fuels have the potential to reduce both particulate matter and NOx emissions and can potentially improve the efficiency of combustion engines. However, their limited stability remains a critical barrier to practical use as an alternative fuel. In this study, we explore the evaporation behavior of thermodynamically stable water-in-oil microemulsions. The water-in-oil microemulsion droplets prepared from different types of oil were acoustically levitated and heated using a continuous laser at different irradiation intensities. We show that the evaporation characteristics of these microemulsions can be controlled by varying water-to-surfactant molar ratio (ω) and volume fraction of the dispersed phase (ϕ). The emulsion droplets undergo three distinct stages of evaporation, namely preheating, steady evaporation, and unsteady evaporation. During the steady evaporation phase, increasing ϕ reduces the evaporation rate for a fixed ω. It is observed that the evaporation of microemulsion is governed by the complex interplay between its constituents and their properties. We propose a parameter (η) denoting the volume fraction ratio between volatile and nonvolatile components, which indicates the cumulative influence of various factors affecting the evaporation process. The evaporation of microemulsions eventually leads to the formation of solid spherical shells, which may undergo buckling. The distinction in the morphology of these shells is explored in detail using scanning electron microscopy imaging.

Study on Spontaneous Combustion Characteristics and Microstructure of Bituminous Coal under Water Immersion.

The stagnant water above the coal seam flows into the goaf, causing the goaf coal to be soaked by water for a long time. Compared with dry raw coal, water-soaked coal has a stronger tendency for spontaneous combustion, which poses a serious threat to mining operators. To unravel the impact of water immersion on coal's self-heating properties, an investigation was conducted employing techniques such as simultaneous thermogravimetric analysis/differential scanning calorimetry (TG/DSC), scanning electron microscopy (SEM), low-temperature nitrogen adsorption based on the BET theory, and Fourier transform infrared spectroscopy (FTIR). The variations in the characteristic temperature, microphysical structure, and active functional groups of bituminous coal with water immersion degrees of 10, 30, 50, and 100% were studied, and the experimental results showed that (1) during the initial stage of coal self-ignition oxidation, moisture can cause a delay in the characteristic temperature points of bituminous coal. When the degree of water saturation in bituminous coal reaches 100%, both the critical temperature (T 1) and the cracking temperature (T 2) peak at 48.14 and 205.06 °C, respectively. However, after the water evaporation phase is complete, water soaking promotes the spontaneous combustion of bituminous coal. (2) The number of pores and fractures in bituminous coal is positively correlated with the amount of water soaked, with the average pore diameter increasing from 10.124 nm in raw coal to 15.547 nm in the A4 coal sample. Moreover, when the degree of water immersion reaches 100%, the proportion of mesopores and macropores increases to 38.89 and 19.95%, respectively. (3) Compared to untreated coal, the number of functional groups in water-soaked coal samples increases. With the increase in water immersion, the hydroxyl (-OH) content of raw coal and four kinds of bituminous coal with different degrees of immersion was 40.8, 41.3, 42, 43.9, and 42.9%, respectively, showing a trend of increasing first and then decreasing. When the degree of water immersion of bituminous coal is 50%, the natural tendency is the strongest. These findings contribute to elucidating the underlying mechanism of water immersion's impact on coal self-ignition, thereby holding significant implications for enhancing fire safety measures in mine working areas.

Fractional precipitation of copiapite-halotrichite efflorescent salts on Au[sbnd]Cu mine tailings under semi-arid climates in northern Chile

