Pile foundation air pressure reverse circulation hole cleaning device and control method

Abstract

The present application relates to the pile foundation cleaning technical field, especially to a kind of pile foundation air pressure reverse circulation hole cleaning purification device and control method, device includes air pressure reverse circulation hole cleaning unit, mud purification circulation unit and control unit, control unit is configured as: the state parameter of real-time acquisition hole cleaning process;Current hole cleaning comprehensive efficiency value is calculated based on state parameter;Current hole cleaning comprehensive efficiency value is compared with preset efficiency threshold value, when current hole cleaning comprehensive efficiency value is lower than preset efficiency threshold value, multiple-dimensional operating parameter is obtained;Based on multiple-dimensional operating parameter, determine hole cleaning efficiency influence characteristic set through pre-constructed hole cleaning efficiency analysis model;According to hole cleaning efficiency influence characteristic set, generate equipment control parameter;According to equipment control parameter, air pressure reverse circulation hole cleaning unit and mud purification circulation unit are synergistically regulated.The intelligent sensing and synergistic regulation of hole cleaning process can be realized, the hole cleaning efficiency is improved and the hole quality is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pile foundation cleaning, and in particular to a pile foundation air pressure reverse circulation hole cleaning and purifying device and control method. BACKGROUND

[0002] In pile foundation engineering construction, the air pressure reverse circulation hole cleaning process generates negative pressure through compressed air to discharge the slurry containing sediment in the pile hole, and the slurry is treated by a purifying unit and then recycled to achieve the purpose of removing sediment at the bottom of the hole and maintaining the stability of the hole wall.

[0003] However, in actual construction process, the hole cleaning effect is largely dependent on the experience of the operator, who needs to manually adjust the operating state of the air compressor, slurry pump and other equipment according to limited parameters such as slurry sand content and sediment thickness. The existing method cannot accurately assess the hole cleaning efficiency in real time, cannot fully perceive the system operating state, and lacks multi-device collaborative optimization capability, resulting in low efficiency of the hole cleaning process and problems such as incomplete hole cleaning or excessive hole cleaning causing hole wall instability. SUMMARY

[0004] The present application provides a pile foundation air pressure reverse circulation hole cleaning and purifying device and control method that can realize intelligent perception and collaborative control of the hole cleaning process, improve the hole cleaning efficiency and guarantee the hole quality, and can effectively solve the problems in the background art.

[0005] To achieve the above purpose, in a first aspect, the present application provides a pile foundation air pressure reverse circulation hole cleaning and purifying device, which comprises an air pressure reverse circulation hole cleaning unit, a slurry purification and circulation unit and a control unit, and the control unit is configured to:

[0006] real-time acquisition of state parameters of the hole cleaning process;

[0007] calculating a current hole cleaning comprehensive efficiency value based on the state parameters;

[0008] comparing the current hole cleaning comprehensive efficiency value with a preset efficiency threshold value, and when the current hole cleaning comprehensive efficiency value is lower than the preset efficiency threshold value, acquiring multi-dimensional operating parameters;

[0009] determining a set of hole cleaning efficiency impact features through a pre-constructed hole cleaning efficiency analysis model based on the multi-dimensional operating parameters;

[0010] generating device control parameters according to the set of hole cleaning efficiency impact features;

[0011] collaboratively controlling the air pressure reverse circulation hole cleaning unit and the slurry purification and circulation unit according to the device control parameters.

[0012] Further, the air pressure reverse circulation hole cleaning unit comprises an air compressor for providing compressed air, an air pipe having one end communicated with the air compressor and the other end extended into the pile hole, and a guide pipe arranged in the pile hole and used for discharging the sediment and slurry mixture;

[0013] The air pipe is arranged inside the guide pipe, and an annular space is formed between the outer wall of the guide pipe and the inner wall of the pile hole; the hole cleaning unit further comprises a slurry supplement assembly communicated with the annular space to supplement slurry into the pile hole, and an elevation adjustment assembly for adjusting the distance between the sediment suction port at the bottom end of the guide pipe and the top surface of the sediment in the pile hole;

[0014] The air pipe delivers the compressed air into the guide pipe to form a slurry gas mixture with the slurry in the pile hole, and the difference in specific gravity between the slurry gas mixture and the slurry generates a negative pressure to drive the slurry carrying the sediment to flow reversely along the guide pipe and be discharged.

[0015] Further, the slurry purification and circulation unit comprises a desanding tank having a desilting device and a screen arranged inside, a slurry pump, and a cyclone separator;

[0016] The desilting device is connected to the sediment discharge end of the guide pipe and used for preliminarily separating the sediment from the discharged sediment and slurry mixture;

[0017] The slurry outlet end of the desilting device is communicated with the slurry inlet end of the cyclone separator through the slurry pump, and the cyclone separator is used for separating fine sand from the slurry;

[0018] The slurry return end of the cyclone separator is communicated with the annular space to form a slurry closed loop circulation channel.

[0019] Further, the state parameters include the sediment content of the slurry in the pile hole and the thickness of the sediment.

[0020] Further, the multi-dimensional operation parameters include the output pressure of the air compressor, the output flow of the air compressor, the outlet depth of the air pipe, the flow rate of the slurry gas mixture in the guide pipe, the delivery flow of the slurry pump, the backflow speed of the slurry, the pressure difference between the inlet and outlet of the cyclone separator, and the sediment content of the purified slurry.

[0021] Further, the set of hole cleaning efficiency influencing features includes at least one of a negative pressure deficiency feature index, a slurry sediment carrying capacity decline index, a cyclone separation efficiency decay index, and a hole wall stability risk index.

