CN104780745B - A kind of regulator cubicle and its cooling control method - Google Patents

Abstract

The invention discloses an electrical cabinet, which comprises a cabinet body and an air-conditioning cabinet, a mounting plate for installing electrical components is arranged in the cabinet body, a controller installation room is arranged on the mounting board, and a There is an air duct with two ends open, and the air outlet on the top of each cabinet communicates with the air duct through a heat dissipation pipe; There is a groove on the ground of the electrical control room, and a cold air pipe is connected to the bottom of the air-conditioning cabinet. Each cabinet is provided with a first pipe and a second pipe. The first pipe is connected between the cold air pipe and the controller installation room. The second pipeline communicates between the cold air pipe and the cold air cover, and the second pipeline is provided with a cold air valve; the invention also discloses a heat dissipation control method for the electrical cabinet. The invention has the advantages of good heat dissipation effect, utilizes natural wind energy to dissipate heat, and has low energy consumption; it can ensure the normal operation of electrical components in the cabinet.

Description

An electric cabinet and heat dissipation control method thereof

technical field

The invention relates to the electrical field, in particular to an electrical cabinet and a heat dissipation control method thereof.

Background technique

The electrical cabinet is a commonly used electrical product. The electrical cabinet is made of steel to protect the normal operation of the components. The materials for making electrical cabinets are generally divided into two types: hot-rolled steel plates and cold-rolled steel plates. Compared with hot-rolled steel sheets, cold-rolled steel sheets are softer and more suitable for the production of electrical cabinets. Electrical cabinets are widely used mainly in chemical industry, environmental protection industry, power system, metallurgical system, industry, nuclear power industry, fire safety monitoring, transportation industry and so on.

During the use of the electrical cabinet, the internal electrical components will generate heat, which will increase the temperature inside the cabinet. When the temperature is too high, it will easily affect the normal use and service life of the internal electrical components. Therefore, the electrical cabinet is equipped with a heat dissipation structure. , Generally, vents or ventilation shutters are set on the electrical cabinet, and some electrical cabinets will be provided with fans at the vents, and the fans will be used to change the airflow in the electrical cabinet to improve heat dissipation efficiency.

The existing electrical cabinet heat dissipation has the following technical problems:

1. Adopt the scheme of installing a fan in the electrical cabinet. Since the fan will vibrate when it is working, this vibration will be transmitted directly to the electrical components inside it through the cabinet body. When various electrical components are in a vibrating state for a long time, their internal The components are easily damaged, which affects the service life. On the other hand, various connecting lines and contacts are also disengaged due to long-term vibration, causing the entire system to fail. Therefore, there are problems in the scheme of using an internal fan;

2. The electrical cabinet is generally placed in the electrical control room. If the electrical control room is not equipped with an air conditioner, the temperature of the entire electrical control room will be very high, especially in summer, due to the high temperature of the external air, the fan in the electrical cabinet has to work for a long time; In addition, if an air conditioner is installed in the electrical control room, most of the cold air generated by the air conditioner is building energy consumption, that is, the air in the entire electrical control room needs to be cooled, so the energy consumption will be high, which is not cost-effective;

3. The control core in the electrical cabinet: the controller does not have a separate heat dissipation structure. Once the controller fails due to untimely heat dissipation, the entire system will be paralyzed and cause immeasurable losses.

Because there are above-mentioned technical problems in prior art, affect use, therefore must improve.

Contents of the invention

The purpose of the present invention is to provide an electrical cabinet with good heat dissipation effect.

The solution of the present invention is: an electrical cabinet, including several cabinets arranged side by side and a cold air cabinet, a mounting plate for installing electrical components is arranged in the cabinet, an air inlet is provided at the lower part of the cabinet, and an air inlet is provided on the air inlet. The fan is also provided with a temperature sensor in the cabinet; a controller installation room is provided on the mounting plate, and the upper part of the controller installation room has an overflow hole, and a cold air cover is provided on the inner wall of the cabinet, and the surface of the cold air cover It is full of air outlets; an air duct with open ends is provided above the cabinet body, and the air outlet on the top of each cabinet communicates with the air duct through heat dissipation pipes; the two ends of the air duct are located at the electrical On the outside of the control room, there are dampers that can be opened and closed at both ends of the air duct, and an exhaust pipe is provided at one end of the air duct, and an exhaust fan is arranged on the exhaust duct; The air-conditioning cabinet is equipped with an air conditioner, and a groove is provided on the ground of the electrical control room. The bottom of the air-conditioning cabinet is connected with a cold air pipe, and the air-conditioning pipe is located in the groove. The cabinet body is located above the groove. Both are provided with a first pipeline and a second pipeline, the first pipeline communicates between the cold air pipe and the controller installation room, the second pipeline communicates between the cold air pipe and the cold air cover, and the second pipeline is provided with There is a cold air valve; a general controller is provided in the air-conditioning cabinet, and the temperature sensor signals in each cabinet are input into the general controller, and the output terminal of the general controller controls the connection of the damper, exhaust fan, and fan and cold air valve.

