Precise dust fall and explosion suppression control method for fully mechanized coal mining face and combined type electric ball valve

Abstract

The invention discloses a precise dust fall and explosion suppression control method for a fully mechanized coal mining face and a combined type electric ball valve, and relates to the technical field of automatic control. The method comprises the following steps: step 1, an intelligent control device synchronously issues a sampling trigger instruction to a dust monitoring assembly, a spray monitoring assembly and a vibration monitoring assembly; when the three sequences simultaneously meet the preset trigger conditions, generating a trigger event and a control starting point; 2, dividing service areas based on a valve group topology table, determining a target service area, and obtaining a candidate sequence from far to near according to the connection sequence of the valve group topology table and a combined manifold; and 3, the target valve position sequence and the action window are issued to a soft opening and closing curve generator so as to drive an execution motor speed reduction self-locking mechanism in each electric ball valve unit. According to the invention, through collaborative optimization in three aspects of monitoring, scheduling and execution, limitations in triggering accuracy, multi-valve coupling control and execution reliability in the prior art are broken through.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automatic control, and in particular to a precision dust suppression and explosion isolation control method for a fully mechanized coal mining face and a combined electric ball valve. BACKGROUND

[0002] At present, in a high-dust environment such as a fully mechanized coal mining face, the commonly used dust suppression and explosion prevention technologies mainly include two categories: one is dust suppression measures based on a spraying device, and the other is safety protection measures based on explosion isolation and suppression devices. The existing spraying systems mostly use a single high-pressure nozzle or spraying pipeline, and realize water spraying for dust suppression through manual or simple timing control. This method is simple in structure, but the spraying switch often lags behind, and it is difficult to respond in a timely manner to sudden dust surges. At the same time, the instability of the spraying water supply, the pressure fluctuations in the pipeline, and the clogging of the nozzle all lead to uneven spraying effects, thereby reducing the dust suppression efficiency. In a complex mining environment, the increase in dust concentration often has a precursor characteristic, and if effective spraying cannot be started accurately in a short time, the dust concentration will quickly accumulate, causing safety hazards.

[0003] In terms of explosion isolation and prevention, the existing technologies generally use a single-cavity explosion isolation shell or set up an independent explosion-proof pipeline structure, and usually assemble an electric control valve or a pressure relief device inside. Such devices are often large in size, complex in structure, and limited in installation location, and when multiple valves are arranged in parallel, they lack flexible regionalized control capabilities. Some improved schemes introduce a multi-valve combined spraying control system, but their scheduling strategies are mostly based on fixed sequences or simple logic, and lack fine scheduling of the coupling relationship between different pipe sections. When multiple valves act simultaneously, water hammer effect and pressure instability are likely to occur, resulting in weakened spraying effect and even pipe damage. In addition, during the execution of the spraying valve, due to the lack of a step-by-step valve position confirmation mechanism, when the valve is stuck or fails to reach the target opening, the existing system often cannot discover and handle it in a timely manner, which may cause spraying failure in a certain area and fail to switch to compensation in a timely manner. Furthermore, the existing monitoring means are mostly single-dimensionally detected for dust concentration, water pressure, or vibration, but lack coordinated judgment of multi-dimensional monitoring results. This easily causes false triggering or missed triggering when a single indicator fluctuates. For example, in the case of temporary decrease in the spraying water source pressure, the system may mistakenly judge that the spraying is ineffective and prematurely close the valve. For another example, under the interference of normal vibration generated by a coal mining machine, the monitoring threshold may be misjudged, and the real dust surge risk cannot be correctly identified. The limitations of a single data source directly restrict the precision control capability of the existing technologies. SUMMARY

[0004] In view of this, the present application provides a fully mechanized coal mining face precise dust fall explosion-proof control method and a combined electric ball valve.

[0005] The technical solutions adopted by the present application are as follows:

[0006] The fully mechanized coal mining face precise dust fall explosion-proof control method comprises:

[0007] Step 1: An intelligent control device synchronously issues a sampling trigger instruction to a dust monitoring component, a spray monitoring component and a vibration monitoring component; generates a dust representative sequence, a spray supply sequence and a vibration disturbance sequence according to collected data; generates a trigger event and a control starting point when the three sequences simultaneously satisfy preset trigger conditions;

[0008] Step 2: Based on a valve group topology table, a service area is divided and a target service area is determined, and a candidate sequence is obtained from far to near according to the connection order of a combined manifold according to the valve group topology table; a reverse coupling opening degree distribution algorithm is executed on the candidate sequence to generate a target valve position sequence and a corresponding action window;

[0009] Step 3: The target valve position sequence and the action window are issued to a soft opening and closing curve generator to drive the execution motor self-locking mechanism in each electric ball valve unit; the valve position is confirmed by a opening degree encoder, and if the target opening degree is not reached within the preset time limit, a safety rollback strategy is triggered.

[0010] Further, the samples obtained by sampling the dust monitoring component are grouped into a group according to the sampling order, and the median value is taken as the representative value of the group to obtain the dust representative sequence; the samples obtained by sampling the spray monitoring component are taken as the smaller value of the adjacent two samples to obtain the spray supply sequence; the samples obtained by sampling the vibration monitoring component are taken as the larger value of the adjacent two samples to obtain the vibration disturbance sequence; when three consecutive representative values in the dust representative sequence appear, and the spray supply sequence at the corresponding time indicates that the spray water source is available, and the vibration disturbance sequence at the adjacent time does not exceed the vibration shielding threshold set by the device, it is determined that a trigger event is generated, and the time of the trigger event is taken as the control starting point.

[0011] Further, in step 2, based on the valve group topology table, the fully mechanized coal mining face is divided into a plurality of service areas, and each electric ball valve unit is recorded with information such as its belonging service area, its connection order with the combined manifold and whether it shares a pipe section with an adjacent electric ball valve unit; the sampling position of the trigger event is taken as the center to determine the target service area, and the electric ball valve units belonging to the target service area are sorted from far to near according to the connection order with the combined manifold as the candidate sequence.

[0012] Furthermore, in step 2, the process of performing the reverse coupling opening allocation algorithm on the candidate sequence specifically includes: for the first electric ball valve unit in the candidate sequence, a three-segment action window is set, the three segments being the pre-rinsing segment, the core spray segment, and the final drainage segment; within the pre-rinsing segment, the electric ball valve unit is placed at the first preset opening, within the core spray segment at the second preset opening, and within the final drainage segment at the third preset opening; for subsequent electric ball valve units in the candidate sequence, it is checked whether they share a pipe segment with the electric ball valve units with allocated action windows; if they share a pipe segment, according to the non-overlapping rule, the start time of its pre-rinsing segment is set to after the previous electric ball valve unit completes the core spray segment and the spray supply sequence fluctuates within the threshold range set by the device within two consecutive samplings; if they do not share a pipe segment, pre-rinsing is allowed. The pre-flushing section overlaps with the closing drainage section of the previous electric ball valve unit. After the pre-flushing section of any electric ball valve unit begins, if the spray supply sequence fails to reach the preset value of spray water source arrival within two consecutive samplings, a bypass switching strategy is executed: the electric ball valve unit is immediately shut down and its core spray section and closing drainage section are skipped, and the start time of the pre-flushing section of the next electric ball valve unit in the candidate sequence is moved forward to the current time; electric ball valve units that do not belong to the target service area are assigned to a default shut-off subset and remain closed throughout the entire action window, but if the valve group topology table marks it as a pressure reducing bypass valve, a small opening is reserved only in the core spray section of the previous electric ball valve unit to buffer pressure; all pre-flushing sections, core spray sections, and closing drainage sections obtained through the above allocation are summarized to form the target valve position sequence and the action window.