[0022] Further, the device regulation parameters include at least one of an air compressor power correction value, an air pipe outlet depth adjustment value, an elevation adjustment assembly lifting amount, a slurry pump rotation speed compensation value, and a cyclone separator working parameter optimization value.

[0023] Further, the calculation method of the current hole cleaning comprehensive efficiency value comprises:

[0024] Obtain the initial sand content, initial sediment thickness, current sand content, current sediment thickness, and cumulative cleaning time for the borehole cleaning operation;

[0025] Based on the initial sediment content, current sediment content, initial sediment thickness, and current sediment thickness, calculate the sediment content improvement rate and sediment thickness improvement rate respectively.

[0026] Based on the predetermined weighting coefficients for sand content and sediment, the improvement rate of sand content and the improvement rate of sediment thickness are weighted and calculated to obtain the weighted value of the improvement rate.

[0027] Calculate the time decay value based on the cumulative running time of the hole cleaning and the predetermined time decay coefficient;

[0028] The current overall efficiency value for hole clearing is calculated based on the weighted value of the improvement rate and the time decay value.

[0029] Furthermore, the sediment weighting coefficient is greater than the sand content weighting coefficient.

[0030] Secondly, the present invention also provides a control method for a pile foundation pneumatic reverse circulation cleaning and purification device, comprising:

[0031] Step S1: Real-time acquisition of status parameters during the cleaning process of the pile foundation air-pressure reverse circulation cleaning and purification device;

[0032] Step S2: Calculate the current overall efficiency value of hole cleaning based on the state parameters;

[0033] Step S3: Compare the current comprehensive cleaning efficiency value with the preset efficiency threshold. When the current comprehensive cleaning efficiency value is lower than the preset efficiency threshold, obtain the multi-dimensional operating parameters of the pile foundation air pressure reverse circulation cleaning and purification device.

[0034] Step S4: Based on the multidimensional operating parameters, determine the set of features affecting the cleaning efficiency through a pre-constructed cleaning efficiency analysis model;

[0035] Step S5: Generate equipment control parameters based on the set of features affecting the orifice cleaning efficiency;

[0036] Step S6: Adjust the pile foundation air pressure reverse circulation hole cleaning and purification device according to the equipment control parameters.

[0037] The technical solution of this invention can achieve the following technical effects: By acquiring state parameters in real time and calculating the comprehensive efficiency value of hole cleaning, isolated parameters such as mud sand content and sediment thickness judged subjectively by humans are transformed into quantifiable and comparable efficiency indicators, avoiding the subjectivity and limitations of human experience and solving the problem of difficulty in accurately assessing hole cleaning efficiency in real time; When the efficiency is not up to standard, by acquiring multi-dimensional operating parameters and combining them with the hole cleaning efficiency analysis model to locate the set of influencing features, instead of focusing on a single device or a single parameter, multi-dimensional state parameters such as the air compressor pressure and flow rate of the air compressor system, the mud pump flow rate and return velocity of the mud system, and the pressure difference of the hydrocyclone separator of the separation system are used, avoiding the problem of not being able to fully perceive the system operating status; Based on the influencing features, equipment control parameters are generated and air pressure and mud are coordinated and controlled, which can solve the problem of control response lag and avoid system imbalance caused by isolated adjustment of a certain device. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the structure of the pile foundation air-pressure reverse circulation hole cleaning and purification device in this invention;

[0039] Figure 2 This is a flowchart of the control method for the pile foundation air-pressure reverse circulation hole cleaning and purification device in this invention. Detailed Implementation

[0040] This application will now be described with reference to the accompanying drawings.

[0041] like Figure 1 As shown, the pile foundation air-pressure reverse circulation hole cleaning and purification device of the present invention includes an air-pressure reverse circulation hole cleaning unit, a mud purification and circulation unit, and a control unit.

[0042] The pneumatic reverse circulation hole cleaning unit includes an air compressor for providing compressed air, a duct with one end connected to the air compressor and the other end extending into the pile hole, and a conduit located in the pile hole for discharging a mixture of sediment and mud. The duct passes through the conduit, and an annular space is formed between the outer wall of the conduit and the inner wall of the pile hole. The hole cleaning unit also includes a slurry replenishing component connected to the annular space to replenish mud into the pile hole, and an elevation adjustment component for adjusting the distance between the bottom suction port of the conduit and the top surface of the sediment in the pile hole. The duct delivers compressed air into the conduit to mix with the mud in the pile hole to form a slurry-air mixture. The specific gravity difference between the slurry-air mixture and the mud generates negative pressure, driving the mud to carry the sediment and flow in the opposite direction along the conduit for discharge.

[0043] The mud purification and circulation unit includes a sand removal box equipped with a scraper and a screen, a mud pump, and a hydrocyclone separator. The inlet end of the sand removal box is connected to the outlet end of the conduit for preliminary separation of the discharged sediment and mud mixture. The outlet end of the sand removal box is connected to the inlet end of the hydrocyclone separator through the mud pump. The hydrocyclone separator is used to separate fine sand from the mud. The return end of the hydrocyclone separator is connected to the annular space to form a closed-loop mud circulation channel.

[0044] The control unit is configured to:

[0045] Real-time acquisition of status parameters during the borehole cleaning process; the status parameters include the sand content of the mud in the pile hole and the thickness of the sediment.

[0046] Calculate the current overall efficiency value of hole clearing based on the aforementioned state parameters;

[0047] The current comprehensive efficiency value of hole cleaning is compared with a preset efficiency threshold. When the current comprehensive efficiency value of hole cleaning is lower than the preset efficiency threshold, multi-dimensional operating parameters are obtained. The multi-dimensional operating parameters include air compressor output pressure, air compressor output flow rate, duct outlet depth, slurry-air mixture flow rate in the duct, mud pump delivery flow rate, mud return velocity, hydrocyclone inlet-outlet pressure difference, and sand content of the purified mud.

