An intelligent ventilation management system and method for power-limited space gas detection

Abstract

The application provides a power limited space gas detection intelligent ventilation management and control system and method, and belongs to the technical field of intelligent management and control of power limited space safety operation, and comprises a perception layer, a main control management and control layer and an execution early warning layer; the perception layer is provided with three layers of composite gas and temperature sensors for collecting environmental data, and is matched with infrared detectors, timers and positioning receiving ends for collecting personnel information; the main control management and control layer processes data by using an industrial single-chip microcomputer with a built-in algorithm, completes verification, trend prediction, air volume calculation and risk grading, and issues instructions, and a supporting storage unit retains full-process data; the execution early warning layer is provided with stepless frequency conversion fans, adjustable air outlets and air speed sensors to realize ventilation regulation and control, and is integrated with audible and visual alarms, power locking and remote transmission units to complete alarm and safety locking operations. The application adopts the above management and control system and method, and solves the problems of poor safety, low intelligentization and blind areas in management and control of the traditional management and control mode.

Description

Technical Field

[0001] This invention relates to the field of intelligent control technology for safe operation in confined spaces in the power industry, and in particular to an intelligent ventilation control system and method for gas detection in confined spaces in the power industry. Background Technology

[0002] Power cable wells, underground power distribution trenches, underground pump rooms, and other confined spaces in power facilities are enclosed and poorly ventilated. Cable heating and water accumulation can easily produce toxic and flammable gases such as methane, carbon monoxide, and hydrogen sulfide. Oxygen deficiency and gas accumulation can easily lead to poisoning and explosions. Therefore, gas monitoring and ventilation coordination are crucial for safety in confined space operations. Currently, the industry's common control methods rely on fixed gas detectors paired with constant-speed ventilation equipment and standardized manual procedures for on-site protection. While the hardware is mature and widely available, the supporting control logic and scheduling methods have inherent shortcomings, making it difficult to adapt to the complex and ever-changing conditions in power facilities, resulting in significant limitations in overall control effectiveness.

[0003] Existing control models all employ a reactive approach, initiating ventilation only after gas concentrations exceed safety thresholds, lacking proactive risk assessment capabilities. Within confined spaces, temperature and humidity, equipment heating, and construction disturbances all contribute to the slow accumulation of gas. When concentrations show a continuous upward trend, the system cannot identify this in advance, only intervening after the levels exceed limits, leaving extremely little time for on-site personnel to evacuate. Furthermore, the detection system relies solely on single-point sensors for data collection, lacking multi-point cross-validation and data noise reduction mechanisms. Sensor drift, dust, and electromagnetic interference generate numerous abnormal values, frequently triggering malfunctions in ventilation fan operation and false alarms, disrupting normal operations and resulting in insufficient control accuracy.

[0004] Traditional ventilation and personnel management are disconnected, and the operational process lacks a closed-loop control mechanism. Ventilation equipment is only set to fixed operating levels, unable to dynamically adjust airflow based on the degree of gas exceedance, gas hazard type, space volume, and ambient temperature. Full-load ventilation results in significant energy consumption when gas levels are only slightly exceeded, while insufficient ventilation power leads to inefficient risk mitigation when gas accumulates rapidly. The system only monitors ambient gas data and cannot link it to personnel on-duty time or status. When personnel work overtime, remain illegally, or gas anomalies occur simultaneously, ventilation enhancement, power outage, and personnel evacuation alerts cannot be implemented concurrently. Furthermore, control only covers the operational phases; there is a lack of precise pre-ventilation verification standards before operations and no mandatory post-operation review and archiving steps, resulting in numerous safety loopholes in the entire process control. Summary of the Invention

[0005] The purpose of this invention is to provide an intelligent ventilation control system and method for gas detection in confined spaces with electrical equipment, which solves the problems of poor safety, low level of intelligence, and blind spots in traditional control methods.