The present invention also designs a kind of heat radiation control method of electric cabinet, and it adopts above-mentioned electric cabinet, it is characterized in that comprising following measures:

a. The air conditioner in the air-conditioning cabinet cools the air in the air-conditioning cabinet, and sends the cold air directly to the controller installation room through the cold air pipe and the first pipe in each cabinet. The first pipe is guaranteed to be unobstructed for a long time, and the cold air enters the controller The installed controller is cooled in the installation room while part of the cold air is released through the overflow hole to reduce the temperature in the cabinet; the cold air valve is usually kept closed to block the connection between the cold air pipe and the cold air cover;

b. The dampers at both ends of the air duct are usually open, and the flow direction of the air in the air duct is the same as that of the outdoor air. The hot air in each cabinet overflows from the cooling pipe into the air duct and finally escapes from the air duct;

c. The temperature sensor in each cabinet measures the temperature t1 in the cabinet and inputs it to the master controller. Four temperature values ta, tb, tc and td are pre-stored in the master controller, ta represents the standard temperature, and tb represents the medium temperature , tc stands for medium high temperature, td stands for high temperature, after the temperature t1 of each cabinet is input into the master controller, the master controller compares it with the four temperature values;

When the number of cabinets with t1 greater than ta accounts for half of the total, or when the number of cabinets with t1 greater than tb accounts for one-third of the total, start the exhaust fan and close the damper for a period of time T;

When the temperature t1 of a certain cabinet is greater than tc, the master controller controls the cold air valve in the cabinet to open, so that the cold air pipe communicates with the air-conditioning hood, and the cold air is released through the air outlet on the air-conditioning hood to reduce the temperature in the cabinet , the cold air valve is not closed until t1 in the cabinet is less than tb;

When the temperature t1 of a certain cabinet is greater than td, the general controller controls the fan of the cabinet to continue to work and close the cold air valve of the cabinet, and the fan works until t1 of the cabinet is smaller than tb.

Compared with the prior art, the present invention has the following beneficial effects: first, at ordinary times, the hot air heated up by the electrical components in each cabinet will directly overflow into the air duct through the heat dissipation pipe due to the principle of the rising of the hot air, and the air duct The two ends are located outside the electrical control room, the air in the air duct communicates with the outside, and the outdoor atmosphere is basically in a flowing state, which will dissipate the hot air accumulated in the air duct in time, which uses the natural wind energy to dissipate heat and reduce energy consumption. In addition, the hot air released directly to the outside will not increase the temperature of the electrical control room. When the air temperature in the electrical control room is low, the cooling efficiency of the air entering the cabinet can be improved; secondly, the separate air-conditioning cabinet is cooled by the air conditioner, The cold air is sent to the controller installation room through the cold air pipe and the direct first pipe in each cabinet. The first pipe is guaranteed to be unobstructed for a long time, and the cold air enters the controller installation room to cool down the installed controller. In this way, as the control core The controller has been given preferential treatment, and can be placed in an air-conditioned environment for a long time, which is not easy to cause failure and reduce the resulting loss; in addition, the cold air in the controller installation room can be released through the overflow hole, which can reduce the temperature in the cabinet, so that the air conditioner only It communicates with each cabinet, but not with the air outside the cabinet. The air conditioner does not need to lower the temperature of the entire electrical control room, and does not need to generate excessive building energy consumption, which can save energy; when the temperature inside the cabinet is too high, it can pass through Open the air-conditioning valve to connect the air-conditioning pipe and the air-conditioning cover, so that the air conditioner is not only connected to the controller installation room, but also can better disperse the air-conditioning directly into the cabinet through the air-conditioning cover to reduce the temperature; moreover, the two ends of the air duct The damper can be closed, and the exhaust fan can work, which can draw up the hot air in all the cabinets and reduce the temperature in the cabinet. For the heat dissipation and cooling scheme mentioned above, the fan does not work, and the cabinet will not generate slight and frequent vibrations, which can reduce the impact on electrical components and prevent the connection stability between terminals and wires. Only when the above heat dissipation and cooling scheme reaches If it is less than required, the fan can continue to work, draw the external wind into the cabinet, and press the hot air in the cabinet out from the top. The probability of this situation is small, the working time of the fan is very small, and the electrical control The air temperature in the cabinet is also relatively low, which can ensure the normal operation of the electrical components in the cabinet.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the description, and are used together with the embodiments of the present invention to explain the present invention, and do not constitute a limitation to the present invention. In the attached picture:

Fig. 1 is the structural representation of embodiment 1;

Fig. 2 is the enlarged view of place A in Fig. 1;

Fig. 3 is the enlarged view of place B in Fig. 1;

Figure 4 is an enlarged view at C in Figure 1;

Fig. 5 is the schematic diagram of embodiment 2 air duct;

Fig. 6 is the structural representation of embodiment 3;

Components marked in the figure: cabinet body 1, air-conditioning cabinet 2, mounting plate 3, air inlet 4, fan 5, temperature sensor 6, controller installation room 7, air-conditioning cover 8, air duct 9, air outlet 10, air outlet 11, Heat dissipation pipe 12, damper 13, electrical control room 14, exhaust pipe 15, exhaust fan 16, air conditioner 17, slot 18, cold air pipe 19, first pipe 20, second pipe 21, controller 22, cold air valve 23, total Controller 24, overflow hole 25, insect-proof net 26.

detailed description

The present invention will be further described below with reference to the accompanying drawings.

Example 1:

As shown in Figures 1, 2, 3, and 4, the electrical cabinet described in this embodiment includes several cabinets 1 and an air-conditioning cabinet 2 arranged side by side, wherein the number of cabinets 1 is generally 3-8 in a row , of course, can be more, according to the actual situation, there is a mounting plate 3 for installing electrical components in the cabinet 1, an air inlet 4 is provided at the lower part of the cabinet 1, and a fan 5 is provided on the air inlet 4. A temperature sensor 6 is also provided in the body 1; a controller installation chamber 7 is arranged on the installation plate 3, and the upper part of the controller installation chamber 7 has an overflow hole 25, and a cold air cover 8 is arranged on the inner wall of the cabinet body 1, The surface of the cold air cover 8 is covered with air outlet holes 10; an air duct 9 with open ends is arranged on the top of the cabinet body 1, and the air outlet 11 on the top of each cabinet body 1 is connected to the air outlet 11 through a cooling pipe 12. The air duct 9 communicates; the two ends of the air duct 9 are located outside the electrical control room 14, and the two ends of the air duct 9 are provided with openable and closable dampers 13, the damper 13 belongs to the prior art, the simplest damper It can be an electric flapper valve, and one of the ends of the air duct 9 is also provided with an exhaust pipe 15, and an exhaust fan 16 is arranged on the exhaust pipe 15; A groove 18 is provided on the ground of the electrical control room 14, and the bottom of the air-conditioning cabinet 2 is connected with a cold air pipe 19, and the cold air pipe 19 is located in the groove 18, and the cabinet body 1 is arranged above the groove 18, and each cabinet body 1 is provided with a first pipeline 20 and a second pipeline 21, the first pipeline 20 communicates between the cold air pipe 19 and the controller installation room 7, and the second pipeline 21 communicates between the cold air pipe 19 and the cold air cover 8 In between, the second pipeline 21 is provided with a cold air valve 23; a general controller 24 is provided in the cold air cabinet 2, and the signals of the temperature sensors 6 in each cabinet 1 are input into the general controller 24 , the output terminal of the master controller 24 is connected to the damper 13 , the suction fan 16 , the fan 5 and the cold air valve 23 .

It should be noted that: after the air conditioner 2 is provided with the air conditioner 17 for refrigeration, the cold air will escape through the air conditioner 19, which is the effect of diffusion, and the air conditioner 17 also has a certain effect. Dispersed well, can install a small fan that inhales from the outside on the air-conditioning cabinet 2 additionally, make the air in the air-conditioning cabinet 2 go out from the air-conditioning pipe 19 better, perhaps can install an additional one on the air-conditioning pipe 19 Only a small fan (power 10W-20W) draws the cold air in the air-conditioning cabinet 2 outwards.

