Air circulation drying and micro-positive pressure double protection integrated device and method for phase separation closed bus

Abstract

This invention discloses an integrated device and method for air circulation drying and micro-positive pressure dual protection of a phase-separated enclosed busbar. The device includes a dual-cylinder dryer assembly, a busbar housing, and a bottom suction branch pipe. The outlet of the dual-cylinder dryer assembly is equipped with an outlet switching valve group, and the outlet of the outlet switching valve group is connected to a drying air supply main pipe. The other end of the drying air supply main pipe is connected to the busbar housing, and an upper air supply branch pipe and a lower air supply branch pipe are respectively installed at the same axial cross-section of the busbar housing. A micro-positive pressure makeup air source inlet pipe is connected to the outside of the busbar housing. A bottom suction branch pipe is located at the lowest point of the bottom of the busbar housing, and the other end of the bottom suction branch pipe is connected to a micro vacuum pump. This invention achieves dynamic matching between heating power supply and molecular sieve desorption requirements through three-stage segmented power control, while also enabling the identification of vertical humidity stratification within the busbar.

Description

Technical Field

[0001] This invention relates to the field of protection technology for isolated phase-enclosed busbars, specifically to an integrated device and method for dual protection of isolated phase-enclosed busbars using air circulation drying and micro-positive pressure. Background Technology

[0002] The isolated phase busbar is a critical power transmission channel between the generator set and the main transformer. To ensure its internal insulation environment, the industry commonly employs air circulation drying and micro-positive pressure protection technology. This involves using a molecular sieve adsorption drying device to dehumidify the air inside the busbar through a closed-loop circulation system. Simultaneously, dry compressed air is introduced into the busbar casing to maintain a micro-positive pressure (typically 300Pa-2500Pa) to prevent the intrusion of external humid air and contaminants. Existing typical devices (such as the GZ45 model) use a single-loop circulation method: "Air inside phase B busbar → Roots blower → adsorption cylinder → dry air refilled into phases A and C busbar → phase B busbar." A PLC is used to automatically control the device's start and stop based on the upper and lower limit signals from the humidity sensor.

[0003] However, in actual engineering operations, most dual-cylinder drying units with air circulation drying and micro-positive pressure protection devices heat and regenerate the adsorbed saturated molecular sieve cylinders at a fixed duration and constant power during the regeneration stage. Typically, even in the later stages of regeneration (when the residual moisture in the desiccant has been significantly reduced), heating continues at rated power. At this point, the heating energy is primarily used to heat the desiccant skeleton and the cylinder itself, rather than for effective moisture desorption. This results in inefficient energy control during the regeneration process and significant energy waste. Furthermore, although the air can be dried to a low relative humidity at the drying cylinder outlet, for isolated closed busbars that are tens of meters long and have an inner diameter exceeding 1 meter, there is a significant problem of uneven airflow distribution within the internal space. The airflow velocity in the bottom region of the busbar shell is extremely low. In addition, liquid water condensing due to temperature differences accumulates at the bottom during shutdown, continuously evaporating and releasing moisture into the surrounding space. This creates a stratified pattern where the top region is relatively dry and the bottom region remains continuously moist, resulting in severe vertical humidity stratification within the busbar. Summary of the Invention

[0004] To address this issue, the present invention provides an integrated device and method for dual protection of air circulation drying and micro-positive pressure for isolated closed busbars, in order to solve the problem that the existing technology lacks the function of sensing and regulating the humidity stratification state in the vertical direction inside the busbar, resulting in continuously high humidity in the bottom area. At the same time, the energy consumption control of the molecular sieve cylinder regeneration process is crude, causing a large amount of energy waste.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] In the first aspect, an integrated device for dual protection of air circulation drying and micro positive pressure for isolated phase closed busbars includes a double-cylinder dryer group, a busbar shell and a bottom suction branch pipe;

[0007] The outlet of the dual-cylinder dryer group is equipped with an outlet switching valve group, and the outlet of the outlet switching valve group is connected to a drying air supply pipe, which is used to introduce the drying air output from the dual-cylinder dryer group into the drying air supply pipe.

[0008] The other end of the main drying gas supply pipe is connected to a busbar housing, and an upper gas supply branch pipe and a lower gas supply branch pipe are respectively installed at the same axial section position of the busbar housing. A micro positive pressure supplementary gas source inlet pipe is connected to the outside of the busbar housing.

[0009] The lowest point of the busbar housing has a bottom suction branch pipe, and the other end of the bottom suction branch pipe is connected to a miniature vacuum pump for actively suctioning the liquid water accumulated at the bottom of the busbar housing.

[0010] Furthermore, the dual-cylinder dryer assembly includes a first drying cylinder and a second drying cylinder, and both the first and second drying cylinders are equipped with electric heaters for alternately executing the drying adsorption working mode and the heating regeneration mode.