The oxidation of pyrite involves a series of chemical reactions that, depending on climatic conditions, can give rise to different mineral phases and morphologies. When oxidation takes place in semi-arid climate, the development of efflorescent salts on the surface of mine tailings is characteristic. These salts are mainly composed of Fe, Al and Mg sulfates and may accumulate valuable metals liberated through the dissolution of tailing minerals.This research aims to describe the evolution of salt precipitation from the economic and environmental perspective. For this purpose, we sampled efflorescent salts formed during the summer season on the surface of a tailing impoundment located in the north of Chile. The materials underwent comprehensive characterization utilizing X-ray techniques and scanning electron microscopy.The findings reveal a fractional precipitation in the crystallized salts. In an advanced oxidation system, characterized by multiple seasons of crystallization, dissolution and oxidation, the dry season begins with the precipitation of sulfates from a highly acidic solution dominated by Fe3+. This solution results from the dissolution and oxidation of the previous season sulfates. This initial stage is characterized by the presence of jarosite and gypsum, which are subsequently replaced by ferricopiapite. Towards the progress of the dry season, copiapite becomes more magnesian and precipitates alongside coquimbite and alunogen. Finally, halotrichite and pickeringite begin to crystallize. Base metal cations such as Co, Cu, Mn, Ni and Zn are preferentially incorporated into halotrichite-pickeringite sulfates during the most advanced evaporation phase.

Phase Separation‐Induced Electrical Conductivity for Liquid Metal‐Embedded Plastic Hybrid Composites with Metallic Conductivity and Recyclability

AbstractConductive fillers‐embedded plastic polymer hybrid composites are crucial electronic materials in modern technologies owing to their tunable conductive properties, low density, and corrosion resistance. However, the application of traditional rigid inorganic conductive fillers‐embedded plastic composites is constrained by their subpar electrical conductivity and mechanical properties. Consequently, liquid metals (LMs) including gallium and gallium‐based alloys, have recently emerged as the preferred conductive flexible fillers over traditional rigid fillers. This work employs a solvent evaporation method and phase separation‐induced conductivity mechanism. The resulting flexible and electrically conductive LM‐polycarbonate (PC) film circuits demonstrate ultrahigh metallic conductivity, robust mechanical performance, excellent solvent recyclability, and notable processability. The fluidic nature of LMs and the superior mechanical properties of the PC polymer confer high electrical stability and durability to the LM‐PC film circuits under diverse mechanical forces and environmental conditions. The LM‐PC film circuits are exceedingly promising and apt for use as flexible conductors in contemporary electrical applications, including electricity transmission and underwater working.

Development of physically based modelling of bubble behaviour for subcooled boiling applications

A methodology for the modelling of phase change phenomena in two-phase flow is presented, based on interface capturing simulation and the mechanistic modelling of interfacial heat and mass transfer. The volume of fluid approach is adopted, utilising a compressive scheme to maintain interface sharpness, allowing a continuum representation of mass and heat source terms to be used. The methodology is verified against analytical solutions for both evaporation and condensation phase change problems, demonstrating excellent agreement even in the case of a large phase density ratio and high rate of evaporation.

Experimental Study of the Effect of the Initial Droplet Diameter on the Evaporation Characteristics of Unsymmetrical Dimethylhydrazine Droplets in a Subcritical Environment

The evaporation characteristics of unsymmetrical dimethylhydrazine droplets with different initial diameters in a subcritical environment were experimentally investigated with the temperature–pressure separation technique. The evaporation processes of unsymmetrical dimethylhydrazine droplets with different initial diameters in this environment have the same general pattern. All the studied droplets exhibit a short transient heating phase and a steady-state evaporation phase obeying d2. Notably, the expansion of the transient heating phase gradually increases with increasing ambient pressure. The change in diameter squared ∆d2max increases from 1.03% at 1 MPa to 12.48% at 5 MPa. Under subcritical conditions, the evaporation rate decreases linearly with decreasing droplet diameter, and the droplet evaporation lifetime increases linearly. Changes in the initial droplet diameter may still have a large effect on droplets smaller than those studied here. When the ambient pressure is not greater than 3 MPa, the change in the steady-state evaporation time for both medium- and large-diameter droplets accounts for more than 70% of the variation in the droplet evaporation lifetime. As the ambient pressure increases to 4 MPa and 5 MPa, the percentage of the change in the transient heating time contributing to the variation in the droplet evaporation lifetime gradually increases to more than 45%.