[0048] Based on the multidimensional operating parameters, a set of features affecting the orifice cleaning efficiency is determined by a pre-constructed orifice cleaning efficiency analysis model; the set of features affecting the orifice cleaning efficiency includes at least one of the following: negative pressure insufficiency index, mud slag carrying capacity decline index, cyclone separation efficiency decay index, and orifice wall stability risk index.

[0049] Based on the set of characteristics affecting the orifice cleaning efficiency, equipment control parameters are generated; the equipment control parameters include at least one of the following: air compressor power correction value, duct outlet depth adjustment value, elevation adjustment component lifting amount, mud pump speed compensation value, and hydrocyclone separator working parameter optimization value.

[0050] The pneumatic reverse circulation hole cleaning unit and the mud purification circulation unit are coordinated and controlled according to the equipment control parameters.

[0051] In this embodiment, by acquiring state parameters in real time and calculating the comprehensive borehole cleaning efficiency value, isolated parameters such as mud sand content and sediment thickness judged subjectively by humans are transformed into quantifiable and comparable efficiency indicators. This avoids the subjectivity and limitations of human experience and solves the problem of difficulty in accurately assessing borehole cleaning efficiency in real time. When the efficiency is not up to standard, by acquiring multi-dimensional operating parameters and combining them with the borehole cleaning efficiency analysis model, the set of influencing features is located. Instead of focusing on a single device or a single parameter, multi-dimensional state parameters such as the air compressor pressure and flow rate of the air compressor system, the mud pump flow rate and return velocity of the mud system, and the pressure difference of the hydrocyclone separator of the separation system are used to avoid the problem of not being able to fully perceive the system's operating status. Based on the influencing features, equipment control parameters are generated and air pressure and mud are controlled in a coordinated manner. This can solve the problem of control response lag and avoid system imbalance caused by adjusting a single device in isolation, such as adjusting only the air compressor pressure while ignoring the borehole wall disturbance caused by the mud return velocity.

[0052] More specifically, the linkage of efficiency threshold triggering, root cause diagnosis, and coordinated regulation achieves a dynamic balance between orifice cleaning efficiency and orifice wall stability. This method first uses the overall orifice cleaning efficiency as the trigger condition to avoid blind regulation when there is no efficiency problem. Then, the model locates the root cause affecting efficiency, such as insufficient negative pressure or the risk of orifice wall instability. If the root cause is the risk of orifice wall instability, the regulation will simultaneously reduce the air compressor pressure and increase the mud return velocity, rather than simply increasing the negative pressure. Finally, through coordinated regulation, the risk of orifice wall instability is avoided while improving efficiency. Multi-dimensional parameter collection covers the entire process of air pressure, mud, and separation, ensuring that the model can identify the chain relationship between parameters. For example, excessive pressure difference in the hydrocyclone separator leads to high sand content in the purified mud, which in turn reduces the mud's slag carrying capacity, ultimately resulting in low orifice cleaning efficiency. The model analysis directly locates the root cause of the hydrocyclone separation efficiency decay, rather than the surface low efficiency. The final generated regulation parameters simultaneously include the optimized values ​​of the hydrocyclone separator operating parameters and the mud pump speed compensation value, which not only solves the separation problem but also adjusts the mud's slag carrying capacity.

[0053] In a specific implementation, as an embodiment of the present invention, based on the composition structure of the annular space, conduit, and mud purification circulation in the purification device, the control unit obtains the mud sand content and sediment thickness respectively through sensor component integration, real-time data transmission, and deviation correction.

[0054] a. The method for real-time acquisition of mud sand content is as follows:

[0055] Sand content sensing components are integrated at two key nodes of the device. The sensing components and the control unit are connected via wired communication to avoid interference with wireless signals inside the hole.

[0056] The first sensing node is set at the slurry return port of the annular space, which is the connecting pipe between the slurry return end of the hydrocyclone separator and the annular space. A miniaturized infrared scattering sand content sensor is installed here. Since the mud at this location has just completed purification and circulation, it can reflect the basic sand content of the mud returning to the hole. The sensor collects sand content data at a preset frequency and transmits it to the control unit in real time.

[0057] The second sensing node is located in the middle of the guide tube. A miniature detection hole is set up at a position close to the slag suction port but without affecting the discharge of slag. A microwave transmission type sand content sensor is built in to directly detect the sand content of the mud carrying the slag at the bottom of the hole that is about to be discharged out of the hole. The sensor is kept flush with the inner wall of the guide tube to avoid obstructing the flow of the slurry-air mixture. The sensor collects sand content data at a preset frequency and transmits it to the control unit.

[0058] After receiving data from the two nodes, the control unit processes the data using a preset weighted algorithm. Since the data from the bottom of the hole is closer to the actual needs of hole cleaning, the weight of the sand content in the mud at the bottom of the hole is higher than that of the sand content in the backflow mud. Based on the weight, the sand content of the mud in the pile hole is calculated.

[0059] b. The method for obtaining the real-time thickness of sediment is as follows:

[0060] Taking advantage of the vertically movable elevation adjustment component in the air-compressed reverse circulation cleaning unit, an array of ultrasonic sensors is integrated at the bottom of the elevation adjustment component, i.e., on the side near the sludge suction port of the guide tube. The sensor's detection direction is vertically downward pointing to the bottom of the hole, and the detection angle covers a 120° range around the sludge suction port of the guide tube, thereby avoiding measurement deviations caused by uneven distribution of sediment at the bottom of the hole.

[0061] When the elevation adjustment component maintains the preset distance between the slag suction port and the top surface of the slag during the hole cleaning process, the ultrasonic sensor emits ultrasonic waves to the bottom of the hole at set time intervals, and calculates the distance between the sensor and the top surface of the slag at the bottom of the hole by the sound wave reflection time.