[0011] Furthermore, the outlet of the upper gas supply branch pipe is located in the upper half of the internal space of the busbar, and the outlet of the lower gas supply branch pipe is located in the lower half of the internal space of the busbar.

[0012] Furthermore, an upper flow regulating valve is provided on the upper air supply branch pipe, and a lower flow regulating valve is provided on the lower air supply branch pipe, for regulating the flow rate of dry air flowing into the busbar.

[0013] Furthermore, the outlets of both the first and second drying cylinders are connected to a regeneration exhaust pipe installed via an outlet switching valve assembly, and the regeneration exhaust pipe is equipped with a regeneration exhaust temperature and humidity composite sensor.

[0014] Furthermore, the inlet pipeline of the micro-positive pressure make-up gas source is equipped with an online dew point meter and an oil content detection sensor. The online dew point meter is used to detect the dew point temperature of the make-up gas source, and the oil content detection sensor is used to monitor the oil mist concentration in the make-up gas source in real time.

[0015] Secondly, a method for integrating air circulation drying and micro-positive pressure dual protection for isolated phase-closed busbars includes the following steps:

[0016] S1: Collect data on the upper air temperature, upper relative humidity, lower air temperature, and lower relative humidity at the cross-section of the busbar shell, calculate the upper dew point temperature and the lower dew point temperature respectively, and then obtain the vertical dew point stratification index; then combine the preset first threshold and the vertical dew point stratification index to determine whether there is a vertical humidity stratification phenomenon in the busbar.

[0017] S2: When S1 determines that there is vertical humidity stratification on the busbar, the controller executes the bottom priority air supply strategy;

[0018] S3: Collect the temperature and relative humidity of the regenerated exhaust pipe, and use the same dew point temperature calculation formula as S1 to obtain the dew point temperature of the regenerated exhaust, and use the dew point temperature of the regenerated exhaust as the state variable to perform three-stage segmented control.

[0019] S4: Obtain the dew point temperature and oil content of the gas source for replenishment. Select the maximum value of the bottom dew point temperature output by S1 as the reference dew point temperature at the bottom of the busbar and determine whether the current conditions allow for gas replenishment.

[0020] Furthermore, the upper dew point temperature and bottom dew point temperature The calculation formula is as follows:

[0021]

[0022]

[0023] in, and These are the empirical coefficients of the Magnus formula. This is the upper transition coefficient. This is the lower transition coefficient;

[0024] Based on the bottom dew point temperature and upper dew point temperature The difference is used to calculate the vertical dew point stratification index at this section location of the busbar shell. Vertical dew point stratification index The magnitude of the value reflects the severity of humidity in the vertical direction due to water vapor content.

[0025] Furthermore, the specific steps of S2 are as follows:

[0026] S2.1: When the S1 determination bus casing confirms the existence of vertical humidity stratification, the controller activates the bottom priority air supply strategy and stops the original upper and lower balanced air supply mode.

[0027] S2.2: The controller sends differentiated control commands to the upper flow regulating valve located on the upper air supply branch pipe and the lower flow regulating valve located on the lower air supply branch pipe, adjusting the opening of the lower flow regulating valve to the first opening value, corresponding to 60%-80% of the rated total flow of the dry air supply main pipe, and adjusting the opening of the upper flow regulating valve to the second opening value, corresponding to 20%-40% of the rated total flow, thereby forcing most of the dry air to be sent into the bottom area with the highest humidity.

[0028] S2.3: While implementing stratified gas supply, the controller simultaneously starts the miniature vacuum pump connected to the bottom suction branch pipe and operates in a preset intermittent mode.

[0029] S2.4: The controller continuously collects and calculates the vertical dew point stratification index of all monitored sections. When the vertical dew point stratification index of each section drops below the preset second threshold and this state continues to reach the preset stable duration, the upper flow regulating valve and the lower flow regulating valve are restored to the balanced opening, the micro vacuum suction pump is stopped, and the normal balanced gas supply mode is restored.

[0030] Furthermore, the specific steps of S3 are as follows:

[0031] S3.1: The controller collects the temperature of the regenerated exhaust gas in real time through a temperature and humidity composite sensor installed on the manifold section of the regenerated exhaust pipe. and relative humidity ;

[0032] S3.2: The controller uses the temperature of the regenerated exhaust gas collected in S3.1. and relative humidity The dew point temperature of the regenerated exhaust gas is calculated using the same dew point temperature calculation formula as in S1. The calculation formula is as follows:

[0033]

[0034] S3.3: Based on a preset third threshold, the dew point temperature of the regenerated exhaust gas is... Make a judgment and execute three-stage segmented power control:

[0035] First, input the preset third threshold and fourth threshold, where the third threshold is greater than the fourth threshold;

[0036] Then, the dew point temperature of the regenerated exhaust gas... Compare with the third and fourth thresholds respectively:

[0037] When the regenerated exhaust dew point temperature When the value exceeds the preset third threshold, the regeneration process is determined to be in the high-efficiency desorption period, and the controller controls the electric heater to operate at 100% full power of the rated power.

