Application of the finite element method of minimum potential energy principle, the displacement vector caused by each carbon - oxygen atom electronegativity difference in each molecule structure is obtained, and with the heavy atoms matrix weighted by Mulliken charge for the corresponding operation, molecular charge parameters was obtained. And then combining with molecular structure natural frequency, the temperatures, and 264 liquid thermal conductivity data of 23 alcohols such as alkane alcohols and naphthenic alcohols, aromatic alcohols, phytol, a 3-parameter nonlinear alcohols organic liquid thermal conductivity estimation model was developed . The model shows that the correlation coefficient between the experimental value and calculated value of the model r > 0.98, Standard error s < 3.98 mW/(m·K), F test value F > 2111. The model was used to calculate thermal conductivity of external prediction set which included 20 thermal conductivity data of tetranheptanol, tetradecanol and 2-octanol at different temperatures. For prediction set, the mean absolute error between the calculated results and the experimental values was 2.66 mW/(m·K) and the average relative error was 1.74%. The results show that the new method is significantly better than the Sastri and Latini estimation methods.

The solubility and supersolubility of L-phenylalanine anhydrate in methanol-water mixed solvent were studied in the temperature range of 293.15—322.15 K, and the crystalline metastable zone of L-phenylalanine anhydrate was obtained. The nucleation order and rate was calculated. Meanwhile, the in?uences of temperature and cooling rate on the width of metastable zone were explored. The water activity of transformation at 297.15 K and 302.15 K were measured, the phase diagram of L-phenylalanine-methanol-water at that temperature was obtained through solubility property. The solubility data were correlated by the modified Apelblat equation, λh equation and van t Hoff equation. The results showed that the solubility of L-phenylalanine obviously increased with the increase of temperature and the decrease of the methanol content; the width of metastable zone decreased with increasing temperature and decreasing cooling rate; the water activity of transformation increased with the increase of temperature.

Visualization experiments were carried out on the melting-solidification cycle process and heat transfer characteristics of the multiple phase change materials (multiple PCMs) using high-definition cameras and infrared thermal imaging technology. Three paraffins (RT65, RT42 and RT27) were used as multiple PCMs and filled into the TES container. The effect of PCM arrangement on thermal performance of the TES container was investigated. The dynamic evolution of solid-liquid interfaces was recorded by a high definition (HD) camera and the variation of temperature distribution was measured by an infrared camera. As the melting-solidification cyclic process was stabilized, the solid-liquid phase change behavior and thermal characteristics of the multiple-PCM TES container were obtained and compared with that of single-PCM TES container. The results show that the PCM with higher phase change temperature should be located near the heated wall. There exist multiple solid-liquid interfaces in multiple-PCM TES container, the paraffins in different PCM units can melt/solidify simultaneously. The uniformity of phase change rate is greatly improved by multiple PCMs, which increases the average phase change rate. The phase change fraction of multiple-PCM TES container is 40% higher than that of single-PCM TES container. Although the sensible heat storage capacity of multiple-PCM TES container is a little lower than that of single-PCM TES container, the variation rate of temperature is reduced, which enables the TES container work more stable. The latent heat storage capacity of TES container is significantly increased by the utilization of multiple PCMs. As a result, the total heat storage capacity of multiple-PCM TES container is 34.6% higher than that of single-PCM TES container.

The pressure drop of gas-liquid two-phase Taylor flow in a rectangular meandering microchannel at low CO₂ pressure (CO₂,5% (vol), N₂,95%(vol)) was measured. By comparing the six gas-liquid phase systems, it is found that the physical properties of the liquid phase have a significant effect on the pressure drop of the gas-liquid two-phase Taylor flow. The pressure drop of two-phase flow showed a linear increasing trend with the increasing liquid velocity for surface tension variation group, while for the viscosity variation group, the pressure drop of two-phase flow had a poor linearity with liquid phase velocity, and the pressure drop of two-phase flow increases regularly with j_{\mathrm{L}}^{2/3} . The comparison between the predicted results from the literatures models and measured data was also made. Considering the effects of the liquid internal circulation, bubble shape and motion, channel characteristic configuration (channel cross section and overall configuration) and physical chemistry of the liquid phase， a two-phase flow pressure drop model was proposed, and a mean deviation ±20% can be obtained.

The heat transfer characteristics of supercritical carbon dioxide in vertical upward tubes under uniform heating were studied experimentally. The inner diameter of the experimental section is 10 mm. The experimental parameters are: pressure 7.5—21 MPa, heat flux 50—413 kW·m^-2, mass flux 519—1500 kg·m^-2·s^-1. The flow heat transfer characteristics in the riser tube were tested under uniform heating conditions. The effects of heat flux, pressure and buoyancy force on the heat transfer characteristics in the circular tube were analyzed. The results show that with the increase of heat flux the heat transfer deterioration occurs, and the peak point of wall temperature moves towards the inlet section. Heat transfer deterioration occurs when the fluid temperature is less than the pseudo-critical temperature and the wall temperature is greater than the pseudo-critical temperature. When increasing pressure, the deterioration of heat transfer is restrained due to the change of physical property tends to be gentle. Buoyancy forces are bad for heat transfer when heat transfer deterioration occurs. Based on the experimental data, the physical properties change and buoyancy influence on heat transfer are considered comprehensively, new supercritical carbon dioxide heat transfer correlations is established, within the range of the experiment condition, deviation from the mean and standard deviation of the predicted values and experimental values were 1.2% and 16.29% respectively.

In the present study, the effects of wettability, surface topography and surfactant on the growth of bubbles and pool boiling heat transfer of straight and gradient square copper pillar arrays with partially-modified surface were investigated. The experimental medium was deionized water, 100, 200, 400, 800 mg·L^-1 in isopropanol solution and n-heptanol solution. The results showed that silver deposition on square copper pillar decreases the wettability, and increases bubble number. Addition of isopropanol or n-heptanol into deionized water decreases the number and departure diameter of bubbles in the heat flux range of 66.1—202 kW·m^-2. However, when the heat flux increases to 413 kW·m^-2, the surfactant can effectively prevent bubbles from merging, so the boiling heat transfer coefficient of the pool boiling decreases first and then increases with the increase of the concentration. The gradient square pillar structure with upper and lower layers of 0.5 mm and 1mm and a spacing of 2 mm promotes the coalescence of bubbles and formation of a gas film on the heating surface, and then worsens pool boiling heat transfer.