[0013] Furthermore, step 3 specifically includes: the intelligent control device sends the target valve position sequence and action window to the soft-opening curve generator; the soft-opening curve generator performs gradual shaping on each opening command and drives the motor reduction and self-locking mechanism to execute; during the execution of each segment, the valve position is confirmed using the opening encoder: when the opening encoder feedback matches the target opening of the current segment, the next segment is entered; if the target opening is not reached within the confirmation time limit set by the device, the subsequent segments of the current electric ball valve unit are stopped and a safety retreat strategy is initiated: the electric ball valve unit is closed, the default shut-off subset remains unchanged, and the next electric ball valve unit in the target valve position sequence continues to be executed; after all action windows are completed, one dust suppression operation cycle ends.

[0014] Furthermore, the non-overlapping rule is as follows: when two electric ball valve units share a pipe section, the start time of the pre-rinse section of the later-opened electric ball valve unit must not be earlier than the end time of the core spray section of the previous electric ball valve unit and the time after the fluctuation of the spray supply sequence within two consecutive samplings is within the range of the device's set threshold.

[0015] Furthermore, the bypass switching strategy includes: if the spray supply sequence does not reach the preset value of the spray water source in the pre-flushing section of any electric ball valve unit, the electric ball valve unit is immediately shut down, and the remaining unexecuted sections are deleted from the target valve position sequence. At the same time, the start time of the pre-flushing section of the next electric ball valve unit in the candidate sequence is adjusted to the current time, and the relevant action timing of other electric ball valve units that share the pipe section with the shut-down electric ball valve unit is postponed.

[0016] A combined electric ball valve includes: an explosion-proof main housing, a combined manifold, several electric ball valve units, an intelligent control device, an inlet device, and a venting labyrinth. The explosion-proof main housing contains a first explosion-proof cavity and several independent explosion-proof secondary cavities. The first explosion-proof cavity houses the intelligent control device, and each of the independent explosion-proof secondary cavities corresponds to one of the electric ball valve units. The combined manifold is fixed to the explosion-proof main housing and communicates with the independent explosion-proof secondary cavities, distributing spray water to each electric ball valve unit. Each electric ball valve unit is mounted on the explosion-proof main housing via an independent explosion-proof secondary cavity, and its valve body is detachably and sealingly connected to the combined manifold. Each electric ball valve unit includes an actuator motor reduction and self-locking mechanism connected to the valve shaft of the electric ball valve unit, used to maintain the valve position when there is no continuous power supply. The intelligent control device is located within the first explosion-proof cavity and includes a control program, a bus interface device, a soft-start / close curve generator, and a log recording unit. The intelligent control device is configured to execute a precursor dust surge identification and reverse coupling opening degree allocation algorithm and output valve position commands. The soft-start / close curve generator is used to shape the valve position command curve. A dust monitoring component, a spray monitoring component, and a vibration monitoring component are all electrically connected to the intelligent control device. The dust monitoring component collects roadway dust information, the spray monitoring component collects spray flow information, and the vibration monitoring component senses equipment vibration disturbance information. An inlet device is used to seal and fix cables and pipes entering the explosion-proof main housing. A venting labyrinth is located on the emission path of the explosion-proof main housing to reduce the energy of the gas passage without damaging the explosion-proof surface.

[0017] Furthermore, the explosion-proof main housing is provided with an annular spacer and a replaceable seal between the first explosion-proof cavity and the independent explosion-proof secondary cavity, and the annular spacer forms a continuous explosion-proof mating surface.

[0018] Furthermore, the combined manifold adopts an integrally formed structure, the valve position interfaces of the combined manifold are symmetrically distributed, and guide ribs are provided between the combined manifold and the venting labyrinth to reduce backflow disturbance.

[0019] By adopting the above technical solutions, this invention achieves the following beneficial effects: First, through synchronous sampling and joint judgment of dust monitoring components, spray monitoring components, and vibration monitoring components, this invention can effectively identify precursors to dust surges, avoid misjudgments from a single data source, and ensure the accuracy of trigger event generation. This allows for timely initiation of spraying before rapid changes in dust concentration, improving the targeting and response speed of dust suppression. Second, this invention divides service areas and determines target service areas based on a valve group topology table. Through a reverse-coupled opening degree allocation algorithm, it achieves sequential and coupled scheduling of multiple electric ball valve units. This not only solves the water hammer effect and pressure instability problems caused by traditional multi-valve parallel control but also ensures a high degree of matching between the spray coverage area and the characteristics of the water supply pipeline, significantly improving spray uniformity and system stability. Simultaneously, this invention introduces a soft-opening / closing curve generator during the execution phase to gradually shape valve position commands. Combined with segmented valve position confirmation and a safety backoff strategy, this enables the electric ball valve unit to achieve precise action in different segments and possesses fault adaptive capability, effectively reducing the risks of valve jamming and spray interruption, and ensuring the continuity and safety of the spraying process. Furthermore, this combined electric ball valve employs a compact design with an explosion-proof main housing, an independent explosion-proof secondary chamber, and a combined manifold. Combined with a venting labyrinth and inlet device, it achieves a balance of safety, maintainability, and sealing, making it suitable for long-term stable operation in complex environments such as high-gas and high-dust conditions. In summary, this invention, through synergistic optimization of monitoring, scheduling, and execution, overcomes the limitations of existing technologies in trigger accuracy, multi-valve coupled control, and execution reliability, significantly improving dust suppression efficiency and explosion-proof safety levels in fully mechanized mining faces. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the process for the precise dust reduction and explosion-proof control method and the combined electric ball valve in the fully mechanized mining face according to an embodiment of the present invention. Detailed Implementation

[0021] All features disclosed in this specification, or steps in all methods or processes disclosed herein, may be combined in any way, except for mutually exclusive features and / or steps.

[0022] Any feature disclosed in this specification, unless otherwise stated, may be replaced by other equivalent or similar features. That is, unless otherwise stated, each feature is merely one example of a series of equivalent or similar features.

[0023] refer to Figure 1 A precise dust suppression and explosion-proof control method for fully mechanized mining faces, the method including:

[0024] Step 1: A smart control device synchronously sends sampling trigger commands to the dust monitoring component, spray monitoring component, and vibration monitoring component; generates a dust representative sequence, a spray supply sequence, and a vibration disturbance sequence based on the collected data; when the three sequences simultaneously meet the preset trigger conditions, a trigger event and a control start point are generated.

[0025] Specifically, the intelligent control device simultaneously sends sampling trigger commands to the dust monitoring component, spray monitoring component, and vibration monitoring component. To ensure the temporal consistency of the three types of data, the intelligent control device adds time stamps to the three types of returned samples and limits the maximum time deviation. For example, the maximum time deviation is limited to no more than 5 milliseconds; samples exceeding this limit are treated as overdue samples. This approach ensures that the three types of samples reflect the state of the same physical time period, avoiding deviations in subsequent judgments due to time misalignment. Sampling can be performed at fixed intervals, such as triggering every 20 milliseconds, continuously obtaining samples over a period of time. Fixed intervals facilitate subsequent grouping and comparison according to the sampling order, and also facilitate engineering implementation and test reproduction. Sampling can be performed at fixed intervals, such as triggering every 20 milliseconds, to continuously obtain samples over a period of time. Fixed intervals facilitate subsequent grouping and comparison based on the sampling order, and also simplify engineering implementation and test reproduction.