[0006] To achieve the above objectives, the present invention provides an intelligent ventilation control system for gas detection in confined power spaces, comprising a sensing layer, a main control layer, and an execution early warning layer, wherein the sensing layer, the main control layer, and the execution early warning layer communicate bidirectionally via an industrial bus. The sensing layer includes a multi-source gas detection module and a personnel status sensing module. The multi-source gas detection module has composite gas sensors and temperature sensors deployed in the upper, middle and lower layers of the limited space to collect gas concentration and ambient temperature data. The personnel status sensing module includes an infrared on-duty detector, a work timer and a positioning receiver to collect data on the number of workers, their location, work duration and off-duty status. The main control and management layer includes an industrial microcontroller and a data storage unit. The industrial microcontroller has a built-in control algorithm program, which is used to receive data collected by the sensing layer, complete data verification, gas trend prediction, ventilation volume calculation, risk classification and judgment and output control commands. The data storage unit is used to store monitoring, alarm and personnel data of the whole operation process. The execution early warning layer includes an intelligent ventilation execution module and an early warning and interlocking module; the intelligent ventilation execution module is equipped with a variable frequency axial flow fan, adjustable air outlets, and wind speed sensors; the early warning and interlocking module includes a graded audible and visual alarm, a working power interlocking switch, and a remote transmission unit.

[0007] Preferably, the variable frequency axial flow fan supports stepless speed regulation from 0 to 100%, the adjustable air outlet can adjust the air delivery angle, and the wind speed sensor transmits the ventilation operation status back to the industrial microcontroller in real time to form a closed loop feedback.

[0008] Preferably, the detection medium of the composite gas sensor includes methane, carbon monoxide, hydrogen sulfide, and oxygen.

[0009] A method for intelligent ventilation control based on gas detection in a confined electrical space includes the following steps: S1. Multi-source data acquisition and fault-tolerant noise reduction verification: The main control layer receives data uploaded by the perception layer, calculates the effective gas concentration by removing extreme values ​​and averaging the data from the three layers of sensors, and then performs time-series smoothing and noise reduction on 5 consecutive frames of effective data; if more than 2 sets of effective data are missing, a fault alarm is triggered and the operation permission is locked. S2. Gas concentration trend prediction: Based on the noise-reduced time-series concentration data, calculate the rate of concentration change and predict the gas concentration trend in the next 30 seconds. Classify the predicted risks into three categories: rapid increase, slow increase, and stable decrease, and match the corresponding pre-ventilation strategies. S3: Multi-parameter fusion dynamic air volume calculation, combined with gas hazard correction coefficient, gas exceedance rate, confined space volume, and temperature correction coefficient, calculates the real-time required ventilation air volume and adjusts the speed of the variable frequency fan and the angle of the air outlet. S4, a four-level risk classification and linkage control system, is divided into four levels: early warning, slight exceedance, moderate exceedance, and severe exceedance, based on the predicted risk and the gas exceedance rate. The system controls ventilation power, audible and visual alarm intensity, and remote alarms according to the level. S5. Personnel-environment collaborative closed-loop control: real-time matching of personnel work status and on-site gas risk level; if personnel stay for too long and there is a warning or above risk, increase the ventilation level and issue an evacuation reminder; if the gas level is severely exceeded and personnel have not evacuated, continuously lock the power supply. S6. After all personnel have evacuated, continue ventilation for 5 minutes, check the gas concentration again, and shut down the ventilation equipment after it meets the standard. All operational data for this operation will be automatically archived.

[0010] The preferred formula for calculating the effective concentration is: ; in, This represents the effective concentration value of the target gas. These are the real-time concentration values ​​collected by sensors at the upper, middle, and lower levels of the space, respectively. The maximum value among the three concentration data sets; It is the minimum value among the three sets of concentration data.

[0011] Preferably, the formula for calculating the concentration change rate is: ; in, The rate of change of gas concentration; This represents the average effective gas concentration at the current moment. This represents the average effective concentration from the previous sampling period. Set a fixed sampling period for the system.

[0012] Preferably, the formula for calculating ventilation volume is: ; in, The required ventilation volume in real time; This is a gas hazard correction factor; This refers to the percentage of gas exceeding the standard. Fixed volume for power-related limited spaces; This is the temperature correction factor.

