Three-dimensional Numerical Simulation Model Research Articles

Gas Fire Coupling Control of Goaf Based on Numerical Simulation

ABSTRACT In response to the problem that traditional gas control methods such as water injection and inert gas fire extinguishing are not effective and have a high level of risk in goaf, this study uses COMSOL software to establish a three-dimensional numerical simulation model of goaf, and combines air leakage intensity, oxygen concentration, and floating coal thickness to calculate the gas fire hazard area, in order to achieve effective control. The results show that the deviation between the data obtained from the numerical simulation and the actual measurement value is about 7 m, which proves that the given solution is reliable. The gas concentration of the wind lane and the upper corner is controlled below 1%, which proves that this method ensures the safety of the working environment. The above results show that the design method realizes the effective control of gas fire in the goaf, and provides reference for mine safety management and gas disaster control.

Analysis of damage characteristics of the rectangular steel container under near-earth explosion loading

In this study, the dynamic response of a semi-buried steel vessel under a near-surface explosion shock load was investigated through full-scale model tests. A three-dimensional precise numerical simulation model of the semi-buried steel vessel structure was established, and the dynamic response and damage consequences under different load conditions were analyzed. The influence of the thickness of corrugated steel on the dynamic damage and antiknock properties of the structure was studied. The results show that the weak part of the rectangular steel vessel structure is mainly located at the connection between the blast-facing panel and the beam column under near-surface explosion conditions. The peak stress and displacement of the blasting surface decrease with the increase in the horizontal angle of the incident wave, whilst/while increase with the height of the explosion. Under the same explosive yield, the main failure mode of the structure is the tearing of the plate and beam under plastic deformation. Increasing the thickness of the corrugated steel can significantly restrain the plastic deformation and acceleration of the plate. When the thickness is increased from 2 mm to 6 mm, the antiknock performance is significantly improved. However, when the thickness is increased from 6 mm to 8 mm, the improvement in antiknock performance slows down. Increasing the height of the enclosing soil can also effectively improve the explosion-proof performance of the structure, with full burial providing the best effect. The research results provide a theoretical basis for the application of rectangular steel vessel structures in the field of protection engineering.

Ammonia energy fraction effect on the combustion and reduced NOX emission of ammonia/diesel dual fuel

With stringent regulations of internal combustion engine on reducing CO2 emission, ammonia has been used as an alternative fuel. Investigating how engine-related performance is affected by partial ammonia replacement of diesel fuel is essential for understanding the combustion. Therefore, in this study, a three-dimensional numerical simulation model is developed for the burning of two fuels of diesel and ammonia based on relevant parameters (i.e., compression ratio, load, ammonia energy fraction, etc.) in a lab-made diesel engine. The consequences of load and compression proportion on combustion and pollutant emissions are investigated for ammonia energy fractions between 50% and 90%. When the ammonia portion rises, the increased ammonia equivalent ratio causes ammonia to move away from the dilute combustion boundary and accelerates the combustion rate of ammonia. An increase in compression ratio significantly increases the specified thermal performance and combustion efficacy. When the compression ratio is 16, as the ammonia energy fractions increases, due to the increase in the proportion of ammonia, that is, the proportion of nitrogen atoms increases, more NOx is generated during the combustion process. When the ammonia substitution rate is 90%, as the compression ratio increases, the cylinder pressure and temperature increase. The combustion efficiency of ammonia increases, generating more NOx and NOx emissions can reach 0.66 mg/m3. At a compression ratio of 18, the NOx emissions can reach 1.59 mg/m3. However, under medium and low load conditions, as the ammonia fraction increases, the total energy of fuel decreases, and the combustion efficiency of ammonia decreases, resulting in a decrease in the heat released during combustion and a decrease in NOx emissions. When the ammonia substitution rate is 90% and the load is 25%, NOx emissions reach 0.1 mg/m3. This research provides theoretical suggestions for the profitable and use ammonia fuel in internal combustion engines in a clean manner.