[0026] Following the sampling order, three adjacent samples from the dust monitoring component are grouped together, and the median value of this group is taken as the representative value, thus obtaining the dust representative sequence. The median value is used because dust monitoring components are prone to isolated maxima or minima before and after sudden increases in mine dust. The median value can filter out individual anomalies without increasing computational complexity, while remaining sensitive to the true upward trend. For example, with a 20-millisecond sampling interval, every three samples form a representative value group, corresponding to a time coverage of 60 milliseconds. In scenarios where dust increases rapidly in fully mechanized mining operations, representative values ​​within the 60-millisecond range can promptly follow the trend while resisting instantaneous fluctuations. Following the sampling order, the smaller value is taken from two adjacent samples from the spray monitoring component to obtain the spray supply sequence. The smaller value is taken because the arrival of the spray water source requires both water pressure and flow rate to meet requirements simultaneously, while short-term peaks commonly found in pipelines do not represent a stable and usable state. Using the smaller value as a criterion ensures that availability is only reflected when there is sufficient supply at two adjacent moments, thus avoiding misjudging instantaneous fluctuations as water source arrival. For example, a sample is generated every 20 milliseconds. Taking the smaller value from each pair of samples is equivalent to filtering out single spikes using a short window of 40 milliseconds, which improves the robustness of the discrimination without slowing down the response. Following the sampling order, the larger value is taken from two adjacent samples of the vibration monitoring component to obtain the vibration disturbance sequence. The reason for taking the larger value is that the vibration disturbance sequence is used to identify mechanical shocks or structural resonances that may cause abnormal dust sensing. Missing peak values ​​would lead to mistaking spurious changes caused by mechanical shocks for dust rise. By taking the larger value, any significant impact can be retained within the short window, thereby improving the ability to intercept disturbances and ensuring that subsequent triggers are only caused by real dust changes.

[0027] Triggering conditions and control start point determination. The intelligent control device simultaneously determines three types of sequences: For the dust representative sequence, it detects whether three consecutively rising representative values ​​appear. A continuous rise means that the subsequent representative value is strictly greater than the previous one, and a balance is not allowed. Three sets are set because a single or two-set rise is easily caused by occasional noise; three consecutive sets more reliably characterize a stable dust rise. For the spray supply sequence, it requires that two adjacent samples corresponding one-to-one with the determination interval of the dust representative sequence reach the preset value of the spray water source arrival within two consecutive samplings. This preset value is fixed according to the equipment specifications before leaving the factory or before commissioning. Using two consecutive samplings as the criterion aims to confirm that the supply has short-term stability and prevent mistaking a single peak as usable. For the vibration disturbance sequence, it requires that the vibration shielding threshold set by the device is not exceeded at times adjacent to the determination interval of the dust representative sequence. This allows for proactive rejection of triggering in the presence of significant mechanical impact, avoiding mistaking instantaneous changes in dust readings caused by impact as a true rise. When all three conditions above are met simultaneously, a trigger event is generated, and the timestamp of this trigger event is used as a control starting point. The reason for setting the control starting point as the timestamp of the trigger event is to ensure that the valve position allocation in step 2 and the execution and verification in step 3 are aligned with the actual start time of dust rise, thereby concentrating spraying during critical periods and reducing resource waste. If any of the three types of samples is missing at a certain moment, that moment will not participate in sequence construction and judgment, and will continue after the three types of samples are complete again. If three consecutive sample absences occur, the intelligent control device records a data incompleteness event and temporarily refrains from triggering until the three types of samples are complete and the above conditions are met. This process avoids triggering when information is incomplete, ensuring the reliability of the judgment.

[0028] In sampling sites with high noise levels or frequent airflow disturbances, the sampling interval can be adjusted to 10 milliseconds to improve temporal resolution. The dust representative sequence still uses the median value of three adjacent samples to maintain suppression of isolated outliers; the spray supply sequence still uses the smaller value of two adjacent samples, and the vibration disturbance sequence still uses the larger value of two adjacent samples. A smaller sampling interval allows for faster capture of the starting point of dust rise, and because the group length remains unchanged, the data shaping method and triggering conditions remain consistent, requiring no changes to subsequent steps in engineering implementation. When there is significant clock drift between field devices, the intelligent control device can include progressively increasing sequence numbers in each sampling trigger command for alignment in the returned samples. If the sequence numbers of the three types of samples are inconsistent, the batch is discarded and the next batch is used. Using sequence number alignment ensures a one-to-one correspondence among the three types of data without the need for an external time source, avoiding false triggers caused by clock asynchrony. To reduce the impact of spikes in extreme environments, the intelligent control device can incorporate a short-term smoothing process limited to the current batch before constructing the representative dust sequence. Specifically, for three samples in the same group, if a single point significantly exceeds the other two before calculating the median value, that single point is replaced with the closest sample before the median value is calculated. This method only applies to the current batch of data and does not involve historical data, further reducing the interference of single-point spikes on the determination of "three continuously rising representative values."

[0029] Step 2: Divide the service area based on a valve group topology table and determine a target service area. According to the valve group topology table, obtain a candidate sequence from far to near according to the connection order with a combined manifold. Perform a reverse coupling opening degree allocation algorithm on the candidate sequence to generate a target valve position sequence and a corresponding action window.

[0030] Specifically, the valve group topology table lists the identification number, service area, connection sequence to the manifold, whether it shares a pipe section with adjacent electric ball valve units, and whether it is marked as a pressure-reducing bypass valve for each electric ball valve unit in a row record format. The connection sequence starts from the supply port of the manifold and increases sequentially along the pipeline according to the actual laying direction. For example, the electric ball valve unit farthest from the supply port is marked as connection sequence 1, and the electric ball valve unit closest to the supply port is marked as connection sequence N. The determination of shared pipe sections is based on whether two electric ball valve units share the same pipe section upstream of the manifold. Based on the valve group topology table, the fully mechanized mining face is divided into several service areas according to the distribution of dust sources and the location of spray coverage. Each service area contains a group of physically adjacent electric ball valve units, and the location is fixed with reference to the area boundary line and the supports, conveying equipment, or roadway mileage markers. For example, the length between adjacent supports is used as a basic unit, divided into 12-meter segments, with 2 to 3 electric ball valve units configured in each segment to form an independent service area. The reason for this setting is that spray coverage and airflow disturbance are usually controlled by local structures. Dividing them according to physical proximity can concentrate the subsequent action windows on the vicinity of the triggering event, reducing unnecessary water consumption.

[0031] Using the sampling location of the trigger event obtained in step 1 as a reference, project this location onto the service area division map. If the sampling location falls within a certain service area, then that service area is the target service area. If the sampling location is located on the boundary between two service areas, calculate the straight-line distance from this location to the nearest electric ball valve unit in each service area, and select the service area with the smaller straight-line distance as the target service area; if the straight-line distances are the same, select the side with the smaller connection sequence to ensure that the side with the longer upstream pipeline is selected so that the pressure at the far end can be prioritized when implementing the reverse coupling strategy. Sort the electric ball valve units belonging to the target service area from farthest to nearest according to their connection order with the combined manifold to obtain the candidate sequence. For example, if the target service area contains 4 electric ball valve units with connection sequences of 1, 2, 3, and 4, then the candidate sequence is 1, 2, 3, and 4. If the distances between two electric ball valve units and the supply port are the same, sort them by installation number from smallest to largest to ensure that the sorting is stable and reproducible. The ordering from far to near allows the first action to be assigned to the far-end electric ball valve unit, which can form a spray barrier in advance. Then, the near end gradually follows, which can reduce the risk of insufficient water supply at the far end due to upstream pressure drop and reduce the impact of water hammer on the near end.

[0032] The execution process of the reverse coupling opening allocation algorithm includes: for the first electric ball valve unit in the candidate sequence, three consecutive time periods are set: a pre-rinsing segment, a core spray segment, and a final drainage segment. Taking a typical field example, the pre-rinsing segment can be set to 2 to 3 seconds to quickly clean the area near the nozzle and the end of the pipeline; the core spray segment can be set to 5 to 8 seconds to form a stable spray curtain in the early stage of dust concentration rise; and the final drainage segment can be set to 2 to 3 seconds to discharge residual water and reduce dripping after spraying stops. This three-segment action window is represented by three consecutive opening commands in the target valve position sequence, and the specific opening is gradually shaped by the soft-opening and closing curve generator in step 3. For subsequent electric ball valve units in the candidate sequence, it is first checked whether they share a pipeline segment with the electric ball valve unit whose action window has been allocated, based on the valve group topology table. If they share a pipeline segment, the start time of its pre-rinsing segment must not be earlier than the end time of the core spray segment of the previous electric ball valve unit and the time after the fluctuation of the spray supply sequence within two consecutive samples is within the device's set threshold range. The reason for this arrangement is that simultaneously opening shared pipe sections would cause the upstream water supply to be diverted in a short period of time, making the spray instability of the remote electric ball valve unit more likely. By arranging them without overlap, the core spray section of the preceding electric ball valve unit is guaranteed to receive continuous water supply. The subsequent electric ball valve unit is then opened after the supply has stabilized, which can reduce the instantaneous pressure drop. If the pipe section is not shared, the pre-flushing section is allowed to overlap with the closing drainage section of the preceding electric ball valve unit, shortening the total time and maintaining continuous supply.

