Self-cleaning air supply device for substation

Abstract

The utility model relates to the technical field of ventilation, cooling and dust removal, and discloses a self-cleaning air supply device for a substation, which comprises a fan box, a filter connected with the fan box in series, and an electric airtight valve arranged between the fan box and the filter. The utility model solves the problems of high dust content of air supply flow, unstable operation of a ventilation system, high energy consumption and the like in the prior art.

Description

Technical Field

[0001] The utility model relates to the technical field of ventilation, cooling and dust removal, in particular to a self-cleaning air supply device for a substation. Background Art

[0002] There are many substations in the chemical plant that serve the process equipment. The substations can be divided into two categories from a functional perspective: regional substations and on-site substations. The so-called regional substations serve the entire chemical plant. They are characterized by relatively large volume, a large distance from the general layout and the equipment, less affected by the equipment during normal operation, and overall independence; while on-site substations are usually built close to the equipment they serve. The problem brought about by this is that the operation of the substation and its equipment is greatly affected by the equipment. The substation located in the thermal power plant is close to the boiler ash treatment system. Under normal boiler operation, several tons of boiler ash need to be loaded every day. During the loading process, the dust is very serious, and due to the large amount of ash, it is impossible to handle this part of the dust by local dust removal or dust exhaust. This brings huge safety hazards to the operation of electrical equipment in the substation. Because the inverter cabinet, switch cabinet, high and low voltage cabinets and other equipment in the substation work under power, they will emit a lot of heat. There are two mainstream practices in the industry for ventilation and cooling of substations: one is to install unit air conditioners and side wall supply and exhaust fans in the substation. The working principle is to turn on the air conditioner for cooling in summer and the relatively hot transition season, and turn off the side wall supply and exhaust fans to save energy. In winter and the transition season with lower temperatures, only the side wall supply and exhaust fans are turned on, and ventilation and cooling are used to remove the excess heat in the room to ensure the indoor temperature requirements and save electricity. This practice has the following safety hazards: when the fan is turned on for ventilation, there is a lot of dust outdoors. Under the mechanical ventilation of the fan, dust enters the room, and then enters the cabinet under the action of the exhaust fans of the inverter cabinet, switch cabinet, high and low voltage cabinet and other equipment. Over time, dust is collected on the circuits and electronic components, affecting the heat dissipation and stable operation of the equipment, causing safety hazards; the second is to install filters on the side wall supply fans to reduce the amount of dust entering. The amount of dust entering the room, other practices and operating modes are the mainstream practice in the same industry. This practice has solved the problem of large amount of dust entering the room under ventilation mode to a certain extent, and improved the operating environment quality of indoor electrical equipment, but it also brought two irreconcilable contradictions. First, in order to increase the dust removal effect, the filter captures a lot of dust per unit time, but the resistance of the filter increases with the increase of dust collection. Therefore, this practice requires frequent cleaning of the filter, otherwise the ventilation system resistance is too large and the air volume is too small, and the waste heat in the room cannot be removed, which brings great difficulties to the ventilation operation of the filter; second, because the filter ventilation system resistance is too large, the air supply volume is too small, and the exhaust volume remains unchanged, the negative pressure in the room increases, and the substation often uses windowless rooms with normally closed fire doors. Under the action of huge negative pressure, the normally closed fire doors themselves are difficult to open by manpower.Due to the above disadvantages, the operation of the substation ventilation system in winter is not stable in actual projects, and the operation time of the substation ventilation system in the transition season is short. When the ventilation system cannot guarantee the temperature environment of the substation, the air-conditioning system must be turned on. Since the energy consumption of the air-conditioning system is much greater than that of the ventilation system, it brings about excessive energy consumption, which is not conducive to the normal development of the "dual carbon" economy. Utility Model Content

[0003] In order to overcome the deficiencies of the prior art, the utility model provides a self-cleaning air supply device for a substation, which solves the problems existing in the prior art, such as large dust content in the air supply airflow, unstable operation of the ventilation system, and high energy consumption.