The advantages of the electrical cabinet described in this embodiment are: first, at ordinary times, the hot air heated up by the operation of the electrical components in each cabinet body 1 will directly overflow into the air duct 9 through the cooling pipe 12 due to the principle of rising hot air, Both ends of the air duct 9 are located outside the electrical control room 14, the air in the air duct 9 communicates with the outside, the outdoor atmosphere is basically in a flowing state, and the hot air accumulated in the air duct 9 will be released in time, which utilizes the The natural wind can dissipate heat, and the energy consumption is small. In addition, the hot air emitted directly to the outside will not increase the temperature of the electrical control room 14. When the air temperature in the electrical control room 14 is low, the cooling efficiency when it enters the cabinet body 1 It can be improved; secondly, the separate air-conditioning cabinet 2 is refrigerated by the air conditioner 17, and the cold air is transported to the controller installation room 7 through the air-conditioning pipe 19 and the direct first pipeline 20 in each cabinet body 1, and the first pipeline 20 is guaranteed to be unobstructed for a long time , the cold air enters the controller installation room 7 and cools down the installed controller 22 (such as programmable logic controller PLC). In this way, the controller 22 as the control core has been given preferential treatment, and can be in an air-conditioned environment for a long time, which is not easy to produce failure, reduce the loss thus produced; in addition, the cold air in the controller installation room 7 can be released through the overflow hole 25, which can reduce the temperature in the cabinet 1, so that the air conditioner 17 only communicates with each cabinet 1, and does not Connected with the air outside the cabinet 1, the air conditioner 17 does not need to reduce the temperature of the entire electrical control room 14, and does not need to generate too much building energy consumption to play an energy-saving role; when the temperature inside the cabinet 1 is too high, it can be opened by opening the cold air valve 23, make the cold air pipe 19 communicate with the cold air cover 8, so that the air conditioner 17 not only communicates with the controller installation room 7, but also can better disperse the cold air directly into the cabinet body 1 through the cold air cover 8 to reduce the temperature; moreover, The damper 13 at air duct 9 two ends can be closed, and exhaust fan 16 can work, and the hot air of all cabinets 1 can be pumped up, and the temperature in cabinet 1 can be reduced. In the heat dissipation and cooling scheme mentioned above, the fan 5 does not work, and the cabinet body 1 will not generate slight and frequent vibrations, which can reduce the impact on electrical components and prevent the stability of the connection between the terminals and the wires. Only the heat dissipation and cooling on the top If the solution fails to meet the requirements, the fan 5 can continue to work, draw the external wind into the cabinet 1, and press the hot air in the cabinet 1 out from the top. The probability of this situation is small, and the fan 5 The working hours are few, and the air temperature in the electrical control room 14 is also relatively low, which can ensure the normal operation of the electrical components in the cabinet 1.

The heat dissipation control method of the electric cabinet described in this embodiment adopts the electric cabinet described in the above embodiment 1, and is characterized in that it includes the following measures:

a, the air conditioner 17 in the air-conditioning cabinet 2 cools the air in the air-conditioning cabinet 2, and directly transports the cold air to the controller installation room 7 through the cold air pipe 19 and the first pipeline 20 in each cabinet 1, the first pipeline 20 Long-term unobstructed, cold air enters the controller installation room 7 to cool down the installed controller 22 while part of the cold air escapes through the overflow hole 25 to reduce the temperature in the cabinet 1; the cold air valve 23 is usually kept closed to block The communication of the cold air pipe 19 and the cold air cover 8;

b. The dampers 13 at both ends of the air duct 9 are usually in an open state, the flow direction of the air in the air duct 9 is the same as that of the outdoor air, and the hot air in each cabinet 1 overflows from the cooling pipe 12 into the air duct 9 and finally escapes air duct 9;

c. The temperature sensor 6 in each cabinet 1 measures the temperature t1 in the cabinet 1 and inputs it to the master controller 24, where four temperature values ta, tb, tc and td are pre-stored in the master controller 24, ta represents standard temperature, tb represents medium temperature, tc represents medium and high temperature, and td represents high temperature. After the temperature t1 of each cabinet 1 is input to the master controller 24, the master controller 24 compares it with the four temperature values;