[0033] If, after the pre-flushing section of any electric ball valve unit begins, the spray supply sequence fails to reach the preset value for spray water supply within two consecutive sampling periods, the electric ball valve unit is immediately shut down, and its core spray section and final drainage section are removed from the target valve position sequence. Simultaneously, the start time of the pre-flushing section of the next electric ball valve unit in the candidate sequence is moved forward to the current time. This approach allows for rapid relocation to other positions when water supply is temporarily insufficient, avoiding wasting time on ineffective sprays and improving overall response efficiency. All electric ball valve units not belonging to the target service area are included in the default shutdown subset and remain closed throughout the entire action window. If the valve group topology table marks an electric ball valve unit as a pressure-reducing bypass valve, then only within the core spray section of the first electric ball valve unit in the candidate sequence is the pressure-reducing bypass valve set to a small opening, such as 10% to 15% opening. This short-term small opening can buffer pressure pulsations near the supply port without significant flow diversion, reducing water hammer caused by subsequent switching. All pre-rinsing sections, core spray sections, and final drainage sections obtained through the above allocation are merged in chronological order to form a target valve position sequence and corresponding action windows. If the spray supply sequence shows an overall insufficient supply during the allocation process, the electric ball valve unit with the shorter connection order in the candidate sequence is retained first, and the last electric ball valve unit is temporarily disabled until the next trigger event for re-allocation. The final target valve position sequence and action windows are continuous and unambiguous on the time axis and can be directly used for execution and verification in step 3. The sorting and allocation from far to near ensures that the spray is established first at the end of the pipeline, which can first form a spray barrier at a location that may be farther away from the dust rising source, followed by the near end. This can reduce the spray insufficiency caused by instantaneous diversion at the far end and ensure that the pressure remains stable at the near end when the final drainage section overlaps with the next pre-rinsing section, thereby increasing the effective spray time ratio within the same total duration.

[0034] In situations where equipment is unevenly distributed, the service area boundary can be divided into segments of 8 to 10 meters. When there is only one electric ball valve unit in a segment, two adjacent segments can be merged into one service area to ensure that each service area contains at least two electric ball valve units. This method avoids overly concentrated allocation caused by single-point areas and improves the schedulability of the action window. When the actual supply capacity of the combined manifold is high and field verification shows that parallel operation is feasible, two electric ball valve units in the candidate sequence that do not share pipe segments can be allowed to partially overlap in time in a stepped manner. Specifically, the pre-flushing section of the latter electric ball valve unit overlaps with the final drainage section of the former electric ball valve unit by 1 to 2 seconds, but must not overlap with any core spray section. This shortens the total time and avoids diversion during critical spraying stages.

[0035] In scenarios with significant pipe diameter variations and long pipelines, the stable confirmation of the spray water source arrival can be increased from two consecutive samplings to three consecutive samplings. That is, the core spray section of the current electric ball valve unit will only continue execution if all three consecutive samplings reach the preset value for spray water source arrival. This method is suitable for systems with slow water supply response and can further reduce false alarms. When triggering events occur continuously and the supply is stable, a set of electric ball valve units closest to the target service area can be selected as a backup set outside the target service area. However, this set will not enter the action window. Only in the next triggering event, if the target service area is different from the previous one, will the first electric ball valve unit in this backup set replace the electric ball valve unit with the highest connection sequence in the new target service area, thus achieving a smooth transition of the spray range between adjacent areas.

[0036] Step 3: Send the target valve position sequence and the action window to a soft-opening / closing curve generator to drive the actuator motor reduction and self-locking mechanism in each electric ball valve unit; confirm the valve position segment by segment through an opening encoder. If the target opening degree is not reached within the preset segment time limit, a safety backoff strategy is triggered.

[0037] Specifically, after generating the target valve position sequence and the action window, the intelligent control device sends both as a time-stamped execution list to a soft-start / close curve generator. To avoid execution drift, the soft-start / close curve generator operates with a fixed control cycle, which can be 10 milliseconds. Each time stamp corresponds to a specific opening target, including a first preset opening for the pre-rinse section, a second preset opening for the core spray section, and a third preset opening for the final drainage section.

[0038] For each segment, a soft-start / close curve generator shapes the target opening into a sequence of "gradual increase phase, steady-state phase, and gradual decrease phase." The duration of the gradual increase phase can be 10% to 20% of the segment's duration, the steady-state phase can be 60% to 80% of the segment's duration, and the gradual decrease phase can be 10% to 20% of the segment's duration. The reason for using a three-stage approach is that the gradual increase suppresses instantaneous pressure waves, the steady-state phase ensures stable spray intensity, and the gradual decrease reduces the probability of water hammer. To reduce vibration caused by gear backlash and seal friction, the opening change within each control cycle is no more than 2 percentage points. A smaller step size allows the actuator motor's reduction and self-locking mechanism to continuously overcome static friction without overshoot, thus making the opening encoder reading closer to the actual valve position. When the encoder reading does not change for three consecutive control cycles and the target opening degree is not reached, a soft-opening curve generator applies a small reciprocating change of 1 percentage point near the current opening degree for no more than 300 milliseconds to loosen the fit between the valve seat and the seal, thus preventing adhesion caused by long-term stillness.

[0039] A soft-opening / closing curve generator outputs the opening command for the current cycle to each electric ball valve unit according to the control cycle, and the corresponding actuator motor reduction and self-locking mechanism rotates the valve shaft accordingly. Since the actuator motor reduction and self-locking mechanism can maintain the current valve position in the power-off state, unnecessary adjustment commands can be reduced during the stable phase, thus lowering heat generation and energy consumption. If the action window contains overlapping segments of multiple electric ball valve units, the soft-opening / closing curve generator strictly issues commands according to the time sequence of the action window, without conflicting with the non-overlapping rules determined in step 2. For segments where overlap is allowed, the subsequent electric ball valve unit only begins to slowly rise after the preceding electric ball valve unit enters the final drainage section. This arrangement ensures that pressure fluctuations upstream of the pipeline are converged before entering another branch.

[0040] After each output opening command, a minimum stabilization time of no less than 50 milliseconds is allowed before reading the opening encoder. If the read value falls within the allowable deviation of the target opening for this cycle, it is considered to be in place, and the cycle proceeds to the next. If two consecutive openings are confirmed, the sampling frequency is halved during the stabilization phase of that segment to further reduce unnecessary fine-tuning. The time limit within the pre-rinse segment can be set to the first 40% of the segment's duration to ensure that the approximation to the first preset opening is achieved in the first half of the segment. The time limit within the core spray segment can be set to the first 30% of the segment's duration to reach the second preset opening early in the segment, allowing the spray to form an effective barrier as quickly as possible. The time limit within the final drainage segment can be set to the first 50% of the segment's duration to reach the third preset opening in the middle of the segment, followed by a slow descent to drain the remaining water. This setting ensures that the key spray effect is established as early as possible, while allowing sufficient time for subsequent slow descent to reduce valve seat impact.