Anomalous Emission from Li- and Na-like Ions in the Corona Heated via Alfvén Waves

The solar ultraviolet intensities of spectral lines originating from Li- and Na-like ions have been observed to surpass the expectations derived from plasmas with coronal approximation. The violation of the coronal approximation can be partially attributed to nonequilibrium ionization (NEI) due to dynamic processes occurring in the vicinity of the transition region. To investigate the impact of these dynamics in the Alfvén wave-heated coronal loop, a set of equations governing NEI for multiple ion species was solved numerically in conjunction with 1.5-dimensional magnetohydrodynamic equations. Following the injection of Alfvén waves from the photosphere, the system undergoes a time evolution characterized by phases of evaporation, condensation, and quasi-steady states. During the evaporation phase, the ionization fractions of Li- and Na-like ions were observed to increase when compared to the fractions in ionization equilibrium, which led to an enhancement in the intensity of up to 1.6. This over-fractionation of Li- and Na-like ions was found to be induced by the evaporation process. While collisions between shocks and the transition region temporarily led to deviations from ionization equilibrium, on average over time, these deviations were negligible. Conversely, under-fractions of the ionization fraction led to a reduction in intensity down to 0.9 during the condensation phase and the quasi-steady state. Given the dependency of the over/under-fractionation on mass circulations between the chromosphere and the corona, these observations will serve as valuable benchmarks to validate not only Alfvén wave models but also other existing mechanisms on coronal heating.

An adaptive thermal management method via bionic sweat pores on electronic devices

Maintaining proper operation temperature is a basial need for electronic devices. However, the current thermal management strategy for electronic devices generally provides a fixed cooling capacity, which cannot be adjusted adaptively based on the working condition. In this study, we report a novel adaptive thermal management method enabling electronic devices to sweat dynamically, similar to human, for adaptive cooling. The proposed method involves the design of adaptive-switching bionic sweat pores, which facilitate the sweating process and sweat evaporation on the surface of electronic devices. To ensure long-term operation, a liquid circulation system is applied as the source of bionic sweat. We conducted experimental research using a test vehicle to evaluate the performance and influencing factors of the method. The results demonstrate that the bionic sweating behavior can provide an additional cooling capacity equivalent to 80% of the original fixed cooling capacity. Furthermore, optimizing factors such as the hydrophily of the evaporation surface, sweating volume, and phase change state of the bionic sweat can enhance the additional cooling capacity. Theoretical analysis further indicates that a maximum additional cooling capacity of up to 208 W/cm2 can be achieved when the bionic sweat was in boiling state.

The key aroma components of steamed green tea decoded by sensomics and their changes under different withering degree

Steamed green tea has a long history and unique aroma, but little is known about its key aroma components. In this study, 173 volatiles in steamed green tea were identified using solvent-assisted flavor evaporation and headspace-solid phase microextraction plus two chromatographic columns of different polarities. Aroma extract dilution analysis revealed 48 highly aroma-active compounds with flavor dilution factors 64–1024. Internal standards were used to calculate odorant active value (OAV), and 11 OAV > 1 key aroma compounds were determined. Omission test identified eight substances, including dimethyl sulfide, (E)-β-ionone, cis-jasmone, linalool, nonanal, heptanal, isovaleraldehyde and (Z)-3-hexenol, as the key aroma active compounds of steamed green tea. With the increase of withering degree, the content of these substances increased first and then decreased except for heptanal and cis-jasmone. Moreover, the water content of 62 % was suggested to be an appropriate withering degree during the processing of steamed green tea.

An approximate analytical model for the frequency response of evaporating droplets under a mixed feeding regime

This work is one of the analytical approaches to evaluate the evaporation frequency response of injected droplets, using the Heidmann analogy of a single droplet that is continuously fed with the same liquid fuel. Based on a linear analysis using the Rayleigh criterion, a dimensionless response factor is determined. The effects due to the variation of the heat transfer coefficient of the feeding process, as well as those due to the characteristic evaporation times and phase delay are analyzed. An abrupt increase of the response factor occurs, when a thermodynamic coefficient of the injected fuel takes certain specific values.