[0038] When the regenerated exhaust dew point temperature When the power drops to between the third and fourth thresholds, the regeneration process is considered to have entered a transition period, and the power of the electric heater is reduced to 40%-60% of its rated power.

[0039] When the regenerated exhaust dew point temperature When the temperature drops to the fourth threshold or below, and this state continues for more than the preset delay time, the regeneration process is determined to have entered an inefficient overheating period. The power supply to the electric heater is then cut off, heating is stopped, and the drying cylinder enters the natural cooling stage.

[0040] The present invention has the following advantages: The present invention obtains the vertical dew point stratification index by calculating the difference between the upper dew point temperature and the bottom dew point temperature, thereby realizing the identification of the vertical humidity stratification state inside the busbar. Combined with the judgment of the vertical dew point stratification index and the preset first threshold, the controller can easily execute the bottom priority air supply strategy, so that most of the dry air is forced to be sent to the bottom area with the highest humidity. This effectively solves the problem of vertical humidity stratification inside the busbar shell caused by uneven airflow distribution, resulting in a relatively dry top area and a continuously humid bottom area. It also reduces the insulation risk of the bottom insulator caused by long-term exposure to a high humidity environment.

[0041] Meanwhile, by using the dew point temperature of the regenerated exhaust gas as a state variable representing the actual desorption state of the molecular sieve, a three-stage segmented power control is implemented to dynamically match the heating power supply with the desorption demand of the molecular sieve. This avoids the problem of ineffective overheating caused by the continued heating at rated power in the later stages of regeneration when the residual moisture of the desiccant has been greatly reduced, thereby reducing energy consumption in the regeneration process and delaying the thermal aging of the molecular sieve.

[0042] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Attached Figure Description

[0043] To more intuitively illustrate the prior art and this application, exemplary drawings are provided below. It should be understood that the specific shapes and structures shown in the drawings should not generally be regarded as limiting conditions for implementing this application; for example, based on the technical concept disclosed in this application and the exemplary drawings, those skilled in the art are able to easily make conventional adjustments or further optimizations to the addition / reduction / classification, specific shapes, positional relationships, connection methods, size ratios, etc. of certain units (components).

[0044] Figure 1 This is a structural diagram of an integrated device for dual protection of air circulation drying and micro-positive pressure for isolated phase closed busbars according to the present invention.

[0045] Figure 2This is a flowchart illustrating the implementation of an integrated method for dual protection of air circulation drying and micro-positive pressure for isolated phase enclosed busbars according to the present invention.

[0046] Explanation of reference numerals in the attached figures:

[0047] 1. Dual-cylinder dryer assembly; 2. Outlet switching valve assembly; 3. Drying gas supply main pipe; 4. Upper gas supply branch pipe; 5. Lower gas supply branch pipe; 6. Bottom suction branch pipe; 7. Miniature vacuum suction pump; 8. Humidity sensor; 9. Regeneration exhaust pipe; 10. Temperature and humidity composite sensor; 11. Gas source inlet pipeline; 12. Busbar housing. Detailed Implementation

[0048] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. It should be understood that these embodiments are merely for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Technical engineers in the field can make some non-essential improvements and adjustments to the present invention based on the above-described content. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] Please see Figure 1 An integrated device for air circulation drying and micro-positive pressure dual protection of a phase-separated enclosed busbar includes a dual-cylinder dryer group 1 consisting of a first drying cylinder and a second drying cylinder. The first and second drying cylinders alternately perform a drying adsorption mode and a heating regeneration mode. Both the first and second drying cylinders are equipped with electric heaters for heating and regenerating the adsorbed molecular sieves.

[0050] Both the outlet pipe of the first drying cylinder and the outlet pipe of the second drying cylinder are equipped with an electric two-position three-way valve of the outlet switching valve group 2. The outlet switching valve group 2 is controlled by the controller and is used to connect the outlet of the drying cylinder that is currently in the drying adsorption working mode to the drying gas supply main pipe 3, while isolating the outlet of the drying cylinder that is in the heating regeneration mode from the drying gas supply main pipe 3 and connecting it to the regeneration exhaust pipe 9.

[0051] The outputs of the two outlet switching valve groups 2 are combined and connected to the drying air supply main pipe 3. When the first drying cylinder is in the drying adsorption working mode, the first drying cylinder outputs dry air into the drying air supply main pipe 3; when the second drying cylinder is in the drying adsorption working mode, the second drying cylinder outputs dry air into the drying air supply main pipe 3.

