89 results about "Mine water inrush" patented technology

The present invention relates to the technical field of coal mine water inrush disaster prevention and control, and relates to an artificial intelligence-based method for identifying a water inrush point in a mine and parameters of a simulation model, comprising the following steps: step 1: establishing a numerical model on the basis of observation data, and determining prior information of parameters to be identified including position coordinates of a water inrush point; step 2: on the basis of the numerical model and the prior information of the parameters, generating a training sample dataset and a test sample dataset for an alternative model; step 3: constructing and training an alternative model neural network; step 4: testing the accuracy of the alternative model; and step 5: executing a simulated annealing algorithm to identify the position of the water inrush point and parameters of a simulation model. By using the method provided by the present invention, the problem in accurate positioning of water inrush points in underground coal mines can be solved, which is of great significance in carrying out scientific disaster management and rescue efforts in a timely manner.

The present disclosure provides an artificial intelligence-based method for enhancing mine safety by identifying and predicting locations of water inrush points in a mine, including the following steps: S1: constructing a numerical model to determine priori information of parameters to be recognized based on observation data, including coordinates of locations of water inrush points; S2: generating a training sample dataset and a test sample dataset of an alternative model based on the numerical model and the priori information of the parameters; S3: constructing and training a neural network of the alternative model; S4: testing an accuracy of the alternative model; and S5: performing a simulated annealing algorithm to identify the locations of water inrush points and simulation model parameters.

The invention provides a coal mine water inrush risk early warning method and system under multi-source information, and relates to the technical field of risk early warning, and the method comprises the steps: employing a multi-source information collection module to regularly collect geological structure data, hydrological data, microseismic signals and environment monitoring data in a coal mine operation area, and constructing a multi-source information database; performing data preprocessing to obtain a standard multi-source information database; carrying out multi-source data fusion, and constructing a water inrush risk comprehensive evaluation model in combination with a geological model, a hydrological model and a micro-seismic analysis model; analyzing the water inrush risk index in real time, and generating water inrush risk early warning information when the model output value is higher than a preset risk threshold value; and performing visual display of the water inrush risk early warning information through a visual interface. The technical problem that the prior art depends on a single data source and cannot comprehensively reflect complex condition changes in a coal mine operation area, so that accuracy of water inrush risk assessment is insufficient, and then early warning of the water inrush risk is missed is solved.

The invention discloses a mine water inflow prediction method and system based on adaptive graph convolution, and relates to the field of coal mine safety. Comprising the steps of making a clustering data set based on historical data; training a water burst scene classifier by using the clustering data set; using the trained water burst scene classifier to identify historical data to obtain different water burst types corresponding to mine water burst; based on different water inflow types and the clustering data set, respectively training to obtain a water inflow prediction model; identifying the new water inflow association index data by using the trained water inflow scene classifier to obtain a target water inflow type; and predicting the new water inflow data by using the target water inflow prediction model to obtain the water inflow. According to the method, a unique adaptive graph convolution formula and a hydrogeological attention mechanism are introduced, the prediction capability and scene adaptability of the prediction model are improved, working face water inflow prediction under different hydrogeological conditions is considered, and important technical support is expected to be brought to coal mine water disaster prevention and control.

The invention discloses a coal mine water inflow prediction method based on a combined model and dynamic collaborative weight distribution, and belongs to the technical field of coal mining, and the method comprises the following steps: 1, collecting and preprocessing time sequence historical data of mine water inflow, and defining the preprocessed data as an original time sequence data set; step 2, constructing an ARIMA model; step 3, constructing a GM (1, 1) model; and 4, constructing an ARIMA-GM combination model to predict the water inflow of the mine, introducing a time attenuation factor, an error sensitivity coefficient and an adjustment factor, and constructing a dynamic collaborative weight distribution mechanism to update and optimize the weight. According to the invention, the precision and stability of mine water inflow prediction can be improved.