[0062] After receiving the distance data from the sensor, the control unit combines it with the current real-time elevation of the elevation adjustment component, which is obtained by the component's built-in displacement encoder. The control unit then calculates the thickness of the sediment at the bottom of the borehole using the formula that the sediment thickness equals the elevation at the bottom of the elevation adjustment component minus the distance between the sensor and the top surface of the sediment.

[0063] To further improve accuracy, the average value of five consecutive sediment thickness data collections is taken. If the deviation of any data from the average value exceeds 1 cm, the data from that collection is automatically discarded and the average value is recalculated to ensure the reliability of the final output sediment thickness data.

[0064] By integrating sensing components into the mud circulation link or elevation adjustment assembly, real-time data on mud sand content and sediment thickness are collected and processed to provide basic parameters for the control unit. The protection scope should not be limited to the specific sensor types, acquisition frequencies, or data processing algorithms mentioned above. From the perspective of sensing components, in addition to infrared scattering and microwave transmission sand content sensors, any sensing technology that can operate stably in a mud environment and output real-time sand content data, such as capacitive sand content sensors, falls within the protection scope of this method. From the perspective of installation location, except for the annular space slurry replenishment and return port and the middle of the guide pipe, any location in the circulation link where mud is discharged from the borehole and returned after purification, or the location associated with the elevation adjustment assembly that can detect sediment at the bottom of the borehole, can be used as a sensing node. From the perspective of data processing, in addition to averaging, any processing method that can eliminate abnormal data and improve parameter accuracy, such as deviation correction algorithms based on historical data, is also included in the protection scope of this method.

[0065] In this embodiment, the sensing components are all integrated into the existing annular space, conduit, and elevation adjustment components of the device, eliminating the need for additional independent detection structures. This does not obstruct the flow of the slurry-gas mixture or the discharge of sediment, nor does it increase equipment costs excessively. When obtaining the mud sand content, dual-node acquisition combined with weighted calculation takes into account the actual state of both the return mud and the bottom mud, avoiding the one-sidedness of single sampling. The sediment thickness is calculated by combining ultrasonic detection with elevation data, and outlier removal and average value processing are added to accurately identify changes in bottom sediment.

[0066] In a specific implementation, as an embodiment of the present invention, the control unit relies on the state parameters obtained in the aforementioned embodiments, and combines the initial parameters with time data acquisition to calculate the overall hole clearing efficiency value, as follows:

[0067] The basic parameters required for calculating the overall efficiency value of borehole cleaning are as follows: the initial sand content and initial sediment thickness at the start of the borehole cleaning operation, and the current sand content, current sediment thickness, and cumulative borehole cleaning operation time at the time of calculating the current overall efficiency value. The initial sand content and current sand content are both data obtained by the control unit through the sensing components in the mud circulation link within the pile hole. The initial sediment thickness and current sediment thickness are both data obtained by the control unit through the sediment detection component within the pile hole. The cumulative operation time is the total time obtained by the control unit through a built-in or external timing component, from the synchronous start of the air-pressure reverse circulation borehole cleaning unit and the mud purification circulation unit to the time of calculation.

[0068] A preset calculation coefficient is determined, which includes at least a sand content weight coefficient, a sediment weight coefficient, and a time decay coefficient. The sediment weight coefficient is greater than the sand content weight coefficient. A higher sediment weight coefficient meets the quality requirement of prioritizing sediment thickness in pile foundation construction and avoids the problem of insufficient sediment removal being masked by slight optimization of sand content.

[0069] The weighting coefficients for sand content and sediment are preset according to the geological conditions of the pile foundation; for example, for gravel mixed with fine sand geology, the value range of the sediment weighting coefficient is 0.55-0.65, and the value range of the sand content weighting coefficient is 0.35-0.45; for silty fine sand geology, the value range of the sediment weighting coefficient is 0.5-0.6, and the value range of the sand content weighting coefficient is 0.4-0.5.

[0070] The longer the hole cleaning operation takes, the greater the equipment energy consumption and component wear, and the actual efficiency will decrease over time. Therefore, a time decay term needs to be introduced. The time decay coefficient represents the efficiency decay rate per unit time. Based on the continuous operation decay characteristics of the air compressor of the air compressor reverse circulation hole cleaning unit and the mud pump of the mud purification circulation unit, if the efficiency decay of the air compressor and mud pump is 0.01-0.03 per hour during continuous operation, the time decay coefficient is converted to (0.01-0.03) / 60 in minutes.

[0071] The formula for calculating the overall efficiency value of hole cleaning is as follows:

[0072] ;

[0073] Where E represents the overall efficiency value of borehole cleaning; S0 represents the initial sand content; S t Indicates the current sediment content; ω S D represents the weighting coefficient for sand content; D0 represents the initial sediment thickness; D t Indicates the current sediment thickness; ω D λ represents the sediment weight coefficient; T represents the cumulative operating time; λ represents the time decay coefficient.

[0074] In the above calculation process, a multi-dimensional collaborative borehole cleaning efficiency evaluation system is constructed by combining the weighted contribution of sand content improvement, the weighted contribution of sediment thickness improvement, and the time decay term. The relative improvement rate eliminates the differences in initial sand content and initial sediment thickness of different pile foundations, allowing efficiency values ​​to be directly compared under different working conditions, avoiding evaluation deviations caused by different initial conditions. The weighting coefficient reflects the actual need for sediment thickness to have a more critical impact on the bearing capacity of pile foundations during construction, preventing the evaluation from being based on a single parameter and ignoring core indicators, and ensuring that the efficiency evaluation is aligned with the key points of the project. At the same time, the introduction of the time decay term can accurately identify hidden inefficiencies where parameters meet the standards but the time consumption is too long, thus comprehensively adapting to the borehole cleaning evaluation needs of different geological conditions and different pile types.