[0052] The outlet end of the drying air supply main pipe 3 is connected to an upper air supply branch pipe 4 and a lower air supply branch pipe 5. The other ends of the upper air supply branch pipe 4 and the lower air supply branch pipe 5 are respectively located at the same axial section position of the busbar housing 12, for inputting dry air into the busbar housing 12. The outlet of the upper air supply branch pipe 4 is located in the upper half of the internal space of the busbar, preferably at a distance of 1 / 5 to 1 / 3 of the inner diameter of the busbar from the top of the busbar housing 12. The outlet of the lower air supply branch pipe 5 is located in the lower half of the internal space of the busbar, preferably at a distance of 1 / 5 to 1 / 3 of the inner diameter of the busbar from the bottom of the busbar housing 12.

[0053] An upper flow regulating valve is installed on the upper air supply branch pipe 4, which is controlled by the controller and is used to regulate the flow rate of dry air flowing into the upper half of the internal space of the busbar.

[0054] The lower air supply branch pipe 5 is equipped with a lower flow regulating valve, which is controlled by the controller and is used to regulate the flow rate of dry air flowing into the lower half of the internal space of the busbar.

[0055] The lowest point of the busbar housing 12 has a bottom suction branch pipe 6, and the other end of the bottom suction branch pipe 6 is connected to a miniature vacuum pump 7, which is used to actively suction the liquid water accumulated at the bottom.

[0056] At least two humidity sensors 8 are installed at the same axial cross-sectional location inside the busbar housing 12, located in the top and bottom regions of the internal space of the busbar housing 12, respectively. The humidity sensors 8 are used to detect the relative humidity and temperature of the air at their respective heights and transmit the detection signals to the controller. A group of humidity sensors 8 is installed every 8-12m along the length of the busbar housing 12, with each group including an upper humidity sensor 8 and a lower humidity sensor 8, forming a distributed dual-height humidity monitoring network along the length of the busbar.

[0057] The outlets of both the first and second drying cylinders are connected to a regeneration exhaust pipe 9 installed via an outlet switching valve assembly 2. This pipe is used to centrally extract the high-temperature, high-humidity desorption exhaust gas discharged from the drying cylinders in heating regeneration mode, facilitating subsequent transport to the waste heat recovery heat exchanger or a safe discharge port. Furthermore, the regeneration exhaust pipe 9 is internally equipped with a regeneration exhaust temperature and humidity composite sensor 10, used to detect the temperature and relative humidity of the regeneration exhaust gas in real time and transmit the detection signal to the controller.

[0058] The outer side of the busbar housing 12 is connected to a micro-positive pressure air supply inlet pipe 11, which is used to replenish dry air into the busbar housing 12 to maintain a micro-positive pressure state.

[0059] An online dew point meter and an oil content detection sensor are installed in the inlet pipeline 11 of the micro-positive pressure make-up gas source. The online dew point meter is used to detect the dew point temperature of the make-up gas source, and the oil content detection sensor is used to monitor the oil mist concentration in the make-up gas source in real time. When the oil content exceeds the standard, the gas source quality grading and processing system is triggered to downgrade or cut off the make-up gas passage to prevent oil contaminants from entering the bus shell 12 and depositing on the surface of the insulator, which would cause a drop in the surface flashover voltage.

[0060] The controller is used to receive data collected by the above sensors. It is installed in the remote control cabinet in the generator set's electrical room and is electrically connected to each sensor, electric regulating valve, suction pump, and electric heater via cables. It also exchanges data with the generator set's distributed control system (DCS) through a communication interface.

[0061] Please see Figure 2 A method for integrating air circulation drying and micro-positive pressure dual protection for isolated phase enclosed busbars includes the following steps:

[0062] S1: Collect the detection data of the upper humidity sensor 8 and the lower humidity sensor 8 at the cross-section of the busbar shell 12 to obtain the upper air temperature, upper relative humidity, bottom air temperature and bottom relative humidity, calculate the upper dew point temperature and bottom dew point temperature respectively, and then obtain the vertical dew point stratification index; then combine the preset first threshold and the vertical dew point stratification index to determine whether there is a vertical humidity stratification phenomenon in the busbar, which facilitates the stratification identification mode based on the vertical dual height dew point temperature difference for quantification identification of stratification status, and provides a basis for subsequent control.

[0063] The controller collects detection data from the upper humidity sensor 8 and the lower humidity sensor 8 at the same cross-sectional position of the same busbar housing 12 at a sampling period, obtaining the air temperature and relative humidity of the upper region and the air temperature and relative humidity of the bottom region, respectively. It then calculates the dew point temperature of the upper and bottom regions to obtain the upper dew point temperature. and bottom dew point temperature .