[0004] The technical solution adopted by the utility model to solve the above problems is:

[0005] A self-cleaning air supply device for a substation comprises a fan box, a filter connected in series with the fan box, and an electric airtight valve arranged between the fan box and the filter.

[0006] As a preferred technical solution, it also includes an inlet air duct, a fan box, a pressure sensor, a stop valve, an electric ball valve, a lateral air duct, and an outlet air duct. The inlet air duct, the fan box, and the outlet air duct are connected in sequence, the lateral air duct is connected to the inlet air duct, the electric airtight valve, the pressure sensor, and the filter are arranged on the inlet air duct, and the stop valve and the electric ball valve are arranged on the lateral air duct.

[0007] As a preferred technical solution, it also includes a joint, and the fan box and the outlet air duct are connected through the joint.

[0008] As a preferred technical solution, the joint is a canvas flexible joint.

[0009] As a preferred technical solution, it also includes a rainproof louver vent arranged at the air inlet of the inlet air duct.

[0010] As a preferred technical solution, the lateral air duct is a seamless steel pipe.

[0011] As a preferred technical solution, the inlet air duct is a galvanized iron air duct.

[0012] As a preferred technical solution, the outlet air duct is a galvanized iron air duct.

[0013] As a preferred technical solution, the pressure sensor includes an on-site pressure sensor and a remote pressure sensor.

[0014] As a preferred technical solution, the fan box is a centrifugal fan box.

[0015] Compared with the prior art, the utility model has the following beneficial effects:

[0016] Under the premise that the dust content of the air sent into the substation meets the environmental quality requirements of the substation, the utility model does not need to manually clean the filter screen frequently, thus solving the problem that the dust content of the air supply airflow is large and seriously affects the safe operation of electrical equipment in the mainstream practice one, and solving the problem that the dust filtering device needs frequent manual dust removal in the mainstream practice two, thus stabilizing the normal operation time of the substation ventilation system in winter, reducing the operation time of the air-conditioning system in the transition season, reducing power consumption, and realizing "dual-carbon" operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the utility model;

[0018] Figure 2 This is the instrument flow chart of the utility model.

[0019] Marks and their corresponding names in the attached drawings: 1—inlet air duct; 2—connector; 3—fan box; 4—electric airtight valve; 5—on-site pressure sensor; 6—remote pressure sensor; 7—filter; 8—rainproof louver air outlet; 9—stop valve; 10—electric ball valve; 11—lateral air duct; 12—outlet air duct. DETAILED DESCRIPTION

[0020] The present invention will be further described in detail below in conjunction with the embodiments and drawings, but the implementation manner of the present invention is not limited thereto.

[0021] Example 1

[0022] like Figure 1 to Figure 2 As shown, the utility model is suitable for the field of ventilation, cooling and dust removal of substations in chemical plants.

[0023] The utility model adopts a pulse-jet self-cleaning air supply system device. Under the premise that the dust content of the air sent into the substation meets the environmental quality requirements of the substation, the air supply device does not need to be frequently cleaned by humans. This solves the problem that the dust content of the air supply airflow in the mainstream method one seriously affects the safe operation of electrical equipment, and solves the problem that the dust filtering device in the mainstream method two requires frequent manual dust removal. It stabilizes the normal operation time of the substation ventilation system in winter, reduces the operation time of the air-conditioning system in the transition season, reduces power consumption, and realizes "dual-carbon" operation.