Interaction characteristics between the large ship-rubber fenders-wharf structure in deep-water considering the flexibility of the wharf structure

High pile-supported wharf structures in offshore deep water have significant flexibility due to long free ends and large slenderness ratios of the pile bodies, resulting in substantial deformation of the pile body under kinds of loads. In the design of this new type of wharves, it is expected to consider the characteristic of elastic deformation of pile body absorbing a portion of the ship impact energy reasonably. However, the existing calculation method still adopts the theoretical formulas of traditional wharf structures, failure to incorporate this advanced design concept fully. In order to solve this, firstly, a comprehensive three-dimensional numerical simulation model encompassing large ship, rubber fenders and wharf structure, was developed using Ansys/LS-Dyna, and the calculation model was validated against the existing research results. Subsequently, dynamic response characteristics of wharf structures during the normal berthing of ships were examined meticulously, and the variations in absorption energy and reaction forces of rubber fenders and wharf structures were analyzed systematically. And then the analysis results were compared with previous research, the limitations of the existing design code for wharf structures were discussed as well. Finally, the findings demonstrate that peak values of absorption energy and energy transfer times increase with the increase of ship loading capacities. And the elastic deformation of the wharf structure indeed absorbs considerable partial of the impact energy effectively, with about 30 % for conditions in this study, leading to lower impact forces acted on the wharf structure. Moreover, the maximum pile top displacement of the wharf structure is also smaller than that reported in the existing literature in the same load condition, indicating that considering the structural flexibility in the design of this new type of wharf structure is more in line with reality, and it is more reasonable and economical as well.

Three-dimensional numerical simulation and theoretical model of a hollow droplet impacting on a solid surface

The phenomenon of a hollow droplet impacting on a solid surface is widely found in various fields. The dynamic characteristics of hollow diesel droplets impacting on a solid surface are studied by combining numerical simulation and theoretical analysis. The dynamic contact angle model presented in this paper couples the advantages of existing dynamic contact angle models for simulating both the spreading and retracting stages. It also considers the continuous variation of the contact angle during the maximum spreading state. Compared to existing models, the maximum error has been reduced from 14.9% to 4.6%. The effects of impact velocity, impact angle, and volume ratio of a hollow droplet on the spreading and jetting characteristics are investigated by three-dimensional numerical simulations. It is found that air entrainment occurred in the counter-jet, and the presence of the impact angle increased the asymmetry of the counter-jet and spreading liquid film, promoting fingerlike splashing at the front liquid film. Based on energy conservation law, the theoretical prediction models of the maximum spreading coefficient of the hollow droplet impacting on the surface and the velocity of the counter-jet at the maximum spreading state are established using the multi-regional modeling method and the energy distribution principle. Compared with existing hollow droplet theoretical models, the proposed theoretical models exhibit a more concise expression, higher accuracy, and wider applicability range.

A Novel Numerical Model Considering Unsaturated Soil Properties and Computational Study on Heat and Moisture Transfer Characteristics of Helix Ground Heat Exchanger

Abstract A novel three-dimensional numerical simulation model for the helix ground heat exchanger was proposed in this paper, which takes into account unsaturated soil properties. This model is more suitable for real working conditions. To validate its accuracy, a miniature model heat transfer experimental platform was constructed. Additionally, the study conducted simulation research using three types of soil with significantly different thermal and moisture characteristics. Moreover, the comprehensive thermal conductivity and water diffusion coefficient of these three soil types were determined by relevant literature and experimental tests. The aim was to comprehensively explore the impact of different soil types on the heat and mass transfer of the helix ground heat exchanger. The results indicate that the numerical model developed in this paper accurately captures the heat and mass transfer characteristics of the helix ground heat exchanger to a certain extent. Increasing the comprehensive thermal conductivity and water diffusion coefficient of the soil can significantly enhance the heat exchange capacity of the exchanger. For instance, under sandy loam conditions, the heat exchange capacity is approximately 20.73% higher compared to clay loam conditions. The study also identifies two distinct areas around the helix ground heat exchanger: the severe change region and the soft change region. In the severe change region, there is a notable decrease in soil water content near the exchanger, which inevitably weakens the thermal conductivity of the soil. It is advised to minimize this effect through measures like active water spraying.