A double-opening refrigeration machine experimental platform was built to collect the dynamic pressure in the oscillating tube at different speeds, and the mechanism of the internal wave relationship of the gas-wave-cooling machine was studied. First, the experiment is simulated by a CFD (computational fluid dynamics) numerical simulation method, the simulated value agree fairly well with the experiment pressure data, which has proven that this simulation method has a high precision. Then，the flow waves diagrams under different rotation rate were plotted based on the experiment pressure data. It shows that when the temperature gap between high pressure gas and low temperature gas reaches maximum, reflect shock wave intensity is the lowest and the relation between waves is most reasonable. Finally, the compression wave oscillation phenomenon is analyzed, which comes to a conclusion that the oscillation increases low temperature gas temperature. When the rotation rate approaches the best optimal value, the weaker the wave energy is and the less its impact is.

The high-speed video and high-speed infrared were used to visual measure the boiling phenomenon on four kinds of monocrystalline silicon surfaces including smooth, cavity, pitch and groove-pitch surfaces. The dynamic evolution process and the local temperature evolution law reveal the boiling enhancement mechanism based on the dynamic process. For the smooth silicon surface, the superheat is 6℃ when the boiling starts under low heat transfer, and this superheat is around 3－4℃ for the three micro-structured surfaces. In addition, compared with the smooth surface, the CHF for cavity, groove-pitch and pitch surfaces are increased by 109%, 129% and 140%, respectively. According to the dynamic evolution of bubble, cavities provide the nucleation sites, decrease the nucleation barrier energy and shrink the energy accumulation stage. Pitches significant increase nucleation sites, decrease departure diameter and departure time of bubbles, which uniform the boiling surface temperature.

Liquid loading, which can reduce the gas rate and even kill the gas well, is a common phenomenon associated with gas well production. Accurate prediction of liquid loading will help operators take measures in time to reduce the hazards, and the critical gas velocity is the key parameter to predict the liquid loading in gas wells. The related researches on the prediction of liquid loading in gas wells are reviewed, and the limitations of the minimum pressure drop model and the liquid droplet model are pointed out. Based on the experimental observations, it is considered that the liquid film model manifests better applicability. Considering the droplet entrainment in gas core and the uneven film distribution along the circumference of the tubing in deviated gas wells, a more practical annular mist flow model is proposed to judge the liquid loading of gas wells with different tubing diameters and inclination angles. The previous indoor experimental and field operating data are used to compare the new model with the six existing prediction models for liquid loading. Considering correctness and prediction error of the model prediction results, it is considered that the new annular mist flow model is better than other models, and can be used to predict liquid loading in gas well accurately and conveniently.

To improve the heat transfer performance of the plastic heat exchange tube, a composite plastic heat exchange tube with a superhydrophobic surface was prepared by a two-step coating method. Firstly, the porous polyvinylidene fluoride (PVDF) hollow fiber membrane was used as the supporting layer, and polydimethylsiloxane (PDMS) was filled with thermal conductive material nano-ZnO as the skin layer to prepare the composite plastic heat exchange tube with a dense outer skin layer. Secondly, the PVDF composite plastic heat exchange tube with superhydrophobic surface was prepared by investigating the influence of teraethoxysilane (TEOS) and ammonia content, which enhanced the dropwise condensation heat transfer performance of steam. The results showed that the outer surface contact angle of the prepared heat exchange tube can reach 154°. Compared with the heat exchange tubes prepared by the melting method and the NIPS method, the total heat transfer coefficient could be increased by 85.3%—147.3%.

To improve the mechanical separation efficiency of the heterogeneous material, a semi-circular cross-section tangential inlet is arranged in the vertical cylindrical separator to form a three-dimensional concave-wall jet. The concave-wall jet flow characteristics are studied by tracer concentration experiment and large eddy simulation. The aim is to reveal the three-dimensional concave-wall jet flow mechanism. The concentration field spread is evaluated along the streamwise and spanwise flow. The results show that the half-value width of the tracer concentration increases with the increase of the inlet Reynolds number. The streamwise spread ratio is in the range of 0.019—0.033 and the spanwise spread ratio is in the range of 0.079—0.161. Under the action of centrifugal force, the concentration half-value width shrinks to 2/3 of the jet width within the scope of 60° in the inlet circumferential direction. There are several streamwise vortices developed from the inner surface of the cylinder, however no vortex along spanwise flow is found. The peak values of tangential velocity half-value width and the vorticity boundary locates at the center of the streamwise vortex. There is not obvious fluctuation in spanwise direction. Secondary flow vortex is not found in the range of 180° in the inlet circumferential direction. The reason is that the ratio of the tangential velocity half-value width to the cylindrical radius is less than 0.1 along streamwise flow. Thus the forming condition of the secondary flow that caused by centrifugal instability is not reached. The concave wall tangential jet effectively reduces the disturbance of the main fluid in the stratifier by the vortex.

An ultra-thin plate heat pipe with a total thickness of 0.85 mm was designed and manufactured. The capillary core of the heat pipe adopts a sintered porous channel structure to realize the combination of the channel and the porous structure. According to this structure, an aluminum mold was manufactured. The heat pipe design combines the features of ultra-thin and easy fabrication, and sets up an experimental platform for heat pipe performance testing. The influence of heating power, copper powder particle size, and number of channels on thermal performance were analyzed. Thermal resistance and maximum heat transport capacity were used to characterize the performance of heat pipes. The results show that when the heating power is 14 W, the temperature of the heated copper block with copper plate and heat pipe is 102℃ and 66℃, respectively, and the heat pipe effectively reduces the temperature of the heat source. When the particle size of the copper powder is larger, the thermal resistance and the heat transfer limit of the heat pipe are also larger. When the particle size decreases, the opposite phenomenon occurs. Compared to the single-channel structure, the dual-channel structure has a lower thermal resistance, and the lowest difference is 21%.

During the condensation of certain mixed vapors, the temperature gradient of the heat transfer surface causes an imbalance in the concentration of the condensate and the surface tension, thereby driving the condensed droplets to spontaneously move. The necessary condition for this kind of phenomenon is the evident bulk temperature gradient on the heat transfer surface. However, in this study, the spontaneous movement of condensate drop was initially observed on the heat transfer surface with uniform temperature distribution, during the condensation of water-ethanol binary vapor mixture. The comparison and analyzation were performed on the characteristics of drop movement between the condensate drops with and without evident initial velocity on uniform temperature surface. It was confirmed that the spontaneous movement occurred when the condensate drops have evident initial velocity, while the random movement occurred when the drops didn t have evident initial velocity (no spontaneous movement). Finally, it was verified the inference that the driven force for the spontaneous movement of condensate drops on uniform temperature surface was, the local temperature distribution and the resulting local imbalance of surface tension around the drops.