[0024] The specific method of the pulse jet self-cleaning air supply system device is as follows: 1. A centrifugal fan box (fan box 3) is used and a filter is connected in series in front of the fan box, and an electric airtight valve 4 is set between the fan box and the filter, close to the fan box. The fan box and the filter 7 are placed on the roof of the substation, connected through the air duct system, and the treated air is sent into the substation; 2. Pressure sensors (including local pressure sensor 5 and remote pressure sensor 6) are set before and after the air filter (filter 7). During the operation of the equipment, the pressure sensor measures the pressure difference before and after the filter; 3. Under normal ventilation conditions, a compressed air pipe (lateral air duct 11) is set at the rear end of the air filter along the air flow direction, and a stop valve 9 and an electric ball valve 10 are set on the compressed air pipe. The stop valve 9 is normally open, and the electric ball valve 10 is normally closed. The electric ball valve 10 receives the signal from the pressure sensor, and the opening of the compressed air pipe faces the filter; 4. When the dust cleaning end receives the signal from the pressure sensor, the air supply from the blower is stopped, the electric airtight valve 4 is closed, and the compressed air electric ball valve 10 is opened to blow the filter in the opposite direction to remove the accumulated dust on the filter; 5. After the blowing time is over, the electric ball valve 10 on the compressed air pipe is closed. To prevent the dust blown out from being brought into the room by the air supply, after the dust sprayed out settles to the ground, the electric airtight valve 4 of the air duct system is opened, and the blower (blower box 3) is restarted. In this way, the substation can be cleaned and the air supply can be realized without cleaning. The above is a brief working process of the utility model.

[0025] Figure 1 The plan view of the pulse jet self-cleaning air supply system is shown, which is the core device of the utility model, and is composed of an air inlet, a filter section, a pressure detection mechanism, a compressed air jet mechanism, an electric airtight valve, a centrifugal fan box, and a canvas flexible joint (joint 2) connected to the end of the downstream air duct. It includes an inlet air duct 1, a lateral air duct 11, and an outlet air duct 12. Preferably, it also includes a rainproof louver air vent 8 provided at the air inlet of the inlet air duct 1.

[0026] Figure 2 The instrument flow chart of the pulse jet self-cleaning air supply automatic control system is shown, which is the auxiliary description of the automatic control of the core device of the utility model. The flow chart explains the types and quantities of automatic control input and output signals involved in the actual operation of the utility model. Among them, DI represents digital input, AI represents analog input, DO represents digital output, AO represents analog output, X1 represents one signal at this test point, and X2 represents two signals at this test point.

[0027] The pressure sensors located before and after the filter output analog signals for continuous measurement of the pressure difference at both ends of the filter; the electric ball valve 10 on the compressed air pipe receives the switch signal from the PLC; the centrifugal fan box 3 receives the switch signal from the PLC; the electric airtight valve 4 on the air duct receives the switch signal from the PLC. The control principle of the pulse spray self-cleaning air supply automatic control system is as follows: in the normal ventilation mode, the pressure sensors on both sides of the filter detect that the pressure difference exceeds the limit value, and input the signal to the PLC, the PLC first closes the centrifugal fan box 3, then closes the electric airtight valve 4 of the air duct system, and then opens the electric ball valve 10 of the compressed air pipe; when the spraying is finished, the electric ball valve 10 of the compressed air pipe is closed first, and the PLC opens the electric airtight valve 4 of the air duct first, and then opens the centrifugal fan box 3 according to the pre-set dust particle settling time.

[0028] The pulse jet self-cleaning air supply system has the following features:

[0029] 1. The pulse jet self-cleaning air supply system uses a centrifugal fan box as the air power source of the device system. The centrifugal fan box receives the pressure sensor signal and has a remote shutdown function. 2. An electric airtight valve is installed on the air duct between the fan box and the filter close to the fan box. The electric airtight valve opens when it is powered on and closes when it is powered off. The electric airtight valve receives the switch signal from the PLC and has a remote shutdown function. 3. Under normal ventilation conditions, a compressed air pipe is installed at the rear end of the air filter along the air flow direction. A stop valve 9 and an electric ball valve 10 are installed on the compressed air pipe. The stop valve 9 is normally open, and the electric ball valve 10 is normally closed. The compressed air pipe is connected to 0.25MPa compressed air. 4. An air filter is installed at the inlet section of the system. The final resistance of the air filter is P o Two sets of static pressure sensors are set on both sides of the air filter. The static pressure sensors on each side include a static pressure local display instrument and a static pressure remote transmission instrument. The working pressure of the pressure sensor should be greater than 1.5 times the fan pressure head, and the measuring range should be 1.2 to 1.3 times the pressure change range at that point. 5. After the dust collection and cleaning is completed, close the electric ball valve 10 on the compressed air pipe. To prevent the sprayed dust from being brought into the room by the air supply, wait until the sprayed dust falls to the ground, open the electric airtight valve of the duct system, and restart the blower. 6. The air duct components of the air supply system are made of galvanized iron sheets. The wind speed in the air duct is 6 to 14 m / s. To ensure the air supply and dust removal effects, the air duct leakage rate Q h ≤0.0117P 0.65 (m 3 / h·m 2 ), where P is the system duct working pressure (Pa).

