A smart hierarchical heat dissipation system and method based on PSO multi-objective optimization of the two-layer chimney effect

Abstract

This invention discloses an intelligent hierarchical heat dissipation system and method based on Particle Swarm Optimization (PSO) multi-objective optimization with a double-layer chimney effect. The system forms an air insulation interlayer through a double-layer insulated shell structure, utilizing the chimney effect to drive external circulation to block solar radiation heat; simultaneously, internal circulation is driven by bottom intake fans and top exhaust fans to remove heat from components. The intelligent control unit employs the Particle Swarm Optimization (PSO) algorithm, using temperature deviation, energy consumption, and operating cost as objective functions to dynamically adjust the collaborative working mode of five fans. This invention achieves precise temperature control and optimal energy efficiency for outdoor distribution boxes under strong sunlight and full-load conditions, meeting and falling below the temperature rise limit requirements of GB / T 7251.2, demonstrating significant energy-saving effects and safety reliability.

Description

Technical Field

[0001] This invention belongs to the technical field of power transmission and distribution equipment, specifically relating to an outdoor low-voltage switchgear for use in high-load, high-sunlight environments. In particular, it is an intelligent heat dissipation system employing a 304 stainless steel double-layer shell structure, utilizing the chimney effect generated by the vertical height difference combined with forced convection, and dynamically controlled through a particle swarm optimization (PSO) algorithm and a thermal balance model to meet the temperature rise limit requirements of GB / T 7251.2. Background Technology

[0002] Outdoor distribution boxes are important terminal devices in power transmission and distribution systems, playing a crucial role in power distribution, metering, and protection. They integrate high-current components such as circuit breakers, instrument transformers, and capacitors, and operate under high load conditions for extended periods, generating significant Joule heat.

[0003] Due to the complex outdoor environment, distribution boxes not only face the problem of internal component overheating but are also subjected to intense external solar radiation. Existing outdoor distribution boxes mostly employ a single-layer structure, relying primarily on natural convection or simple fan ventilation for heat dissipation. However, a single-layer structure cannot effectively block solar radiation heat, resulting in extremely high surface temperatures and direct heat transfer to the interior. Furthermore, to achieve high protection ratings such as IP45 (rain and dust protection), the enclosure's sealing is enhanced, further worsening heat dissipation conditions.

[0004] When the temperature inside the enclosure is too high, it can lead to increased contact resistance of components, accelerated aging of insulation materials, and even fire accidents. In particular, for complex distribution boxes containing large-capacity capacitor banks and kiloampere-level circuit breakers, traditional heat dissipation designs are difficult to meet the stringent temperature rise limits required by the GB / T 7251.2 standard.

[0005] Therefore, effectively optimizing the structure of outdoor distribution boxes, enhancing heat dissipation capacity using physical principles, and implementing intelligent temperature control based on real-time operating conditions are important means to reduce accidents and ensure the safe operation of the power grid. Summary of the Invention

[0006] Purpose of the invention: The purpose of this application is to provide a dual-layer chimney effect intelligent hierarchical heat dissipation system and method based on PSO multi-objective optimization, which can effectively control the temperature rise of components in outdoor distribution boxes under strong sunlight and full load conditions, and adjust the heat dissipation strategy in a timely manner according to environmental parameters, thereby reducing the occurrence of thermal failures and improving the safety and reliability of outdoor distribution boxes in extreme environments. Technical solution

[0007] To achieve the above objectives, the present invention provides the following technical solution: 1. System Structure A dual-layer chimney effect intelligent hierarchical heat dissipation system based on PSO multi-objective optimization includes a distribution box body (1000a) containing multiple heat-generating components. The system is characterized by further comprising a dual-layer insulated shell structure (500), a bottom air intake assembly (1000), a top-layer interlayer exhaust fan (900), a bottom inner box air intake fan (910), a compensation chamber exhaust fan (700), a left-side interlayer exhaust fan (510a), a right-side interlayer exhaust fan (310a), a temperature monitoring module (100), and a control unit (100a). Double-layer insulated shell structure (500): including an inner functional box and an outer protective cover, with a closed air insulation interlayer (400 / 600) between them.

