Space 4 K Joule-Thomson (JT) throttling cooling is one of the key technologies for deep space exploration missions. Based on the existing experimental system of a precooled 4 K JT cryocooler, the effects of the precooling temperature and the high pressure on the maximum cooling capacity are analyzed theoretically. Then, the optimal precooling temperature and high pressure under different working conditions are involved. The experimental studies are developed to verify the theoretical calculations. The maximum cooling performance were tested under five different high pressures (0.829 MPa, 1.103 MPa, 1.775 MPa, 1.837 MPa, and 2.154 MPa) at the final pre-cooling temperature of 15 K and three different pre-cooling temperatures (11.5 K, 15.0 K and 18.0 K) at high pressure 1.773 MPa. The trend of the experimental results is in good agreement with the theoretical values. The study on the influence of precooling temperature and pressure characteristics will be helpful for optimizing the coupling matching of the compressor and precooling cooler for the 4 K JT system.

Based on the laboratory scale of the impinging entrained-flow bed gasifier, the coal gas slurry was used as the raw material for gasification experiments. The particle information in images was identified by image post-processing algorithm and the particle tracking algorithm was used to calculate the particle trajectory. The particle size, particle velocity and particle motion angle were analyzed by statistical method. The results show that the averaged particle size of the jet flow region near the burner tip concentrates at 325－375 μm, which is larger than the original coal particles. The velocity of most particles concentrates at 1－2 m·s^-1 and almost keeps constant during the movement. The motion angles of most particles do not change with time, which means the trajectories of most particles show rectilinear motion. The distribution of all particle trajectories shows a fan-shaped ray starting from the burner tip.

The semi-circumferential heating of the solar heat absorber tube has an effect on the convective heat transfer coefficient in the tube. Base on this, convection heat transfer experimental system and mathematical model of transverse corrugated tube are established to analyze the heat transfer performance of molten salt with different groove width and height. The results show that the circumferentially temperature of inner wall increases, and the circumferentially local Nusselt number decreases first and then increases to stability with transverse corrugated tube from adiabatic side to heated side. The axial temperature of inner wall with groove obviously lower than that of smooth section, the axial local Nusselt number of groove in transverse corrugated tube is relatively large, and the convergence of after groove and smooth section is minimal. The axial local Nusselt number of heated side and the average Nusselt number in transverse corrugated tube decrease with the groove width increases, while the PEC(comprehensive performance evaluation factor) rises. The axial local Nusselt number, the average Nusselt number and Nu/Nu _ST (enhanced heat transfer ratio) increase with the groove height increment. The PEC of transverse corrugated tube is obvious affected by groove width, while the Nu/Nu _ST is remarkable affected by groove height. The Nusselt number rule equation of molten salt in transverse corrugated tube with circumferentially non-uniform heat flux is obtained, and the maximum deviation of Nu between calculated and simulated value is within ±7%.

The numerical simulation is used to simulate the convective condensation heat transfer characteristics of the fully developed section of the H-type and round fin-tube heat exchanger channels under wet conditions. The SIMPLER algorithm is used to calculate the pressure and velocity coupling. The wet flue gas flow rate ranges from 1 to 5 m/s, and the water vapor mass fraction ranges from 5% to 13%. The effects of different inlet velocity and water vapor mass fraction on heat and mass transfer coefficient, heat transfer, condensate flow rate and fin efficiency of H-shaped finned tube and circular finned tube were discussed. The calculation results show that the heat transfer capacity of H-type finned tube is obviously stronger than that of circular finned tube, but the condensation production is less than that of circular finned tube. Meanwhile, the total finned efficiency and latent heat finned efficiency of H-type finned tube are less than that of circular finned tube.

To fully understand the drop-like flow phenomenon of the horizontal tube falling film, this paper uses water as the experimental fluid, and uses a high-speed high-definition camera to visualize the drop-shaped flow of the horizontal tube under different pipe spacings. The droplet flow in low Reynolds number Re≤200 and tube spacing s≤40 mm is observed. Based on the different flow characteristic, the droplet flow can be divided into accumulation droplet flow, incomplete droplet flow, pendant droplet flow, complete droplet flow and incomplete retracting droplet flow. According to the experimental results, the partition map of droplet flow is presented. The concept of separation length is proposed, and the effect of flow rate on separation length is discussed. The relationship between dropping site spacing and flow rate in droplet flow at low Reynolds number was studied. The results show that the flow pattern of droplet flow is influenced not only by flow rate but also by tube spacing. With the increase of tube spacing in Re≤120, the flow patterns between tubes are converted from accumulation droplet flow to incomplete droplet flow to pendant droplet flow, and to complete droplet flow. When 25 mm≤s≤40 mm, as the flow rate increases, the flow patterns are successively converted from incomplete droplet flow to pendant droplet flow, and to incomplete retracting droplet flow. The separation length increases linearly in two stages with the increase of Re. The growth rate in Re≤60 is smaller than it in 60<Re≤140. The correlation of separation length with Re is established in this paper. In addition, the dropping site spacing of droplet flow is investigated. The dropping site spacing decreases with the increase of flow rate in Re≤100, and remains stable in the range of 100<Re≤200. Meanwhile, the dropping site spacing of droplet flow with Re is established.