Experimental study of Gas-To-Liquid (GTL) and diesel fuel blends evaporation behaviour and droplet lifetime through Leidenfrost effect

Gas to Liquid (GTL) fuel is considered a clean alternative fuel and has been given much attention to replacing conventional fuel. Evaporation behaviour and droplet lifetime are critical aspects that need to be determined as these aspects can affect the fuel spray properties and improve the combustion process. In this study, a set of GTL–diesel fuel blends are prepared, which are G20, G50, G80, and G100 (the number represents the GTL percentage fuel ratio in the fuel blends). Subsequently, using a single droplet drop test on the hot plate (Leidenfrost effect), the GTL fuel blends droplet lifetime and evaporation behaviour are visualised using a high-speed camera connected to long-distance microscopy. An image processing system and a MatLab were used to measure and analyse the droplet evaporation data. Comparing the fuel characterisation of the GTL fuel and conventional diesel fuel, the GTL fuel shows a lower value in all properties tested except for the calorific value, cetane number, and vapour pressure. The qualitative results through the Leidenfrost effect have shown that increasing the GTL fuel ratio (20% to 100%) decreases the heating phase duration (37.3 % to 14.4 %) and evaporation rate (1.29 mm 2/s to 1.10 mm 2/s) while increasing their steady evaporation phase duration and droplet lifetime. The shorter period to achieve steady evaporation is beneficial as the spray inside the chamber has a limited time to evaporate for combustion.

Numerical simulation of conduction problem with evaporation based on a SPH model improved by a fractional order convection-diffusion equation

Smoothed particle hydrodynamics (SPH) simulations of phase transitions are not accurate because of the decrease in liquid particles at the end of the evaporation phase transition. In this paper, we establish a numerical model of droplet evaporation suitable for SPH by introducing a time fractional-order convection–diffusion equation. This model was used to study the evaporation process of droplets under different environments, and the stationary evaporation of droplets was simulated by combining convection–diffusion equations of different orders to determine the optimal order. The results conformed to the “D2 Law,” confirming the effectiveness and accuracy of our method. The model was then used to study the phase transition process of droplets impacting flat and curved surfaces. Among the tested equations, the 0.1-order convection–diffusion equation had the best correction effect on the evaporation model. This equation improved the accuracy of the calculation and had a good corrective effect for both static evaporation and the evaporation of droplets impacting flat and curved surfaces.

Numerical modelling and evaluation of a novel sorption module for thermally driven heat pumps and chillers using open-source simulation library

Sorption modules are the core component of thermally driven heat pumps and chillers. The efficiency of these devices strongly depends on the advantageous design of sorption modules. In this paper a calibrated and validated numerical model for an innovative sorption module with a combined evaporator-condenser is presented. The adsorption heat exchanger is based on flat tube-lamella design directly crystallized with the zeotype adsorbent silico-alumino-phosphate-34. The prediction quality of the model regarding the efficiency is within the measurement uncertainty (±0.02 kJ/kJ). Besides the good prediction quality of this integral performance indicator, the root mean square deviation of the transient outlet temperatures is in the range of 1.1…1.9 K, which is a very good agreement. Since the performance indicators efficiency and power density strongly depend on the temperature boundary conditions and half cycle times, an in-depth analysis of the experimental data using the method of heat and mass transfer resistances is suggested that overcomes this limitation. This analysis allows for a direct comparison with other sorption module designs. In a first step this analysis revealed that the evaporator-condenser component limits the sorption process during evaporation. Compared to other designs the evaporator-condenser has a 3–5 times higher volume scaled heat and mass transfer resistance (17 dm3K/kW) in the evaporation phase underlining the necessity to further optimize this component in future modules.

Hydrological, meteorological, and watershed controls on the water balance of thermokarst lakes between Inuvik and Tuktoyaktuk, Northwest Territories, Canada