[0064] Dew point temperature represents the temperature at which moist air is cooled to saturation under constant pressure and humidity. Dew point temperature is calculated instead of relative humidity because within a closed busbar, a temperature difference may exist between the top and bottom, causing relative humidity readings to differ even if the water vapor partial pressure is the same at both locations. Directly using the relative humidity difference introduces temperature interference, leading to misjudgments of the degree of stratification; the dew point temperature difference more accurately reflects the absolute gradient of water vapor content between the upper and lower regions. Upper dew point temperature. and bottom dew point temperature The calculation formula is as follows:

[0065]

[0066]

[0067] in, and These are empirical coefficients for the Magnus formula, applicable to saturated vapor pressure at the water surface. This is the upper transition coefficient. This is the lower transition coefficient. The calculation formula is as follows:

[0068]

[0069]

[0070] in, and These are the relative humidity levels of the upper and bottom areas, respectively. and These are the air temperatures of the upper and lower regions, respectively. It is the natural logarithm.

[0071] Based on the bottom dew point temperature and upper dew point temperature The difference is used to calculate the vertical dew point stratification index at this section location of the busbar shell 12. Vertical dew point stratification index The magnitude of the value reflects the severity of humidity in the vertical direction due to water vapor content.

[0072] When the calculated vertical dew point stratification index When the humidity exceeds the first threshold preset by the system, it is determined that there is vertical humidity stratification inside the busbar housing 12 at that cross-sectional position, and the insulation environment risk of the bottom area is higher than that of the upper area.

[0073] S2: When S1 determines that vertical humidity stratification exists on the busbar, the controller executes a bottom-priority air supply strategy. The lower flow regulating valve is adjusted to a first opening value corresponding to 60%-80% of the rated total flow, and the upper flow regulating valve is adjusted to a second opening value corresponding to 20%-40% of the rated total flow. Simultaneously, the bottom micro-vacuum pump 7 is activated intermittently to actively remove accumulated liquid at the bottom until the vertical humidity stratification at all sections drops below the second threshold and remains there for a preset duration, after which the balanced air supply mode is restored. Through the synergy of bottom-priority air supply and active removal of accumulated liquid at the bottom, dry air is targeted and delivered to the bottom area with the highest humidity as needed, facilitating the elimination of liquid water evaporation sources of moisture.

[0074] The specific steps of S2 are as follows:

[0075] S2.1: When the determination bus housing 12 in S1 confirms the existence of vertical humidity stratification, the controller activates the bottom priority air supply strategy and stops the original upper and lower balanced air supply mode.

[0076] S2.2: The controller sends differentiated control commands to the upper flow regulating valve located on the upper air supply branch pipe 4 and the lower flow regulating valve located on the lower air supply branch pipe 5, adjusting the opening of the lower flow regulating valve to the first opening value, corresponding to 60%-80% of the rated total flow of the dry air supply main pipe 3, and adjusting the opening of the upper flow regulating valve to the second opening value, corresponding to 20%-40% of the rated total flow, thereby forcing most of the dry air to be sent to the bottom area with the highest humidity.

[0077] S2.3: While implementing stratified gas supply, the controller simultaneously starts the miniature vacuum pump 7 connected to the bottom suction branch pipe 6, and operates in a preset intermittent mode, for example, running for 10 minutes and stopping for 50 minutes as one cycle, actively sucking and removing the liquid water accumulated at the bottom of the busbar housing 12.

[0078] S2.4: The controller continuously collects and calculates the vertical dew point stratification index of all monitored sections. When the vertical dew point stratification index of each section drops below the preset second threshold and this state continues to reach a preset stable duration, such as 30 minutes, the controller determines that the humidity stratification has been fully eliminated. Then, it restores the upper flow regulating valve and the lower flow regulating valve to the balanced opening, stops the micro vacuum suction pump 7, ends the bottom priority air supply strategy, and restores the normal balanced air supply mode.

[0079] S3: Collect the temperature and relative humidity of the regeneration exhaust pipe 9, and use the same dew point temperature calculation formula as S1 to obtain the regeneration exhaust dew point temperature. Then, use the regeneration exhaust dew point temperature as the state variable to perform three-stage segmented control. This allows the actual desorption state of the molecular sieve to be represented by the regeneration exhaust dew point temperature, so that the heating power supply and desorption demand are dynamically matched, avoiding ineffective overheating in the later stage of regeneration, reducing regeneration energy consumption and delaying the thermal aging of the molecular sieve.

[0080] The specific steps for S3 are as follows:

[0081] S3.1: The controller collects the temperature of the regenerated exhaust gas in real time through a temperature and humidity composite sensor installed on the manifold section of the regenerated exhaust pipe 9. and relative humidity .