[0013] The preferred four-level risk control strategy is as follows: for the early warning level, pre-ventilation at 30% of the rated air volume and low-frequency audible and visual warnings are used; for the slightly excessive level, ventilation at 60% of the rated air volume and medium-frequency audible and visual warnings are used; for the moderately excessive level, ventilation at 85% of the rated air volume and high-frequency audible and visual warnings are used, and an alarm is pushed to the background; for the severely excessive level, ventilation at 100% of the rated air volume and the highest level audible and visual alarms are used, while the operating power is locked and an emergency evacuation order is issued.

[0014] Therefore, the present invention employs the above-mentioned intelligent ventilation control system and method for gas detection in confined power spaces, and the technical effects are as follows: 1. Based on the prediction of gas concentration trends and the multi-parameter dynamic hierarchical ventilation method, risk prevention intervention and stepless adjustment of ventilation volume can be achieved, which can not only significantly shorten the response time for gas risk handling, but also reduce the operating energy consumption of ventilation equipment by more than 30%, taking into account both operational safety and energy-saving requirements.

[0015] 2. Through a data fault tolerance mechanism that uses three layers of sensors to cross-de-extreme values ​​and time-series smoothing and noise reduction, abnormal data caused by sensor drift and on-site interference are effectively eliminated, reducing the probability of false alarms and ventilation false triggers by more than 90%, thereby improving the stability of on-site control and the accuracy of detection.

[0016] 3. Establish a closed-loop control logic that links personnel status with the gas environment, and simultaneously connect the pre-operation verification, dynamic control during operation, and post-operation review and archiving of the entire closed-loop system to eliminate safety blind spots such as the disconnect between human and machine control and the fragmentation of the operation process, so as to achieve full monitoring and traceability of confined space operations.

[0017] 4. A four-level linkage execution strategy is adopted, which automatically matches ventilation, audible and visual warnings, and power interlocking actions according to the gas risk level. The risk gradient handling logic is clear. In the event of a sudden severe exceedance, the power supply to the operation can be forcibly cut off and a remote alarm can be pushed, thus preventing poisoning and explosion-related safety accidents from the mechanism. Attached Figure Description

[0018] Figure 1 This is a diagram illustrating the architecture of an intelligent ventilation control system for gas detection in a confined electrical space according to the present invention. Figure 2 This is a flowchart of an intelligent ventilation control method for gas detection in a confined space in an electrical system, according to the present invention. Detailed Implementation

[0019] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0021] Example 1 like Figure 1As shown, this invention provides an intelligent ventilation control system for gas detection in confined power spaces. It establishes a hierarchical intelligent control hardware system. The entire system consists of three layers: a perception layer, a main control layer, and an execution and early warning layer, which are linked sequentially from top to bottom. Each layer of equipment establishes a bidirectional data transmission path through an industrial bus to realize the upward collection of environmental and personnel data and the downward output of control commands. The entire hardware system uses mature industrial equipment, which is easy to modify and highly versatile.

[0022] The perception layer, serving as the system's data input source, comprises two types of acquisition units: a multi-source gas detection module and a personnel status perception module. The multi-source gas detection module deploys composite sensors for methane, carbon monoxide, hydrogen sulfide, and oxygen, along with a temperature sensor, in three layers—upper, middle, and lower—within the confined space. These sensors collect real-time simulated signals of gas concentration and ambient temperature, converting them into digital signals and uploading them to the main control layer via a bus. This layered deployment ensures comprehensive capture of gas distribution across the entire space, avoiding the data gaps caused by single-point monitoring. The personnel status perception module is equipped with an infrared on-duty detector, a work timer, and a personnel positioning receiver. After personnel enter the confined space wearing positioning tags, the module continuously collects information on the number of workers, their real-time location, cumulative work time, and their off-duty status, simultaneously uploading this data to the main control module. This provides personnel-level data support for the host system to achieve human-machine collaborative management.