The invention provides a metal mine water inrush channel multi-field cooperative monitoring and grading early warning method, and relates to the technical field of mine safety monitoring, and the method comprises the steps: laying a monitoring subsystem in a surrounding rock of a metal mine excavation working face, and collecting data; processing the data of each subsystem by adopting a feature extraction method to obtain each feature parameter; processing each characteristic parameter by adopting a cross-time scale parameter ratio method to obtain a mutation identification index and a mutation mark; according to each characteristic parameter, processing by adopting a multi-field collaborative discrimination strategy to obtain a current evolution stage; according to the abrupt change mark, the abrupt change identification index of each characteristic parameter and the current evolution stage, a grading early warning judgment mechanism is adopted for processing, and an early warning grade is obtained; and early warning information is displayed in real time in the monitoring center, and emergency response measures are pushed. According to the invention, quantitative evaluation and graded early warning of water inrush disasters can be realized, and a more accurate, timely and reliable monitoring and early warning means is provided for mine safety production.

The invention relates to a fault waterproof coal pillar design method. The method comprises the steps that geomechanical parameters of a coal seam are obtained; and analyzing various hydrogeological conditions influencing waterproof coal pillar design, and calculating waterproof coal pillar design parameters under different hydrogeological conditions by using a preset program according to the geomechanical parameters of the coal seam. According to the method, the waterproof coal pillar design parameters under different hydrogeological conditions are calculated by using the preset program, so that the calculation efficiency and accuracy are improved, and the possibility of human errors is reduced. By comprehensively considering the specific hydrogeological conditions of the coal seam area, the design parameters of the waterproof coal pillar can be calculated more accurately, and potential safety hazards caused by inaccurate estimation can be reduced. By means of the accurate waterproof coal pillar design, water in a water-bearing layer or a water guiding fault can be effectively prevented from rushing into the coal mine working face, the risk of safety accidents such as mine water inrush is greatly reduced, and the safety of coal mine production is guaranteed.

The invention discloses an ISCSO-KELM-based mine water inrush source accurate identification method and system, relates to the technical field of coal mine safety, and takes water chemical indexes as input of a KELM model. On the basis of chaotic mapping initialization, a mutualism strategy and a Levy flight strategy are introduced. And finally, performing automatic optimization on two key parameters, namely a kernel function parameter and a regularization coefficient of the KELM by using an ISCSO algorithm, and establishing a discrimination model based on ISCSO-KELM. According to the improved sodat swarm optimization algorithm, chaotic mapping is introduced to improve the distribution diversity of population initialization, a mutualism strategy and a Levy flight strategy are introduced, information exchange between individuals and optimal individuals is enhanced, the carelessness of mining is expanded, and the optimization precision and speed of the algorithm are improved. According to the method, the problem of the suitability of parameter selection in the KELM model is solved, and the accuracy of mine water inrush source identification is improved.

The invention relates to a progressive composite early warning method for mine water inrush based on micro-seismic monitoring, which is characterized in that a high-precision micro-seismic monitoring system fully covering a top plate and a bottom plate can effectively and comprehensively collect full-seismic field information in real time, and can greatly improve the vertical positioning precision of a micro-seismic event; meanwhile, a comprehensive and rich micro-seismic data index library is established, a calculation method of a core data variation rate is provided, different early warning data core indexes and auxiliary indexes are matched for different water inrush types, and corresponding index early warning values are calculated; the development position and development degree of a potential water inrush channel are obtained through quantitative analysis of the damage degree of a floor water-resisting layer based on a micro-seismic monitoring system, and a four-level water inrush degree early warning level is formed; finally, the index early warning value and the channel early warning value are integrated, double early warning of the time progress and the space position is achieved, the corresponding early warning level is determined according to the floor water inrush composite early warning level table, progressive composite early warning is achieved, and safety production is guided to have a basis.

An intelligent discrimination method and apparatus for a mine water inrush source, a device, and a storage medium. The method comprises: acquiring a water chemical index of a water source sample to be discriminated (S1), wherein the water chemical index comprises a plurality of inorganic indexes and a plurality of organic indexes; and inputting the water chemical index into a preset water source discrimination model to obtain a water source type of said water source sample (S2). In addition to inorganic indexes for discrimination, organic indexes are added, so that the problem of being difficult to accurately discriminate, by means of inorganic water chemical indexes, water samples with similar component is solved, thereby improving the accuracy of water source type discrimination.