[0082] S3.2: The controller uses the temperature of the regenerated exhaust gas collected in S3.1. and relative humidity The dew point temperature is calculated in real time using the same formula as in S1. The calculation formula is as follows:

[0083]

[0084] S3.3: Based on a preset third threshold, the dew point temperature of the regenerated exhaust gas is... The system makes a judgment and executes three-stage segmented power control to achieve dynamic matching between the regeneration heating energy supply and the actual desorption requirements of the molecular sieve.

[0085] First, input the preset third and fourth thresholds. These thresholds define the preset dew point temperature boundaries dividing the three regeneration stages, with the third threshold being greater than the fourth. The preset range for the third threshold is 35℃-45℃; the preset range for the fourth threshold is 10℃-20℃. The third threshold represents the dew point characteristic of the exhaust gas when a large amount of adsorbed water in the molecular sieve is in a vigorous desorption state; when the regeneration exhaust gas dew point temperature... Above the third threshold, the exhaust gas contains high levels of water vapor, and the heating energy is mainly consumed for water desorption. The fourth threshold indicates the exhaust gas dew point characteristic where most of the desorbable water in the molecular sieve has been desorbed. When the regenerated exhaust gas dew point temperature... When the water vapor content in the exhaust gas drops to the fourth threshold or below, the contribution of continued heating to desorption is already very low.

[0086] When the regenerated exhaust dew point temperature When the value exceeds the preset third threshold, the regeneration process is determined to be in the efficient desorption period. The controller controls the electric heater to operate at 100% full power of the rated power to provide sufficient heat to overcome the adsorption potential energy and latent heat of vaporization of water.

[0087] When the regenerated exhaust dew point temperature When the temperature drops to between the third and fourth thresholds, the regeneration process is considered to have entered the transition period. A large amount of easily desorbable moisture has been removed, and the controller reduces the power of the electric heater to 40%-60% of the rated power to match the reduced desorption rate.

[0088] When the regenerated exhaust dew point temperature When the temperature drops to the fourth threshold or below, and this state continues for more than a preset delay time, such as 15 minutes, it is determined that the regeneration process has entered an inefficient overheating period. Most of the desorbable moisture in the desiccant has been desorbed, the controller cuts off the power to the electric heater, stops heating, and the drying cylinder enters the natural cooling stage.

[0089] S4: Obtain the dew point temperature and oil content of the replenishing gas source. Select the maximum value of the bottom dew point temperature output from S1 as the reference dew point temperature at the bottom of the busbar. Determine whether the current conditions allow for replenishing gas; otherwise, prohibit replenishing gas and issue an alarm signal. This step quantitatively compares the quality of the replenishing gas source with the actual humidity level of the bottom area inside the busbar using dew point temperature, and combines this with the oil content index to establish a dual-parameter quantitative criterion for replenishing gas access, thus preventing the damage to the internal insulation environment of the busbar caused by inferior gas sources from the source.

[0090] The specific steps for S4 are as follows:

[0091] S4.1: The controller obtains the quality parameters of the make-up gas source in real time through the online dew point meter and oil content detection sensor installed in the inlet pipeline 11 of the micro-positive pressure make-up gas source. The quality parameters of the make-up gas source include the dew point temperature and the oil content of the gas source.

[0092] S4.2: The controller selects the maximum value from the bottom dew point temperatures of all monitored sections calculated by S1 as the reference dew point temperature representing the humidity level of the bottom area inside the busbar.

[0093] S4.3: Compare the gas source dew point temperature and oil content with the bus bottom reference dew point temperature determined in S4.2 and the preset oil content threshold to make a gas supply access decision.

[0094] The first parameter criterion is the comparison between the gas source dew point temperature and the reference dew point temperature at the bottom of the busbar. The controller determines whether the gas source dew point temperature meets the requirement of gas source dew point temperature ≤ reference dew point temperature at the bottom of the busbar - preset safety temperature difference margin. The preset safety temperature difference margin ranges from 3℃ to 8℃.

[0095] This criterion ensures that the supplementary gas has a sufficient drying advantage over the air in the most humid area inside the busbar. If this criterion is met, it means that the supplementary gas operation can have a positive effect on diluting and drying the overall environment inside the busbar. If this criterion is not met, it means that the dew point temperature of the supplementary gas source is too high, and the supplementary gas will introduce additional moisture load.

[0096] The second criterion is a comparison between the oil content of the gas source and a preset oil content threshold. The preset oil content threshold is set to 0.01 mg / m³.

[0097] The controller determines whether the oil content of the gas source meets the requirement of ≤0.01mg / m³. If it does, it means that the oil mist pollution level of the supplementary gas source is within the allowable range. If it does not meet the requirement, it means that the oil content of the gas source exceeds the standard, and the supplementary gas will introduce oil mist pollutants into the busbar.