Numerical study on dynamic flow of flexible extension nozzle in rocket motors

The use of extension nozzles in rocket propulsion systems is one of the effective methods to increase the geometric expansion ratio and thrust of the nozzle. As a new type of extension nozzle, the flexible extension nozzle can achieve continuous changes in nozzle expansion ratio. To explore the characteristics of the flow field structure at the “bulge” structure and the step structure in the actual configuration of the flexible extension nozzle, and the impact on the performance of the nozzle, a three-dimensional numerical simulation model of the flexible extension nozzle was first established to study the flow field at the “bulge” structure, and then a two-dimensional unsteady numerical simulation model was established by using the coupling technology of dynamic grid and overlapping grid to study the flow field at the step structure. The results show that during the unfolding of the nozzle surface, a complex flow structure of “expansion fan-mixing layer-shock-vortex” were formed in the step area at the junction of the fixed section and the moving extension section. The specific impulse loss of the 3D model is larger than that of the 2D model due to the consideration of the “bulge” structure. The flow loss of the “bulge” structure and the step structure to the nozzle is 0.73% and 0.65% respectively.

Study on influence of ink material properties on deposited filaments in direct ink writing based on numerical simulations

Direct ink writing (DIW) is one of the most popular additive manufacturing (AM) techniques and deposited filament (DF) is one of the basic and critical elements in the process. Ink material properties have significant influence on DIW. However, influence of ink material properties on DF have not been fully studied. To address this barrier, in this paper, a three-dimensional (3D) numerical simulation model for DF was established through volume of fluid (VOF) method. And effect of ink material properties including viscosity properties and static contact angle on DF were studied based on the established numerical simulation model.

Numerical Simulations for in-Plane Distribution of Platinum Degradation in Dynamic Operating Conditions of Polymer Electrolyte Membrane Fuel Cells

Predicting degradation of polymer electrolyte membrane fuel cells (PEMFCs) is an important issue from the viewpoint of durability and cost. In fact, in technical roadmaps regarding fuel cell of each country, high targets of durability and performance are set for transport applications especially for heavy duty vehicles. One of important degradation process takes place in catalyst layer. PEMFC catalysts are typically platinum or platinum alloys and consist of nanoparticles to increase the electrochemically active surface area (ECSA). However, these particles are not stable in dynamic operating conditions of the transport applications. A typical degradation mechanism of the catalyst is the electrochemical Ostwald ripening mechanism, and it is known that the platinum particle size distribution shifts to larger particle diameter, resulting in lower ECSA and lower performance. Therefore, predicting platinum catalyst degradation is important to enhance durability of the products.Various numerical models for catalyst degradation of PEMFC have been proposed and used to explore degradation mechanisms. Many of these are zero or one-dimensional models, but factors that affect catalyst degradation, such as temperature, potential, and humidity, have non-uniform distributions in the active area of large-size (several hundred cm2) cells. Furthermore, these factors change unsteadily due to the dynamic operating conditions. In order to predict the degradation of cells, it is necessary to analyze the dynamic behavior of large-area cells, but there are few spatially resolved catalyst degradation predictions [1].In this analysis, transient analysis of a large-area cell for a dynamic operating conditions is performed to predict in-plane distribution of catalyst degradation. Furthermore, we will analyze changes in the power generation performance of the cells when these degradations progress. A three-dimensional numerical simulation model based on our original methodology [2] was used as the performance prediction model for the PEMFC. Catalyst degradation considers the mechanisms of platinum dissolution, oxidation, and platinum oxide dissolution [3]. The in-plane distribution of platinum degradation is predicted from the time-series results of in-plane distributions of temperature, potential, humidity, etc., obtained by the performance prediction model. The performance of the PEMFC at the time of progressive degradation is analyzed by reflecting the effect of ECSA decrease due to platinum degradation in the performance prediction model. Although this method considers only a part of the catalyst degradation process, a path is presented to analyze the distribution of catalyst degradation under dynamic operating conditions in large-area cells.