The ammonia-based flue gas desulfurization (FGD) using spray scrubber is widely used for removing SO₂ from flue gas. However, the reports about mass transfer coefficient of SO₂ in the ammonia-based desulphurization process are little in the literature and a further investigation is needed, even though the mass transfer coefficient of SO₂ is much needed for optimizing the design and operation of the absorption tower of ammonia-based FGD system. On basis of experiments of absorbing SO₂ with ammonia in a lab-scale spray scrubber, the mass transfer rate per unit gas-liquid interfacial area was investigated by calculating the motion of droplets and liquid membrane. The correlation to predict the mass transfer coefficient of SO₂ absorption by ammonia was also proposed, including parameters pH, u_g and L/G. The yielding correlation could be used for quantitatively predicting the mass transfer rate per unit gas-liquid interfacial area under different operating conditions such as pH, gas flow rate and liquid-to-gas ratio. The comparison results show that the calculated SO₂ mass transfer rate agrees well with the measured data. The relative error between the calculated mass transfer rate and the measured data is within ±12%. The established mass transfer coefficient expression can provide a theoretical reference for the optimal design and operation of spray tower ammonia desulfurization.

In the vapor-water two-phase flow between vertical tube bundles of steam generators, void fraction is an important parameter. Gamma ray method was used to measure the void fraction distribution under high temperature and high pressure. The experimental pressures were 5, 7, 9 MPa, respectively，the mass flow was 300 kg/(m²?s), and the thermodynamic vapor quality ranged from 0.003 to 0.4. The distribution of the void fraction in vertical tube bundles was obtained and the effects of thermodynamic vapor quality and volume fraction were investigated. Compared with the classical formula calculation model, in the low-dry zone, the relative error between Miropolskii model, Smith model and Armand model with the experimental data are more than 30%, in areas with high dryness, error is small. Based on Armand model, a practical correlation of average void fraction and volume fraction on the section was calculated by multiple linear regression. It can be concluded that the correlations agree well with Japan Nuclear Power Engineering Corporation (NUPEC) experimental data, the relative error is less than 15%. The results show that a gamma ray method can be used to measure and predict the distribution of the void fraction in vertical tube bundles under high-temperature and high-pressure effectively. In general, it is of great significance to the structural design and flow characteristics of steam generator.

To study the heat transfer performance of the pulsating heat pipe in the middle and low temperature region, an ethane pulsating heat pipe was designed, and the low-temperature Stirling refrigerator was used as the cold source. The effects of heating power and inclination angle on the heat transfer performance of ethane pulsating heat pipe were studied experimentally in different temperature regions. The results showed that in the temperature region of －40℃ and －70℃, when the inclination angle was less than 45°, the inclination angle had little effect on the heat transfer temperature difference. When the inclination angle was between 45° and 90°, the heat transfer temperature difference significantly increased with the increase of the inclination angle. At a low heating power, the inclination angle had little effect on the heat transfer temperature difference. At a high heating power, the inclination had a great influence on the heat transfer temperature difference. It was also found that under the same inclination angle, with the increase of heating power, the heat transfer temperature difference gradually increased, and the heat transfer resistance showed a tendency to decrease first and then increase.

The HPLC and LC-MS, GC-MS and other analytical methods were used to qualitatively and quantitatively analyze the intermediates and final products of Ni/W₂C catalyzed glucose hydrotreating under different process conditions. Ni-W₂C was recently reported as a promising catalyst for the hydrogenolysis of cellulose or glucose to EG with the highest yield of 75%, yet this was achieved at the substrate concentration less than 1% because the concentrated substrate will lead to coking. This meant low productivity and high cost for commercial production, thus hinder this promising process from industry application. Therefore, insights into the reaction network to elucidate the coking mechanism and to optimize the process are needed. In this work, the mechanistic study on the glucose conversion, especially with the concentrated glucose substrate, over 2%Ni-30%W₂C/AC was systematically carried out. The reaction parameters including temperature, initial glucose concentration and H₂ pressure have been investigated and the results, in combination with the intermediate analysis by LC, LCMS and GCMS, showed that three parallel reaction pathways including retro-aldol reaction, isomerization and hydrogenation were involved in the reaction. C₂ product (EG) was originated from glucose hydrogenolysis while the C₃ products (1,2-PG and glycerol) were originated from fructose hydrogenolysis, and the dehydration of fructose led to 5-HMF and finally to coke in concentrated glucose conversion. Based on these understanding, the ratio of C₃ products to C₂, on the one hand, has been manipulated by tuning of isomerization of glucose into fructose with base additive and on the other hand, coking has been avoided by accelerating its competing reactions even at the glucose concentration of 10%（mass）. More interestingly, it was indicated that glucose of low concentration favors retro-aldol reaction while the one of high concentration tends to hydrogenate.

A series of graphene oxide composite metal catalysts were prepared and evaluated for their activity in the direct synthesis of dimethyl carbonate (DMC) by methanol vapor phase oxidative carbonylation. The results show that the catalyst PdCl₂-CuCl₂-KOAc/AC@GO-HCl has the best catalytic activity and stability. The space time yield (STY) of DMC was between 800－900 g·(L cat) ^-1·h^-1, and the catalytic activity was stable in 16 h without significant decrease. Methanol selectivity was maintained above 95%, and CO selectivity was between 35%－40%. Combined with results of XRD and XPS analyses, it was found that the formation of the active species Cu₂Cl(OH)₃ improved the catalytic activity of the catalyst, while both CuO and KCl could cause the deactivation of the catalyst.