[0098] S4.4: The controller performs the admission action based on the combined result of the above two criteria:

[0099] When both conditions are met, the quality of the supplementary gas source is deemed qualified, and the micro-positive pressure system is allowed to perform supplementary gas operation into the busbar.

[0100] If any condition is not met, the controller immediately determines that the gas source quality is unqualified, executes the action of prohibiting gas supply, keeps the gas supply pipeline valve in the closed state, and at the same time sends an alarm signal of unqualified gas source quality to the unit's distributed control system (DCS) through the human-machine interface and external communication interface, notifying the operators to investigate and deal with the gas source problem in a timely manner.

[0101] This invention identifies the vertical humidity stratification state inside the busbar by setting an upper humidity sensor 8 and a lower humidity sensor 8 at the same cross-sectional position of the busbar housing 12, and calculating the difference between the upper and lower dew point temperatures to obtain a vertical dew point stratification index. Combining the vertical dew point stratification index with a preset first threshold, the controller can easily execute a bottom-priority air supply strategy, forcing most of the dry air into the bottom area with the highest humidity. This effectively solves the problem of vertical humidity stratification inside the busbar housing 12, where the top area is relatively dry and the bottom area is continuously damp due to uneven airflow distribution, reducing the insulation risk to the bottom insulators caused by prolonged exposure to high humidity.

[0102] Meanwhile, by collecting the temperature and relative humidity of the regenerated exhaust gas in real time and calculating the dew point temperature of the regenerated exhaust gas, the dew point temperature of the regenerated exhaust gas is used as a state variable representing the actual desorption state of the molecular sieve. Three-stage segmented power control is implemented to dynamically match the heating power supply with the desorption demand of the molecular sieve. This avoids the problem of ineffective overheating caused by the continued heating at rated power in the later stage of regeneration when the residual moisture of the desiccant has been greatly reduced. This reduces the energy consumption of the regeneration process and delays the thermal aging of the molecular sieve.

[0103] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An integrated device for dual protection of air circulation drying and micro-positive pressure for isolated phase enclosed busbars, characterized in that, It includes a double-cylinder dryer assembly (1), a busbar housing (12), and a bottom suction branch pipe (6); The outlet of the dual-cylinder dryer group (1) is provided with an outlet switching valve group (2), and the outlet of the outlet switching valve group (2) is connected to a drying air supply pipe (3) for introducing the drying air output from the dual-cylinder dryer group (1) into the drying air supply pipe (3). The other end of the drying gas supply main pipe (3) is connected to a busbar housing (12), and an upper gas supply branch pipe (4) and a lower gas supply branch pipe (5) are respectively provided at the same axial section position of the busbar housing (12). A micro positive pressure supplementary gas source inlet pipe (11) is connected to the outside of the busbar housing (12). The lowest point of the busbar housing (12) has a bottom suction branch pipe (6), and the other end of the bottom suction branch pipe (6) is connected to a micro vacuum suction pump (7) for actively suctioning the liquid water accumulated at the bottom of the busbar housing (12).

2. The integrated device for dual protection of air circulation drying and micro-positive pressure for isolated phase enclosed busbars according to claim 1, characterized in that, The dual-cylinder dryer group (1) includes a first drying cylinder and a second drying cylinder, and both the first drying cylinder and the second drying cylinder are equipped with electric heaters for alternately performing the drying adsorption working mode and the heating regeneration mode.

3. The integrated device for dual protection of air circulation drying and micro-positive pressure for isolated phase enclosed busbars according to claim 1, characterized in that, The outlet of the upper gas supply branch pipe (4) is located in the upper half of the internal space of the busbar, and the outlet of the lower gas supply branch pipe (5) is located in the lower half of the internal space of the busbar.

4. The integrated device for dual protection of air circulation drying and micro-positive pressure for isolated phase enclosed busbars according to claim 1, characterized in that, An upper flow regulating valve is provided on the upper air supply branch pipe (4), and a lower flow regulating valve is provided on the lower air supply branch pipe (5) to regulate the flow rate of dry air flowing into the busbar.

5. The integrated device for dual protection of air circulation drying and micro-positive pressure for isolated phase enclosed busbars according to claim 2, characterized in that, The outlets of the first drying cylinder and the second drying cylinder are both connected to a regeneration exhaust pipe (9) installed through an outlet switching valve group (2), and a regeneration exhaust temperature and humidity composite sensor (10) is installed inside the regeneration exhaust pipe (9).

6. The integrated device for dual protection of air circulation drying and micro-positive pressure for isolated phase enclosed busbars according to claim 1, characterized in that, The micro-positive pressure make-up gas source inlet pipeline (11) is equipped with an online dew point meter and an oil content detection sensor. The online dew point meter is used to detect the dew point temperature of the make-up gas source, and the oil content detection sensor is used to monitor the oil mist concentration in the make-up gas source in real time.