CO₂ is considered to be an ideal alternative refrigerant with good environmental properties and excellent thermodynamic properties. Compared with the traditional refrigerant, the flow boiling heat transfer characteristics of CO₂ is very different that the heat transfer deterioration and dry-out will make its capability of heat transfer decrease dramatically. It is of much concern to predict the dry-out point precisely when CO₂ flow boiling in tube. However, the existing dry-out point prediction formula fitted is mostly based on their own experimental data. The predicted results of the correlation are biased because of too few data and the limited range of variable parameters. Therefore, by organizing and analyzing 4986 experimental data points collected from 17 articles, the influence of several factors such as mass flow rate, heat flux, saturated temperature and pipe diameter on the dry-out point has been found. And a formula for predicting dry-out points is given by fitting the data points respectively according to the pressure, 90% of the data points has a deviation of less than 15%. The prediction accuracy is greatly improved and it has a great agreement with experiment data. The formula is of great significance to the prediction of dry-out points and the prevention of heat transfer deterioration.

Transverse cracks are easily produced in ultra-supercritical boiler vertical water wall special-shaped fin region near intermediate heater. It is the hidden trouble of water wall leakage and explosion. Take special-shape fin region from a 660 MW ultra-supercritical boiler as research object. Temperature fields and thermal stress fields were obtained by numerical model. Based on calculation data, temperature and thermal stress characteristics were analyzed. The influence of varying load operation and water wall geometry size was also considered. The results show that the axial tensile stress and equivalent stress of the tube wall beside the shaped fin to the apex of the fire side are large, and the alternating load of the boiler is prone to alternating thermal stress, resulting in transverse crack. The highest temperature of the whole model is located at water wall special-shape fin center. Axial stress and equivalent stress are also large in this region. It deserves special attention. Equivalent stress is large in connection point of special-shape fin and tube wall, which results in materials failure and cracks. Cracks may extend to fire-side tube of special-shape fin region.

Numerical investigations of the axial conduction effect on the local heat transfer performance of the printed circuit heat exchanger (PCHE), which has straight channels and use supercritical pressure carbon dioxide (SCO₂) as working fluid, were conducted under laminar conditions. Variations of local heat flux, heat transfer coefficient, heat effectiveness and entropy generation due to heat transfer in PCHEs were obtained under the conditions with or without axial conduction, when the wall thickness, diameter as well as the inlet temperature difference between the two sides get changed. Then, the effect of the axial heat conduction could be analyzed by comparing the results with/without the axial conduction. It was found that the axial conduction could greatly impact the temperature distributions in both solid and fluid domains and lead to significant changes to the convective heat transfer of SCO₂ in PCHEs. When the axial conduction exists, the local heat flux variations get more even along the flow direction, and smaller heat transfer coefficient of the cold side as well as larger heat transfer coefficient of the hot side in the region of T<T _pc are also observed. The axial conduction would enlarge the peak heat effectiveness slightly and bring it to a lower bulk temperature. The heat transfer entropy production mainly occurs in the high temperature region, and the axial heat conduction can effectively reduce the local heat transfer entropy. Increasing the wall thickness and diameter can increase the influence of axial heat conduction, while increasing the inlet temperature difference, the influence of axial heat conduction does not change much.

The flow field in a stirred tank with three-blade swept-back HEDT combined impeller for polyethylene polymerization was simulated. The effects of the installation height of impellers (C ₁), the distance between two impellers (C ₂) and the rotational speed of the combined impeller(N) on the flow field in the stirred tank were analyzed, and the simulation results were validated by PIV experiments. The comparison between the three-blade swept-back HEDT and the three-blade swept-six straight blade disc turbine combined propeller are carried out. The results show that when the ratio of propeller spacing to vessel diameter is 0.35, the fluid flow between the blades in the stirred tank is the best, and the velocity distribution of the upper fluid in the stirred tank is improved. When the installation height of impellers to vessel diameter is 0.29, an overall circulation occurs under the combined paddle, which is beneficial to the mixing of the bottom fluid of the kettle. When N = 90 r/min, the fluid velocity distribution in the kettle is uniform, and the jet direction produced by the upper HEDT blade tends to be horizontal. The comparison between the combined impeller and the three-blade swept-six-straight blade disc turbine shows that the flow pattern of the two combined impellers is similar, but the mixing power of the former can be significantly reduced. The research results can provide reference for engineering application of three-blade sweep-HEDT combined impeller in the polyethylene polymerization reactor.

The regenerator is an important equipment for waste heat recovery and energy recycling of the horseshoe flame glass furnace, which plays an important role in reducing the overall energy consumption of the glass furnace. The regenerator with low thermal efficiency not merely causes an ample amount of energy waste, but also may diminish the lifetime of the glass furnace. Enhancing the thermal efficiency of the regenerator has become a pressing problem to be solved in the glass industry. With the purpose of studying the influence of various parameters of regenerator on thermal efficiency, a numerical simulation model of regenerator is established by using computational fluid dynamics theory and porous media model. Subsequently, combined lance analysis and variation law of gas thermodynamic properties, a thermal efficiency model of the regenerator is established. Finally, Fluent is used to simulate the temperature field and velocity field inside the regenerative chamber with different parameters. Simultaneously, the thermal efficiency data for calculation is collected from the temperature field and the influence of each parameter on the thermal efficiency of the regenerator is analyzed. The results prove that under the premise of ensuring sufficient fuel combustion, reducing the combustion air inlet speed, checkers porosity and refractory brick equivalent diameter are beneficial to augmenting the heat transfer capacity of air and brick, as well as improving the thermal efficiency of the regenerator. Nevertheless, at inlet area of 0.9—1 m² the thermal efficiency of the regenerative chamber is higher.