[0023] The core of the main control and management layer is an industrial microcontroller with built-in algorithms and an independent data storage unit, serving as the computing hub and scheduling center of the entire system. The microcontroller continuously receives comprehensive data on gas, temperature, and personnel from the sensing layer. It performs batch calculations based on internally integrated algorithms for multi-source data fault tolerance verification, gas trend prediction, dynamic airflow calculation, and risk classification. After calculation, it generates corresponding ventilation, early warning, and interlock control commands according to the risk level and sends them down to the execution and early warning layer devices. Simultaneously, it completely stores monitoring data, control parameters, alarm records, and personnel information throughout the entire operation process in the storage unit, ensuring data traceability.

[0024] The early warning layer comprises an intelligent ventilation execution module and an early warning interlocking module. Both types of equipment receive commands from the main control unit and execute safety control actions. The intelligent ventilation execution module is equipped with a 0-100% stepless speed-regulating variable frequency axial flow fan, multi-angle adjustable air outlets, and a wind speed sensor. The fan adjusts its operating power in real time based on the air volume parameters output by the main control unit, and the air outlets simultaneously adjust their air delivery angles to ensure airflow covers the entire area of ​​the confined space. The wind speed sensor transmits the ventilation operation status back to the main control unit in real time, forming a closed-loop feedback. The early warning and interlocking module integrates a graded audible and visual alarm, a field operation power interlocking switch, and a remote data transmission unit. It can trigger corresponding intensity audible and visual alerts based on different risk levels. In cases of severe risk, it directly cuts off the power supply to the space and simultaneously pushes alarm information to the back-end management terminal through the transmission unit, achieving dual on-site and remote warnings.

[0025] like Figure 2 As shown, the intelligent ventilation control method for gas detection in confined power spaces, which is the supporting invention, relies on the collaborative operation of a three-layer hardware system. It strictly follows the safety standard of "ventilation first, detection second, operation third, real-time monitoring, and post-operation verification" for confined power spaces. It achieves risk pre-positioning, precise ventilation, human-machine linkage, and closed-loop control of the entire process by relying on multi-level data interaction and multi-formula quantitative calculation.

[0026] After system power-on initialization, the system first enters the multi-source data acquisition and fault-tolerant noise reduction verification phase. The main controller continuously receives concentration data uploaded by the three-layer gas sensors. It first performs cross-verification using the extreme value removal and mean value formula to eliminate abnormal extreme values ​​caused by sensor drift, dust, and electromagnetic interference. Then, it performs time-series smoothing and noise reduction processing on five consecutive frames of valid data to obtain stable and reliable global gas concentration values. If more than two sets of valid and usable data from the three-layer sensors are missing, the main controller directly determines that the detection equipment is faulty, triggers an audible and visual alarm, and locks the operation permission, prohibiting confined space operations, thus avoiding mis-control caused by distorted data from the source.

[0027] The main control module prioritizes cross-validation of the gas concentration data collected by the three-layer sensors, eliminating outlier data to avoid misjudgments caused by single-point interference. The effective concentration calculation formula is as follows: ; in, This represents the effective concentration value of the target gas. These are the real-time concentration values ​​collected by sensors at the upper, middle, and lower levels of the space, respectively. The maximum value among the three concentration data sets; It is the minimum value among the three sets of concentration data.

[0028] After removing extreme values, the main control module performs time-series smoothing and noise reduction on five consecutive frames of valid data to obtain stable and reliable real-time gas concentration parameters. If more than two sets of valid data are missing, the main control module immediately triggers a sensor fault alarm and simultaneously locks the work access, prohibiting confined space operations.

[0029] After data verification, the main control system enters the gas concentration trend prediction and risk assessment process. The main control system retrieves the average effective concentration over a continuous time series, calculates the gas rise trend using the concentration change rate formula, and predicts the change in spatial gas concentration within the next 30 seconds. If the concentration rises too rapidly, it is determined to be a rapid accumulation risk, and Level 1 pre-ventilation is initiated in advance; if the concentration rises slowly, Level 2 pre-ventilation is initiated; if the concentration is stable or decreasing, the existing ventilation conditions are maintained. This step breaks away from the traditional passive response mode of ventilation after exceeding the standard, intervening in advance before the gas reaches the safety threshold, thus extending the window for on-site personnel to take evacuation measures.