Abstract. Thermokarst lake water balances are becoming increasingly vulnerable to change in the Arctic as air temperature increases and precipitation patterns shift. In the tundra uplands east of the Mackenzie Delta in the Northwest Territories, Canada, previous research has found that lakes responded non-uniformly to year-to-year changes in precipitation, suggesting that lake and watershed properties mediate the response of lakes to climate change. To investigate how lake and watershed properties and meteorological conditions influence the water balance of thermokarst lakes in this region, we sampled 25 lakes for isotope analysis five times in 2018, beginning before snowmelt on 1 May and sampling throughout the remainder of the ice-free season. Water isotope data were used to calculate the average isotope composition of lake source water (δI) and the ratio of evaporation to inflow (E/I). We identified four distinct water balance phases as lakes responded to seasonal shifts in meteorological conditions and hydrological processes. During the freshet phase from 1 May to 15 June, the median E/I ratio of lakes decreased from 0.20 to 0.13 in response to freshet runoff and limited evaporation due to lake ice presence that persisted for the duration of this phase. During the following warm, dry, and ice-free period from 15 June to 26 July, designated the evaporation phase, the median E/I ratio increased to 0.19. During the brief soil wetting phase, E/I ratios did not respond to rainfall between 26 July and 2 August, likely because watershed soils absorbed most of the precipitation which resulted in minimal runoff to lakes. The median E/I ratio decreased to 0.11 after a cool and rainy August, identified as the recharge phase. Throughout the sampling period, δI remained relatively stable and most lakes contained a greater amount of rainfall-sourced water than snow-sourced water, even after the freshet phase, due to snowmelt bypass. The range of average E/I ratios that we observed at lakes (0.00–0.43) was relatively narrow and low compared with thermokarst lakes in other regions, likely owing to the large ratio of watershed area to lake area (WA/LA), efficient preferential flow pathways for runoff, and a shorter ice-free season. Lakes with smaller WA/LA tended to have higher E/I ratios (R2 = 0.74). An empirical relationship between WA/LA and E/I was derived and used to predict the average E/I ratio of 7340 lakes in the region, which identified that these lakes are not vulnerable to desiccation, given that E/I ratios were < 0.33. If future permafrost thaw and warming cause less runoff to flow into lakes, we expect that lakes with a smaller WA/LA will be more influenced by increasing evaporation, while lakes with a larger WA/LA will be more resistant to lake-level drawdown. However under wetter conditions, lakes with a larger WA/LA will likely experience a greater increases in lake level and could be more susceptible to rapid drainage.

Preparation of organic-filled compatible nanocomposite membranes for enhanced CO2 permselectivity

Ideally structured nanocomposite membranes may possess the maximum desired separation properties of both filler particles and the host polymer matrix. To approach this goal in this study, some nanocomposite dense membranes were prepared using Pebax 1657 and polyaniline nanofiber (PANI) with closed structural properties in their different concentrations by applying various ethanol/water solvent mixtures and the solution method casting and solvent evaporation phase inversion. The structural characteristics of the membranes were evaluated using SEM, FTIR (ATR), and XRD analysis and then their CO2 and CH4 permeabilities were measured. The structural analysis revealed that the prepared nanocomposite membranes have defect-free structures and the amorphous PANI nanofibers were dispersed uniformly within the nanocomposite membranes leading to their lower crystallinities. As the nanofiber loading increased in the continuous phase, both CO2 permeability and selectivity of the nanocomposite membranes were increased simultaneously and passed over the 1991 Robeson upper bound limit and approached that of 2008. CO2 permeability and ideal CO2/CH4 selectivity of the nanocomposite membrane loaded by 10 wt. % of the PANI nanofibers were increased to 121.2 Barrer and 33, respectively, revealing 64 and 40 % increments.

Simulation of Membrane Fabrication via Solvent Evaporation and Nonsolvent-Induced Phase Separation.

Block copolymer membranes offer a bottom-up approach to form isoporous membranes that are useful for ultrafiltration of functional macromolecules, colloids, and water purification. The fabrication of isoporous block copolymer membranes from a mixed film of an asymmetric block copolymer and two solvents involves two stages: First, the volatile solvent evaporates, creating a polymer skin, in which the block copolymer self-assembles into a top layer, comprised of perpendicularly oriented cylinders, via evaporation-induced self-assembly (EISA). This top layer imparts selectivity onto the membrane. Subsequently, the film is brought into contact with a nonsolvent, and the exchange between the remaining nonvolatile solvent and nonsolvent through the self-assembled top layer results in nonsolvent-induced phase separation (NIPS). Thereby, a macroporous support for the functional top layer that imparts mechanical stability onto the system without significantly affecting permeability is fabricated. We use a single, particle-based simulation technique to investigate the sequence of both processes, EISA and NIPS. The simulations identify a process window, which allows for the successful in silico fabrication of integral-asymmetric, isoporous diblock copolymer membranes, and provide direct insights into the spatiotemporal structure formation and arrest. The role of the different thermodynamic (e.g., solvent selectivity for the block copolymer components) and kinetic (e.g., plasticizing effect of the solvent) characteristics is discussed.