The precise regulation of the composite latex geometry is important for the controllable preparation of polymer hollow microspheres to achieve specific specifications. Based on one-step microfluidic device, extensive experiments for double droplet preparation are conducted and the flow pattern diagram dependent on capillary number of continuous phase, Ca _W2, and the flow rate ratio of oil phase to inner phase, R _O/W1, is obtained, and further the effects of the Ca, R _O/W1 and the diameter of external phase tube on the large double droplets size are discussed in this work. As Ca _W2 increases, the droplet sizes, regarding inner diameter, shell thickness and outer diameter, decrease because of a large drag force generated by a continuous phase. With the R _O/W1 increasing, the inner diameter decreases, while the shell thickness increases. However, as for the outer diameter of such double droplet, it initially decreases and then increases. In addition, the droplet sizes increase as the tube diameter increases under the same flow rate of all three phases, but it is always limited by the tube diameter. The present work could provide some guidelines for controllable and precise fabrication of double droplets with large diameter.

A Pd-Ce-O/SiO₂ catalyst with Ce as auxiliary was prepared by microemulsion method for oxidative carbonylation of phenol to synthesize diphenyl carbonate (DPC). The activity evaluation results showed that the catalyst performance increased with the increase of the amount of Ce. When the Ce/Pd molar ratio was 10/1, the phenol conversion rate was 64.4%, and the diphenyl carbonate selectivity was 83.4%. The XRD results showed that part of Ce⁴⁺ entered into PdO crystal lattice, therefore the electrons of deactivated Pd could easily be transferred to Ce. So the Pd-Ce-O/SiO₂ catalyst could be easily regenerated and showed better performance. According to the above mentioned results, Pd-O/CeO₂ was designed and prepared for oxidative carbonylation of phenol. However, unlike Pd-Ce-O/SiO₂, Pd-O/CeO₂ showed poor catalytic performance. The phenol conversion and DPC selectivity was only 24.0% and 23.3% respectively. The characterization results showed that PdO was the main species of Pd on the surface of Pd-Ce-O/SiO₂, but there was more PdO₂ on Pd-O/CeO₂. Because Pd(Ⅱ) is the active site for oxidative carbonyation, Pd-O/CeO₂ exhibited inferior activity to Pd-Ce-O/SiO₂. In addition, in Pd-O/CeO₂ catalyst, the surface Pd content was lower than that of other catalyst because of the strong interaction between Pd species and CeO₂. That s one of the reasons for the poor activity of Pd-O/CeO₂.

To investigate the effect of ZSM-5 zeolite as carrier and Ce doping on the low temperature denitrification activity and water/sulfur resistance of the catalyst, the effects of carrier type and Ce doping on the performance of the catalyst were studied by molecular dynamics simulation and experimental research. Molecular dynamics simulations showed that ZSM-5 zeolite as a carrier significantly inhibited the adsorption of H₂O on its surface compared with γ-Al₂O₃. Adding Ce to the active component not only inhibited the adsorption of H₂O on its surface, but also mitigated the poisoning effect of SO₂ on the catalyst. The experimental study found that Mn-Fe-Ce/ZSM-5 has better denitration activity under low temperature and water/sulfur resistance. The addition of Ce has a positive effect on improving the low temperature activity and water/sulfur resistance of the catalyst. ZSM-5 zeolite as carriers also play an important role in improving the water resistance of the catalyst. The SEM, XRD, BET, TG-DTG and other characterization methods and BaCl₂ bubbling experiments were carried out to analyze the mechanisms for the improvement of sulfur resistance of Mn-Fe-Ce/ZSM-5 catalyst. It was found that the addition of Ce increased the oxygen storage and oxygen release capacity of the catalyst. Oxidation of SO₂ in the flue gas to SO₃ avoids the reaction of SO₂ with the active component, so that the active component on the surface of the catalyst is not destroyed, and the catalytic reaction performance of the catalyst is ensured.

Sulfur resistance is a key indicator for evaluating catalyst performance during denitration. It is important to study the effect of SO₂ on the physicochemical properties of catalysts. The rare earth concentrate catalyst was obtained by roasting the Bayan Obo rare earth concentrate. Using the sulfur resistance test bed of the catalyst and combining scanning electron microscope (SEM), Brunner Emmett Teller(BET), X-ray diffraction (XRD) and in situ Fourier transform infrared spectroscopy (FT-IR), the adsorption of SO₂ on the catalyst surface under the atmosphere of O₂, NH₃ and NO, as well as the influence of different SO₂ concentrations on catalytic denitrification were analyzed. The results show that SO₂ can significantly promote the denitrification performance of rare earth concentrate catalysts. The NO conversion rate increased from 28% to 50% at 300℃ and increased from 42% to 75% at 350℃. SEM, BET and XRD results illustrated that the surface structure and chemical composition of the catalyst remain unchanged before and after denitrification. The rare earth concentrate had good sulfur resistance. The FT-IR results verified that the adsorption of SO₂ increased B acid sites on the surface of the rare earth concentrate catalyst. The adsorption capacity of the catalyst for NH₃ was enhanced, contributing to increase catalyst activity. The results can provide valuable basic data reference for the anti-sulfur performance of the Bayan Obo rare earth concentrate catalyst NH₃-SCR denitrification application process.