The invention aims to provide a coal mine water inrush body deep ex-situ dredging and restoring method and system, and belongs to the technical field of coal mine water disaster prevention and control. The system comprises a water inrush body recognition module, a drainage depressurization system, a closed pipeline collection system, a storage stratum screening and well design module, a high-pressure storage ectopic dredging system and a safety monitoring system. According to the method, the water inrush body is identified by finely evaluating the hydrogeological conditions, the optimal hydrogeological parameters are obtained by using the parameter inversion model and the particle swarm optimization, and drainage and pressure reduction are guided; a reservoir capacity grade dynamic evaluation system is established, a deep suitable stratum is screened, collected mine water is stored back to the deep part by using high-pressure equipment, and full-period safety monitoring is performed in combination with a multi-source data fusion early warning model. The strategic reserve of the mine water depth is achieved, the underground water ecology is effectively maintained, and the treatment cost and the safety risk are remarkably reduced.

The present invention discloses a mine water inrush disaster prevention and control evaluation method based on intelligent identification and early warning of fault water, which relates to the technical field of mine water inrush disaster prevention and control. The method includes: first installing the required system, then analyzing and selecting the main parameters, weighting each parameter by entropy weight method, and calculating the weight of each parameter; importing the weight of each parameter into the PSO-SVM model of the extended Toth model to form an extended Toth flow field model, namely the ETFM model, which is further extended to the coal mine floor water inrush characteristics, and defining the comprehensive water pressure field distribution P t Finally, the corresponding water inrush risk warning value is derived based on game theory. By introducing a multidimensional fusion model, optimization algorithms, real-time data acquisition, and intelligent control, this invention addresses technical issues inherent in traditional methods, such as single monitoring parameters, insufficient intelligence in the warning model, low system integration, and passive prevention and control measures.

The invention discloses a mine water inrush disaster prevention and control evaluation method based on fault water intelligent identification and early warning, and relates to the technical field of mine water inrush disaster prevention and control. The method comprises the steps that firstly, a needed system is installed, then main parameters are selected through analysis, weight calculation is conducted on all the parameters through an entropy weight method, and the weight of each parameter is obtained through calculation; importing the weight of each parameter into a PSO-SVM model of the extended Toth model to form an extended Toth flow field model, namely an ETFM model, further extending to coal mine floor water inrush characteristics, and defining comprehensive water pressure field distribution Pt; and finally, obtaining a corresponding water inrush risk early warning value according to the game theory. By introducing a multi-dimensional fusion model, an optimization algorithm, real-time data acquisition and intelligent control, the technical problems of single monitoring parameter, insufficient intelligence of an early warning model, low system integration level, passive prevention and control measures and the like in a traditional method are solved.

The present invention discloses a prediction method for coal mine water inrush based on a combined model and dynamic collaborative weight allocation, belonging to the technical field of coal mine exploitation, which comprises the following steps: Step 1, collect the historical time series data of the mine water inrush and perform preprocessing, and define the preprocessed data as the original time series data set; Step 2, construct an ARIMA model; Step 3, construct a GM(1,1) model; Step 4, construct an ARIMA-GM combined model for predicting the mine water inrush, and introduce a time decay factor, an error sensitivity coefficient and a regulation factor to construct a dynamic collaborative weight allocation mechanism for weight update and optimization. The present invention can improve the accuracy and stability of the prediction of the mine water inrush.

The invention discloses a mine water inrush prediction method, device, equipment, medium and product, and relates to the field of mine water disaster prediction.The method comprises the steps that to-be-predicted data of a mine is received; inputting to-be-predicted data into the mine water disaster prediction model, and outputting a prediction result of whether water inrush occurs in the mine; the mine water disaster prediction model is trained by the following steps: acquiring a plurality of groups of training samples and the influence weight of each influence factor in each group of training samples on water inrush; obtaining the score of each group of training samples according to the influence weight of each influence factor of each group of training samples; obtaining a water inrush average value and a water inrush variance of the water inrush sample; obtaining a training average value and a training variance of all training samples; when the water inrush average value, the training average value, the water inrush variance and the training variance meet preset conditions, all the training samples are determined as target training samples; and training the deep learning model according to the target training sample. The accuracy of the water inrush prediction result can be improved.