[0008] Bottom air intake assembly (1000): Located at the bottom of the outer protective cover, used to introduce ambient cold air.

[0009] Top-mounted interlayer exhaust fan (900): Located at the top of the double-layered insulated shell structure, used to drive external circulation.

[0010] Bottom inner box air inlet fan (910): Located at the bottom of the inner functional box, used to drive internal circulation.

[0011] Left-side interlayer exhaust fan (510a) and right-side interlayer exhaust fan (310a): respectively installed on the left and right walls of the air insulation interlayer (400 / 600) to enhance external circulation.

[0012] Exhaust fan (700) for the compensation chamber: located on the upper right side of the reactive power compensation chamber.

[0013] Temperature monitoring module (100): used to detect the temperature of each compartment, the temperature of the air insulation layer and the ambient temperature inside the main body of the distribution box (1000a).

[0014] Control unit (100a): Electrically connected to each of the above-mentioned fans and temperature monitoring modules, used to execute intelligent control algorithms.

[0015] 2. Intelligent control methods A smart hierarchical heat dissipation method based on PSO multi-objective optimization for the two-layer chimney effect, applied to the above system, includes the following steps: B1 (Monitoring): The temperature monitoring module is used to monitor the temperature of each compartment inside the distribution box in real time. Temperature of the air insulation interlayer. Temperature and ambient temperature .

[0016] B2 (Judgment): If the temperature of any compartment exceeds the first temperature threshold. (e.g., 45℃) then retrieves the number of the highest temperature compartment and its current load rate. .

[0017] B3 (Calculation and Optimization): Based on the highest temperature compartment number and current load rate and ambient temperature The target heat dissipation mode is determined using a thermal balance calculation model; the target heat dissipation mode includes the target operating power of each fan.

[0018] B4 (Execution): Control each exhaust fan to operate according to the target heat dissipation mode.

[0019] Core control methods The intelligent control unit (100a) performs the following steps: S1 Status Sensing: Real-time temperature monitoring of each compartment Ambient temperature Air insulation interlayer temperature, Tcav and load current .

[0020] S2 thermal-fluid coupling calculation: Calculate the total calorific value: (Where, Ij is the current of the j-th component, Rj is the equivalent resistance of the j-th component, α is the solar radiation absorptivity of the outer protective shield surface, Asurf is the surface area of ​​the outer protective shield, Gsolar is the solar radiation intensity, and η is the solar radiation thermal conversion efficiency).

[0021] Calculate the natural ventilation head: Where g is the acceleration due to gravity (9.8 m / s²), H is the height of the air insulation interlayer, ρout is the air density at the interlayer outlet, ρin is the air density at the interlayer inlet, ρavg is the average air density, ΔT is the temperature difference between the interlayer inlet and outlet, and Tavg is the average absolute temperature of the interlayer. S3PSO multi-objective optimization: Establish the objective function: in, , For each fan speed vector, For the maximum temperature deviation, Total energy consumption of the fan. For compartment temperature imbalance, These are the weighting coefficients.

[0022] Constraints: (GB / T 7251.2 Limit) Let j be the maximum speed limit of each fan. The optimal speed of each fan is determined using the particle swarm optimization algorithm. .

[0023] S4 Tiered Implementation and Feedback: like , Enter natural ventilation energy-saving mode and turn off or reduce the power of mechanical fans; like (If the rate of temperature rise exceeds the threshold), a powerful cooling mode is triggered, increasing the fan power to the maximum limit. like consistently higher This triggers an alarm and activates emergency full-power cooling.

[0024] Preferred solution: The distribution box body (1000a) is vertically divided into four independent compartments: a dedicated metering compartment, an incoming line compartment, an outgoing line compartment, and a reactive power compensation compartment.

[0025] The control unit (100a) has a built-in heat balance calculation model, which is used to calculate the total heat generation based on the real-time load current, ambient temperature and solar radiation intensity. And according to the chimney effect formula Calculate the natural ventilation head.

[0026] Step B3 includes: querying the base fan power from a preset temperature rise sensitivity lookup table based on the current ambient temperature; and calculating the total heat generation based on the current load rate. The power of the basic wind turbine is corrected.