7. A method for integrating air circulation drying and micro-positive pressure dual protection for isolated phase enclosed busbars, characterized in that, Includes the following steps: S1: Collect the upper air temperature, upper relative humidity, lower air temperature and lower relative humidity data of the busbar shell (12) section, calculate the upper dew point temperature and lower dew point temperature respectively, and then obtain the vertical dew point stratification index; then combine the preset first threshold and the vertical dew point stratification index to determine whether the busbar has a vertical humidity stratification phenomenon. S2: When S1 determines that there is vertical humidity stratification on the busbar, the controller executes the bottom priority air supply strategy; S3: Collect the temperature and relative humidity of the regenerated exhaust pipe (9), and use the same dew point temperature calculation formula as S1 to obtain the regenerated exhaust dew point temperature, and use the regenerated exhaust dew point temperature as the state variable to perform three-stage segmented control. S4: Obtain the dew point temperature and oil content of the gas source for replenishment. Select the maximum value of the bottom dew point temperature output by S1 as the reference dew point temperature at the bottom of the busbar and determine whether the current conditions allow for gas replenishment.

8. The integrated method for dual protection of air circulation drying and micro-positive pressure for isolated phase enclosed busbars according to claim 7, characterized in that, The above: upper dew point temperature and bottom dew point temperature The calculation formula is as follows: in, and These are the empirical coefficients of the Magnus formula. This is the upper transition coefficient. This is the lower transition coefficient; Based on the bottom dew point temperature and upper dew point temperature The difference is calculated for the vertical dew point stratification index of the busbar shell (12) at this cross-section location. Vertical dew point stratification index The magnitude of the value reflects the severity of humidity in the vertical direction due to water vapor content.

9. The integrated method for dual protection of air circulation drying and micro-positive pressure for isolated phase enclosed busbars according to claim 7, characterized in that, The specific steps of S2 are as follows: S2.1: When the determination bus housing (12) of S1 confirms the existence of vertical humidity stratification, the controller activates the bottom priority air supply strategy and stops the original upper and lower balanced air supply mode. S2.2: The controller sends differentiated control commands to the upper flow regulating valve located on the upper air supply branch pipe (4) and the lower flow regulating valve located on the lower air supply branch pipe (5), adjusting the opening of the lower flow regulating valve to the first opening value, corresponding to 60%-80% of the rated total flow of the dry air supply main pipe (3), and adjusting the opening of the upper flow regulating valve to the second opening value, corresponding to 20%-40% of the rated total flow, thereby forcing most of the dry air into the bottom area with the highest humidity. S2.3: While implementing stratified gas supply, the controller simultaneously starts the miniature vacuum pump (7) connected to the bottom suction branch pipe (6) and operates in a preset intermittent mode; S2.4: The controller continuously collects and calculates the vertical dew point stratification index of all monitored sections. When the vertical dew point stratification index of each section drops below the preset second threshold and this state continues to reach the preset stable duration, the upper flow regulating valve and the lower flow regulating valve are restored to the balanced opening, the micro vacuum suction pump (7) is stopped, and the normal balanced gas supply mode is restored.

10. The integrated method for dual protection of air circulation drying and micro-positive pressure for isolated phase enclosed busbars according to claim 7, characterized in that, The specific steps of S3 are as follows: S3.1: The controller collects the temperature of the regenerated exhaust gas in real time through a temperature and humidity composite sensor installed on the manifold section of the regenerated exhaust pipe (9). and relative humidity ; S3.2: The controller uses the temperature of the regenerated exhaust gas collected in S3.

1. and relative humidity The dew point temperature of the regenerated exhaust gas is calculated using the same dew point temperature calculation formula as in S1. The calculation formula is as follows: S3.3: Based on a preset third threshold, the dew point temperature of the regenerated exhaust gas is... Make a judgment and execute three-stage segmented power control: First, input the preset third threshold and fourth threshold, where the third threshold is greater than the fourth threshold; Then, the dew point temperature of the regenerated exhaust gas... Compare with the third and fourth thresholds respectively: When the regenerated exhaust dew point temperature When the value exceeds the preset third threshold, the regeneration process is determined to be in the high-efficiency desorption period, and the controller controls the electric heater to operate at 100% full power of the rated power. When the regenerated exhaust dew point temperature When the power drops to between the third and fourth thresholds, the regeneration process is considered to have entered a transition period, and the power of the electric heater is reduced to 40%-60% of its rated power. When the regenerated exhaust dew point temperature When the temperature drops to the fourth threshold or below, and this state continues for more than the preset delay time, the regeneration process is determined to have entered an inefficient overheating period. The power supply to the electric heater is then cut off, heating is stopped, and the drying cylinder enters the natural cooling stage.

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