[0041] A safety rollback strategy is triggered under any of the following circumstances: The opening encoder reading fails to reach the target opening degree at the end of the segment's time limit; the opening encoder reading remains unchanged for three consecutive control cycles despite the application of anti-stickiness micro-excitation; or a significant rollback occurs during the stabilization phase, i.e., the opening encoder reading continuously deviates in the opposite direction to the target opening degree for more than 200 milliseconds. A soft-start / close curve generator immediately sets the opening command of the electric ball valve unit to closed and terminates subsequent segments of the electric ball valve unit in the target valve position sequence; the default shutdown subset remains unchanged; and the next segment of the electric ball valve unit continues to execute according to the time sequence of the action window. If the electric ball valve unit shares a pipe segment with other electric ball valve units, the associated subsequent segments are postponed as a whole for the remaining duration of the terminated segment, ensuring no overlap with other core spray segments.

[0042] When the opening encoder continuously determines the position twice and completes the slow descent phase within the stable phase of a segment, the segment is considered complete. If the segment is a pre-rinse segment, it immediately switches to the slow rise phase of the core spray segment; if the segment is a core spray segment, it immediately switches to the slow rise phase of the final drainage segment; if the segment is a final drainage segment, the electric ball valve unit is marked as completed for this execution. If the segment is terminated due to a safety backoff strategy, the termination time and the identification number of the corresponding electric ball valve unit are recorded to quickly bypass the fault location in the next trigger event and avoid repeated attempts at the same location. To ensure consistency with the sequence determined in step 2, a soft-start / close curve generator checks whether the current time is within a segment of the action window at the beginning of each control cycle. If it is not within the range, no opening command is output. If an overall insufficient supply indication occurs during the execution of the spray supply sequence, a soft-start / close curve generator closes the electric ball valve unit at the end of the pre-rinse segment and keeps the electric ball valve unit in the core spray segment running until the action window ends.

[0043] In scenarios with stiff piping and high water hammer sensitivity, the gradual rise and fall phases can be replaced with multi-stage steps, each lasting 200 milliseconds and with an amplitude of 1 to 2 percentage points. This stepped approach allows for fine-tuning of the pressure wave leading edge during commissioning by adding or removing stages, enabling rapid on-site verification. For the core spray section, a dual-ratio gradual rise with a faster initial section and a slower subsequent section can be used, ensuring the second preset opening is reached quickly, followed by a slower approach to reduce overshoot and retraction. This method is suitable for configurations with high inertia in the actuator's reduction geared self-locking mechanism.

[0044] In highly unstable dusty environments, to avoid instantaneous encoder jumps caused by occasional vibrations, a double confirmation can be used when the encoder is in position: the interval between the two readings should be no less than 80 milliseconds, and the encoder is considered in position only if both readings are within the allowable deviation. This method improves the robustness of the position determination. When the encoder shows no change for a long time near a small opening, an unlocking attempt can be made before closing. This is done by performing a reciprocating motion around the current opening with an amplitude of 2 percentage points and a frequency of once every 100 milliseconds, lasting no more than 500 milliseconds. If there is still no change, a safety backoff strategy is executed. This method improves the probability of valve release without relying on historical data and weights.

[0045] A combined electric ball valve includes: an explosion-proof main housing, a combined manifold, several electric ball valve units, an intelligent control device, an inlet device, and a venting labyrinth. The explosion-proof main housing contains a first explosion-proof cavity and several independent explosion-proof secondary cavities. The first explosion-proof cavity houses the intelligent control device, and each of the independent explosion-proof secondary cavities corresponds to one of the electric ball valve units. The combined manifold is fixed to the explosion-proof main housing and communicates with the independent explosion-proof secondary cavities, distributing spray water to each electric ball valve unit. Each electric ball valve unit is mounted on the explosion-proof main housing via an independent explosion-proof secondary cavity, and its valve body is detachably and sealingly connected to the combined manifold. Each electric ball valve unit includes an actuator motor reduction and self-locking mechanism connected to the valve shaft of the electric ball valve unit, used to maintain the valve position when there is no continuous power supply. The intelligent control device is located within the first explosion-proof cavity and includes a control program, a bus interface device, a soft-start / close curve generator, and a log recording unit. The intelligent control device is configured to execute a precursor dust surge identification and reverse coupling opening degree allocation algorithm and output valve position commands. The soft-start / close curve generator is used to shape the valve position command curve. A dust monitoring component, a spray monitoring component, and a vibration monitoring component are all electrically connected to the intelligent control device. The dust monitoring component collects roadway dust information, the spray monitoring component collects spray flow information, and the vibration monitoring component senses equipment vibration disturbance information. An inlet device is used to seal and fix cables and pipes entering the explosion-proof main housing. A venting labyrinth is located on the emission path of the explosion-proof main housing to reduce the energy of the gas passage without damaging the explosion-proof surface.

[0046] Specifically, the explosion-proof main housing is integrally cast or welded from thick plates. The housing wall thickness is preferably in the range of 10 mm to 12 mm. Continuous reinforcing ribs with a height of 3 mm to 5 mm are provided on the outer surface to improve rigidity and form a heat conduction path. An annular flange with a thickness of not less than 12 mm is provided on the outer periphery of the housing. The annular flange is connected to the housing by a full-penetration weld, and the weld is confirmed to be free of cracks by magnetic particle inspection. The explosion-proof main housing contains a first explosion-proof cavity and several independent explosion-proof secondary cavities. The first explosion-proof cavity is located in the upper center of the housing to shorten the wiring length from the intelligent control device to the inlet device. The independent explosion-proof secondary cavities are symmetrically arranged on both sides of the first explosion-proof cavity, preferably in a quantity of 5. Each independent explosion-proof secondary cavity has a removable top cover with a thickness of 8 mm. An annular explosion-proof mating surface with a width of 8 mm and a length of not less than 15 mm is provided between the top cover and the cavity. The mating clearance is controlled within the range of 0.1 mm to 0.2 mm. The reason for using a removable top cover is that maintenance of a single electric ball valve unit can be performed without opening the first explosion-proof chamber, reducing the risk of accidental contact with electrical components.

[0047] The combined manifold adopts a one-piece molded structure, achieving a smooth transition between the main channel and branch channels through precision casting. The inner diameter of the main channel is preferably 25 mm, and the inner diameter of the branch channels is preferably 15 mm. The branches are symmetrically distributed on the outer wall of the manifold, with a consistent center-to-center distance. A guide rib is installed between the combined manifold and the venting labyrinth. The guide rib is 2 mm to 3 mm high and its length covers 60% to 80% of the full circumference of the branch merging section. The guide rib is used to suppress the vortex zone formed by branch backflow, making the pressure wave propagation more uniform in the initial stage of spraying, thereby reducing the initial water hammer intensity. The combined manifold is connected to the valve body flange in the independent explosion-proof secondary cavity by a face seal. The seal uses a hydrolysis-resistant elastomer with a cross-sectional diameter of 3 mm to 4 mm and a 0.5 mm chamfered groove to prevent assembly shearing. The reason for choosing a face seal instead of a threaded seal is that a face seal is more accommodating for repeated disassembly and assembly, has a shorter sealing line, and a lower probability of leakage.

[0048] Each electric ball valve unit uses a stainless steel valve body and a polished ball valve core with a surface roughness preferably not exceeding 0.4 micrometers. The valve seat is made of reinforced polytetrafluoroethylene (PTFE), with the pre-compression controlled between 0.2 mm and 0.3 mm to achieve a balance between sensitive opening and closing and reliable sealing within the range of 0.2 MPa to 10 MPa. External leakage control is achieved through a combination of double packing seals and dust rings. The packing is made of graphite-reinforced composite material, and the axial pressure ring hardness is not less than 90 Shore A, ensuring resilience after multiple openings and closings. The actuator motor reduction and self-locking mechanism uses a permanent magnet DC motor with a worm gear reduction, with a reduction ratio preferably between 40:1 and 60:1. The worm gear self-locking angle design ensures irreversible rotation in the power-off state. The advantage of using worm gear self-locking is that the valve position does not require continuous power during the stable spray phase, significantly reducing temperature rise and noise. Each electric ball valve unit is equipped with an opening encoder, coaxially connected to the valve shaft, with a resolution of not less than 1 degree. The encoder is placed inside an independent explosion-proof secondary cavity and fixed with an anti-loosening structure to avoid drift caused by long-term vibration.