[0075] In specific implementation, as an embodiment of the present invention, the overall efficiency value of hole cleaning can reflect the overall effect of the operation. When the efficiency value is lower than the preset threshold, it indicates that there is an abnormality or the efficiency is not up to standard in the hole cleaning process. At this time, it is necessary to analyze the operating status to determine the factors affecting efficiency.

[0076] Specifically, the control unit presets a threshold value for the overall cleaning efficiency based on the pile foundation geological type and pile diameter. For geological formations with high sediment density and difficult removal, the threshold is set relatively high; for geological formations with easily flowing sediment and relatively easy removal, the threshold is set relatively low. Simultaneously, it dynamically fine-tunes the threshold according to the cleaning stage: in the initial cleaning stage, due to the large amount of sediment, the threshold is lowered by a certain percentage to avoid misjudgments of efficiency caused by excessive initial sediment; in the final cleaning stage, to ensure the final cleaning quality, the threshold is raised by a certain percentage. The threshold parameters are stored in the control unit's preset database and can be modified according to actual project requirements.

[0077] The control unit compares the calculated current hole clearing efficiency value with a preset threshold: if the current efficiency value is greater than or equal to the threshold, the hole clearing efficiency is determined to be up to standard, and the control unit maintains the current operating state and does not start multi-dimensional parameter acquisition; if the current efficiency value is less than the threshold, the hole clearing efficiency is determined to be down to standard, and a multi-dimensional parameter acquisition command is immediately generated.

[0078] The control unit collects parameters from the sensing or detection modules of each key component of the device according to instructions. The frequency of all parameter collection is consistent with the frequency of efficiency value calculation to ensure correspondence in the time dimension. The specific acquisition method is as follows:

[0079] The air compressor's output pressure and flow rate are directly read using its built-in pressure sensor and vortex flow sensor. Since the duct is installed inside the conduit, the duct outlet depth is synchronized with the conduit's suction port depth. The real-time elevation of the conduit is obtained through the displacement encoder of the elevation adjustment component, and the duct outlet depth is calculated. The flow velocity of the slurry-air mixture inside the conduit is detected by an ultrasonic flow sensor located near the suction port in the middle of the conduit. The slurry pump's delivery flow rate is obtained through an electromagnetic flow meter on the slurry pump outlet pipeline. The slurry return velocity is obtained through a turbine flow meter on the annular space slurry return pipeline. The pressure difference between the inlet and outlet of the cyclone separator is calculated using pressure sensors installed at both ends, obtaining the inlet-outlet pressure difference of the cyclone separator. The sand content of the purified slurry is obtained through a capacitive sand content sensor near the annular space connection at the slurry return end of the cyclone separator. The above parameter acquisition uses a synchronous triggering mechanism to ensure that all data are acquired at the same time, avoiding analysis errors caused by time differences.

[0080] In this embodiment, parameter acquisition is only initiated when the efficiency value is below a threshold, avoiding the waste of control unit computing power and sensor energy consumption caused by traditional full-process acquisition. Multi-dimensional parameters cover the entire system of air-pressure cleaning, mud circulation, and cyclone separation, comprehensively capturing the causes of low efficiency and avoiding the problems of missed or false judgments in traditional single-parameter acquisition. It should be noted that this embodiment triggers multi-dimensional parameter acquisition of key operating states of the air-pressure reverse circulation cleaning unit and mud purification circulation unit based on the comparison result of the overall cleaning efficiency value and the preset threshold. Its protection scope should not be limited to the specific threshold setting method, parameter acquisition frequency, sensor type, and parameter type mentioned above. From the perspective of threshold setting, regardless of the pile foundation geology... Whether setting thresholds based on pile diameter, borehole cleaning stage, or engineering quality requirements, as long as reasonable judgment standards are preset based on the borehole cleaning efficiency target, they all fall within the protection scope of this method. From the perspective of parameter acquisition, except for ultrasonic flow velocity sensors and electromagnetic flowmeters, all detection equipment that can accurately acquire corresponding operating parameters is applicable to this method. From the perspective of parameter types, in addition to the eight parameters listed, all operating parameters related to air-pressure reverse circulation borehole cleaning and mud purification circulation that affect borehole cleaning efficiency are included in the acquisition scope and are also protected by this method. From the perspective of triggering logic, regardless of how the frequency of comparing efficiency values ​​with thresholds is set, as long as whether the efficiency meets the standard is used as the condition for initiating multi-dimensional parameter acquisition, it conforms to the core concept of this method.

[0081] In specific implementation, as an embodiment of the present invention, the borehole cleaning efficiency analysis model includes a geologically adapted parameter association library and an index calculation engine, as detailed below:

[0082] Establish correlation rules between performance characteristics and multidimensional parameters according to the geological type of the pile foundation, and clarify the influence weight of each parameter on the characteristics; for example, the negative pressure deficiency characteristic index is related to the air compressor output pressure, air compressor output flow rate, slurry-air mixture velocity in the duct, and duct outlet depth, among which the slurry-air mixture velocity in the duct has the highest weight and the duct outlet depth has the lowest weight; the mud slag carrying capacity reduction index is related to the mud pump delivery flow rate, mud return velocity, and sand content of the purified mud, among which the sand content of the purified mud has the highest weight; the cyclone separation efficiency decay index is related to the inlet and outlet pressure difference of the cyclone separator and the sand content of the purified mud, among which the inlet and outlet pressure difference of the cyclone separator has a higher weight; the borehole wall stability risk index is related to the duct outlet depth, mud return velocity, and slurry-air mixture velocity in the duct, among which the mud return velocity has the highest weight.