The CuMgAl hydrotalcite-type (CMA-HT) precursors was prepared by co-precipitation process, in which the molar ratio of n(Cu²⁺)∶n(Mg²⁺)∶n(Al³⁺) was 10∶65∶25. The CuMgAl hydrotalcite catalysts were obtained by calcining at various temperatures. The catalysts were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG), X-ray powder diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), N₂-adsorption, H₂-temperature programmed reduction (H₂-TPR), H₂-temperature programmed desorption (H₂-TPD), CO₂-temperature programmed desorption (CO₂-TPD) and NH₃-temperature programmed desorption (NH₃-TPD). The catalytic performance of CMA catalysts for the hydrogenation of furfuryl alcohol to 1,2-pentanediol and 1,5-pentanediol were investigated in the autoclave. The results indicated that the calcination temperatures had significantly influence on the structure and catalytic activity of the catalyst. The metal sites and basic sites increased firstly and then decreased with rising the calcined temperatures. The sample calcined at 600℃ possesses the suitable metal and basic sites. It exhibited the superior activity for the hydrogenolysis of furfuryl alcohol as the synergistic effect between the surface metal sites and the basic sites. Under the condition of 140℃ and H₂ pressure of 4 MPa, the conversion of sterol and the yield of pentanediol reached 74.13% and 58.36%, respectively, after 8 h of reaction.

A supported Cu catalyst was prepared by using a co-precipitation method. The Cu catalyst was modified by adding alkaline earth metal strontium to improve the activity and selectivity for the hydrogenation of fructose to prepare mannitol. Systematic characterizations, with ICP-MS, XRD, TEM, H₂-TPR, XPS and CO₂-TPD, showed that the increase catalytic activity of the catalyst is due to the fact that the formation of SrCO₃ formed on the surface of the support can increase the specific surface area of the catalyst and improve the dispersion of the copper species. In addition, the medium-strong basic sites formed on the surface of SrCO₃ can activate the carbonyl group into β-furanose which can be easily hydrogenated into mannitol. Fructose conversion of around 100% and mannitol selectivity of 79% were achieved in the conditions of 1.1 mol·L^-1 fructose concentration, catalyst dosage of 6% of reactant quality, reaction temperature of 373 K, hydrogen pressure of 4.0 MPa and Cu/Sr atomic ratio of 7∶1. The excellent stability of the Cu-Sr/SiO₂ catalyst remained basically unchanged after recycling for 20 times.

The catalyst alters the binding energy of some chemical bonds in coal. It makes the conditions of pyrolysis milder, and adjusts the yield and composition of the product by promoting the micromolecules dissociation from coal. As a result, the conversion and the quality of product are increased. However, the chemical structure of coal is very complex, the catalytic pyrolysis mechanisms in coal are very difficult to study at the molecular level. Therefore, benzoic acid (C₆H₅COOH) is selected as the coal-based model compound to investigate the effect of valence states change of catalysts during catalytic pyrolysis by using density functional theory (DFT) method, in which NiO and Ni are selected as catalysts. The results showed that there are two reaction pathways for C₆H₅COOH pyrolysis. One is CO₂ and C₆H₆ are directly formed from C₆H₅COOH. The other is that C₆H₆COO is produced from H migration of C₆H₅COOH, then, C₆H₆ and CO₂ are obtained from C₆H₆COO decomposition. On NiO(100), the favorable reaction pathway is that *C₆H₅COO and *H are formed from C₆H₅COOH dissociative adsorption. Finally, *CO₂ and *C₆H₆ are produced from *C₆H₅COO decomposition with the assistance of *H. On Ni(111), the favorable reaction pathway is that *C₆H₅COO and *H are formation from *C₆H₅COOH decomposition, which C₆H₅COOH is nondissociative adsorption. Eventually, *CO₂ and *C₆H₆ are obtained. In general, Ni-based catalyst can promote C₆H₅COOH pyrolysis and change the pyrolysis pathways of benzoic acid, but the products are still the same. The catalytic effect decreases when NiO is reduced to metallic Ni.

The MnO _x /ZrO₂ catalyst was prepared by the equal volume impregnation method with commercial ZrO₂ as carrier, and the catalytic ozone degradation effect of the target pollutant methyl orange solution was studied. The factors of calcination temperature and MnO _x loading content were studied to determine the optimal catalyst preparation condition. It turned out that, the catalyst would get the best catalytic activity with 15% MnO _x loading and being calcined at 400℃, and the decolorization efficiency of methyl orange was 92.8% over the catalyst of 15%MnO _x /ZrO₂ (400℃), which increased by 36.1% compared with that in the ozonation without catalyst after 60 min of reaction. Also, the initial pH of methyl orange solution (pH =2.7,6.5,8.7,10.8) was investigated during the catalytic ozonation process. The 15%MnO _x /ZrO₂ (400℃) catalyst performed a higher catalytic efficiency of 95% at pH=2.7 than that value of 6.5 without adjustment by acid or alkali. The catalyst cycle test showed a better stability for 15%MnO _x /ZrO₂ (400℃), and the decolorization rate of methyl orange slightly drop down to about 85% after three times reuse. Moreover，the loss of MnO _x was an important reason for the descent of catalyst activity by characterization experiments.

The high-salt dyeing wastewater was simulated by reactire blue MB-R and sodium sulfate. The effects of different channel height and spacer orientation on the anti-fouling performance and energy consumption of RO membrane modules were compared. The results showed that the membrane flux decline could be slowed down and the membrane running time could be prolonged by increasing the spacer thickness appropriately. However, the anti-fouling performance of the membrane module could not be improved significantly with the increase of the spacer thickness when the spacer thickness was increased to a certain extent. On the other hand, the influence of spacer orientation on the anti-fouling performance of membrane module was very obvious. The results suggested that when the spacer thickness remained unchanged and the spacer orientation changed from 40° to 45°, the membrane flux decline rate decreased by 3.9% after 165 min of operation, the filtration time of one low pressure flushing cycle was prolonged by 35.7%, and the flux recovery rate was increased by 4.5% after the low pressure flushing. The comprehensive analysis based on the trade-off effects and the feed channel pressure drops indicated that a better anti-fouling performance and lower operation energy consumption can be obtained when the feed channel height was set at 30 mil and the spacer orientation was set at 45°.

Membrane distillation (MD) has the advantages of low operating pressure, operating temperature and operating cost, so it has broad application prospects in water treatment. But the wetting and fouling during the MD process will reduce the efficiency of it, which hiders its steps of industrialization. There are many factors that may lead to wetting and fouling, the existence of surfactant is one of them. Surfactant can lower the surface tension of the solution significantly, and might change the property of the feed solution as well. This research add sodium dodecyl sulfate (SDS) into the salty water as feed solution to study the effects of surfactant on direct contact membrane distillation (DCMD) process. The wetting and fouling phenomenon was studied as a function of the SDS concentration, the valence of the added electrolyte, and the different membranes. And results showed that the increase of SDS concentration would make the wetting more severe. It can also be concluded that the omniphobic membrane was the first while the PVDF membrane was the last in an order of the resistance to wetting. When changing NaCl into CaCl₂, the aggregations of Ca²⁺ and SDS weaken the wetting phenomenon but their deposits on membrane lead a fouling. The interaction energies between the colloid and the membrane surface were calculated. And the data manifested that the attraction of PVDF membrane was the largest while the omniphobic membrane was the smallest, which was consistent with the experimental results.