[0049] The intelligent control device is mounted on a suspended support plate within the first explosion-proof chamber. The support plate is made of aluminum alloy, 6 mm thick, and a thermally conductive interface material with a thickness not exceeding 0.5 mm is coated between the support plate and the housing to form a stable thermal path. A grounding terminal is installed within the first explosion-proof chamber, connected to the housing with low resistance. The cross-sectional area of ​​the grounding conductor is not less than 4 square millimeters, and the grounding screw is equipped with a spring washer to prevent loosening. The intelligent control device is connected to the dust monitoring component, spray monitoring component, and vibration monitoring component via shielded cables. The wiring harness is laid along a dedicated cable tray within the housing, with a minimum bending radius not less than 8 times the cable's outer diameter. Using shielded cables and standardized wiring reduces electromagnetic crosstalk between sampling channels, making the dust representation sequence, spray supply sequence, and vibration disturbance sequence more stable. The intelligent control device includes a control program, a bus interface device, a soft-start / shutdown curve generator, and a log recording unit. The control program is responsible for executing the precursor dust surge identification and reverse coupling opening allocation algorithm and outputting valve position commands; a soft-opening / closing curve generator performs gradual shaping of the valve position commands; a log recording unit records time stamps, valve positions, and trigger events for post-event traceability. A bus interface device is used for interaction with the host computer, and the cable length can be controlled within 10 meters according to the site layout.

[0050] The dust monitoring unit is positioned at the edge of the downstream spray zone of the combined manifold, 1.2 to 1.5 meters above the ground, avoiding direct spray path and ensuring an unobstructed passage. The spray monitoring unit is installed at one of the upstream inlets of the combined manifold and at the inlets of each branch, facilitating the assessment of overall supply and local availability. The vibration monitoring unit is installed in the middle of the side wall of the explosion-proof main housing to obtain representative machine vibration data. A replaceable dustproof window, 2 mm thick, made of tempered glass, is installed in front of the dust monitoring unit, with a grille in front. The grille opening side length is no greater than 8 mm to prevent large particles from impacting and damaging the optical path. The spray monitoring unit uses a direct-flow and pressure composite sensor, with a 6 mm diameter drain port on the housing for discharging accumulated water and impurities. The vibration monitoring unit is externally equipped with a flexible vibration damping pad, 2 to 3 mm thick, to reduce the impact of high-frequency mechanical noise on the measurement. All three types of components use detachable terminals with a crimping length of no less than 6 mm. All terminals are crimped with marking sleeves in the same direction to ensure that maintenance personnel can match them one by one when replacing them, thus avoiding misconnection and false triggering.

[0051] The inlet device consists of a cable clamping section and a secondary sealing section. The cable clamping section uses a combination of a conical pressure ring and a pressure cap. After the pressure cap is tightened, it forms a uniform circumferential pressure on the outer sheath of the cable, suitable for cables with diameters from 8 mm to 12 mm. The secondary sealing section adopts a stepped labyrinth, with 3 to 4 steps, each step having a depth of not less than 3 mm, and a total labyrinth channel length of not less than 25 mm. The cable clamping section provides the first layer of tensile and torsional protection, preventing external forces from directly acting on the wiring inside the first explosion-proof cavity; the stepped labyrinth extends the gas propagation path and reduces the channel wind speed, allowing the leading edge of the external flame to be cooled during passage, working together with the explosion-proof mating surface to achieve explosion protection. Independent sealing rings are installed between each step, with a cross-sectional diameter of 2 mm to 3 mm and a compression rate controlled at 20% to 30%, ensuring elastic rebound even after temperature changes and long-term compression.

[0052] The venting labyrinth is positioned along the venting path of the explosion-proof main housing, employing a multi-chamber series baffled channel design. The cross-sectional area of ​​each chamber decreases progressively, with the first chamber having a cross-section of 1000-1200 mm², and the final chamber having a cross-section of 400-600 mm². The chambers are connected by offset slits, with the slit width controlled within the range of 0.6-0.8 mm. This combination of multi-chamber series and offset slits allows the high-temperature, high-pressure gas mass to diffuse within each chamber and fully exchange heat with the metal walls. The offset slits cause multiple changes in airflow direction, dividing the flame front into multiple small-scale vortices, resulting in a progressive decrease in temperature and velocity, ultimately reducing the energy of the gas channel without damaging the explosion-proof surface. The venting labyrinth features a removable maintenance cover secured with four evenly distributed bolts, with a recommended tightening torque of 12-16 Nm. During maintenance, removing the maintenance cover allows for the cleaning of scale and dust deposits within the channel, restoring the flow cross-section.

[0053] First, position the combined manifold using locating pins and connect it to the inner wall of the explosion-proof main housing. The locating pins are 6 mm in diameter, and the clearance should not exceed 0.05 mm, ensuring that the manifold branches are aligned with the axes of the independent explosion-proof secondary cavities. Install the electric ball valve units one by one into the corresponding independent explosion-proof secondary cavities, simultaneously pressing the valve body flange against the face seal of the combined manifold. Tighten the fixing bolts crosswise, gradually increasing to the target tightening torque to avoid damage to the seals due to unilateral overpressure. Install the opening encoder and complete the coaxial calibration with the valve shaft, ensuring radial runout does not exceed 0.1 mm. Fix the intelligent control device to the support plate and complete the wiring to the dust monitoring component, spray monitoring component, and vibration monitoring component according to the markings. Ground the shielding layer at one end locally to avoid forming a loop. Install the inlet device and confirm that the cable clamping part and the secondary sealing part are evenly clamped. Install the inspection cover of the venting labyrinth and tighten it in a diagonal sequence. A hydrostatic pressure test is conducted on the seal between the combined manifold and the valve body. The test pressure is 1.1 times the maximum working pressure, and the pressure is maintained for 5 minutes. No leakage is considered acceptable. A rust-proof layer is applied to the explosion-proof joint surface, with a coating thickness of no more than 0.02 mm, to ensure that the joint surface is not filled by the coating.

[0054] The explosion-proof main housing can be made of ductile iron instead of thick welded plates, with a wall thickness maintained in the range of 10 mm to 12 mm. Ductile iron has higher impact resistance at the same wall thickness, making it suitable for sites with strong vibrations; thick welded plates are more convenient for small-batch customization and subsequent hole adjustments. The choice between the two can be made based on production line and on-site maintenance preferences. A flared transition can be used at the junction of branch lines and the main channel, with a flared length of 6 mm to 8 mm and an inlet angle of 30 degrees to 45 degrees. The flared transition helps reduce local resistance at the junction, allowing for faster flow establishment in the pre-flushing section and easier formation of a uniform spray curtain near the nozzle.

[0055] The slits in the venting labyrinth can be arranged in a staggered fan shape, with the center angle of each slit offset by no less than 30 degrees. This staggered fan shape further increases the number of times the airflow changes direction, allowing the high-temperature air mass to achieve more thorough heat exchange attenuation within a shorter total length, making it suitable for locations with limited installation space. The cable clamping section can employ a double-conical pressure ring structure with different inner and outer cone angles, the outer cone angle being 5 to 8 degrees greater than the inner cone angle. The double-conical structure generates more uniform radial pressure on the cable sheath under the same tightening torque, reducing the risk of localized damage while improving tensile strength.