The nano-perovskite catalyst La_0.9Sr_0.1Co_1-xFe_xO₃ was prepared by citric acid-EDTA complex method. The catalysts exhibit excellent catalytic activities for the simultaneous removal of NO and soot. Among them, the La_0.9Sr_0.1Co_0.7Fe_0.3O₃ exhibits the best catalytic activity and wide activity window. The maximum NO conversion is 32.5% at 380.0℃, and the maximum soot combustion rate (T_m) is 368.5℃. The results of H₂-TPR and NO-TPD indicate that the Fe-doping can significantly improve the reduction performance at the low temperature, surface oxygen species activity and NO adsorption performance of catalyst, leading to the enhancement of the catalytic activity. The XPS results show a strong interaction between Co and Fe. With increasing of Fe-doping, the surface adsorbed oxygen concentration and (Co⁴⁺) content could increase on the surface catalyst, it is essential to improve the catalytic oxidation ability. Based on the previous works, the commercial DPF carrier is used to coating the CeO₂ coat, and the La_0.9Sr_0.1Co_0.7Fe_0.3O₃ catalyst is further loaded to carry out the actual diesel engine bench test. The results show that the catalyst has good catalytic activity for simultaneous removal of NO_x and soot. The best NO conversion can reach 23.0%, and the T_m was 341.0℃, indicating that the Fe-doping in the nano-perovskite catalysts can effectively improve the catalytic activity. It is expected that this study will provide strong theoretical support for the design and development of future four-way exhaust catalysts.

The crystallization process is an energy-efficient solid-liquid separation and purification technology in chemical unit operation, which is widely used in food, medicine, dye and other production processes. The crystallization of sodium acetate was studied by ultrasound, image and optical turbidimetry simultaneously, in which the crystal size distribution (CSD) was obtained by ultrasonic forward model combined with the optimum regularization technique (ORT) algorithm. By implementing a series of experiments at various stirring and cooling rates, the crystallization temperature and particle size were measured, and the crystal shape was also determined via image analysis. The results showed that the faster cooling rate the higher crystal growth rate, and the faster stirring rate promoted crystal growth at the initial stage but the average size decreased due to particle wear and breakage in the later stage. The crystallization temperature detected by ultrasonic method was slightly lower than that of optical turbidimetry under the same condition but the deviation was within 15%. In addition, the crystal growth and the morphology had been directly observed and characterized by the image method, which yielded a close trend with ultrasonic method, and the deviation of median diameter measured by these two methods was less than 15% once the crystal precipitated steadily. As a whole, the optical methods are more suitable for local characteristic measurement in the early stage compared with the ultrasonic method, and the latter is more appropriate for probing the continuous process of particle size change.

In the actual industrial process, the interference of outliers is inevitable. Existing methods of dealing with outliers can cause bias in model estimates and do not take into account the effects of potential outliers. In view of the above shortcomings, using student distributed noise to deal with potential outliers, this paper proposes a variational Bayesian method based on student distribution noise, and combines it with over-sampling structure to introduce a variational Bayesian method to robust identification based on over-sampling structure. The simulation experiments show when the outlier has a large influence, it still maintains a small identification error, while the traditional identification method is no longer applicable, and it also overcomes the huge cost of adding additional test signals to the traditional structure. Therefore, the algorithm in this paper is more suitable for practical industrial process identification.

Aiming at the large inertia, nonlinearity and large delay of the controlled object in the temperature control of the electric heated water bath device, RBF (radial basis function) neural network cascade control system based on the IDE(improved differential evolution) algorithm is designed. The IDE algorithm is used to optimize the initial parameters of the RBF neural network. The optimized RBF neural network is used to identify the Jacobian information of the controlled object of the main control loop, and then the online adjustment of the parameters of the main control loop PID (proportional integration differentiation) controller is realized. Aiming at the problem that the main control loop controller contains output noise which leads to the decline of control performance, the Kalman filter is introduced to redesign the main loop of the cascade control. The output value of the control object is processed by the Kalman filter algorithm and then returned to the closed loop control system. The simulation test of the IDE-RBF-PID-PI cascade control system is carried out for the common electric heated water bath device in the micro chemical industry. The results show that the IDE-RBF-PID-PI cascade control system greatly improves control performance compared to conventional cascade control. The Kalman filtering algorithm introduced in the main control loop effectively reduces the output noise of the control system, and the control effect is close to the ideal state without noise.

The comprehensive research and application of heat exchanger networks has been proven to be effective in improving energy efficiency, and the comprehensive research on power exchange networks for recovering higher quality energy is still in its infancy. To solve the problem of stream matching limited by complex driving force constraints in indirect work exchange network synthesis, an extended superstructure considering inter-stage heat integration is established in this paper. Based on the linear fitting operation curves of compressors and turbines, an identification method is proposed for searching feasible stream matches between work sources and sinks. Specific to the highly non-convex and non-linear relationship among pressure, flowrate and temperature, a relaxation strategy is proposed to optimize the inlet temperature of each stage by heat integration, and a mixed-integer nonlinear programming model is established with the objective of minimizing the total annual cost (TAC) model is solved using GAMS and the optimal indirect work exchange network structure is obtained. Finally, an example is given to verify the validity and feasibility of the proposed method.

Process safety has always been one of the most important issues in the chemical industry, fault detection and diagnosis(FDD) is one of the most powerful tools for chemical process abnormal events management, which provides guarantee for process safety. With the development of deep learning, many intelligent learning algorithms have been proposed, but these algorithms are rarely applied to FDD. In this paper, a novel chemical process fault diagnosis method is proposed based on sparse filtering and logistic regression (SFLR) .The main idea of this method is to divide chemical process raw data into training data and test data firstly, then standardized and whitening preprocessing, and then train sparse filtering(SF) model with three layers of neural networks, and use the SF model for unsupervised feature learning. Finally, logistic regression(LR) model with supervised learning is used to classify the chemical process health conditions using learned features. The proposed method was verified by the TE process and the non-catalytic oxidation of cyclohexane to cyclohexanone. The results show that the proposed method has high diagnostic accuracy, and the case study shows that the proposed method can diagnose faults in a timely and effective manner.