Stress–Structural Failure of a 610 m Crushing Station Left-Side Tunnel Section in Jinchuan II Mine: A Numerical Simulation Study

To address the stress–structural failure phenomenon that can be induced by the excavation of a left-side tunnel section of a 610 m crushing station, an unmanned aerial vehicle was used in this study to collect the geological conditions and rock mass information of the working face, and important geometric information such as the attitude and spacing of rock mass were extracted. Based on the identified attitude and spacing information, a three-dimensional rock mass structure and numerical simulation model of the 610 m crushing station left-side tunnel section were constructed using discrete element numerical simulation software (3DEC) (version 5.0). The results show that the surrounding rock instability of the left-side tunnel section of the 610 m crushing station is controlled by both the stress field in the contact zone between reddish-brown granite stratum and the gray-black-gray gneiss stratum. The cause of stress–structural failure is that the joint sets (JSet #2 and JSet #3) are most likely to form unfavorable blocks with the excavation surface due to unloading triggered by the excavation. Therefore, stress–structural failure disasters in jointed strata sections are one of the key issues for surrounding rock stability during crushing station excavation. It is suggested to adopt ‘optimized excavation parameters + combined support forms’ to systematically control stress–structural failure after unloading due to the excavation from three levels: surface, shallow, and deep. The stress–structural failure mechanism of deep rock mass is generally applicable to a large extent, so the results of this research have reference value for engineering projects facing similar problems around the world.

Study on the Fracture Resistance of Mixed Fiber Concrete Lining in a Reverse Fault Tunnel

With the increasing complexity of engineering environments in tunnel construction, some projects are located in areas with adverse geological conditions, including areas prone to fault movements and other geological hazards. Fiber-reinforced concrete can significantly enhance structural performance in such challenging conditions. Currently, the application of high-performance steel-polypropylene fiber in tunnel linings and its anti-fault performance are quite limited. Therefore, this paper focuses on studying the application of steel-polypropylene mixed fiber-reinforced concrete in tunnel lining under reverse fault movements. In this paper, the constitutive relationship of mixed fiber-reinforced concrete is modified based on literature data. Utilizing the Najar formula, fiber-related variables were designed, and a three-dimensional numerical simulation model of a reverse fault tunnel was established. By designing various parameter combination cases, the structural response of tunnel linings was calculated and studied. then the influence patterns of mixed fiber parameters on the anti-fault performance of tunnel linings are summarized, the relationships between main variables are explored, and a reasonable value range for the two fibers is determined, which can provide guidance for practical engineering.

Numerical Analysis of Concrete Deep Beams Reinforced with Glass Fiber-Reinforced Polymer Bars

This research aimed to generate data through a verified numerical model. The data were subsequently used to introduce a simplified analytical expression for the prediction of the shear strength of concrete deep beams reinforced with glass fiber-reinforced polymer (GFRP) reinforcing bars. A three-dimensional (3D) numerical simulation model for a large-scale GFRP-reinforced concrete deep beam (300 × 1200 × 5000 mm) was developed and validated against published experimental data. A parametric study was then conducted to examine the effects of key variables on the behavior and shear strength of GFRP-reinforced concrete deep beams. Eighteen 3D numerical models were developed to study the interaction between the concrete compressive strength (f’c), the shear span-to-depth ratio (a/h), the spacing between web reinforcement (s), and the shear strength. The a/h value was either 1.0 or 1.5. The values of f’c were 28, 37, and 50 MPa. The spacings between the web reinforcement, if present, were 100 and 200 mm. The results of the parametric study indicated that the shear strength of deep beam models increased almost linearly with an increase in f’c and a decrease in the stirrup spacing irrespective of the value of a/h. The strength reduction caused by increasing a/h was more pronounced for the beam models with the lower f’c and greater stirrup spacing. The simplified analytical expression introduced in the present study provided a reasonable prediction for the shear strength of GFRP-reinforced concrete deep beams.