[0030] Based on the noise-reduced time-series concentration data, the main control module calculates the real-time rate of change of gas concentration, predicts the trend of gas concentration change in the next 30 seconds, and realizes early warning and control of risks. The formula for calculating the rate of change of concentration is as follows: ; in, The rate of change of gas concentration; This represents the average effective gas concentration at the current moment. This represents the average effective concentration from the previous sampling period. The system has a fixed sampling period of 1 second.

[0031] The main control module classifies and predicts risk levels based on the rate values: The risk of a rapid increase was assessed, and Level 1 pre-ventilation was initiated. The risk of a slow increase was assessed, and level two pre-ventilation was initiated. If the concentration is determined to be stable or decreasing, the current ventilation status should be maintained.

[0032] Simultaneously assessing risk levels, the main control unit performs dynamic ventilation volume calculations based on multi-dimensional parameters. It retrieves four types of parameters: gas hazard correction coefficient, real-time gas exceedance rate, fixed volume of confined space, and ambient temperature correction coefficient. These parameters are then substituted into the air volume calculation formula to determine the optimal ventilation volume required for the current scenario. Based on the calculation results, the variable frequency fan speed and air outlet angle are precisely adjusted. Compared to traditional fixed-level ventilation, this method matches ventilation power to the actual risk level on-site. For minor risks, low-power ventilation reduces energy consumption; for high risks, full-power ventilation quickly dilutes harmful gases, balancing safety and energy efficiency.

[0033] The main control module combines four parameters—gas hazard level, concentration exceedance rate, confined space volume, and ambient temperature—to dynamically calculate the optimal ventilation volume in real time, achieving stepless and precise ventilation control. The dynamic air volume calculation formula is as follows: ; in, The required ventilation volume in real time, in meters (m). 3 / h; The value is 1.5 for flammable and explosive gases, 1.2 for toxic gases, and 1.0 for oxygen-deficient environments. The gas exceedance rate is calculated as the ratio of the real-time effective concentration to the industry safety threshold concentration. For power-related limited spaces with fixed volumes, data should be pre-entered into the system database; This is a temperature correction factor. The value is 1.2 for ambient temperatures >35℃, 1.0 for temperatures between 20℃ and 35℃, and 0.9 for temperatures <20℃.

[0034] Based on the calculated air volume, the main control module precisely controls the speed of the variable frequency fan and adjusts the air outlet angle to ensure that the ventilation airflow fully covers the confined space, achieving the dual goals of rapid risk mitigation and energy-saving operation.

[0035] The issuance of ventilation parameters simultaneously initiates a four-level risk classification and linkage control system. The main control system, combining the predicted risk of rising concentrations with the real-time concentration exceedance rate, classifies the concentration into four levels: early warning, slight exceedance, moderate exceedance, and severe exceedance. Each level is matched with ventilation power, audible and visual alarm intensity, and remote alarm strategies: low-volume pre-ventilation and low-frequency alerts are provided only when the concentration is rising slowly; standard-volume ventilation and prompts personnel to shorten work hours are provided for slight exceedances; ventilation power is increased and a background alarm is pushed for moderate exceedances; and the fan operates at full load, high-frequency audible and visual alarms are activated, and the power supply is forcibly cut off, thus forcibly terminating on-site construction work from a hardware perspective.

[0036] Warning level: The gas concentration is rising continuously even though the gas level is not exceeded. The system starts the second-level pre-ventilation, maintains the air volume at 30% of the rated capacity, and activates the low-frequency audible and visual warning to remind the operators to pay attention to environmental changes.

[0037] Mild exceedance level: Exceedance ratio 1 < S ≤ 1.5, the system operates in standard ventilation mode with 60% rated air volume, and a medium-frequency audible and visual warning is activated to remind operators to shorten the operation time and strengthen on-site monitoring.

[0038] Moderate exceedance level: Exceedance ratio 1.5 < S ≤ 2.0. The system operates in enhanced ventilation mode at 85% of rated air volume, activates high-frequency audible and visual alarms, and simultaneously pushes alarm information to the remote backend to remind personnel to prepare to evacuate the site.