To investigate the extraction efficiency and extraction mechanism of sulfoxide compounds in heavy metal cadmium in water, the extraction of cadmium in aqueous solution by diisooctyl sulfoxide (DIOSO) was reported. DIOSO was prepared and used as an extractant to explore its aqueous solution. Under this condition, a maximum extraction percentage was 99.7 %. To the recycling of extractant, we also carried out cadmium stripping experiments with different stripping agents, the results demonstrated that nearly all of the Cd(Ⅱ) ( 99.86%) in the organic phase could be reverse extracted into the aqueous phase when the NaOH concentration reached 0.2 mol/L. On this basis, combining spectrum and thermodynamic analysis, the extraction process of Cd (Ⅱ) from aqueous solutions by DIOSO may be happened between ion associations. Successfully extracted of Cd(Ⅱ) by DIOSO could provide important theoretical research foundation to heavy metals Cd(Ⅱ) in industrial wastewater pollution.

Considering the characteristics of strong multivariable coupling, significant non-linearity and parameter time-varying in the wastewater treatment processes, a multi-kernel relevance vector machine (MRVM) is proposed for soft-sensor modeling. Particle swarm optimization algorithm is further used to optimize multi-kernel weights and kernel parameters. Meanwhile, the time difference (TD) method is introduced to improve the dynamic characteristics of MRVM. The proposed model was demonstrated through a WWTP simulated case study by comparison with relevance vector machine (RVM) with a single kernel, back propagation (BP) neural network and the genetic algorithm-based support vector machine (GA-SVM). Results showed that the proposed model achieved better prediction accuracy. Finally, the robustness of the models is discussed in the context of data drift and anomalies.

In the processes of complicated chemical production, the appearance of model mismatch in multivariable predictive control systems usually will cause fluctuations in product quality. To deal with this problem, a deep dive mismatched sub-models diagnostic method and its correction algorithm are proposed. Considering that the control variable is the combined responses of the control channel and the disturbance channel in industrial field, by the successive moving of the operational variables into disturbance channel, we evaluate the impact of the moving on the quality index of the model, then identify the source of the mismatched sub-model according to its performance judging. Furthermore, the historical data were used to identify the details of the mismatched parts of the model by the autoregressive moving average model identification method, so that the original sub-model can be corrected. The dynamic simulation of the experiment was carried out by Wood-Berry distillation process. The results demonstrate the effectiveness of the algorithm.

The dynamic optimization operation of heat pump heating based on economic goals is of great significance, but the uncertainty of the change of ambient temperature and model parameters in the operating interval will bring great challenges to the actual optimization and control. In this work, based on well-established model of heat pump heating system with more detailed consideration, an improved dynamic optimal control strategy was proposed to improve the practical energy cost saving of the system. Firstly, the nonlinear dynamic model of the heat pump heating system was established and a dynamic real time optimization (D-RTO) problem was formulated with a comprehensive objective function to be minimized, the frequencies of compressor and water pump were used as manipulating variables for the control purpose. Then, with initially predicted ambient temperature in the future 24 h, the optimal frequency trajectories of the compressor and water pump were obtained through solving the optimization problem, and the system was controlled based on the optimal trajectories of present time. And then, at the next time point, based on the update of ambient temperature prediction and on line model correction, the optimal control trajectories were updated by solving the optimization problem and were executed again. The operation was repeated until the 24th hour is reached. Computing results of case study show that the proposed method can further improve the practical cost saving for the heat pump heating system, and can realize the requirement of terminal state constraint at the same time. This study has practical significance for the dynamic real time optimization of chemical processes with periodic and uncertain operating parameters.

Lubrication and wear characteristics have been closely watched by the machinery industry. In this paper, relationship between attrition amount and lubricating oil characteristics was studied by attrition test of galvanized steel balls in liquid with vibrating mixer. Two kinds of vials made of Teflon (PTFE) and stainless steel were used and four kinds of liquids including synthetic lubricating oil were selected, the attrition test was carried out at different temperatures and then corresponding attrition amount was measured. The amount of attrition was obtained by different method, zeroing with standard weights was implemented to improve the accuracy of the method. From the perspective of movement of steel balls in the lubricating oil, combined with the theory of fluid mechanics, relationship between attrition amount and characteristics of lubricating oil was derived. Based on this relationship, experimental data obtained when using PFTE vials and stainless steel vials were correlated respectively. It was found that the motion of steel balls in lubricating oil was consistent when using different vials. In addition, the attrition test method proposed in this paper could be used to evaluate the lubricating performance of other lubricating oils.

Based on the thermohydrodynamic lubrication theory, a quasi three-dimensional thermohydrodynamic model of the spiral-grooved mechanical face seals considering the mass and energy conservation was established. The finite element method was applied to simultaneously solve the average energy equation of the cross film and the heat conduction equations of the rotor and stator. The equation and temperature equations obtained the film pressure, temperature, and temperature distribution of the seal ring. The sealing performance of THD and HD under the different spiral-grooved parameters was compared. The results show that the thermal effect of high viscosity fluid film can t be neglected. Compared with the THD model, HD model overestimates the opening force and friction coefficient but underestimates the leakage rate. When taking the opening force as the objective, the optimal value of the groove depth from THD is smaller than one from HD model. The increase in the groove-dam ratio and the groove number leads to the rise in the leakage rate of the seal. The influence of the spiral-grooved parameters on the friction coefficient is opposite to the opening force. The increase in the groove depth and the groove-dam ratio is help for reducing the temperature rise of the liquid film and the seal rings.