A data-driven approach to the strength evaluation of airfield rigid pavement using in situ instrumentation data

The pavement strength evaluation plays a vital role in the airfield operation and management. Traditionally, the evaluation has relied on the Heavy Weight Deflectometer (HWD) test. This method encounters challenges, including interruptions in airfield operations, limited coverage of inspection locations, extensive time required for data collection and analysis. This paper introduces a methodology for evaluating the structural strength of airfield rigid pavement using instrumentation data, aiming to enhance both the efficiency and accuracy of such evaluations. Strain responses, collected using the instrumentation system at Chengdu Tianfu International Airport under HWD loading, are extensively analyzed. A three-dimensional numerical simulation model encompassing nine slabs was formulated, leveraging finite element analysis to replicate pavement working conditions that were not covered by the instrumentation samples. The merging of the instrumentation and simulation samples resulted in a comprehensive database for diverse pavement working conditions. This facilitated the establishment of a data-driven framework for the fusion of mechanical models. From this database, a neural network mapping model was developed to correlate the instrumentation data with the pavement slab modulus and subgrade reaction modulus. These correlations were subsequently employed for the calculation of the pavement classification number (PCN). The primary advantages of the proposed method include real-time monitoring and evaluation of airfield rigid pavement strength without interference to airfield operations. The developed method has been deployed at seven hub airports in China, encompassing Shanghai Pudong International Airport (PVG), Beijing Capital International Airport (PEK), and Chengdu Tianfu International Airport (TFU), etc.

Numerical analysis of the effect of energy distribution on weld width during oscillating laser welding of aluminum alloy

The weld morphology of aluminum alloy oscillating laser welding has an important influence on the quality of welded joints. To understand the formation process of the weld morphology, the three-dimensional numerical simulation model and energy distribution model for circular shaped oscillating laser welding of 6061 aluminum alloy are developed in this paper to analyze the characteristics of weld morphology and the effect of the energy distribution on the weld width. The cross section of the weld and the energy distribution on the processing surface are obtained under the conditions of different oscillation frequencies. It is found that the left width of the weld is larger than the right width of the weld and the energy density on the left side of the weld is more concentrated than that on the right side of the weld. With the oscillation frequency increases, the weld width and peak of energy density decrease. Furthermore, the formation mechanism of the difference in weld width is revealed based on the energy distribution law of the oscillating laser welding process, which is of great significance for improving the quality of aluminum alloy oscillating laser welding.

A New Integrated Model for Simulating Adaptive Cycle Engine Performance Considering Variations in Tip Clearance

The low-fidelity simulation method cannot meet the requirements for predicting the performance of an adaptive cycle engine (ACE), especially when considering tip clearance variations in the compression and expansion systems. The tip clearances of the components of an ACE, such as the adaptive fan and turbine, vary drastically under different operating conditions. Though the tip clearance significantly impacts the engine’s performance, including its thrust and fuel consumption, variations in tip clearance are not considered in traditional ACE simulation models. This paper developed a new integrated model for predicting ACE performance, including multi-fidelity simulation models of the components and a newly developed, simplified model for predicting tip clearance. Specifically, the integrated model consists of a zero-dimensional (0D) engine performance simulation model, a three-dimensional (3D) adaptive fan numerical simulation model, a one-dimensional (1D) low-pressure-turbine (LPT) mean line model, and a multi-dimensional (MD) tip clearance prediction model. The integrated model solved the problem of considering the impact of tip clearance on an ACE and further improved the accuracy of thrust and fuel consumption predictions. Specifically, considering variations in the tip clearances under the design conditions, the differences in the thrust and specific fuel consumption (SFC) of the ACE are 1% and 0.3%, respectively. In conclusion, the integrated model provides a useful tool for evaluating the performance of an ACE while considering tip clearance variations.