[0039] Severe exceedance level: Exceedance ratio S > 2.0, the system starts 100% full-load powerful ventilation, triggers the highest level audible and visual alarm, immediately shuts off the on-site work power, forcibly terminates all work, and pushes an emergency evacuation command.

[0040] Throughout the tiered control process, the system synchronously operates a personnel-environment collaborative interlocking control logic. The main controller compares personnel on-duty time, residence status, and on-site gas risk levels in real time. If personnel are detected to be working overtime or staying in violation of regulations, and the site is at or above the warning risk level, the system automatically increases the ventilation power by one level and plays an audio evacuation reminder. If personnel fail to evacuate in time and the gas level reaches the severe exceedance standard, the system continuously locks the operating power until the gas level in the space returns to a safe standard and all personnel have left the confined space, eliminating the safety blind spot where environmental monitoring and personnel control are independent of each other.

[0041] After all personnel have evacuated the confined space, the system enters the closed-loop review and archiving step for the entire operation, completing the full control loop for a single operation. The system automatically maintains the ventilation equipment running continuously for 5 minutes, after which it re-collects data from the three layers of sensors to verify the gas concentration. The ventilation equipment can only be shut down after all indicators meet the standards; if the concentration still exceeds the standard, the ventilation and monitoring process continues in a loop. After the entire operation is completed, the main control system automatically archives the gas monitoring data, fan speed parameters, alarm records at all levels, and personnel operation logs for this operation, completely preserving the safety control data for the entire process, facilitating future safety reviews and accountability.

[0042] The system and control method of this invention are described in the context of a typical operation scenario for power cable wells in urban power distribution networks.

[0043] First, deploy the equipment on-site and initialize the parameters. Select a volume of 80m³. 3 Using an underground power cable well as the implementation scenario, a set of integrated composite gas sensors for methane, carbon monoxide, hydrogen sulfide, and oxygen, along with a temperature sensor, were deployed in the upper, middle, and lower layers of the cable well. An infrared on-duty detector and personnel positioning receiver were installed at the wellhead. A variable frequency axial flow fan and multi-angle adjustable ventilation vents were fixedly installed inside the well. All equipment was connected to an industrial main control microcontroller. Beforehand, staff entered basic fixed parameters into the main control system, including the cable well volume, national and industry safety thresholds for various gases, gas hazard correction coefficients, and temperature correction coefficients. Equipment debugging and communication testing were completed to ensure normal network connectivity and stable data transmission for all equipment.

[0044] Secondly, an intelligent pre-operation control process is implemented. Before personnel enter the site, the system automatically powers on and initiates initial detection. The main control module collects data from three layers of sensors in real time, eliminates abnormal data through cross-validation formulas, and obtains stable gas concentration and temperature data inside the well after time-series noise reduction. The system simultaneously calculates the rate of change of gas concentration and predicts the risk level. If all gas parameters inside the well meet the standards and the concentration shows no upward trend, the system automatically unlocks the operation permission, allowing personnel to enter the well for construction; if the system detects a slow increase in gas concentration but does not reach the standard, the system initiates secondary pre-ventilation in advance, continuously ventilating at 30% of the rated air volume until the environmental parameters inside the well are completely stable and qualified, thus avoiding safety risks in the early stages of operation.

[0045] Then, dynamic intelligent control of the operation process is implemented. After the operators enter the well wearing positioning tags, the system continuously collects environmental data and personnel status data in a loop. In this implementation scenario, the temperature inside the well rises to 36℃ due to the heat generated by the cable equipment, and trace amounts of combustible gas gradually accumulate. The system calculates in real time that the gas level is slightly exceeded, with an exceedance rate S=1.3. At the same time, it detects that the ambient temperature is higher than 35℃, and automatically applies a temperature correction factor of 1.2 and a combustible gas hazard correction factor of 1.5, combined with an 80m... 3 The system accurately calculates the optimal real-time ventilation volume based on the space's volume and controls the ventilator to continuously and precisely ventilate at 60% of its rated capacity. During ventilation, the system continuously verifies gas data and updates ventilation parameters in real time, avoiding energy waste caused by full-load ventilation and quickly suppressing continuous gas accumulation. Simultaneously, the system monitors work duration in real time. When it detects that the work duration is approaching the warning threshold and gas levels are slightly above the standard, it proactively issues a voice reminder to prompt personnel to expedite their work and avoid prolonged stays.