According to the mine water inrush identification method and device, the electronic equipment and the storage medium, the preprocessed mine video frame data serves as the input of the initial model, and on the premise that the background influence is eliminated, the distinguishing capacity of the water flow dynamic characteristics and the static background can be enhanced. Moreover, the initial model comprises a residual shrinkage layer and a convolution block attention layer, thereby enhancing the attention of the water flow features and the inhibition of background interference, and remarkably improving the performances in water flow edge detection and complex background segmentation. Besides, the mask of the intermediate video frame data is used as an actual mine water inrush label to carry out back propagation adjustment on the initial model to obtain a video segmentation model, and the identification capability of the dynamic characteristics of the water flow is further enhanced, so that the video segmentation model can timely and accurately execute mine water inrush identification in a mine changeable environment.

The invention discloses an intelligent identification and early warning method for a mine water inrush source based on the fusion of multiple data sources, and belongs to the technical field of mine water inrush source identification. The method specifically comprises: real-time collection of mine water inrush source data, including water pressure, flow, temperature, conductivity, pH value, chemical composition, mine sound wave and vibration signal, and preprocessing the collected mine water inrush source data, data fusion of the preprocessed mine water inrush source data, obtaining a comprehensive index after the fusion of the mine water inrush source data, establishing a mine water inrush source identification model, training the mine water inrush source identification model based on historical data of the mine water inrush source, using the trained model, according to the comprehensive index after the fusion of the mine water inrush source data, identifying the type of the mine water inrush source, and according to the identification result of the mine water inrush source identification model, combining the historical data of the mine water inrush source and the fused comprehensive index, performing trend analysis and early warning level determination.

This invention discloses an acid-resistant sealing grouting material suitable for the treatment of acidic mine water inrush, its preparation method, and its application. It belongs to the technical field of mine groundwater pollution prevention and control and mine water hazard management. The acid-resistant sealing grouting material, by weight, comprises: 8-12 parts nano-hydroxyapatite, 1.5-3 parts sodium alginate, 5-8 parts porous adsorbent material, 100 parts cement, 25-35 parts water glass, 3-5 parts quicklime, 0.5-1.0 parts retarder, and 50-65 parts water. The acid-resistant sealing grouting material of this invention can immobilize iron and manganese, exhibits strong acid resistance and good pressure resistance, and is suitable for grouting materials used in sealing goaf areas and fissures in closed mines.

An intelligent discrimination method and apparatus for a mine water inrush source, a device, and a storage medium. The method comprises: acquiring a water chemical index of a water source sample to be discriminated (S1), wherein the water chemical index comprises a plurality of inorganic indexes and a plurality of organic indexes; and inputting the water chemical index into a preset water source discrimination model to obtain a water source type of said water source sample (S2). In addition to inorganic indexes for discrimination, organic indexes are added, so that the problem of being difficult to accurately discriminate, by means of inorganic water chemical indexes, water samples with similar component is solved, thereby improving the accuracy of water source type discrimination.

The invention discloses a mine water inrush and sand inrush disaster early warning method and system based on tracing monitoring. The method comprises the steps that firstly, multi-source heterogeneous monitoring data in a mine potential hazard source area and an associated mine channel are collected in real time; 2, performing noise reduction and standardization processing on the multi-source heterogeneous monitoring data to generate a standardized feature data set; 3, inputting the standardized characteristic data set into a water inrush and sand inrush early warning model, and outputting a water inrush and sand inrush occurrence probability and disaster scale prediction result; fourthly, when the disaster scale prediction result or the water inrush and sand inrush occurrence probability reaches an early warning threshold value, early warning information is generated and sent; the system comprises a data acquisition module, a data transmission module and a data processing and early warning module, wherein the data acquisition module comprises an intelligent rock particle assembly, a multi-sensor integration module, a while-drilling test unit and a time domain reflection monitoring unit. Therefore, according to the design, early warning of mine water inrush and sand inrush disasters can be achieved.

The utility model provides a coal mine underground water inrush early warning and monitoring device, which comprises a detection cylinder, a fixed support and a monitoring host, a filter component and a flow guide component are arranged in the detection cylinder, the filter component divides the detection cylinder into a raw water area and a water filtering area which are sequentially arranged along the axial direction, and the flow guide component is arranged in the raw water area. The flow guide assembly sequentially penetrates through the raw water area and the water filtering area, a first water quality detection assembly and a second water quality detection assembly are arranged in the raw water area and the water filtering area respectively, the detection barrel is connected with the fixing support, and an alarm assembly and an image acquisition assembly are arranged on the fixing support. The monitoring host is in communication connection with the first water quality detection assembly, the second water quality detection assembly, the alarm assembly and the image acquisition assembly. The device is simple to operate, can provide a comprehensive and comprehensive data basis for coal mine water inrush danger judgment, and has higher accuracy and stability.