The effect of water on coking and heat transfer inhomogeneity of supercritical aviation kerosene in a curved mini-channel

Water addition to aviation kerosene draws increasing attention in increasing heat sink and suppressing coke formation for regenerative cooling of scramjet engines. However, the effect of water on flow, reaction and heat transfer, particularly the thermal inhomogeneity in curved cooling channel is rarely reported. In the present study, the effect of water on coking and heat transfer inhomogeneity characteristics of China aviation kerosene, RP-3 studied in a uniformly heated curved mini-channel. A transient three-dimensional numerical simulation model with hybrid pyrolysis and steam reforming reactions of RP-3 is established and validated. The results show that there exists serious mass and thermal stratification in the curved mini-channel due to secondary flow and species diffusion. Specifically, RP-3 and water are diffused to concentrate at the bottom heating wall surface while coke deposition and light gaseous species, e.g., H2, CH4, CO are concentrated at the top heating wall surface. The thermal difference between the top and bottom heating walls is significant. Temperature and coke content of the top heating wall are much higher than those of the bottom heating wall. The gas film and coke deposition formed at the top heating wall surface lead to serious heat transfer deterioration. Therefore, the heat transfer coefficient at the bottom wall of the curved channel is much higher than that of the top wall. Water addition enhances secondary flow and thus exacerbates the coking and heat transfer inhomogeneity in the curved cooling channel. With water content increasing from 0 to 15 wt%, the secondary flow velocity increases by 288.2%, the conversion of RP-3 increases by 114.8% and the average coke content on the heating walls decreases by 40%. Meanwhile, the average heat transfer coefficient increases by 33.9% at the bottom heating wall but decreases by 18.0% at the top heating wall with the increase of water content.

Viscoelastic Numerical Simulation Study on the Co-Extrusion Process of Tri-Composite Tire Tread.

The co-extrusion process is widely used to produce composite tire treads with better performance. This study investigated the rubber co-extrusion flow process and quality influencing factors of tri-composite tire tread through numerical simulation and experimental methods. Here, RPA 2000 rubber processing analyzer was used to carry out rheological tests on the three rubber materials, the PTT viscoelastic constitutive model was fitted, and the fitting curves were in good agreement with the test data. Then, a three-dimensional viscoelastic numerical simulation model of the tri-composite tread co-extrusion process was established using Ansys Polyflow software. The parameter evolution technique is adopted in the model establishment to improve the calculation convergence. In addition, a global remeshing function is used to avoid excessive mesh deformation. A co-extrusion experiment is conducted to verify the model's accuracy using a tri-screw extruder. The extruded tread size error rate between the experiment and simulation is less than 6%. The variation of the velocity field, pressure field and shear rate field during extrusion is analyzed, and the formation mechanism of die swell is explained simultaneously. Finally, the influence of process parameters (inflow rate and traction speed) and die structure (convergence angle and thickness) on the extruded tire tread shape and quality was investigated, which can provide theoretical guidance for improving tread quality and production efficiency. Furthermore, the numerical simulation method can assist the design of the die plate in enhancing the efficiency of the die plate design.

Analysis of the Effect of Exhaust Configuration and Shape Parameters of Ventilation Windows on Microclimate in Round Arch Solar Greenhouse

The round-arch solar greenhouse (RASG) is widely used in the alpine and high latitude areas of China for its excellent performance. Common high temperature and high humidity environments have adverse effects on plants. It is extremely important to explore a reasonable and efficient ventilation system. A three-dimensional numerical simulation model of greenhouse ventilation considering crop canopy airflow disturbance was established. A robust statistical analysis to determine the validity of the model was calculated to thoroughly validate its overall performance. Microclimate distribution characteristics of nine kinds of exhaust configuration in greenhouse in summer were analyzed comparatively. It was determined that the highest ventilation efficiency could be achieved by adopting the combined configuration of rolling film at the south corner of the greenhouse and pivoting the window at the north side of the roof. In winter, the opening angle of ventilation window at the north side of the roof was less than 40° to ensure the rapid cooling of the interior of the greenhouse without the crops being affected by the cold environment. Through optimization analysis, the ventilation configuration with a deviation angle of 25° and a width of 900 mm is more reasonable (10 m span). The research results provide theoretical guidance for the design of the ventilation structure in RASG and further improve the sustainable development of the facility’s plant production.