[0027] Step B3 and step B4 also include calculating the chimney effect natural ventilation volume at the current moment. ,like Greater than the preset minimum safe ventilation volume If so, the operating power of each exhaust fan in the target cooling mode is reduced to enter energy-saving mode. Beneficial effects: Dual heat insulation mechanism: The double-layer structure combined with external circulation blocks more than 90% of solar radiation heat from entering the inner box, reducing the heat load of the inner box.

[0028] Optimal energy efficiency: Under the premise of meeting the temperature rise requirements, the PSO algorithm coordinates the five fans to work together, reducing the overall energy consumption of the system by more than 30%.

[0029] Rapid response: Predictive control based on a thermal balance model eliminates the lag of traditional temperature control, ensuring that the temperature rise of components is always below the national standard limit, improving the safety and service life of the equipment, and achieving energy-saving operation.

[0030] Hierarchical intelligent control: Automatically switches between various modes such as natural ventilation, energy-saving mode, and powerful heat dissipation according to real-time operating conditions to adapt to different environmental needs. Attached Figure Description

[0031] Figure 1This application provides a schematic diagram of a dual-layer chimney effect intelligent hierarchical heat dissipation system based on PSO multi-objective optimization. Figure 2 This application provides an embodiment of an airflow path diagram (showing internal and external dual circulation).

[0032] Figure 3 The intelligent control flowchart provided in this application embodiment (including steps S1-S4)

[0033] Figure 4 The temperature rise sensitivity comparison provided in the embodiments of this application is intended to illustrate the concept.

[0034] Figure 5 The PSO algorithm curve provided in the embodiments of this application Labeling Explanation: 1000a: Distribution Box Body, 100: Temperature Monitoring Module, 100a: Control Unit, 200: Rainproof Cap, 310: Right-side Louvered Air Inlet, 310a: Right-side Interlayer Exhaust Fan, 400 / 600: Air Insulation Interlayer, 500: Double-layer Insulation Shell Structure, 510: Left-side Louvered Air Inlet, 510a: Left-side Interlayer Exhaust Fan, 700: Compensation Chamber Exhaust Fan, 900: Top Interlayer Exhaust Fan, 910: Bottom Inner Chamber Air Inlet Fan, 1000: Bottom Air Inlet Assembly. Detailed Implementation

[0035] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0036] Please refer to Figure 1 and Figure 2 An intelligent hierarchical heat dissipation system based on PSO multi-objective optimization for double-layer chimney effect in this application embodiment includes a distribution box body (1000a) containing multiple heat-generating components, as well as a double-layer heat-insulating shell structure, a bottom air intake component, a top air exhaust component, left and right air insulation layers, a temperature monitoring module, and a control unit.

[0037] 1. Implementation of physical structure The double-layer thermal insulation shell structure (500) has an inner layer made of 1.5mm thick aluminum-zinc coated sheet and an outer layer made of 2mm thick SUS304 stainless steel, with external dimensions of 1350mm (width) × 1800mm (height) × 700mm (depth). A 50mm thick closed air insulation interlayer (400 / 600) is formed between the two.

[0038] The distribution box body (1000a) is vertically divided into four independent compartments: a dedicated metering compartment, an incoming line compartment, an outgoing line compartment, and a reactive power compensation compartment.

[0039] Dedicated metrology room: Equipped with current transformers, located at the top rear view.

[0040] Incoming Line Compartment: Equipped with knife switches, incoming line circuit breakers, and low-voltage transformers, located in the upper middle section.

[0041] Outgoing line room: Equipped with IoT smart circuit breakers, located in the lower middle section.

[0042] Reactive power compensation room: Capacitor bank and knife fuse are installed in the lower part; the exhaust fan (700) of the compensation room is located in the upper right side of the room.

[0043] The bottom air inlet assembly (1000) is located at the bottom of the outer protective cover, employing a full-width louver structure with an opening area of ​​not less than 0.75m², for introducing ambient cold air. The left and right walls of the air insulation interlayer (400 / 600) are respectively provided with louvered air inlets (510 / 310), connecting to the independent compartments of the inner functional housing. A common confluence chamber is located at the top of the inner functional housing.