Aiming at the problem that network parameters are difficult to be optimally determined, the model convergence speed is slow and the structure is complex in the traditional incremental random vector functional-link networks (I-RVFLNs), an optimized incremental random vector functional-link networks algorithm, namely O-I-RVFLNs, is proposed. Different from the traditional I-RVFLNs, the proposed O-I-RVFLNs algorithm sets a desired residual error vector, and then selects the input weights and biases that can reach or less than the expected residual error as the input parameters of the node each time a hiddennode is added, thereby improving the convergence rate of the network. In addition, considering that the modeling error of the algorithm is smaller and smaller and the downward trend is less obvious in the process of continuous iteration updating, the RMSE difference between adjacent iterations of each index parameter is considered in the termination condition of the algorithm, and the corresponding convergence criteria are formulated by referring to the Western Electricity Rules in statistical process control. Finally, based on UCI energy efficiency data and actual blast furnace industrial data, the proposed O-I-RVFLNs algorithm is verified and applied. The results show that compared with other RVFLNs algorithms, the data model built by the proposed algorithm can obtain more compact network structure, better generalization performance and prediction accuracy.

The business of fragrances has become a multibillion-dollar market, and the development of fragrance tuned technology enriches modern social life. In this study, the inverse machine learning model for fragrance tuned design is proposed. The molecular surface charge density distribution based on the conductor-like screening model (COSMO) is used as the structural descriptor of the fragrance molecule to design the final fragrance tuned product. First, the fragrance attributes are identified and transform attributes into target properties according to needs. Then, change odor scores and establish the Inverse Machine Learning (IML) models, in which the input variables are odors and the output variable is molecular structure descriptor. Based on the trained IML models, the structure descriptors of the potential product are predicted according to the target properties. Finally, the candidate tuned mixtures were screened out using Euclidean-based method in the specified database. In this paper, two types of fragrant examples are taken as examples. The framework is used to design the fragrance, and the experimental data and odor radar map are used to verify the experimental results.

The individual heat exchanger network structure is basically stereotyped when it is optimized by random walk algorithm with compulsive evolution (RWCE) to a certain stage, and it is difficult to destroy or change the heat balance in the certain local optimal structure and search for better solutions. Therefore, this paper explores the characteristics of structural changes in the evolution of individuals and analyzes the keys to structural evolution. It is found that heat exchange unit has great effects on the structural evolution. Therefore, the structure-fusion strategy is proposed to organize the heat exchange units of two individuals into one structure, which could expand the evolution potentiality of individual network structure. The new individual structure is optimized by RWCE to form better configuration, through the process that all heat exchange units compete with each other and the structural evolution potentiality work at full capacity. Finally, two examples are applied to verify the effectiveness of the strategy and achieve considerable optimization results.

The concentration of the substrate during fermentation is often not measured online. In this paper, Gaussian process regression (GPR) is used to establish an estimation model of substrate concentration, and its soft measurement is realized. Different from traditional regression models, the GPR model can not only predict the quality value, but also provide the estimation variance. In order to improve the prediction performance of the model in the nonlinear fermentation process with correlated variables, the input variables of the model are selected by the k-nearest neighbor mutual information (k-MI) method before the model development. The application results of penicillin fermentation process show the ideal prediction performance based on the kMI-GPR model.

In the nonlinear time-delay cement burning system, an improved on-line echo state network predictive control model is proposed for the problem that the traditional predictive control method has long adjustment time and low control precision. Therefore, we firstly combine the L1-norm constrained recursive least squares method with the echo state network to construct an on-line prediction model to address these issues. Then, the structure of predictive control model is constructed based on the improved prediction model of echo state network. And particle swarm optimization (PSO) algorithm with global optimization capability is utilized for rolling to ensure that the actual output follows the setting value of the controlled variable quickly, accurately and smoothly. Finally, the simulation prediction experiments of the free calcium oxide content in the cement burning system are conducted using the improved predictive control model. The results show that the improved predictive control model has good performance and application prospects.

For the complex and changing operation conditions, the traditional soft sensor methods for the dynamic liquid level lack effective model updating mechanism and have poor prediction accuracy. To solve this problem, an adaptive model updating strategy based on the fuzzy evaluation is proposed in this paper. A model performance evaluation module based on the fuzzy inference for the tendency of the change of the oil liquid is constructed to dynamically update the model, which is used to realize the reverse inference verification for the original model. Firstly, an offline multi-model prediction model for the dynamic liquid level was established; Then, a fitting optimization index of the oil liquid was put forward to do real-time output evaluation for the online output of the dynamic liquid level; Finally, the field production data verification in Liaohe Oilfield shows that the method can effectively improve the prediction accuracy and generalization ability of the model, and can meet the production needs of the oilfield site.