[0083] Then, set standard threshold values ​​for different geological conditions. For example, for geological conditions with high sediment density, the air compressor output pressure threshold is set higher, and the slurry flow rate threshold is also increased accordingly. For geological conditions with easily flowing sediment, the mud return velocity threshold is set higher, and the hydrocyclone differential pressure threshold is relatively low. The index calculation engine has a built-in specific calculation logic, which calculates the index by combining the difference between the actual parameter value and the threshold with the corresponding weight. For example, the index range is set to 0-1, and 0.6 is used as the anomaly judgment threshold. An index lower than 0.6 indicates that there is a corresponding performance problem.

[0084] In practical implementation, after receiving the synchronously collected multi-dimensional operating parameters, the control unit first classifies them into air compressor system, mud system, and separation system. The air compressor system includes air compressor output pressure, air compressor output flow rate, duct outlet depth, and flow velocity of slurry-air mixture in the duct. The mud system includes mud pump delivery flow rate, mud return velocity, and sand content of purified mud. The separation system includes the pressure difference between the inlet and outlet of the hydrocyclone separator. Then, abnormal data is eliminated. If the deviation of a single parameter value from the average of the previous three values ​​exceeds the preset deviation, the average of the previous three values ​​is used to replace the abnormal value to ensure the stability of the input parameters.

[0085] Subsequently, the borehole cleaning efficiency analysis model calls the parameter association library of the corresponding geology and substitutes the pre-processed parameters into the index calculation of each efficiency characteristic. For example, for geology with high sediment density, when calculating the negative pressure deficiency characteristic index, the pre-processed air compressor output pressure, air compressor output flow rate, slurry-air mixture flow velocity in the duct, and duct outlet depth are combined with corresponding weights, and the contribution value of each parameter is obtained through preset calculation logic. Then, the negative pressure deficiency characteristic index is obtained by summing them up. Similarly, according to the corresponding association rules and calculation logic, the mud carrying capacity reduction index, the cyclone separation efficiency decay index, and the borehole wall stability risk index are calculated respectively.

[0086] Finally, the orifice cleaning efficiency analysis model filters out all efficiency features with indices below 0.6 to form a set of orifice cleaning efficiency influence features. For example, if the calculated negative pressure deficiency feature index and cyclone separation efficiency decay index are both below 0.6, while the mud carrying capacity decline index and orifice wall stability risk index are above 0.6, then the output will include a set containing the negative pressure deficiency feature index and the cyclone separation efficiency decay index.

[0087] In this embodiment, the borehole cleaning efficiency analysis model constructs parameter association rules and sets adaptation thresholds according to the geological type of the pile foundation, which can adapt to different geological conditions and meet the efficiency analysis needs of different scenarios such as high sediment density or easy flow. The control unit classifies multi-dimensional operating parameters by system and removes abnormal data, which can ensure the stability of the parameters input to the model. By calculating each efficiency characteristic index through multi-parameter weighting, it can simultaneously cover multiple dimensions such as air pressure, mud, separation system and borehole wall stability, and prevent the omission of potential efficiency risks. Finally, the set of feature components with indices below the abnormal threshold is selected, which can be used to indicate efficiency problems in the borehole cleaning process.

[0088] It should be noted that the pre-constructed orifice cleaning efficiency analysis model transforms multi-dimensional operating parameters into a set of characteristic indices reflecting orifice cleaning efficiency. Its protection scope should not be limited to the specific parameter association rules, index calculation logic, model structure, and types of efficiency characteristics mentioned above. From the perspective of parameter association, except for parameters such as air compressor output pressure and the flow rate of the slurry-air mixture in the duct, all operating parameters that reflect orifice cleaning efficiency, such as the speed of the sand box scraper, the negative pressure value in the duct, and the slurry supply flow rate of the slurry supply component, are included in the model association logic and fall within the protection scope of this method. From the perspective of model construction, except for the weighted summarization calculation logic, all algorithms that can achieve quantitative association between parameters and efficiency characteristics, such as machine learning algorithms and statistical regression algorithms based on historical orifice cleaning data, are applicable to this method as long as they can output a identifiable efficiency characteristic index. From the perspective of efficiency... In terms of the types of characteristics, apart from indices such as insufficient negative pressure, decreased mud carrying capacity, reduced cyclone separation efficiency, and borehole wall stability risk, all problem types related to borehole cleaning efficiency, such as insufficient mud replenishment, airflow disturbance, and equipment wear, are also included in the protection scope of this method after being transformed into a feature set through the model. From the perspective of geological adaptation, regardless of the geological preset parameter thresholds and weights of the model, such as clay layer, gravel layer, or moderately weathered rock layer, as long as it can adapt to the performance analysis requirements under the corresponding working conditions, it conforms to the core concept of this method.

[0089] In specific implementation, as an embodiment of the present invention, the generation of equipment control parameters needs to be based on the characteristics of performance impact, and specifically match the problem and the correspondence between equipment and parameters, transforming abstract characteristic indices into specific equipment control instructions;

[0090] First, it is necessary to construct a mapping library between performance characteristics and equipment parameters. The mapping library is constructed according to the pile foundation geological type. The target control equipment and parameter adjustment rules corresponding to each type of performance characteristic are determined. At the same time, the collaborative constraint relationship between equipment is marked. The specific implementation is as follows:

[0091] The negative pressure deficiency characteristic index corresponds to the air compressor and the air duct. The control parameters are the air compressor power correction value and the air duct outlet depth adjustment value. The rule is that for every unit the index is lower than the abnormal judgment threshold, the air compressor power is corrected and increased by a fixed proportion of the base power, and the air duct outlet depth is adjusted and raised by a fixed proportion of the current depth. The coordination constraint is that after the air duct is raised, it must be ensured that the distance between the duct suction port and the top surface of the sludge is not less than a specific value.