[0046] Further implement human-machine collaborative interlocking emergency control. If an emergency occurs during operation, and combustible gas rapidly accumulates and its concentration rises sharply within the well, the system will identify the risk of a rapid gas increase through a trend prediction formula, immediately upgrade the ventilation level, activate an 85% enhanced ventilation mode, and trigger a high-frequency audible and visual warning. If the gas concentration continues to rise to a level severely exceeding the standard, the system will immediately activate 100% full-load ventilation, forcibly shut off the power supply to the well, prohibit all construction operations, and simultaneously send an emergency alarm message to the back-end management personnel, reminding on-site personnel to evacuate immediately, completely preventing explosions and poisoning accidents.

[0047] Finally, a closed-loop verification and data archiving process is performed after the operation is completed. After all personnel have evacuated the cable well, the system does not immediately stop working but automatically initiates the post-operation verification process. The system maintains ventilation for 5 minutes, after which it re-collects gas data from the entire well for verification. When all gas concentrations and oxygen content return to within safe threshold ranges, the system determines the environment is acceptable and automatically shuts off the ventilation equipment; if parameters do not meet the standards, the system continues ventilation and cyclical monitoring until the environment is completely safe. All data throughout the operation, including gas detection data, ventilation speed parameters, early warning records, personnel operation time, and equipment operating status, are automatically stored and archived, forming a standardized operation log for convenient subsequent safety reviews and traceability management.

[0048] Therefore, this invention employs the aforementioned intelligent ventilation control system and method for gas detection in confined power spaces. It utilizes a layered hardware architecture as its carrier and a multi-step progressive intelligent control method as its core. It relies on multi-layer sensor cross-verification to solve monitoring distortion problems, on time-series concentration prediction to achieve proactive risk intervention, on multi-parameter fusion dynamic calculation to achieve stepless and precise ventilation adjustment, on human-machine interlocking to eliminate potential hazards from unauthorized personnel operations, and on pre- and post-operation process review and archiving to form a complete safety closed loop. The entire system features interconnected hardware and progressively advancing algorithms, requiring no continuous manual intervention. It can autonomously adapt to complex operating conditions such as temperature changes, dynamic gas accumulation, and personnel entry and exit in confined power spaces, comprehensively reducing the probability of poisoning and explosion-related safety accidents. Simultaneously, it effectively reduces the long-term energy consumption of ventilation equipment, demonstrating strong practicality for engineering implementation.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A smart ventilation control system for gas detection in confined electrical spaces, characterized in that, It includes a perception layer, a main control and management layer, and an execution early warning layer. The perception layer, the main control and management layer, and the execution early warning layer communicate bidirectionally through an industrial bus. The sensing layer includes a multi-source gas detection module and a personnel status sensing module. The multi-source gas detection module has composite gas sensors and temperature sensors deployed in the upper, middle and lower layers of the limited space to collect gas concentration and ambient temperature data. The personnel status sensing module includes an infrared on-duty detector, a work timer and a positioning receiver to collect data on the number of workers, their location, work duration and off-duty status. The main control and management layer includes an industrial microcontroller and a data storage unit. The industrial microcontroller has a built-in control algorithm program, which is used to receive data collected by the sensing layer, complete data verification, gas trend prediction, ventilation volume calculation, risk classification and judgment and output control commands. The data storage unit is used to store monitoring, alarm and personnel data of the whole operation process. The execution early warning layer includes an intelligent ventilation execution module and an early warning and interlocking module; the intelligent ventilation execution module is equipped with a variable frequency axial flow fan, adjustable air outlets, and wind speed sensors; the early warning and interlocking module includes a graded audible and visual alarm, a working power interlocking switch, and a remote transmission unit.