[0044] 2. Fan and Monitoring System The fan system includes: Top-mounted interlayer exhaust fan (900): installed at the top of the double-layer insulated shell structure, with an air volume of not less than 200m³ / h and adjustable power.

[0045] Bottom inner box air inlet fan (910): Located at the inlet of the common junction cavity at the bottom of the inner functional box, with an air volume of not less than 150m³ / h and adjustable power.

[0046] Left-side interlayer exhaust fan (510a) and right-side interlayer exhaust fan (310a): respectively installed on the left and right side walls of the air insulation interlayer, with a single unit air volume of not less than 100m³ / h.

[0047] Exhaust fan for compensation room (700): Located on the upper right side of the reactive power compensation room, with an air volume of not less than 120m³ / h.

[0048] The temperature monitoring module (100) includes: Temperature sensors for each compartment: PT100 resistance temperature detectors, accuracy ±0.5℃, are installed in the middle of the dedicated metering room, incoming line room, outgoing line room, and reactive power compensation room, respectively.

[0049] Interlayer temperature sensor: installed at the middle height of the air insulation interlayer (400 / 600).

[0050] Ambient temperature sensor: Installed in the shade outside the main body of the distribution box (1000a) to avoid direct sunlight.

[0051] The control unit (100a) uses an ARM Cortex-M4 microcontroller and is electrically connected to each sensor and the fan via an RS485 bus. The sampling period is 1 second and the control period is 10 seconds.

[0052] 3. Heat dissipation principle and airflow path The system creates a dual-circulation airflow path during operation: External circulation (blocking heat source): external cold air → bottom air intake assembly (1000) → air insulation interlayer (400 / 600) (absorbs solar radiation heat conducted by the outer steel plate) → rises due to heat → discharged by left interlayer exhaust fan (510a) / right interlayer exhaust fan (310a).

[0053] Internal circulation (removes heat): external cold air → bottom air intake assembly (1000) → bottom inner box air intake fan (910) → inner layer compartments (flows through the surface of heating elements to remove heat) → converges to the top common confluence cavity → top interlayer exhaust fan (900) and compensation chamber exhaust fan (700) discharge.

[0054] 4. Implementation of intelligent control logic The control unit (100a) performs the following steps: Real-time calculation: Built-in thermal balance calculation model, based on formula Calculate the total calorific value. .

[0055] According to the chimney effect formula Calculate the natural ventilation head and estimate the natural ventilation volume. .

[0056] Hierarchical control: Step B1: Real-time temperature monitoring of each compartment Ambient temperature Solar radiation intensity Gsolar (obtained via external sensor or network) and load current I.

[0057] Step B2: Determine if there is (e.g., 45°C). If applicable, identify the highest temperature compartment (e.g., incoming line compartment) and the current load rate. .

[0058] Step B3: Consult the "Temperature Rise Sensitivity Comparison Table" (e.g., ...). Figure 4 As shown, the base power Pbase is obtained by mapping the ambient temperature range to the base fan power. Correct the result based on Ptotal: Ptarget = Pbase + k⋅Ptotal; Calculate the natural ventilation volume Qnat. If Qnat ≥ Qmin (minimum safe ventilation volume, such as 50 m³ / h), then enter the energy-saving mode and reduce the fan power to Peco = 0.6⋅Ptarget. Execute the PSO optimization algorithm to solve for the optimal combination of wind turbine speeds. .

[0059] Step B4: Each fan operates according to the optimization results; Monitor the rate of temperature change dt / dT in real time. If dt / dT < ϵ (e.g., -0.5℃ / min) and continues for thold (e.g., 5 minutes), then increase the power by 10%. When all Ti≤Tset2 (38℃), enter basic maintenance mode: If the number of overheating events (Nover≤2) in the past 30 minutes, switch to natural ventilation mode (turn off mechanical fan). If Nore>2, enter low-speed mechanical exhaust mode (each fan maintains 30% speed).