This invention belongs to the field of mine water control and carbon dioxide sequestration technology, and particularly relates to a layered negative carbon grouting method for preventing mine water inrush. The steps are as follows: S1, injecting a first-order grout to form a first-order grouting area; S2, injecting a first-order carbon dioxide to displace the first-order grout, forming a first-order carbon injection area, where the first-order carbon dioxide reacts with the first-order grout to form a first-order stone layer; S3, injecting a second-order grout, which displaces unreacted first-order carbon dioxide to form a second-order grouting area; S4, injecting a second-order carbon dioxide, where the second-order grout, unreacted first-order carbon dioxide, and second-order carbon dioxide fully react to form a second-order stone layer; repeating S1-S4 until the parameters required for preventing mine water inrush are met, completing the grouting process. This invention simultaneously achieves mine water inrush prevention and carbon dioxide sequestration.

The invention relates to a method for resolving a water inrush flow path of water inflow of a mine water inrush point changing along with time, a water inrush process is divided into a plurality of time periods by taking one hour as a unit, the water inflow at the beginning moment of each time period serves as the water inflow of each time period, the time-varying water inrush problem is converted into the quasi-time constant water inrush problem, and the time-varying water inrush flow path of the mine water inrush point is calculated according to the time-varying water inrush flow path. Establishing a corresponding relation between the quasi time and the actual time; calculating to obtain a water inrush path by adopting a constant water inrush mine laneway water inrush path calculation method; and converting each moment in the water inrush path into actual time to obtain the water inrush path under the actual time. The mine water inrush path determined by the method is closer to the actual water inrush flow spreading condition, and the resolving result is beneficial to providing a theoretical basis for the escape of miners and the design of a ground emergency rescue scheme.

The application discloses a mine water inrush accident rescue training system, which comprises a water inrush training module, wherein the water inrush training module comprises a training device, the training device comprises a wall body and a water outlet mechanism arranged above the wall body, the water outlet mechanism has a first water outlet position and a second water outlet position in the vertical direction, at the first water outlet position, the water outlet mechanism flows out in a dripping state, and at the second water outlet position, the water outlet mechanism flows out in a straight flow state. The mine water inrush accident rescue training system can simulate the precursors of the early stage of water inrush on site, so that the training personnel can personally experience the state of the early stage of water inrush in the mine, then the water outlet mechanism moves to the second water outlet position, the water outlet state is in a straight flow state and flows downward, the training personnel can personally experience the state of water flow in different water inrush periods, and the adaptability of the training personnel to the water flow state in different periods is improved.

The present application relates to water gushing treatment equipment technical field, specifically for a kind of mine water gushing environmental protection treatment processing equipment and treatment method, comprising: stirring mechanism is rotationally connected with processing equipment main body, the processing equipment main body is provided with guiding mechanism;Filtering mechanism is provided with filter plate;Beneficial effect is: filter plate filters water and intercepts the water in water, and the water filtered after the settlement is discharged through water outlet pipe, so that screw rod is rotated along the threaded hole of the moving block, so that the moving block slides along the connecting box, so that the scraper follows sliding, the accumulated sediment can be pushed out through the drain groove of the filtering mechanism by the scraper, and is discharged through the drain outlet, by the above mutual cooperation, when the device is treated to mine water gushing, without waiting for the settlement in mine water gushing to settle down before water is discharged, improve work efficiency, and the cleaning rod on the device can clean filter plate, reduce the risk of filter plate blockage.

The invention belongs to the technical field of water inrush source identification, and particularly relates to a CNN-LSTM-Attention-based multi-source data fusion water inrush source identification system, which comprises a CNN module, an LSTM module, an attention mechanism module, a CNN-LSTM-Attention model construction module and a model evaluation index module, and is characterized in that a CNN-LSTM-Attention model can effectively fuse static characteristics and dynamic evolution laws of hydrochemical data, and the model evaluation index module is used for evaluating the dynamic evolution laws of the hydrochemical data. The precision and robustness of water source identification are obviously improved; the introduction of the attention mechanism enhances the interpretability of the model, so that the model can focus on key discrimination indexes like domain experts, and the transparency and reliability of decision making are improved; the model provides a new technical path for intelligent identification of a water inrush source of a coal mine, and promotes the normal form transformation of water disaster prevention and control from'experience-driven 'to'data-driven'.