2. The intelligent ventilation control system for gas detection in a confined space according to claim 1, characterized in that, The variable frequency axial flow fan supports stepless speed regulation from 0 to 100%, and the adjustable air outlet can adjust the air delivery angle. The wind speed sensor transmits the ventilation operation status back to the industrial microcontroller in real time to form a closed loop feedback.

3. The intelligent ventilation control system for gas detection in a confined space according to claim 1, characterized in that, The composite gas sensor detects media containing methane, carbon monoxide, hydrogen sulfide, and oxygen.

4. A method for intelligent ventilation control of gas detection in a confined space in an electrical facility, based on the intelligent ventilation control system for gas detection in a confined space in an electrical facility as described in any one of claims 1-3, characterized in that, Includes the following steps: S1. Multi-source data acquisition and fault-tolerant noise reduction verification: The main control layer receives data uploaded by the perception layer, calculates the effective gas concentration by removing extreme values ​​and averaging the data from the three layers of sensors, and then performs time-series smoothing and noise reduction on 5 consecutive frames of effective data; if more than 2 sets of effective data are missing, a fault alarm is triggered and the operation permission is locked. S2. Gas concentration trend prediction: Based on the noise-reduced time-series concentration data, calculate the rate of concentration change and predict the gas concentration trend in the next 30 seconds. Classify the predicted risks into three categories: rapid increase, slow increase, and stable decrease, and match the corresponding pre-ventilation strategies. S3: Multi-parameter fusion dynamic air volume calculation, combined with gas hazard correction coefficient, gas exceedance rate, confined space volume, and temperature correction coefficient, calculates the real-time required ventilation air volume and adjusts the speed of the variable frequency fan and the angle of the air outlet. S4, a four-level risk classification and linkage control system, is divided into four levels: early warning, slight exceedance, moderate exceedance, and severe exceedance, based on the predicted risk and the gas exceedance rate. The system controls ventilation power, audible and visual alarm intensity, and remote alarms according to the level. S5. Personnel-environment collaborative closed-loop control: real-time matching of personnel work status and on-site gas risk level; if personnel stay for too long and there is a warning or above risk, increase the ventilation level and issue an evacuation reminder; if the gas level is severely exceeded and personnel have not evacuated, continuously lock the power supply. S6. After all personnel have evacuated, continue ventilation for 5 minutes, check the gas concentration again, and shut down the ventilation equipment after it meets the standard. All operational data for this operation will be automatically archived.

5. The intelligent ventilation control method for gas detection in a confined electrical space according to claim 4, characterized in that, The formula for calculating the effective concentration is: ； in, This represents the effective concentration value of the target gas. These are the real-time concentration values ​​collected by sensors at the upper, middle, and lower levels of the space, respectively. The maximum value among the three concentration data sets; It is the minimum value among the three sets of concentration data.

6. The intelligent ventilation control method for gas detection in a confined electrical space according to claim 4, characterized in that, The formula for calculating the rate of concentration change is: ； in, The rate of change of gas concentration; This represents the average effective gas concentration at the current moment. This represents the average effective concentration from the previous sampling period. Set a fixed sampling period for the system.

7. The intelligent ventilation control method for gas detection in a confined electrical space according to claim 4, characterized in that, The formula for calculating ventilation air volume is: ； in, The required ventilation volume in real time; This is a gas hazard correction factor; This refers to the percentage of gas exceeding the standard. Fixed volume for power-related limited spaces; This is the temperature correction factor.

8. The intelligent ventilation control method for gas detection in a confined electrical space according to claim 4, characterized in that, The four-level risk control strategy is as follows: for the early warning level, pre-ventilation with 30% of the rated air volume and low-frequency audible and visual warnings are used; for the slightly excessive level, ventilation with 60% of the rated air volume and medium-frequency audible and visual warnings are used; for the moderately excessive level, ventilation with 85% of the rated air volume and high-frequency audible and visual warnings are used, and an alarm is pushed to the background; for the severely excessive level, ventilation with 100% of the rated air volume and the highest level audible and visual alarms are used, while the operating power is locked and an emergency evacuation order is issued.

Images