Molecular dynamics study of the wettability effect on the evaporation of thin liquid sodium film

The nanoscale liquid sodium film exists in the porous wick of the sodium heat pipe. Understanding its evaporation is essential for further exploring the heat transfer inside the heat pipe. Due to the solid–liquid interaction, surface wettability has significant effects on evaporation. In this work, molecular dynamics is adopted to study these effects. A cuboid evaporation system is constructed. It consists of the bottom solid surface and thin liquid sodium film. By changing the potential well depth between solid and liquid atoms, four surfaces with different wettability are built. The 400 K equilibrium evaporation is achieved. The self-diffusion coefficients of liquid atoms on four surfaces are acquired. The non-equilibrium is introduced by increasing the heat source wall’s temperature to 600 K. The main phase of evaporation is in 0–8 ns. The variation of gas atoms number is observed. The evaporation rate, average heat flux, and heat transfer coefficient are acquired. The results indicate that evaporation could be improved with surface wettability. For the 0°, 58° hydrophilic surface, the heat transfer efficiency could reach 96.9 %, 96.3 % respectively. The surface wettability effects are achieved by two paths: it enhances the heat transfer in the solid–liquid contact region and intensifies the atoms’ collision heat transfer inside the liquid film.

Cracking behavior of sisal fiber-reinforced clayey soil under wetting-drying cycles

Climate variables such as rainfall and high temperature can influence clayey soil moisture and the development of cracks, which can further give rise to environmental and geological disasters. This study investigates the influence of different soil thicknesses, fiber content, and three wetting-drying cycles on soil moisture evaporation and the formation and development of cracks. A photographing system and weighing equipment are used to track the changes in soil mass and cracks during three wetting-drying cycles. Resulting photos of the cracks are quantified and analyzed by image processing technology. Results show that the thicker soil layer can prolong the normal evaporation phase and reduce the stress concentration on the surface, resulting in a delay in cracking. However, this could lead to the development of wide cracks and the formation of shallow ditches, which is an irreversible process with multiple wetting-drying cycles. Sisal fibers are able to effectively solve the aforementioned problems in terms of, reducing the development of longitudinal and lateral cracks and shallow ditches. This further reduces the rate of sudden cracking and helps to maintain the soil’s structural integrity. The healing ability of wetting-drying cycles for cracks increases with the sisal fiber content. These findings indicate that soil cracking is influenced by many factors, though there are no absolute factors that promote or hinder the development of cracks. Therefore, methods that can amplify the positive effects while weakening the negative effects should be explored.

Effect of ambient temperature and water content on emulsified heavy fuel oil droplets evaporation: Evaporation enhancement by droplet puffing and micro-explosion

In this study, the evaporation characteristics of emulsified heavy fuel oil (HFO) with water content from 0 to 30 % at the ambient temperatures of 673, 773, and 873 K are experimentally studied. Three distinguishing phases can be clarified and summarized, including initial heating, fluctuation evaporation, and steady evaporation phases. The fluctuation evaporation phase involves the two sub-phases of heat equilibrium and secondary heating, which are first discovered in the evaporation of emulsified HFO. And the heat equilibrium sub-phase is the distinguishing feature of emulsified HFO from other blended fuels. The duration of the initial heating phase and the fluctuation evaporation phase decreases with the elevated ambient temperature but increases with rising water content. However, the variation of micro-explosion intensity with ambient temperature and water content is the opposite. The time consumed in the fluctuation evaporation phase determines the droplet lifetime. The difference between the evaporation characteristics of HFO and emulsified HFO is that the fluctuation evaporation phase of HFO is not distinct, which is due to the violent and frequent micro-explosion occurring in the emulsified HFO droplet. Consequently, the droplet lifetime of emulsified HFO is significantly shorter than that of HFO. Eventually, a regression formula for the dependences of droplet lifetime from temperature and water content is proposed, which can provide a reference for the practical application of emulsified HFO.