When the number of cabinets 1 whose t1 is greater than ta accounts for half of the total, or when the number of cabinets 1 whose t1 is greater than tb accounts for one-third of the total, start the exhaust fan 16 and close the damper 13 for a period of time T;

When the temperature t1 of a certain cabinet 1 is greater than tc, the general controller 24 controls the cold air valve 23 in the cabinet 1 to open, so that the cold air pipe 19 communicates with the cold air cover 8, and the cold air passes through the air outlet 10 on the cold air cover 8 To reduce the temperature in the cabinet 1, the cold air valve 23 is not closed until t1 in the cabinet 1 is less than tb;

When the temperature t1 of a certain cabinet 1 is greater than td, the general controller 24 controls the fan 5 of the cabinet 1 to continue to work and close the cold air valve 23 of the cabinet 1, and the fan 5 works until the t1 of the cabinet 1 is less than tb until.

In addition to the advantages mentioned above, this cooling method also has the following advantages:

1. Centralized heat dissipation scheme:

When the temperature of more cabinets 1 rises (when the number of cabinets 1 with t1 greater than ta accounts for half of the total), or when the temperature of some cabinets 1 is at medium temperature (that is, the number of cabinets 1 with t1 greater than tb accounted for one-third of the total), start the ventilation and heat dissipation scheme to cool all the cabinets together so that they can work normally. minutes), the heat in the cabinet 1 can be basically drawn away, so that the electrical components can work normally; The air inside has been updated to make the temperature of the controller installation room 7 a little lower.

2. Individual heat dissipation scheme:

For a single cabinet 1, the temperature is relatively high, and when the temperature of other cabinets 1 is not as high as the heat dissipation conditions of the above-mentioned centralized ventilation, there are two ways. One is when the temperature t1 of a certain cabinet 1 is greater than tc, that is During medium and high temperature, the master controller 24 controls the cold air valve 23 in the cabinet 1 to open, so that the cold air pipe 19 communicates with the cold air cover 8, and the cold air is released through the air outlet 10 on the cold air cover 8 to reduce the temperature in the cabinet 1. When the temperature in the cabinet body 1 is at a high temperature, that is, when the temperature t1 of the cabinet body 1 is greater than td, the general controller 24 controls the fan 5 of the cabinet body 1. Continue to work and close the cold air valve 23 of the cabinet 1 at the same time, and the fan 5 works until t1 of the cabinet 1 is less than tb. Utilize fan 5 to continuously work and cool down. This kind of individual heat dissipation scheme is until the temperature in the cabinet 1 is lower than tb, below tb, wait for the temperature of more cabinets 1 to rise to tb, and then start the centralized heat dissipation scheme.

Such a centralized heat dissipation scheme plus individual heat dissipation schemes not only ensures the overall operation, but also ensures the normal operation of a single cabinet, and the effect is better.

The four temperature values of ta, tb, tc and td can be set by those skilled in the art according to the situation, such as: ta is 35 degrees Celsius; tb is 40 degrees Celsius; tc is 45 degrees Celsius; td is 50 degrees Celsius; obviously, according to the region The four temperature values can be adjusted according to different situations, but it must be ensured that ta is smaller than tb and smaller than tc and smaller than td.

As some improvements of the above-mentioned scheme: the two ends of the air duct 9 can be provided with leaking openings at a distance of 50 centimeters to 1 meter from the air duct opening, that is, a plurality of notches are drawn on the bottom surface of the air duct 9 to prevent rainwater from entering.

Example 2:

As shown in Figure 5, the electrical cabinet described in this embodiment is different from Embodiment 1 in that: the bottom surface of the air duct 9 is a structure with a high middle and low sides. Such a scheme can prevent rainwater from entering the air duct, so that rainwater cannot The central flow prevents rainwater from entering the cabinet body 1.

Also can be provided with some rows of water retaining rods on the bottom surface of air duct 9 and carry out waterproofing.