This work studied the macromolecular structure model of Zaoquan coal from Ningdong, China by means of various characterizations such as industrial analysis, elemental analysis, X-ray photoelectron spectroscopy and ¹³C nuclear magnetic resonance (NMR), combined with computer-aided techniques. After annealing dynamics simulation and fully geometric structural optimizations, the bond length, bond angle and the spatial configuration of coal molecular structure were changed significantly compared with the initial one. Also the arrangement mode of the aromatic layers became nearly parallel. The calculated spectra of Fourier transform infrared and ¹³C NMR agreed well with those in experiments, which further confirmed the obtained coal molecular model. Based on the molecular model, the effects of final temperature and heating rate upon chemical behavior of coal pyrolysis were studied by using the reactive force field molecular dynamics simulations. It was shown that the reaction rate was gradually increased as temperature increased. The heating rate was rather significant for gas generation during coal pyrolysis. In simulations, most of the fragments produced were below C₁₅, while the species of macromolecules were the minority. As heating rate increased, the gas, liquid and solids products were all decreased. In addition, according to the results of reaction molecular dynamics simulation, the formation mechanism of CO₂ in the pyrolysis process was traced, and three different CO₂ formation paths were obtained.

The centripetal turbine efficiency varies greatly with the change of operating parameters and the type of working fluid, and a one-dimensional analysis model of radial-inflow turbine is introduced. The effects of evaporation and condensation temperature on the turbine efficiency were investigated, and a comparative analysis on thermodynamic and economic performances of the organic Rankine cycle (ORC) system with constant turbine efficiency and dynamic turbine efficiency was presented. NSGA-Ⅱ is employed to conduct multi-objective optimization of ORC system, which was to select the optimal working fluid and determine the optimal evaporation and condensation temperature. Meanwhile, the optimal operating parameters of ORC system with constant and dynamic turbine efficiency were compared, and the variation of turbine efficiency with heat source temperature was studied. The results show that the turbine efficiency increases with the decrement of evaporation temperature or the increment of condensation temperature. After introducing dynamic turbine efficiency, the increment of net power output with increasing evaporation temperature slows down, and the sequence order of some working fluids changed. The optimal working fluid and the optimal operating parameters are different between ORC system with constant and dynamic turbine efficiency, which indicates that constant turbine efficiency will cause errors in selection of optimal working fluids and determination of operating parameters. As the heat source inlet temperature raises, the difference of optimal evaporation temperature and net power output between the ORC system with constant and dynamic turbine efficiency increases. The higher heat source inlet temperature is, the greater error caused by adopting constant turbine efficiency will be.

Combined extraction of alumina from coal gangue and red mud was studied. The effect of red mud on the alumina extraction of coal gangue and the consumption of Na₂CO₃ was investigated. The effect of the red mud on the activation process of coal gangue by Na₂CO₃ calcination was studied by way of TG-DSC and XRD. The results showed that the dissolution of alumina for the mixed “coal gangue-red mud-Na₂CO₃” sample increased with the Na/Al molar ratio and the calcination temperature. The alumina dissolution of the mixed sample reached 91.7% when the Na/Al molar ratio was 1.2 and the calcination temperature was 850℃ at the Al/Si molar ratio of 1. The consumption of Na₂CO₃ decreased 77.9% at this condition by comparison with that of coal gangue activated directly by Na₂CO₃. The results of TG-DSC and XRD showed that the interactions among coal gangue, red mud and Na₂CO₃ were weak at <700℃ and were strengthened at >800℃. The addition of red mud would make the phases in the mixed sample selectively transformed into nepheline and zeolite with a Na∶Al∶Si molar ratio of 1∶1∶1 owing to the adjustment of the Al/Si molar ratio of the sample.

At normal temperature of (20±2.0)℃, using actual domestic wastewater as influent substrate and carbon fibre as biological carriers (filling rate 35%), the simultaneous nitrification and denitrification via nitrite was achieved in a sequencing batch biofilm reactor under limited DO concentrations. The results of fluorescence in-situ hybridization (FISH) demonstrated that the ammonia oxidizing bacteria (AOB) became the dominant species in the nitrification process under limited DO concentration. During the anoxic and the initial aerobic process, the external COD was taken up and converted to polyhydroxyalkanoate (PHA), which can be used as internal carbon sources for the following denitrification. DO=0.5 mg/L, the NH₄ ⁺-N removal, TN removal and simultaneous nitrification and denitrification efficiency was more than 95%, 80.4% and 77.9%, respectively. The concentration of NO _x ^--N in the effluent was less than 10 mg/L and mainly in the form of NO₂ ^--N. When the DO concentration was controlled at 2.0, 1.2 and 0.5 mg/L, the N₂O emission was 1.38, 2.39 and 1.65 mg/L, respectively. Both the aerobic denitrification process of AOB and the denitrification of NO _x ^--N with PHA as carbon source at the presence of lower oxygen can lead to the release of N₂O. The long time of lower DO conditions promoted AOB s competitive advantage, formed a micro-environment for denitrifiers, reduced the COD degradation rate, and provided an external carbon source as an electronic donor for denitrification, thereby reducing N₂O emissions.

The occurrence and thermal stability of mercury in six samples of three coal ranks in two coal fields were studied by stepwise chemical extraction method and temperature programmed pyrolysis method. The results show that mercury in coal can be divided into five fractions: exchangeable mercury (F1), carbonate+sulfate+oxide bound mercury (F2), silicate+aluminosilicate bound mercury (F3), sulfide bound mercury (F4) and residual mercury (F5). Among them, F2, F4 and F5 account for over 90%, especially F4 ranges from 45.2% to 82.1%. Mercury speciation is heavily related to coal rank in this study. The proportion of F4 is significantly increased with increasing the degree of coalification, whilst both F2 and F5 are gradually decreased, which can be inferred that mercury combined with carbonate, sulfate and organic matter transfer to the sulfide during the metamorphic process of coal. The thermal release characteristics of mercury in coal depend on its speciation. F1 has the weakest thermal stability which completely releases when the temperature is lower than 150℃, but F3 is the strongest with the release temperature above 600℃. The release temperature of the other mercury species is between F1 and F3. As a result, the order of release temperature is F1 < F5 < F2 < F4 < F3. Based on the above findings, it should be an effective method to transform mercury into much more sulfide with stable state for stabilizing mercury speciation in liquid and solid by-products of coal combustion and other related processes.