[0030] Example 2

[0031] like Figure 1 to Figure 2As shown, as a further optimization of Example 1, based on Example 1, this embodiment also includes the following technical features:

[0032] The pulse jet self-cleaning air supply system has the following necessary technical features: 1. The pulse jet self-cleaning air supply system adopts a centrifugal fan box as the air power source of the system. The design air volume of the centrifugal fan box is the heat Q (kW) calculated based on the heat generated by the substation equipment and the heat load of the enclosure structure in the ventilation mode, and then based on the lower indoor design temperature t n (℃), calculation temperature of outdoor ventilation in winter t w (℃), the air volume G (kg / s) calculated by hot air balance is calculated as follows: Where c = 1.01 kJ / (kg·℃); the design pressure head of the centrifugal fan box ΔP is the resistance of the pipeline system ΔP x Add filter final resistance ΔP f . The power distribution parameters of the centrifugal fan box are 380V / 3N / 50HZ, and the centrifugal fan box has a remote shutdown function when receiving pressure sensor signals. Because in normal ventilation and non-dust removal mode, the centrifugal fan box is located behind the air filter and the electric airtight valve along the air flow direction, the centrifugal fan box is selected as an ordinary centrifugal fan box. This arrangement prevents the dust-laden airflow from directly entering the fan, improves the operating environment of the centrifugal fan box, and uses an ordinary centrifugal fan box instead of a dust-proof fan box to save equipment investment. When the centrifugal fan box receives the alarm signal from the pressure sensor, it immediately cuts off the power supply of the centrifugal fan box, and the centrifugal fan box is in a shutdown state; 2. An electric airtight valve is installed on the air duct between the fan box and the filter, close to the fan box. The electric airtight valve is equipped with a DC 24V power supply. The size of the electric airtight valve is the same as the size of the air duct. After the electric airtight valve is fully closed, the pressure difference is 100P a Hourly air leakage: <4.3m 3 / h·m 2. The electric airtight valve opens when it is powered on and closes when it is powered off. The electric airtight valve has a remote closing function when it receives a signal from a pressure sensor. The electric airtight valve works with power in normal ventilation mode and non-dust removal mode. At this time, the electric airtight valve is in an open state, ensuring that the air supply duct system is in an open state. When the electric airtight valve receives an alarm signal from the pressure sensor, the electric airtight valve is powered off and closes the valve, sealing the air supply duct entering the room at the entrance of the centrifugal fan box; 3. Under normal ventilation conditions, a compressed air pipe is set at the rear end of the air filter along the air flow direction. A stop valve 9 and an electric ball valve 10 are set on the compressed air pipe. The stop valve 9 is normally open and the electric ball valve 10 is normally closed. The compressed air pipe is connected to 0.25MPa compressed air. The compressed air injection time generally does not exceed 0.2s. The compressed air pipe is made of seamless steel pipe, and its standards should comply with A106 GR.B, ASME B36.10M, wall thickness: S-40mm, and the designed wind speed in the compressed air pipe is 10m / s; 4. An air filter is set at the inlet section of the system, and the final resistance of the air filter is P o Two sets of static pressure sensors are set on both sides of the air filter. The static pressure sensors on each side include a static pressure local display instrument and a static pressure remote transmission instrument. The working pressure of the pressure sensor should be greater than 1.5 times the fan pressure head, and the range should be 1.2 to 1.3 times the pressure change range at that point. Let the pressure sensor before the filter be numbered P f The pressure sensor after the filter is numbered P b , set the control program on the PLC controller of the substation control center, and its control logic is as follows: f >0.8P o , close the centrifugal fan box, close the electric airtight valve, open the compressed air electric ball valve, and start dust collection and cleaning. The dust collection and cleaning time generally does not exceed 0.2s; 5. After the dust collection and cleaning is completed, close the electric ball valve on the compressed air pipe. To prevent the dust blown out from being brought into the room by the air supply, wait until the dust sprayed out falls to the ground, open the electric airtight valve of the air duct system, and restart the air supply fan. The dust falling time is determined according to the following method, with the particle size d p The dust particle settling speed is (m / s), where ρ p ——Dust particle density (kg / m 3 ), ρ g ——Gas density (kg / m 3 ), g——acceleration due to gravity (m / s 2 ), d p ——Dust particle diameter (m), C D ≈0.44. Assuming the height of the upper edge of the air inlet from the ground is H (m), the time required for dust particles to settle is (s), i.e. (s). 6. The air duct components of the air supply system are made of galvanized iron sheets. The wind speed in the air duct is 6 to 14 m / s. To ensure the air supply and dust removal effects, the air duct leakage rate Q h ≤0.0117P 0.65 (m 3 / h·m 2 ), where P is the system duct working pressure (Pa).