[0056] The following is an example from the specific implementation process:

[0057] Site and Equipment Configuration (Fixed Conditions): The number of electric ball valve units is 5, with identification numbers and connection order to a combined manifold from farthest to nearest as V1, V2, V3, V4, and V5. Distances along the manifold: V1 is 48 meters, V2 is 36 meters, V3 is 24 meters, V4 is 12 meters, and V5 is 6 meters. Service Area Division: The target working face is divided into two service areas: Area A includes V1, V2, and V3, and Area B includes V4 and V5. Trigger Sampling Settings: The sampling interval is denoted as... (seconds), in this example, we take... The control cycle is denoted as (seconds), in this example, we take... Valve position target: The opening degree of the pre-flushing section is recorded as... (Percentage), the opening degree of the core spray section is recorded as... (Percentage), the opening of the final drainage section is recorded as... (Percentage), take , , Pre-rinse duration: The pre-rinse duration is recorded as... (seconds), the duration of the core spray segment is recorded as (seconds), the duration of the final drainage section is recorded as... (seconds), take , , Segment Gradual Change Rule: Each segment consists of three parts: gradual rise, steady state, and gradual fall; the gradual rise and fall each account for 20% of the segment duration, and the steady state accounts for 60%. Single Valve Rated Flow Rate: The flow rate when the valve position is 100% is denoted as... (liters / second), in this example, we take... (Equivalent to 30 liters / minute). Instantaneous flow rate. Approximately given in proportion to the opening: ;in This represents the target or actual opening degree (percentage) at that moment. Opening encoder tolerance: [Values ​​are missing from original text]. Percentage points, core spray section Percentage point. Trigger threshold: The preset value for when the spray water source is in place is recorded as... (megapascal), in this example, we take The vibration shielding threshold is denoted as (m / s) In this example, we take... .

[0058] Step 1: The dust sample sequence is denoted as (mg / m³) This refers to the sampling sequence number. In this example, there are 9 samples within a decision window. The dust samples were grouped into sets of three adjacent samples in the sampling order, and the median of each group constituted a representative sequence of dust samples. (mg / m³), of which Group number: The three representative values ​​increase strictly in ascending order. The spray pressure sample sequence is denoted as... (megapascal), in this example, we take The spray supply sequence is obtained by taking the smaller value from each pair of adjacent samples in the sampling order. (megapascal): Within the time periods corresponding to the three dust collection windows, it is required that two consecutive samples be taken at least twice. For example, for the first group of correspondences have The other two groups are similarly satisfied.

[0059] The vibration acceleration sample sequence is denoted as (m / s) In this example, we take... The vibration disturbance sequence is obtained by taking the larger value from each pair of adjacent values. (m / s) ): At adjacent times of the three dust windows, there were Triggering event and control start point. All three conditions must be met simultaneously; the time of the last sample in group 3 is taken as the triggering event time. If the absolute start time of this window is denoted as... If the time is seconds, then the time for the 9th sample is... This time is the starting point of a control.

[0060] Step 2: Project the sampling location of the trigger event along the working surface to a distance of 43 meters from the supply port. This location falls within region A, therefore region A is a target service area. The electric ball valve units within region A are arranged from farthest to nearest according to their connection sequence with a combined manifold, resulting in... The candidate sequences are assigned three-stage action windows sequentially, adhering to the non-overlapping rule of shared pipe segments (the pre-rinse segment of the next unit is not started before the core spray segment of the previous unit ends and the spray supply is stable). Using a control starting point as a reference, an initial timetable is obtained: [The text abruptly ends here, likely due to an incomplete sentence or missing information.] : This is the pre-rinse section. As the core spray section, This is the final drainage section; targeting The pre-rinse phase should begin no earlier than 108.18 seconds and require two consecutive stable samplings; in this example, the starting time is 108.22 seconds. Similarly, V2 will be assigned after V2 according to the same rules. V4 and V5, which do not belong to a target service area, will be assigned to a default shutdown subset, and the entire action window will remain closed.

[0061] Step 3: Implement each segment in three stages: gradual increase, stabilization, and gradual decrease. Use the target opening degree for any segment. (Percentage) and Duration (seconds) indicates that the gradual ascent and descent each account for a portion of the total time. Stable The maximum opening change in each control cycle shall not exceed 2 percentage points. The number of offset steps required to achieve the target opening. With single step amplitude They are respectively Taking V1 as an example: Pre-rinse section , : , Percentage point. Core spray section. , : , Percentage point. Final drainage section. , : , Percentage points. All satisfy the constraint that the single-cycle percentage should not exceed 2 percentage points.

[0062] Calculating water consumption per valve using the opening area method: To facilitate engineering calculations, an equivalent "opening area minus time" is introduced. (Percentage in seconds) represents the equivalent opening integral across three segments: gradual ascent, steady state, and gradual descent. For any segment... ,in The target opening (percentage) of the segment. The duration of the segment (in seconds). Water consumption for the segment. (Promoted) to For example, using V1: ; ; ; .

[0063] The time limits within each segment are set as follows: pre-rinse segment accounts for 40% of the segment time, core spray segment accounts for 30% of the segment time, and final drainage segment accounts for 50% of the segment time. Taking the V1 pre-rinse segment as an example, the time limit within the segment is... At the end of each control cycle, the opening encoder is read. If the difference between the opening and the target opening of the current segment falls within the allowable deviation, it is determined that the target opening has been reached; otherwise, the approach continues. If the target opening has not been reached by the end of the segment, a safety backoff strategy is triggered.

[0064] A comparison of success and regression: To demonstrate operability, calculations are given for a normal V1 entry and a V2 trigger-safe regression strategy. V1 normal entry: Considering the dynamic lag of the motor reduction self-locking mechanism and valve seat friction, the actual opening degree... (Percentage) simplified to target opening degree The first-order lag approximation, with the time constant denoted as... (seconds), the equivalent opening loss caused by friction is denoted as (Percentage points). This example uses... , During the gradual rise phase of the pre-rinse section (linear rise, slope denoted as ), Within (percentage points / second), The response of a first-order system to a ramp input is: Substitute have to Entering a stable phase (the objective remains unchanged). The response of a first-order system to a step is Within the time limit of the segment hour ,and The difference was 1.09 percentage points, falling within the allowable deviation of the pre-rinsing section. Within the percentage point, the judgment is in place and no rollback is triggered.

[0065] V2 triggers a safety backoff strategy: Considering the high friction of the valve body at this location, a time constant is used. equivalent loss The pre-flushing section's gradual rise and steady-state responses are respectively... , Substituting, we can get Due to the time limit within the segment. Not yet reached The allowable deviation range (difference from 20 by more than 2 percentage points) at time [time value missing]. Trigger a safety rollback strategy: Immediately shut down V2, delete its core spray section and final drainage section, and move the start of V3's pre-rinse section forward to the current moment according to the bypass switching strategy. Seconds (satisfies the non-overlapping rule because the core spray segment of V1 ended at 108.18 seconds and the spray supply was stable within two consecutive samples).

[0066] Estimated actual water consumption before V2 rollback: For ramp input from 0 to 0.4 seconds, the corresponding actual opening integral is... Substituting the values, we get approximately... (Percentage in seconds). For a step input between 0.4 and 0.8 seconds, the integral is... Substituting the values, we get approximately... (Percentage in seconds). Therefore, the actual opening integral before rollback is: Corresponding water consumption .

[0067] Based on the above results, the key times for this action window are as follows: V1: Executed in the predetermined three-segment sequence from 100:18 to 110:18; V2: Pre-rinse segment begins at 108:22, triggers a safety rollback strategy and shuts down at 109:02, subsequent segments are deleted; V3: Pre-rinse segment begins at 109:02, ends at 111:02, followed by the core spray segment from 111:02 to 117:02, and the final drainage segment from 117:02 to 119:02; V4 and V5: Located in a default shutdown subset, always shut down. The water consumption of V3 is equivalent to that of V1 (same target and duration). Total water consumption for this action window. .

[0068] This invention is not limited to the specific embodiments described above. The invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.

Claims

1. A method for precise dust reduction and explosion-proof control in fully mechanized mining faces, characterized in that, The method includes: Step 1: A smart control device synchronously sends sampling trigger commands to the dust monitoring component, spray monitoring component, and vibration monitoring component; generates a dust representative sequence, a spray supply sequence, and a vibration disturbance sequence based on the collected data; when the three sequences simultaneously meet the preset trigger conditions, a trigger event and a control start point are generated. Step 2: Divide the service area based on a valve group topology table and determine a target service area. According to the valve group topology table, obtain a candidate sequence from far to near according to the connection order with a combined manifold. Perform a reverse coupling opening degree allocation algorithm on the candidate sequence to generate a target valve position sequence and a corresponding action window. Step 3: Send the target valve position sequence and the action window to a soft-opening / closing curve generator to drive the actuator motor reduction and self-locking mechanism in each electric ball valve unit; confirm the valve position segment by segment through an opening encoder. If the target opening degree is not reached within the preset segment time limit, a safety backoff strategy is triggered.