A series of acidic deep eutectic solvents (DESs) EMIES/nC₉H₁₀O₂（n=0.25, 0.5, 1, 2, 4） were synthesized by simply heating the mixture of 1-ethyl-3-methylimidazolium ethylsulfate (EMIES) and 3-phenylpropionic acid (C₉H₁₀O₂). The structure of EMIES/nC₉H₁₀O₂ was determined by FTIR, ¹H NMR and TGA characterization. The extraction-oxidation desulfurization system was developed to remove sulfides from model oil using EMIES/nC₉H₁₀O₂ as the extractant and catalyst, H₂O₂ as the oxidation. The influences of raw material ratio, reaction temperature, O/S ratio, amount of DESs and different sulfide on the desulfurization performance were investigated. The experimental results demonstrated the optimal reaction conditions were molar ratio of EMIES to C₉H₁₀O₂ of 1∶1, temperature of 50℃, O/S ratio of 8, the amount of DESs of 1.5 g and 5 ml model oil. Removal rate of DBT, 4, 6-DMDBT and BT reached 94.8%, 91.6% and 46.4%, respectively, under the optimal condition. The DESs can be reused for 6 times without significant decrease in activity. In addition, the desulfurization mechanism of the oxidation-extraction desulfurization system was discussed.

Under the condition of simulating coal-fired hot flue gas as heat source and medium, quasi-east lignite was used as raw material to carry out carbonization activation (one-step method) to prepare powdery activated coke by one-dimensional settling furnace, and the adsorption capacity of activated coke to Hg⁰ was investigated. Further, the effects of SO₂, H₂O, O₂, CO₂, H₂O+O₂, SO₂+O₂ and H₂O+SO₂+O₂ on Hg⁰ removal efficiency were examined in flue gas. The results indicate that the coke has high adsorption performance for Hg⁰ removal. The N₂ atmosphere was used as comparison, the O₂, SO₂+O₂ and H₂O+SO₂+O₂ are beneficial for Hg⁰ removal, while the H₂O, CO₂, SO₂ and H₂O+O₂ have inhibiting effect on Hg⁰ removal. Furthermore, the spectra of Hg 4f were determined by XPS, in order to explore the mechanism of inhibition and promotion of Hg⁰ adsorption by activated coke under different flue gas. H₂O can inhibit the adsorption of active coke on Hg⁰via covering the active coke sites and blocking the pores, SO₂ can inhibit the adsorption through the competitive adsorption of SO₂ and HgO on the active coke, and CO₂ that adsorbed on the active coke micropore also can inhibit the adsorption of active coke on Hg⁰. In the atmosphere of O₂ and SO₂+O₂, the Hg⁰ is oxidized into HgO and HgSO₃, separately. And the HgSO₃ further oxidized into HgSO₄ by O₂. Besides, in the atmosphere of H₂O+SO₂+O₂, Hg⁰ is oxidized into HgO and HgSO₄.

The evaluation of biomass chemical looping gasification (CLG) was conducted via a thermogravimetric analyzer and a fixed bed reactor using CoFe₂O₄ as oxygen carrier. The effects of mass ratio (oxygen carrier to biomass), steam content and reaction temperature on the CLG reactivity of biomass were explored and the recyclability of oxygen carrier was also studied. The oxygen carriers of fresh and reacted were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The TGA results indicate that CoFe₂O₄ can provide lattice oxygen to effectively improve the biomass gasification. The optimal performance can be achieved when the mass ratio, steam content and temperature are 0.8, 50%, and 900℃, respectively. After 5 cycles of reaction, high quality syngas can still be obtained. The oxygen carrier can be recycled and there is no obvious sintering and agglomeration.

In this study, carbon-coated magnetic hydrothermal carbon (NiFe₂O₄@C) was constructed from nickel ferrite and glucose as a reusable high-efficiency adsorbent, and the hypochlorite was catalyzed by oxidation to remove strontium from wastewater. The effects of initial pH, coagulation pH, reaction temperature, co-existing substance and hypochlorite dosage on thallium removal were examined, and mechanism on thallium removal was investigated by X-ray powder diffractometry (XRD), X-ray photoelectron spectroscopy (XPS) and electron spin resonance spectroscopy (ESR). When the initial concentration of thallium was 20 mg/L, the initial pH was 10, the adsorbent dosage was 0.5 g/L, and the sodium hypochlorite dosage was 10 mmol/L, the thallium removal efficiency reached more than 99%. Ca²⁺, Mg²⁺, EDTA, and DPTA can inhibit thallium removal. The adsorption process is more suitable for the pseudo-first order kinetic model, and isothermal adsorption is more suitable for the description of Langmuir and Temkin equation. The saturated adsorption capacity is high up to 989 mg/g. The removal mechanism of Tl(I) by NiFe₂O₄@C was mainly surface hydroxyl complexation and oxidation precipitation. Material regeneration experiments show that NiFe₂O₄@C has a good ability of desorption and regeneration. This study provides a theoretical and technical reference for thallium removal in wastewater.

By comparing the advantages and disadvantages of the existing air source heat pump air conditioning system, a new type of frost-free air source heat pump air conditioning system is proposed. The biggest novelty of this heat pump system is that the heat exchange tower has realized as "one tower in three uses", which can not only run and regenerate effectively without frost in winter, but also improve the performance after evaporative cooling in summer. Through constructing the heat pump system platform, the effects of ambient temperature, humidity, air volume flow rate, inlet solution temperature, solution volume flow rate and solution concentration on dehumidification performance, outlet air and solution temperature are studied. It is concluded that the outlet air and solution temperature increase with the increase of inlet air temperature, humidity, volume flow rate, solution temperature and the decrease of solution volume flow rate. As inlet air temperature rises from -4℃ to 2.5℃, the air outlet temperature increased by 3.32℃, solution tower export solution temperature increased by 1.62℃. As the rise of the solution tower entrance solution temperature, air outlet temperature increased by 1.9℃, export solution temperature increased by 2.66℃. Dehumidification efficiency is mainly affected by air and solution volume flow rate. The inlet air temperature and humidity, solution temperature and solution concentration affect it little, the dehumidification rate increases with higher outdoor air humidity, air volume flow rate, solution volume flow rate and lower solution temperature.

Using methylene blue (MB) as the target pollutant, the active substances of MB degradation in Fe²⁺/H₂O₂ system were studied experimentally. The influence characteristics of main reaction conditions on MB degradation were clarified. The results showed that HO₂· had no ability to directly degrade MB and the capacity of the Fe²⁺/H₂O₂ system for MB degradation mainly came from ·OH radicals. The degradation of MB by Fe²⁺/H₂O₂ system can be divided into a rapid reaction stage and a uniform reaction stage. The MB degradation ratio in the rapid reaction phase decreased with the increase in temperature. The degradation ability of MB in the system increased first and then decreased with the increase of the initial concentration of H₂O₂. Under this experimental conditions, the optimal initial concentration of H₂O₂ was 5 mmol·L^-1. The degradation capacity of MB in the system increased monotonously with the inerease of Fe²⁺ initial concentration. The degradation rate of MB increased with the increase of initial concentration of MB, but the degradation ratio of MB increased first and then decreased with it. Ensuring the rate of ·OH production and its effective utilization are key to improving the oxidizing ability of the system and the utilization of H₂O₂.