[0092] The mud carrying capacity decline index corresponds to the mud pump. The control parameter is the mud pump speed compensation value. The rule is that for every unit the index is lower than the abnormal judgment threshold, the mud pump speed is increased by a fixed proportion of the base speed. The collaborative constraint is that the mud return speed after the speed is increased must not be lower than the minimum mud replenishment speed of the current geology.

[0093] The cyclone separation efficiency decay index corresponds to the cyclone separator. The control parameters are the optimized values ​​of the cyclone separator's working parameters, including the inlet pressure and the split ratio. The rule is that for every unit the index falls below the abnormal judgment threshold, the cyclone separator's inlet pressure is optimized and increased by a fixed proportion of the benchmark pressure, and the split ratio is optimized and adjusted by a fixed proportion of the benchmark value. The coordinating constraint is that the increase in inlet pressure must not exceed the rated output pressure of the mud pump.

[0094] The orifice wall stability risk index corresponds to the duct and the elevation adjustment component. The control parameters are the duct outlet depth adjustment value and the elevation adjustment component lifting amount. The rule is that for every unit the index is lower than the abnormal judgment threshold, the duct outlet depth is adjusted and raised by a fixed proportion of the current depth, and the elevation adjustment component is further raised by a fixed proportion of the current lifting amount. The collaborative constraint is that after the component is raised, the duct suction port must still be able to cover the sludge distribution area.

[0095] Furthermore, the mapping library stores the baseline parameters of each device. The baseline parameters are preset according to the geological type. The baseline parameters of the devices are higher in geological geology with high sediment density than in geological geology with easy sediment flow.

[0096] In practical implementation, after receiving the set of features affecting the orifice cleaning efficiency, the control unit calls the corresponding geological correlation mapping library to filter out the target control equipment and parameters corresponding to each type of feature. For example, when the set includes the negative pressure insufficient feature index and the cyclone separation efficiency attenuation index, the target equipment is matched as air compressor, air duct, and cyclone separator, and the corresponding control parameters are air compressor power correction value, air duct outlet depth adjustment value, and cyclone separator working parameter optimization value.

[0097] Then, the control value is calculated according to the mapping library rules and the actual deviation value of the performance characteristic index; first, the degree of deviation between the performance characteristic index and the anomaly judgment threshold is determined, and then, based on the degree of deviation and the preset ratio, combined with the equipment reference parameters or current parameters, the specific value of each type of control parameter is calculated to ensure that the adjustment range of the value matches the severity of the performance problem.

[0098] Then, the collaborative constraint relationships in the mapping library are called to verify whether the calculated control parameters conflict. For example, the air compressor power correction value and the cyclone separator inlet pressure optimization value are verified. If the output pressure of the mud pump cannot meet the cyclone separator inlet pressure optimization requirements after the air compressor power is increased, the cyclone separator inlet pressure optimization value is reduced by a certain percentage, and the air compressor power correction value is adjusted accordingly to ensure that the two are compatible. The duct outlet depth adjustment value and the elevation adjustment component lifting amount are verified. If the duct suction port spacing is less than the constraint requirements after the duct is raised, the elevation adjustment component lifting amount is added to ensure that the constraint conditions are met.

[0099] Finally, the control parameters after collaborative verification are sorted by equipment to form a list of directly executable parameters, which is then transmitted in real time to the execution modules of the air pressure reverse circulation hole cleaning unit and the mud purification circulation unit.

[0100] In this embodiment, an association mapping library between performance characteristics and equipment parameters is constructed according to the geological type of the pile foundation. Preset equipment benchmark parameters, parameter adjustment rules, and inter-equipment coordination constraints under different geological conditions to achieve matching between the characteristics of borehole cleaning efficiency and the target control equipment and parameters. By combining the deviation between the performance characteristic index and the anomaly judgment threshold, a quantitative control value is calculated to avoid fuzzy operation guidance and enable the control parameters to be directly executed. Then, through collaborative verification, equipment parameter conflicts are checked to prevent system imbalance caused by the optimization of a single equipment.

[0101] like Figure 2 As shown, the present invention also provides a control method for a pile foundation pneumatic reverse circulation cleaning and purification device, comprising the following steps:

[0102] Step S1: Real-time acquisition of status parameters during the cleaning process of the pile foundation air-pressure reverse circulation cleaning and purification device;

[0103] Step S2: Calculate the current overall efficiency value of hole cleaning based on the state parameters;

[0104] Step S3: Compare the current comprehensive cleaning efficiency value with the preset efficiency threshold. When the current comprehensive cleaning efficiency value is lower than the preset efficiency threshold, obtain the multi-dimensional operating parameters of the pile foundation air pressure reverse circulation cleaning and purification device.

[0105] Step S4: Based on the multidimensional operating parameters, determine the set of features affecting the cleaning efficiency through a pre-constructed cleaning efficiency analysis model;

[0106] Step S5: Generate equipment control parameters based on the set of features affecting the orifice cleaning efficiency;

[0107] Step S6: Adjust the pile foundation air pressure reverse circulation hole cleaning and purification device according to the equipment control parameters.

[0108] The core logic of this control method embodiment is consistent with that of the previous embodiment of the pile foundation air pressure reverse circulation hole cleaning and purification device. Each step corresponds to the preset function of the control unit and the collaborative operation requirements of the execution unit in the device. The parameter types, model construction ideas and control targets involved are all matched with the device embodiment, realizing the same hole cleaning process control function as the control unit in the device embodiment. The specific implementation details and technical effects can be referred to the relevant records of the device embodiment, and will not be repeated here.