2. The precise dust suppression and explosion-proof control method for fully mechanized mining faces as described in claim 1, characterized in that, For samples obtained from the dust monitoring component, three adjacent samples are grouped together according to the sampling order, and the median value is used as the representative value of the group to obtain the dust representative sequence. For samples obtained from the spray monitoring component, the smaller value of two adjacent samples is taken according to the sampling order to obtain the spray supply sequence. For samples obtained from the vibration monitoring component, the larger value of two adjacent samples is taken according to the sampling order to obtain the vibration disturbance sequence. When three consecutively rising representative values ​​appear in the dust representative sequence, and the spray supply sequence at the corresponding time indicates that the spray water source is available, and the vibration disturbance sequence at the adjacent time does not exceed the vibration shielding threshold set by the device, a trigger event is determined to be generated, and the time of the trigger event is used as the control start point.

3. The method for precise dust suppression and explosion-proof control in fully mechanized mining faces as described in claim 2, characterized in that, In step 2, based on the valve group topology table, the fully mechanized mining face is divided into several service areas, and information such as the service area to which each electric ball valve unit belongs, its connection order with the combined manifold, and whether it shares a pipe section with adjacent electric ball valve units is recorded. The target service area is determined with the sampling location of the triggering event as the center, and the electric ball valve units belonging to the target service area are sorted from far to near according to their connection order with the combined manifold as candidate sequences.

4. The precise dust suppression and explosion-proof control method for fully mechanized mining faces as described in claim 3, characterized in that, Step 2, specifically the process of executing the reverse coupling opening allocation algorithm on the candidate sequence, includes: For the first electric ball valve unit in the candidate sequence, a three-segment action window is set, with the three segments being the pre-rinsing segment, the core spray segment, and the final drainage segment; within the pre-rinsing segment, the electric ball valve unit is placed at the first preset opening; within the core spray segment, it is placed at the second preset opening; and within the final drainage segment, it is placed at the third preset opening; for subsequent electric ball valve units in the candidate sequence, it is checked whether they share a pipe segment with the electric ball valve units whose action windows have been allocated; if they share a pipe segment, according to the non-overlapping rule, the start time of its pre-rinsing segment is set to after the previous electric ball valve unit completes the core spray segment and the spray supply sequence fluctuates within the threshold range set by the device within two consecutive samples; if they do not share a pipe segment, its pre-rinsing segment is allowed to be aligned with the previous one. The closing and draining sections of an electric ball valve unit are executed concurrently. After the pre-rinsing section of any electric ball valve unit begins, if the spray supply sequence fails to reach the preset value of the spray water source within two consecutive samplings, a bypass switching strategy is executed: the electric ball valve unit is immediately shut down and its core spraying section and closing and draining section are skipped, and the start time of the pre-rinsing section of the next electric ball valve unit in the candidate sequence is moved forward to the current time; electric ball valve units that do not belong to the target service area are assigned to a default shut-off subset and remain closed throughout the entire action window, but if the valve group topology table marks it as a pressure-reducing bypass valve, a small opening is reserved only in the core spraying section of the previous electric ball valve unit to buffer pressure; all pre-rinsing sections, core spraying sections, and closing and draining sections obtained through the above allocation are summarized to form the target valve position sequence and the action window.

5. The precise dust suppression and explosion-proof control method for fully mechanized mining faces as described in claim 4, characterized in that, Step 3 specifically includes: the intelligent control device sends the target valve position sequence and action window to the soft-opening curve generator; the soft-opening curve generator performs gradual shaping on each opening command and drives the motor reduction and self-locking mechanism to execute; during the execution of each segment, the valve position is confirmed using the opening encoder: when the opening encoder feedback matches the target opening of the current segment, the next segment is entered; if the target opening is not reached within the confirmation time limit set by the device, the subsequent segments of the current electric ball valve unit are stopped and a safety backoff strategy is initiated: the electric ball valve unit is closed, the default shut-off subset remains unchanged, and the next electric ball valve unit in the target valve position sequence continues to be executed; after all action windows are completed, one dust suppression operation cycle ends.

6. The method for precise dust suppression and explosion-proof control in fully mechanized mining faces as described in claim 5, characterized in that, The non-overlapping rule is as follows: when two electric ball valve units share a pipe section, the start time of the pre-rinse section of the later-opened electric ball valve unit must not be earlier than the end time of the core spray section of the previous electric ball valve unit and the time when the spray supply sequence fluctuates within the range of the device's set threshold within two consecutive samplings.

7. The method for precise dust reduction and explosion-proof control in fully mechanized mining faces as described in claim 6, characterized in that, The bypass switching strategy includes: if the spray supply sequence does not reach the preset value of the spray water source in the pre-flushing section of any electric ball valve unit, the electric ball valve unit is immediately shut down, and the remaining unexecuted sections are deleted from the target valve position sequence. At the same time, the start time of the pre-flushing section of the next electric ball valve unit in the candidate sequence is adjusted to the current time, and the relevant action sequence of other electric ball valve units that share the pipe section with the shut-down electric ball valve unit is postponed.

8. A combined electric ball valve for use in the method of any one of claims 1 to 7, characterized in that, It includes: The system comprises an explosion-proof main housing, a combined manifold, several electric ball valve units, an intelligent control device, an inlet device, and a venting labyrinth. The explosion-proof main housing contains a first explosion-proof cavity and several independent explosion-proof secondary cavities. The first explosion-proof cavity houses the intelligent control device, and each of the independent explosion-proof secondary cavities corresponds to one of the electric ball valve units. The combined manifold is fixed to the explosion-proof main housing and communicates with the independent explosion-proof secondary cavities, distributing spray water to each electric ball valve unit. Each electric ball valve unit is mounted on the explosion-proof main housing via an independent explosion-proof secondary cavity, and its valve body is detachably and sealingly connected to the combined manifold. Each electric ball valve unit includes an actuator motor reduction and self-locking mechanism. The locking mechanism is connected to the valve shaft of the electric ball valve unit to maintain the valve position when there is no continuous power supply. The intelligent control device is located in the first explosion-proof cavity and includes a control program, a bus interface device, a soft-opening / closing curve generator, and a log recording unit. The intelligent control device is configured to execute a precursor dust surge identification and reverse coupling opening degree allocation algorithm and output a valve position command. The soft-opening / closing curve generator is used to perform curve shaping on the valve position command. The dust monitoring component, the spray monitoring component, and the vibration monitoring component are all electrically connected to the intelligent control device. The dust monitoring component is used to collect roadway dust information, the spray monitoring component is used to collect spray flow information, and the vibration monitoring component is used to sense equipment vibration disturbance information. The introduction device is used to seal and fix the cables and pipes entering the explosion-proof main housing; the venting labyrinth is set on the discharge path of the explosion-proof main housing to reduce the energy of the gas passage without damaging the explosion-proof surface.

9. The precision dust suppression and explosion-proof combined electric ball valve for fully mechanized mining faces as described in claim 2, characterized in that, An annular spacer and a replaceable seal are provided between the first explosion-proof cavity and the independent explosion-proof secondary cavity in the explosion-proof main housing. The annular spacer forms a continuous explosion-proof mating surface.

10. The precision dust suppression and explosion-proof combined electric ball valve for fully mechanized mining faces as described in claim 3, characterized in that, The combined manifold adopts an integral molding structure. The valve positions of the combined manifold are symmetrically distributed, and guide ribs are provided between the combined manifold and the venting labyrinth to reduce backflow disturbance.

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