In the process of complex chemical modeling, the traditional static neural network modeling can not meet certain accuracy because of the time sequence, high nonlinearity and high dimension of process data. To solve this problem, a feature extracted from auto-encoder based echo state network (FEAE-ESN) is proposed in this paper. In the traditional echo state network (ESN) method, the number of nodes in the reserve pool of ESN is large, and then the dimension of the reserve pool output is very high. Therefore, to solve this problem, the auto-encoder is used to extract features from the reserve pool output of well-trained ESN. Through the feature extraction of auto-encoder, on one hand, the dimension of the output of the reserve pool can be effectively reduced, thereby reducing the complexity of the data; on the other hand, the collinearity of the outputs of the original reserve pool can be removed through extracting features, which can further improve the calculation performance of generalized inverse. Ultimately, the modeling accuracy of ESN is improved. The proposed FEAE-ESN is applied to modeling the Tennessee-Eastman process. The simulation results verify the effectiveness of the proposed method.

Hydrophobically-modified titanium dioxide-modified calcium alginate microspheres (E@Alg@s-TiO₂ microspheres) stabilized oil-in-water (O/W) type Pickering emulsion is used for two-phase interfacial enzyme catalysis. Compared with the traditional two-phase free enzyme system, the system immobilizes the enzyme at the emulsion interface in a green and gentle manner, and strengthens the two-phase interface enzyme catalyzed reaction. The research results are summarized as follows: when the oil-water ratio is 1∶1.2, the O/W emulsion is obtained; the concentration of the microspheres is 3%(mass). The O/W system has a good enhancement effect on the biphasic enzyme-catalyzed hydrolysis reaction, with 96% conversion rate and 7.8 times higher enzyme activity than the free enzyme in conventional two-phase system, 5 batches cycles with 80% of residue enzyme activity. This study further expands the application range of the enzyme-loaded alginate microsphere-stabled Pickering emulsion system, which is expected to provide a green platform for the interfacial biocatalysis process.

Studying the flame characteristics of liquid fuel atomized combustion helps to understand the entire combustion process. A new counter-flow combustor based on the technology of electro-spraying was designed. Experiment studies on electro-spraying shape and flame characteristics were carried out using alcohol as fuel. The primary focus is paid on the effects of strain rate and equivalent ratio on flame characteristics at different fuel flow rate, including flame temperatures and dimensionless diameter of the flame. The results show the boundary between atomized core regions and satellite regions of the spray gradually disappears when increasing alcohol flow rate, the liquid column of spray appears when fuel flow rate arrives 13 ml/h. The flame remains stable when the equivalent ratio is less than 1 but oscillates when the equivalent ratio is more than 1, dimensionless diameter of the flame decreases with increasing equivalent ratio. As the strain rate increases, the dimensionless diameter of the flame and the temperature decrease.

The in situ reforming of volatiles from municipal solid waste by pyrolytic carbon is a good method for improving pyrolysis products. In this process water vapor plays an important role on product conversion. In order to understand the role of water vapor during the reforming process, oil phase and aqueous phase in the pyrolysis liquid are separated and then D₂O was used to replace the aqueous phase to mix with oil so that hydrogen transfer between liquid, gas and solid can be tracked in the reforming process. The vaporized oil/char reforming process was performed at 600℃, 700℃ and 800℃, respectively. The oil phase and deuterium concentration in the liquid (oil and aqueous phase together) after reforming were measured with help of GC-MS and IR-MS(isotope ratio mass spectrometry); at the same time deuterium concentration in the solid phase was also checked. It has been found that char gasification by water vapor at all testing temperature ranges is very weak, at 700℃ 2% of deuterium in D₂O was remained in the char when the ratio of D₂O/char was 2/1. While oil gasification by water vapor during char-catalytic reforming process is very intense: at 800℃ 78.68% of total oil-water mixture is gasified, and the aliphatic hydrocarbons in the oil are decomposed to a large extent, but the aromatic hydrocarbons are found to account for 96.17% of the oil phase after reforming. Simultaneously 59% of deuterium in D₂O was found to transfer into syngas when the ratio of D₂O/oil was 2/3. The research results obtained here will provide guide for improving the final products of MSW pyrolysis.

The thermally regenerative ammonia-based battery (TRAB) exhibits unique advantages and good application prospects in the recycling of waste resources. By constructing TRAB to treat Cu²⁺-containing waste liquid and recovering electric energy and copper resources, the effects of different Cu²⁺ concentrations on battery power generation performance and Cu²⁺ removal of waste liquid were studied. The results showed that, with the increasing Cu²⁺ concentration less than 0.2 mol/L, the maximal power, the total charge, and the energy density and copper removal rate increased during the discharging. A very-low final concentration and a high removal rate of Cu²⁺ indicated that TRAB is feasible for the treatment of waste water containing Cu²⁺. The two-step treatment method using TRAB combined with electrocoagulation method in the follow-up study is expected to further improve the treatment effect, and has good economic and application prospects.

A total of 5 kinds of activated carbons were selected, including 3 kinds of commercial activated carbons, one of which was impregnated with HCl solution and KOH solution, to study the influence of space velocity and adsorption temperature on the adsorption of volatile organic compounds (VOCs), and the influence of types of VOCs and characteristics of adsorbents on the adsorption and desorption of VOCs at high temperature and low concentration. It was found that the space velocity had a great effect on the adsorption penetration time, but did not affect the adsorption capacity. Adsorption temperature and the concentration of VOCs was found to have a great influence on the adsorption capacity, and when the adsorption temperature was 150℃, adsorption capacity of adsorbent to toluene can only reach 40% of that at 90℃. High-boiling adsorbates are more easily adsorbed and more difficult to desorb.