The invention relates to the technical field of mine monitoring, in particular to a multi-parameter mine hydrological automatic monitoring and alarming system, which comprises the following steps of: calculating a hydrological parameter of each monitoring point of a mine based on historical hydrological time sequence data and real-time hydrological parameters of each monitoring point of the mine; generating a multi-parameter prediction sequence of each monitoring point in a future preset time period through a space-time prediction model; inputting into a dynamic digital twinborn model for calculation, and constructing spatial amplification response of prediction uncertainty in a roadway, a fault and a water-bearing structure based on internal change trend consistency and time sequence discrete characteristics of the multi-parameter prediction sequence; outputting a space-time distribution diagram of the overall water burst risk of the mine in a future preset time period; and automatically generating and executing an alarm instruction corresponding to the spatial position and the risk level of the high-risk area. According to the method, space cascade enhanced identification of uncertain risks is realized, and the risk amplification area is accurately delineated by performing grid coupling with the preset geologic structure sensitivity distribution diagram.

The utility model discloses a magnetically installed mine water inrush early warning device, and relates to the technical field of mine water inrush early warning. The humidity sensor comprises a positioning seat and a humidity sensor arranged at the front end of the positioning seat, and further comprises a connecting seat arranged in the middle of the rear end of the humidity sensor, and an adsorption magnetic block is arranged at the rear end of the connecting seat. According to the utility model, the mounting seat can be connected to the front end of the connecting seat by magnetically connecting the adsorption magnetic block with the metal sheet which can be magnetically connected with the adsorption magnetic block, and meanwhile, the adsorption magnetic block is limited from up, down, left and right directions by utilizing the magnetic clamping groove; furthermore, the humidity sensor for quickly and stably carrying out early warning on the mine water inrush sudden accident is magnetically mounted at the front end of the positioning seat; and the stabilizing sleeve is screwed and fixed outside the fixing sleeve through threaded connection, so that the purposes of further limiting and stabilizing the mounting seat and the connecting seat which are magnetically connected in the front-back direction and conveniently disassembling, repairing and replacing the early warning module can be achieved.

The invention provides an underground coal mine gushing water treatment device and method, and relates to the technical field of coal mine gushing water treatment.The underground coal mine gushing water treatment device comprises a staged purification assembly and a feeding assembly, the staged purification assembly comprises a reaction tank, and the reaction tank is provided with a dosing opening and used for purifying gushing water; the feeding assembly comprises a medicine storage tank, a movable disc and a motor, the medicine storage tank is provided with a medicine outlet, the movable disc is rotatably connected with the medicine storage tank and covers the medicine outlet, the movable disc is provided with a medicine feeding opening communicated with the medicine outlet, and the motor is connected with the movable disc. The dosing port is provided with a first position communicated with the dosing port and a second position disconnected from the dosing port, and the motor is in transmission connection with the movable disc so that the dosing port can be switched between the first position and the second position. According to the invention, the chemical reagent can be automatically put into the reaction tank in a time-sharing manner, the labor intensity of workers is reduced, the agglomeration phenomenon of the chemical reagent in gushing water is avoided, and the coal mine gushing water treatment efficiency can be ensured.

The invention provides a flowing water roadway rapid plugging method based on negative pressure monitoring and flow velocity feedback, and relates to the technical field of mine water inrush treatment, and the method comprises the following steps: S1, obtaining parameters of a to-be-treated roadway, and calculating the length of a water blocking plug according to the parameters; s2, two roadway penetrating holes are constructed in the roadway to be processed, a negative pressure environment is established through the first roadway penetrating hole, and an average flow velocity calculation model is established after the negative pressure is stable; s3, solving the average flow velocity calculation model, and determining an aggregate pouring regulation and control method of the initial water blocking section according to a solving result; s4, sand and gravel materials and fiber materials are poured through the other hole, and top sealing and water blocking plug forming are sequentially achieved while the length of the water blocking plug is increased; by means of the steps, the problems that in the prior art, blindness exists in the pouring process, the particle size selection basis is fuzzy, blocking stage judgment is lagged, roof contact is difficult, and roof sealing is not tight can be solved.