This work presents the preparation of homogeneous anion exchange membrane (AEM) based on quaternized polyvinyl chloride (PVC) via straight forward quaternization of PVC with 1-methylimidazole (N-MI). In particular, the preparation avoids the use of toxic chloromethylation. The optimized AEM PVC-N-MI-5 shows ion-exchange capacity (IEC) and transport number of 2.89 mmol·g^–1 and 98.4%, respectively. The water uptake and swelling ratio are 4.24% and 0.21%, lower than the commercial AEM JAM-5 (4.87% and 3.33%). The NaCl removal ratio, current efficiency and energy consumption of the as-prepared AEM were 98.38%、55.8% and 5.1 kW·h·(kg NaCl)^－1, respectively, comparable to commerical JAM-5(93.0%, 55.2% and 4.6 kW·h·(kg NaCl)^－1). The cost-effective PVC and relatively good performance are suggestive of the potential electrodialysis application.

Under mild reaction conditions, flaky iron phosphate dihydrate was successfully synthesized using sodium dodecyl benzene sulfonate (SDBS), and mixed with lithium hydroxide and citric acid by ball milling, and prepared by carbothermal reduction method. The effects of SDBS on FePO₄·2H₂O morphology and the electrochemical properties of LiFePO₄/C were studied. The phase, morphology and electrochemical properties of the synthesized samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and charge-discharge test. The LiFePO₄/C plate-like electrode material achieves excellent electrochemical performance under 2.0—4.2 V at 25℃. It delivers a specific discharge capacity of 166.4 mA·h·g^–1 at 0.1 C with initial Coulombic efficiency up to 99.6% and exhibits a capacity retention of 99% after 500 cycles at 1 C.

To provide boundary conditions for the analysis of the consequences of the accident, a self designed loop device was adopted. Air was used as experimental medium. The buried pipeline gas leakage experiment was carried out under different soil depths (0—60 cm), leak hole diameter (1—4 mm) and leakage pressure (10—50 kPa). The variation of gas leakage amount, dynamic pressure and pressure drop before leak point under different conditions were studied. The results showed that when other conditions remained the same, dynamic pressure peak increased as the leakage pressure increased, increased as the leak hole diameter incresed and decreased as the soil depth increased. In the process of leakage, the gasflow rate increased before the leak point and decreased after the leak point, then, the pressure and gas flow rate in the pipeline remained stable quickly. The gas leakage amount decreased as the soil depth increased, but the influence was small. The gas leakage amount increased approximately exponentially with the increases of leak hole diameter, the gas leakage amount increased linearly with the increases of leakage pressure. The larger the dynamic pressure peak, the larger the gas leakage amount. The larger the gas leakage amount, the larger the pressure drop before the leak point. The quantitative relation formula between gas leakage amount with soil depth, leak hole diameter and leakage pressure, quantitative relation formula between gas leakage amount with dynamic pressure peak, quantitative relation formula between gas leakage amount with pressure drop before leak point were fitted by Matlab program. To generalize the formula, the calculation results were compared with the theoretical model for calculating gas leakage amount of overhead pipelines. By adding the coefficient \alpha , three quantitative relations of gas leakage amount of buried gas pipeline under the condition of small hole leakage (d ≤ 20 mm) and subsonic flow (P≤ 90 kPa) were obtained.

The basic methodological theory as well as its feasibility of the chemical explosion mode analysis (CEMA) method in flame extinction mechanism study was particularly emphasized. The interaction between detailed chemistry and thermal/mass mixing as well as its impact on flame extinction was analyzed. The concept of factor determines the key reaction kinetic factors that dominate the flame flameout limit of ethylene. The results show that the CEM with positive eigenvalues firstly appeared at the stoichiometric location in the near-extinction condition, so positive CEM could play as an important criterion for the detection of combustion instability. The extinction limit of opposed-flow diffusion flame resulted from the comprehensive interaction between heat release and chain branching and termination reactions. It is found that the branching reaction R32 (H+O₂ \stackrel{\mathrm{}\mathrm{}\mathrm{}\mathrm{}\mathrm{}\mathrm{}\mathrm{}\mathrm{}}{?} O+OH) and exothermic reaction R81(OH+CO \stackrel{\mathrm{}\mathrm{}\mathrm{}\mathrm{}\mathrm{}\mathrm{}\mathrm{}\mathrm{}}{?} H+CO₂) were most significant for the ethylene flame extinction limit, which could be largely broadened with the enhancements of these two recations. On the contrary, enhancement of the termination reaction R49 (H+HCO \stackrel{\mathrm{}\mathrm{}\mathrm{}\mathrm{}\mathrm{}\mathrm{}\mathrm{}\mathrm{}}{?} H₂+CO) was unforable to ethylene flammability. The CEMA theory with the concepts of explosive index and bifurcation index was a systematical tool to reveal the impact of detailed chemical kinetics on flame extinction mechanism.

A new gel-type fire extinguishant with core-shell structure is designed which aims at the integrated innovation in the form of the extinguishant to overcome the shortcomings of environmental protection, efficiency and corrosiveness of traditional extinguishant. The gas-phase silicon dioxide, aqueous ammonium dihydrogen phosphate solution, gellan gum and methyl hydrogen silicone combined to prepare the extinguishant by high-speed shearing method. The pressure resistance and fire extinguishing effectiveness of the extinguishant are characterized, and the synergistic mechanism of the extinguishant is studied. The obtained results show that the damage rate is minimal when the size of as-prepared particles ranged between 100—200 μm and the exerting pressure is less than 1.2 MPa.The extinguishant has better performance in suppression class A fire and played a synergistic effect in the process of fire extinguishing: the water acts as an inert component which could evaporate rapidly and cool down the fuel; the ammonium dihydrogen phosphate acts as a chemical component which decomposed by heat absorption and capturer a dicals of the flame for cutting the chain reaction. The gel adheres to the wooden surface and forms an isolation layer, the smoldering and resurgence are inhibited by continuous cooling. Fire-extinguishing performance of gel-type core-shell structure powder fire extinguishing medium is better than that of ordinary ABC dry powder, and the cost is lower, which has a good application prospect.