Application of the Heat Penetration Distance in the Design of the Hole Spacing of Ground-Coupled Heat Pumps

Due to issues such as heat accumulation, the site area, and project investment, the reasonable determination of the hole spacing for heat exchangers has become one of the key design points of the ground-coupled heat pump system. Based on the definition of heat penetration in heat transfer and the research method of the inverse problem, a direct algorithm of the heat penetration distance in the aquifer was proposed using the analytical solution to the mathematical model for one-dimensional heat convection–conduction problems. Taking a vertical ground-coupled heat pump project in Hefei, Anhui Province, China, as an example, a three-dimensional hydro-thermal coupling numerical simulation model was established, and the influence radius during the refrigeration and heating periods under the action of a single borehole heat exchanger was determined. Comparing the heat penetration distance with the influence radius, the results show that the relative errors of the results obtained by the two methods are less than 10%, which verifies the rationality and effectiveness of the calculated penetration distance in the aquifer. At the end of the cooling or heating period, the heat penetration distance in the aquifer is calculated to be 7.59 m. Therefore, the proposed method is straightforward and efficient, which can provide a convenient approach to determining the reasonable hole spacing of the heat pump system.

STUDY ON ELIMINATING RETROGRADE CONDENSATE POLLUTION IN LOW-PERMEABILITY CONDENSATE GAS RESERVOIR

With the decrease of pressure during the production process of low-permeability condensate gas reservoirs, different degrees of retrograde condensate pollution appear in the area near the wellbore, resulting in a rapid decrease in the productivity of gas wells. Due to the poor physical properties of low-permeability condensate gas reservoirs, conventional single measures such as circulating gas injection and huff and puff gas injection cannot effectively relieve the condensate pollution in the near-wellbore area. For this reason, this paper explores the WH1 gas well in the W low-permeability condensate gas reservoir and conducts research on the retrograde of reverse condensate pollution in a single well. First, 12 groups of inside evaluation experiments for the decontamination of retrograde condensates are carried out using the core of the condensate gas reservoir W and 6 different agents. According to the experimental results, methanol + CO<sub>2</sub> huff and puff are selected as the optimal agent for decontamination by retrograde condensate. Secondly, by analyzing the physical properties of the W low-permeability condensate gas reservoir and the production performance parameters of the WH1 well, a three-dimensional numerical simulation model of the single well of the WH1 gas well is established, and the PVT phase state matching and production performance history matching are carried out for the model. Finally, the single-well numerical simulation model of the WH1 gas well, combined with the experimental results, is used to simulate the obturation effect of CO<sub>2</sub> injection after methanol injection. Among them, the change of reservoir physical properties in the near-wellbore area after methanol injection is simulated by the method of local grid refinement. The research shows that after the simulated well is injected with 20m3 methanol when the CO<sub>2</sub> injection volume in a single cycle is 120 × 10<sup>4</sup> m<sup>3</sup>, the injection rate is 4 × 10<sup>4</sup> m<sup>3</sup>/d, and the well soaking time is 11 days. The reservoir pollution removal effect is the best in the area near the wellbore. From the change of liquid saturation in the near-wellbore area, it can be concluded that the damage of retrograde condensate is relieved by about 87.1%. This study has formed a set of efficient technical means for removing reverse condensate pollution in W low-permeability condensate gas reservoirs. It provides some technical guidance for the formulation of a rational development mode of condensate gas reservoirs.