[0060] 5. Experimental Results Under ambient temperature of 40℃, solar radiation intensity of 800W / m², and full load conditions (100% load rate), this system can control the highest temperature inside the enclosure to below 45℃, which is 10-20℃ lower than traditional heat dissipation systems. The fan energy consumption is also reduced by about 35%, fully meeting the temperature rise limit requirements of GB / T 7251.2 (temperature rise at bus connection ≤60K, temperature rise at capacitor room temperature ≤20K).

[0061] 6. Implementation details of the PSO algorithm Particle swarm optimization algorithm parameter settings: Number of particles: 30 Maximum number of iterations: 100 Inertia weight: ω = 0.8 → 0.4 (linearly decreasing) Learning factor: c1=c2=2.0 Search space: 5 dimensions (corresponding to the rotational speeds of 5 wind turbines), range of each dimension Fitness function: in, , This represents the average temperature of each compartment.

[0062] Optimize processes such as Figure 5As shown, the particle iteratively updates its position and velocity in the 5-dimensional search space, eventually converging to the global optimum or near-optimal solution. In summary, this application, through the combination of a double-layer physical heat insulation structure and intelligent temperature control using the PSO algorithm, completely solves the heat dissipation problem of outdoor distribution boxes under high load and strong sunlight environments, possessing extremely high engineering application value and promising prospects for widespread adoption.

[0063] (Note: The above embodiments are merely preferred embodiments of this application and are not intended to limit the scope of this application; all equivalent changes and modifications made within the scope of protection of this application shall fall within the scope of this application.)

Claims

1. A smart hierarchical heat dissipation system and method based on PSO multi-objective optimization for a double-layer chimney effect, comprising a distribution box body (1000a) containing multiple heat-generating components, characterized in that, It also includes a double-layer insulated shell structure (500), a bottom air inlet assembly (1000), a top interlayer exhaust assembly (900), a bottom inner box air inlet assembly (910), a compensation chamber exhaust fan (700), a left interlayer exhaust fan (510a), a right interlayer exhaust fan (310a), a temperature monitoring module (100), and a control unit (100a). The double-layer thermal insulation shell structure (500) includes an inner functional box and an outer protective cover, with a closed air thermal insulation interlayer (400 / 600) between them. The bottom air intake assembly (1000) is located at the bottom of the outer protective cover and is used to introduce ambient cold air; The top interlayer exhaust assembly (900) is located on the top of the double-layer heat-insulating shell structure and is used to exhaust hot air from each compartment; The bottom inner box air inlet fan (910) is located at the bottom of the inner functional box and is used to deliver cold air to each compartment of the inner functional box; The left-side interlayer exhaust fan (510a) and the right-side interlayer exhaust fan (310a) are respectively installed on the left and right sides of the air insulation interlayer (400 / 600); The temperature monitoring module (100) is used to detect the temperature of each compartment, the temperature of the air insulation layer, and the ambient temperature inside the distribution box body (1000a). The control unit (100a) is electrically connected to the temperature monitoring module (100), the top interlayer exhaust fan (900), the bottom inner box air inlet fan (910), the left interlayer exhaust fan (510a), the right interlayer exhaust fan (310a), and the compensation chamber exhaust fan (700); The control unit (100a) is used to calculate the chimney effect driving force based on the detection results of the temperature monitoring module (100), and control the working power of the top interlayer exhaust fan (900), the bottom inner box air inlet fan (910), the left interlayer exhaust fan (510a), the right interlayer exhaust fan (310a) and the compensation chamber exhaust fan (700).

2. The intelligent hierarchical heat dissipation system based on PSO multi-objective optimization for double-layer chimney effect as described in claim 1, characterized in that, The distribution box (1000a) is internally divided vertically into four independent compartments: a dedicated metering compartment, an incoming line compartment, an outgoing line compartment, and a reactive power compensation compartment. The dedicated metering room is equipped with a metering transformer; The incoming line room is equipped with a knife switch, an incoming line circuit breaker, and a low-voltage transformer; The outgoing line room is equipped with an IoT smart circuit breaker. The reactive power compensation room is equipped with capacitor banks and knife-blade fuses. The exhaust fan (700) of the compensation chamber is located on the upper right side of the reactive power compensation chamber and is electrically connected to the control unit (100a).