The electrochemical oxidation mechanism of phenol on the surface of Pt electrode was studied by electrochemical in situ spectroscopy. In 0.1 mol/L Na₂SO₄ solution, the reaction potential of electrochemical oxidation of phenol on Pt electrode is +0.9—1.0 V (vs SCE), and the oxygen evolution potential is +1.3 V. In situ infrared spectroscopy showed that electrode potential had a great influence on oxidation behavior of phenol. When the potential was lower than 0.9 V, the main intermediates of phenol oxidation were dihydroxyhenzene, quinone and a few alcohols. When the potential was controlled between 0.9 V and 1.1 V, the structure of benzene ring was destroyed, and the main intermediates were ketones, acids, alcohols and CO₂. According to the changes in absorption peak of functional group, phenol oxidation on the platinum electrode surface was as follows: phenol, dihydroxyhenzene, quinone, ketone, alcohol, acid and CO₂. The potential of ammonia oxidation on the platinum electrode surface was + 0.5 V, which indicated that ammonia in competition with phenol oxidation in the low potential region (< 0.9 V).

Phosphate accumulating organisms (PAOs) has been enriched successfully in an anaerobic-aerobic sequencing batch reactor (AO-SBR) with the influent of the domestic sewage with C/P ratio greater than 50.The average anaerobic phosphorus release amount was 15 mg·L^-1. The concentration of effluent \mathrm{P}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{3}\text{-}}-P was less than 0.5 mg·L^-1. On the 74 th day, the operation mode was adjusted to anaerobic-anoxic-aerobic, and \mathrm{N}{\mathrm{O}}_{\mathrm{3}}^{\text{-}}-N was added at the beginning of anoxic zone to enrich the denitrifying phosphorus accumulating bacteria(DPB). The best efficiency of denitrifying phosphorus removal performance were acquired when the influent COD concentration was 250 mg·L^-1 and the \mathrm{N}{\mathrm{O}}_{\mathrm{3}}^{\text{-}}-N concentration was constant in the system. Meanwhile the ratio of average denitrifying phosphorus removal to phosphorus removal was 87.1%. Anoxic pH effect tests showed that the rate of denitrifying phosphorus removal is related to the pH value, DPB preferred higher pH for phosphorus removal, and the maximum specific phosphorus removal rate of 2.1 mg P·(g VSS·h)^-1 is obtained at pH=7.0. In the subsequent experiments, \mathrm{N}{\mathrm{O}}_{\mathrm{3}}^{\text{-}}-N was supplied from the effluent reactor and drainage ratio was increased. These methods ensured that the pH of the anaerobic reactor was closed to 7.0. The comparison with the unadjusted stage showed that the rate of denitrifying phosphorus removal increased. The reactor was operated for 160 days, and the COD removal and denitrifying phosphorus removal process were stably completed.

The reactivity of oxygen carriers is curial for biomass chemical looping gasification (CLG) process. Two kinds of manganese-iron composite oxygen carriers of MnFeO₃ and MnFe₂O₄ were synthesized by sol-gel combustion method. Though the in situ infrared, CLG experiments with straw were carried out. It indicated that the ferromanganese composite oxides accelerated the release rate of pyrolysis products and enhanced the yield of CO and CO₂, which promoted the carbon conversion efficiency. Further tests in fix-bed were to prove the feasibility of MnFeO₃ and MnFe₂O₄ and the influence by coupling with steam. It showed that components of H₂ and CO in syngas could be improved significantly by introducing steam and the gasification efficiency for MnFeO₃ and MnFe₂O₄ was 94.49% and 92.76% individually. The XRD analysis demonstrated that MnFeO₃ and MnFe₂O₄ transformed to a combination of (Fe, Mn)O during the reduction process and both of them exhibit recyclable crystalline phase variation. Moreover, multiple redox tests showed MnFe₂O₄ exhibited a decreasing tendency of gasification efficiency because of agglomeration, its typical surface morphology changed from scattered particles to blocky structure. However, MnFeO₃ formed a granular porous structure which helped to maintain a stable reactivity. Thus, MnFeO₃ was considered to have better applicability in CLG process.

At normal temperature of (20±2.0)℃, the characteristics of N₂O eimssion and extracellular polymeric substance(EPS) production were studied during simultaneous nitrification and denitrification(SND) process under different C/N ratio (C/N=3.0,5.0, 8.0 and 10.0). When C/N increased from 3.0 to 10.0, the heterotrophic bacteria increased rapidly, DO decreased and the nitrification process was inhibited. The effluent NH₄⁺ increased from below 0.5 mg/L to (7.85±1.42) mg/L, and the N₂O emission decreased from (2.68±0.17) mg/L to (1.02±0.12) mg/L. When C/N was 8.0, the maximum total notrogen removal efficiency was 80.4%±3.5%. The accumulation of PHA(poly-β-hydroxyalkanoate) increased firstly and then decreased. Both nitrifier denitrification and heterotrophic denitrification resulted in N₂O production. The anoxic area located in the biofilm decreased with the decreasing of C/N ratio, which weakened the denitrification process. With the increase of C/N ratio, N₂O diffused into the anoxic region of biofilm can be effectively reduced. The microbial EPS secretion decreased from (57.6±5.6) mg / g VSS to (32.7±3.2) mg / g VSS. The TB-EPS content accounts for 65.8%—68.8% of the total EPS. Under low C/N, the content of polysaccharide (PS) in compact EPS (TB-EPS) increased, the biofilm was more compact, the resistance of N₂O diffusion into the anoxic zone increased, and the release increased.