[0033] The utility model can effectively block the dust from entering the substation, and provide a good working environment and heat dissipation conditions for the inverter cabinet, switch cabinet, high and low voltage cabinet and other equipment in the substation. For the ventilation system itself, the self-cleaning air supply mode is adopted, eliminating the frequent manual dust cleaning operation.

[0034] Case 1: A substation located in Korla, Xinjiang. In winter ventilation mode, the heat generated by its indoor electrical equipment is 80kW, the heat consumption of the enclosure structure is 20kW, and the indoor design temperature is t n =5(℃), outdoor calculated temperature for ventilation in winter t w =-7 (℃), the air volume G (kg / s) calculated by hot air balance is calculated as follows: Where c = 1.01 kJ / (kg·℃); calculated G = 24752 m 3 / h; centrifugal fan box design pressure head pipeline system resistance ΔP=120Pa, filter final resistance ΔP f =350Pa, fan pressure head ΔP x =470Pa, select fan No.9A, fan power 4kW, power distribution parameters 380V / 3N / 50HZ, centrifugal fan box receives pressure sensor signal with remote shutdown function. The air duct parts of the air supply system are made of galvanized iron sheets. According to the wind speed in the air duct of 6-14m / s, the air duct size is selected as 1000*630mm. In order to ensure the air supply effect and dust removal effect, the air duct leakage rate Q h ≤0.0117P 0.65 (m 3 / h·m 2 ), where P is the system air duct working pressure (Pa), that is, Q h ≤0.638(m 3 / h·m 2 ). An electric airtight valve is installed on the air duct between the fan box and the filter, close to the fan box. The electric airtight valve is equipped with a DC 24V power supply. The size of the electric airtight valve is the same as the air duct size, 1000*630mm. After the electric airtight valve is completely closed, the pressure difference is 100P a Hourly air leakage: <4.3m 3 / h·m 2. The electric airtight valve opens when it is energized and closes when it is de-energized. The electric airtight valve receives the signal from the pressure sensor and has a remote closing function. The electric airtight valve works with power in normal ventilation mode and non-dust removal mode. At this time, the electric airtight valve is in an open state, ensuring that the air supply duct system is in an open state. Under normal ventilation conditions, a compressed air pipe is set at the rear end of the air filter along the air flow direction. A stop valve 9 and an electric ball valve 10 are set on the compressed air pipe. The stop valve 9 is normally open and the electric ball valve 10 is normally closed. 0.25MPa compressed air is connected to the compressed air pipe. The compressed air blowing time generally does not exceed 0.2s. The compressed air pipe is made of seamless steel pipe, and its standards should comply with A106 GR.B, ASME B36.10M. The wall thickness is: S-40mm, and the design wind speed in the compressed air pipe is 10m / s. An air filter is set at the inlet section of the system, and the final resistance of the air filter is ΔP f =350Pa, two sets of static pressure sensors are set on both sides of the air filter. The static pressure sensors on each side include a static pressure local display instrument and a static pressure remote transmission instrument. The working pressure of the pressure sensor should be greater than 1.5ΔP of the fan pressure head. x , that is, the working pressure of the pressure sensor is 0~590Pa, and the measuring range should be 1.2 to 1.3 times the pressure variation range of this point. Let the pressure sensor before the filter be numbered P f The pressure sensor after the filter is numbered P b , set the control program on the PLC controller of the substation control center, and its control logic is as follows: f >0.8P o When Pb-P f When the pressure is >280Pa, first close the centrifugal fan box, then close the electric airtight valve, and then open the compressed air electric ball valve to start dust collection and cleaning. The dust collection and cleaning time generally does not exceed 0.2s. After the spray dust collection and cleaning is completed, first close the electric ball valve on the compressed air pipe to prevent the dust blown out from being brought into the room by the air supply. After the dust sprayed out falls to the ground, open the electric airtight valve of the air duct system and restart the air supply fan. The dust falling time is determined according to the following method, with the particle size d p The dust particle settling speed is (m / s), where ρ p ——Dust particle density (kg / m 3 ), ρ g ——Gas density (kg / m 3 ), g——acceleration due to gravity (m / s 2 ), d p ——Dust particle diameter (m), C D ≈0.44. Assuming the height of the upper edge of the air inlet from the ground is H (m), the time required for dust particles to settle is (s), i.e. (s), where dp =100μm, C D ≈0.44,ρ p =1.2kg / m 3 , ρ g =0.00055kg / m 3 , H=0.5m, and t=5.56s is obtained by substituting it into the formula. That is, 5.56s after the spraying ends, the electric airtight valves of the air duct system are opened in sequence, and the blower is restarted.