3. The intelligent hierarchical heat dissipation system based on PSO multi-objective optimization for a double-layer chimney effect as described in claim 2, characterized in that, The side wall of the air insulation interlayer (400 / 600) is provided with a louvered air inlet (510 / 310), which connects to each independent compartment of the inner functional box. The top of the inner functional box is provided with a common confluence cavity, and the bottom inner box air inlet fan (910) is connected to the air inlet end of the common confluence cavity.

4. The intelligent hierarchical heat dissipation system based on PSO multi-objective optimization for double-layer chimney effect as described in claim 1, characterized in that, The control unit (100a) has a built-in heat balance calculation model, which is used to calculate the total heat generation based on the real-time load current I, ambient temperature (Tamb), and solar radiation intensity (Gsolar). And according to the chimney effect formula Calculate the natural ventilation head.

5. The intelligent hierarchical heat dissipation system based on PSO multi-objective optimization for double-layer chimney effect according to claim 4, characterized in that, The control unit (100a) also stores a temperature rise sensitivity lookup table, which is used to query the corresponding target operating mode of the fan under different ambient temperatures; the temperature rise sensitivity lookup table contains the mapping relationship between the ambient temperature range and the basic fan power.

6. A smart hierarchical heat dissipation method based on PSO multi-objective optimization for a two-layer chimney effect, applied to the system described in any one of claims 1-5, characterized in that, Including the following steps: B1. The temperature of each compartment and the ambient temperature inside the distribution box body (1000a) are monitored in real time by the temperature monitoring module (100); B2. If the temperature of any compartment exceeds the first temperature threshold (Tset1), obtain the number of the compartment with the highest temperature and its current load rate (λ). B3. Based on the number of the highest temperature compartment, the current load rate (λ), and the ambient temperature (Tamb), the target heat dissipation mode is determined using a heat balance calculation model; the target heat dissipation mode includes the target operating power of the top interlayer exhaust fan (900), the bottom inner box air inlet fan (910), the left interlayer exhaust fan (510a), the right interlayer exhaust fan (310a), and the compensation chamber exhaust fan (700); B4. Control the operation of each exhaust fan according to the target heat dissipation mode.

7. The method according to claim 6, characterized in that, Step B3 includes: Based on the current ambient temperature (Tamb), the base fan power is retrieved from the preset temperature rise sensitivity lookup table. Total heat generation calculated based on the current load rate (λ) Regarding the power of the basic wind turbine After correction, the target power Ptarget = Pbase + k⋅Ptotal is obtained, where k is the power conversion coefficient.

8. The method according to claim 7, characterized in that, The steps following step B3 and before step B4 include: B5. Calculate the natural ventilation volume due to the chimney effect at the current moment. , where Cd is the flow coefficient, A is the ventilation cross-sectional area, and ρavg is the average air density of the interlayer; B6. If Greater than the preset minimum safe ventilation volume Then, reduce the operating power of each exhaust fan in the target heat dissipation mode to [the specified value]. To enter energy-saving mode; where β is the energy-saving coefficient, 0 < β < 1.

9. The method according to claim 6, characterized in that, Step B4 includes: B401. Ensure that each exhaust fan operates according to the target heat dissipation mode described above; B402. Real-time monitoring of the rate of temperature change in each compartment. ; B403. If the rate of temperature decrease Below the preset rate threshold And the duration reaches the preset time threshold. If so, the operating power of each exhaust fan in the target heat dissipation mode is increased; B404. When the temperature of all compartments is not higher than the second temperature threshold. This causes each exhaust fan to enter basic maintenance mode; the second temperature threshold Less than the first temperature threshold .

10. The heat dissipation method for outdoor distribution boxes based on double-layer structure and chimney effect according to claim 9, characterized in that, Step B404 includes: Get the preset time period before the current time The internal compartment temperature exceeds the first temperature threshold. Number of times ; If the number No more than the number of times threshold In this case, the natural ventilation mode is used as the basic maintenance mode, and each exhaust fan stops running or maintains the lowest speed. If the number Exceeding the threshold In this case, the low-speed mechanical exhaust mode is used as the basic maintenance mode, and each exhaust fan maintains low speed operation.

Images