The thermal pyrolysis of liner low density polyethylene (LLDPE) has been carried out in a closed pressure reactor. The effects of pyrolysis temperature, residence time and reactor pressure on the yield, molecular weight and melting point of the products were investigated. The characterization of the products has been carried out using Fourier transform infrared (FTIR) spectroscopy. The results indicate that the PE wax obtained under the conditions of residence time of 15—60 min and pyrolysis temperature of ~260℃ exhibited better performance, with the melting point above 100℃ and the molecular weight of between 1400 and 4700. The FTIR show that the main components are linear alkanes and olefins. According to the kinetic analysis, since the closed reaction system increased the reaction pressure, the pyrolysis temperature and activation energy were reduced, the LLDPE cracking reaction was promoted, and the generation of gas molecule was suppressed, which facilitated the formation of PE wax.

MnO₂ is regarded as the most attractive electrode material for supercapacitor (SC) because of its low cost and non-toxic nature, high natural abundance, and superb theoretical specific capacitance. The tantalum capacitor electrode material MnO₂ still has a problem of poor conductivity and easy peeling during charging and discharging. In this study, a sandwich MnO₂/CNTs/MnO₂ mesoporous composite is fabricated by a facile galvanostatic electrochemical deposition approach on the surface of carbon paper pre-oxidized by nitric acid, and the middle layer of CNTs was added by a simple smear-drying method. The crystal structure, surface morphology and pore characteristics of the sandwich composite are characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and nitrogen adsorption test. The prepared composite shows a sandwich structure with mesopores of about 5 nm, which could ensure the efficient diffusion of electrolyte ions. Three-dimensional carbon paper could provide abundant conductive sites for attachment of MnO₂. The synthesized α-MnO₂ has a fluffy and porous morphology, which could reduce the expansion stress of the composite effectively. The intermediate layer of carbon nanotubes (CNTs) serve as conductive media relay between the inner and outer layers of MnO₂ to further improve the conductivity of composite. The composite exhibits excellent electrochemical performance: the electrode has a reversible specific capacity of 428.8 F·g^-1 at a current density of 0.1 A·g^-1 and an outstanding specific capacitance retention of ca. 80% at 5 A·g^-1. Moreover, the electrode still has an excellent cycle stability (95% retention rate) at a current density of 1 A·g^-1 after 6000 cycles.

The factors affecting the service life of composites were analyzed by the changes of macroscopic, microscopic and mechanical properties before and after aging of glass fiber reinforced plastics under corrosive conditions. The analysis shows that the service life of fiberglass reinforced plastics under corrosion conditions is affected by three factors of temperature, time and corrosion medium concentration. Based on the bending strength retention rate of composites, a three-layer BP neural network model with a structure of 3-10-1 is used to predict the service life of composites. Through the comparison and error analysis of the forecast data and the measured data, and the random extraction of 6 sets of test data for detection, the results show that the predicted value obtained by BP Neural network model has a good fitting fit with the measured value.

Graphene oxide(GO) was prepared by improved Hummers method. Hydrothermal reduction was performed at 180℃ under acidic conditions (pH=5). Reduced graphene oxide (RGO) with different reduction degrees was prepared by adjusting hydrothermal reduction time. The effects of different hydrothermal reduction time on RGO structure and supercapacitive performance were studied. The results showed that RGO with different degree of reduction could be prepared by controlling the time of hydrothermal reduction. With the increase of hydrothermal reduction time, the specific capacitance of the RGO electrode increases at the beginning and then decreases through electrochemical testing. When the hydrothermal reduction time was 6 h, the RGO electrode showed the best supercapacitive performance, and its specific capacitance reached 251 F/g at 1 A/g current density, which was 225% higher than the GO electrode. After 500 charge and discharge cycles, the RGO-6 electrode has a specific capacitance retention rate of 92%, which has excellent cycle stability.

7-Hydroxy-4-methylcoumarin was used as the core to react with acryloyl chloride to obtain a fluorescent monomer. Under the action of emulsifier polyoxyethylene octylphenol ether-10 (OP-10) and initiator ammonium persulfate, it was prepared by emulsion polymerization with acrylamide, styrene and modified nanoparticles to obtain a fluorescent emulsion. The products were characterized by infrared spectroscopy, nuclear magnetic resonance spectroscopy, particle size analysis, ultraviolet spectroscopy, fluorescence spectroscopy and ultraviolet accelerated aging test. The optical properties and application properties were investigated. The particle size distribution of the fluorescent emulsion of the composite nanoparticles is more uniform and the properties are more stable. When applied to the surface of the paper, it was found that the initial whiteness of the paper was improved, and the paper strength and water resistance were greatly improved. After UV aging, it was found that the target product has a better effect of inhibiting the yellowing of the paper.

At present, pipeline leak detection methods can effectively detect sudden leaks. While the leak signals caused by slow leak are relatively gentle and easily submerged in noise, there are problems such as low sensitivity and inaccurate location for slow leak detection. Based on this, a slow leak detection is proposed with signal enhancement. The shortcoming of the small pressure decline rate of slow leak can be overcome by compressing (drawing and shifting) the pressure signals. Based on the advantages of the sharp waveforms and sensitive to sudden leaks of acoustic signals, the acoustic signal transmitter model with pressure signal as input and virtual acoustic signal as output is established, which overcomes the shortcoming of the leak pressure signal being easily submerged in the pressure fluctuations and noise of the pipeline, and achieves the slow leak signal enhancement. And the virtual acoustic signal is reconstructed based on the adjacent interpolation method. Then accurate location is achieved by the cross-correlation of corresponding virtual acoustic signals. The results show that the method has significant signal enhancement and positioning accuracy, and achieves accurate detection of slow leakage.