[0035] As described above, the utility model can be implemented well.

[0036] The above is only a preferred embodiment of the utility model and does not limit the utility model in any form. According to the technical essence of the utility model, within the spirit and principles of the utility model, any simple modification, equivalent replacement and improvement made to the above embodiment still falls within the protection scope of the technical solution of the utility model.

Claims

1. A self-cleaning air supply device for a substation, characterized in that: It comprises a fan box (3), a filter (7) connected in series with the fan box (3), and an electric airtight valve (4) arranged between the fan box (3) and the filter (7); The invention also comprises an inlet air duct (1), a fan box (3), a pressure sensor, a stop valve (9), an electric ball valve (10), a lateral air duct (11), and an outlet air duct (12); the inlet air duct (1), the fan box (3), and the outlet air duct (12) are connected in sequence; the lateral air duct (11) is connected to the inlet air duct (1); the electric airtight valve (4), the pressure sensor, and the filter (7) are arranged on the inlet air duct (1); and the stop valve (9) and the electric ball valve (10) are arranged on the lateral air duct (11).

2. A self-cleaning air supply device for a substation according to claim 1, characterized in that: It also includes a joint (2), and the fan box (3) is connected to the outlet air duct (12) through the joint (2).

3. A self-cleaning air supply device for a substation according to claim 2, characterized in that: The joint (2) is a canvas flexible joint.

4. A self-cleaning air supply device for a substation according to claim 1, characterized in that: It also includes a rainproof louver air outlet (8) arranged at the air inlet of the inlet air duct (1).

5. A self-cleaning air supply device for a substation according to claim 4, characterized in that: The lateral air duct (11) is a seamless steel pipe.

6. A self-cleaning air supply device for a substation according to claim 1, characterized in that: The inlet air duct (1) is a galvanized iron air duct.

7. A self-cleaning air supply device for a substation according to claim 1, characterized in that: The outlet air duct (12) is a galvanized iron sheet air duct.

8. A self-cleaning air supply device for a substation according to claim 1, characterized in that: The pressure sensor comprises an on-site pressure sensor (5) and a remote pressure sensor (6).

9. A self-cleaning air supply device for a substation according to any one of claims 1 to 8, characterized in that: The fan box (3) is a centrifugal fan box.

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