[0109] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A pneumatic reverse circulation hole cleaning and purification device for pile foundations, the device comprising a pneumatic reverse circulation hole cleaning unit, a mud purification and circulation unit, and a control unit, characterized in that, The air compressor reverse circulation hole cleaning unit includes an air compressor for providing compressed air, a duct with one end connected to the air compressor and the other end extending into the pile hole, and a conduit located in the pile hole for discharging a mixture of sediment and mud. The mud purification and circulation unit includes a sand removal box equipped with a scraper and screen, a mud pump, and a hydrocyclone separator. The control unit is configured to: Real-time acquisition of status parameters during the hole cleaning process; Calculate the current overall efficiency value of hole clearing based on the aforementioned state parameters; The current overall efficiency value of hole cleaning is compared with a preset efficiency threshold. When the current overall efficiency value of hole cleaning is lower than the preset efficiency threshold, multi-dimensional operating parameters are obtained. Based on the aforementioned multidimensional operating parameters, the set of features affecting the orifice cleaning efficiency is determined through a pre-constructed orifice cleaning efficiency analysis model. Based on the set of characteristics affecting the orifice cleaning efficiency, generate equipment control parameters; The pneumatic reverse circulation hole cleaning unit and the mud purification circulation unit are coordinated and controlled according to the equipment control parameters.

2. The pile foundation pneumatic reverse circulation hole cleaning and purification device according to claim 1, characterized in that, The air duct is installed inside the conduit, and an annular space is formed between the outer wall of the conduit and the inner wall of the pile hole; the air pressure reverse circulation cleaning unit also includes a slurry replenishing component that communicates with the annular space to replenish mud into the pile hole, and an elevation adjustment component for adjusting the distance between the bottom suction port of the conduit and the top surface of the sediment in the pile hole. The duct delivers compressed air into the conduit to mix with the mud in the pile hole to form a slurry-air mixture. The difference in specific gravity between the slurry-air mixture and the mud creates negative pressure, driving the mud to carry sediment and flow in the opposite direction along the conduit to be discharged.

3. The pile foundation pneumatic reverse circulation hole cleaning and purification device according to claim 2, characterized in that, The slag inlet of the sand removal box is connected to the slag outlet of the guide pipe, which is used to perform preliminary slag separation on the discharged slag and mud mixture. The discharge end of the sand removal box is connected to the inlet end of the hydrocyclone via the mud pump. The hydrocyclone is used to separate fine sand from the mud. The return end of the cyclone separator is connected to the annular space, forming a closed-loop circulation channel for mud.

4. The pile foundation pneumatic reverse circulation cleaning and purification device according to claim 3, characterized in that, The state parameters include the sand content of the mud in the pile hole and the thickness of the sediment.

5. The pile foundation pneumatic reverse circulation hole cleaning and purification device according to claim 4, characterized in that, The multi-dimensional operating parameters include air compressor output pressure, air compressor output flow rate, duct outlet depth, slurry-air mixture flow rate in the duct, mud pump delivery flow rate, mud return velocity, hydrocyclone inlet-outlet pressure difference, and sand content of the purified mud.

6. The pile foundation pneumatic reverse circulation hole cleaning and purification device according to claim 5, characterized in that, The set of characteristics affecting orifice cleaning efficiency includes at least one of the following: insufficient negative pressure characteristic index, mud carrying capacity reduction index, cyclone separation efficiency decay index, and orifice wall stability risk index.

7. The pile foundation pneumatic reverse circulation cleaning and purification device according to any one of claims 3-6, characterized in that, The equipment control parameters include at least one of the following: air compressor power correction value, duct outlet depth adjustment value, elevation adjustment component lifting amount, mud pump speed compensation value, and cyclone separator operating parameter optimization value.

8. The pile foundation pneumatic reverse circulation hole cleaning and purification device according to claim 7, characterized in that, The method for calculating the current overall efficiency value of hole cleaning includes: Obtain the initial sand content, initial sediment thickness, current sand content, current sediment thickness, and cumulative cleaning time for the borehole cleaning operation; Based on the initial sediment content, current sediment content, initial sediment thickness, and current sediment thickness, calculate the sediment content improvement rate and sediment thickness improvement rate respectively. Based on the predetermined weighting coefficients for sand content and sediment, the improvement rate of sand content and the improvement rate of sediment thickness are weighted and calculated to obtain the weighted value of the improvement rate. Calculate the time decay value based on the cumulative running time of the hole cleaning and the predetermined time decay coefficient; The current overall efficiency value for hole clearing is calculated based on the weighted value of the improvement rate and the time decay value.

9. The pile foundation pneumatic reverse circulation hole cleaning and purification device according to claim 8, characterized in that, The sediment weighting coefficient is greater than the sand content weighting coefficient.

10. A control method for a pile foundation pneumatic reverse circulation hole cleaning and purification device, characterized in that, include: Step S1: Real-time acquisition of status parameters during the cleaning process of the pile foundation air-pressure reverse circulation cleaning and purification device; Step S2: Calculate the current overall efficiency value of hole cleaning based on the state parameters; Step S3: Compare the current comprehensive cleaning efficiency value with the preset efficiency threshold. When the current comprehensive cleaning efficiency value is lower than the preset efficiency threshold, obtain the multi-dimensional operating parameters of the pile foundation air pressure reverse circulation cleaning and purification device. Step S4: Based on the multidimensional operating parameters, determine the set of features affecting the cleaning efficiency through a pre-constructed cleaning efficiency analysis model; Step S5: Generate equipment control parameters based on the set of features affecting the orifice cleaning efficiency; Step S6: Adjust the pile foundation air pressure reverse circulation hole cleaning and purification device according to the equipment control parameters.

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