Example 3:

As shown in Figure 6, the electrical cabinet described in this embodiment includes several cabinets 1 and an air-conditioning cabinet 2 arranged side by side, wherein the number of cabinets 1 is generally 3-8 in a row, and of course there can be more According to the actual situation, there is a mounting plate 3 for installing electrical components in the cabinet 1, an air inlet 4 is provided at the lower part of the cabinet 1, a fan 5 is provided on the air inlet 4, and a fan 5 is provided in the cabinet 1. Temperature sensor 6; a controller installation chamber 7 is provided on the mounting plate 3, the upper part of the controller installation chamber 7 has an overflow hole 25, and a cold air cover 8 is provided on the inner wall of the cabinet body 1, and the surface of the cold air cover 8 is Covered with air outlet holes 10; an air duct 9 with open ends is provided above the cabinet body 1, and the air outlet 11 on the top of each cabinet body 1 communicates with the air duct 9 through a heat dissipation pipe 12; Both ends of the air duct 9 are located outside the electrical control room 14, and both ends of the air duct 9 are provided with openable and closable dampers 13, and one of the ends of the air duct 9 is also provided with an exhaust pipe 15 , an exhaust fan 16 is provided on the exhaust pipe 15; an air conditioner 17 is provided in the air-conditioning cabinet 2, a groove 18 is provided on the ground of the electrical control room 14, and an air-conditioning pipe 19 is connected to the bottom of the air-conditioning cabinet 2, The cold air pipe 19 is located in the groove 18, the cabinet body 1 is arranged above the groove 18, and each cabinet body 1 is provided with a first pipeline 20 and a second pipeline 21, and the first pipeline 20 communicates with the cold air pipe. 19 and the controller installation room 7, the second pipeline 21 communicates between the cold air pipe 19 and the cold air cover 8, and the second pipeline 21 is provided with a cold air valve 23; General controller 24, the temperature sensor 6 signal in each cabinet 1 is all input in this general controller 24, and the output terminal of this general controller 24 controls and connects described damper 13, exhaust fan 16, fan 5 and cold air valve 23; both ends in the air duct 9 are provided with an insect-proof net 26, and the insect-proof net 26 is 1 meter to 2 meters apart from the air duct mouth; the insect-proof net 26 can adopt a metal mesh; The insects in the air duct 9 are electro-killed and insect-proof. The structure of the insect-proof grid is a prior art. The insect-proof grid is disclosed in the Chinese patent ZL2009201214549. In addition, the existing electric mosquito swatter also has the structure of the insect-proof grid. As long as the electric mosquito swatter is amplified, the specific structure of the insect-proof grid is the prior art, and will not be described in detail here.

The heat dissipation control method of the electrical cabinet described in this embodiment is different from the heat dissipation control method described in Embodiment 1 in that it also includes the following measures: both ends of the air duct 9 are provided with an insect-proof grid, and the air duct 9 The insects inside are electrocuted to prevent insects.

Finally, it should be noted that: the above is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, it still The technical solutions recorded in the foregoing embodiments may be modified, or some technical features thereof may be equivalently replaced. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (2)

1. An electrical cabinet, comprising several cabinets (1) arranged side by side and an air-conditioning cabinet (2), in which a mounting plate (3) for installing electrical components is provided in the cabinet (1), and in the cabinet (1) The lower part is provided with an air inlet (4), a fan (5) is arranged on the air inlet (4), and a temperature sensor (6) is also arranged in the cabinet (1); it is characterized in that the mounting plate (3) There is a controller installation room (7) on the top, the upper part of the controller installation room (7) has an overflow hole (25), and a cold air cover (8) is provided on the inner wall of the cabinet body (1), and the cold air cover (8) ) surface is covered with vents (10); above the cabinet (1) is provided with an air duct (9) open at both ends, and the vents (11) at the top of each cabinet (1) pass through The radiating pipe (12) communicates with the air duct (9); the two ends of the air duct (9) are located outside the electrical control room (14), and the two ends of the air duct (9) are provided with openable, The damper (13) of closing is also provided with an exhaust duct (15) at one of the ends of the air passage (9), and an exhaust fan (16) is provided on the exhaust duct (15); (2) is provided with air conditioner (17) inside, is provided with groove (18) on the ground of electrical control room (14), and described air-conditioning cabinet (2) bottom is connected with air-conditioning pipe (19), and this air-conditioning pipe (19) Located in the groove (18), the cabinet body (1) is arranged above the groove (18), and each cabinet body (1) is provided with a first pipeline (20) and a second pipeline (21). The first pipeline (20) communicates between the cold air pipe (19) and the controller installation chamber (7), and the second pipeline (21) communicates between the cold air pipe (19) and the cold air cover (8). The second pipeline (21) is provided with a cold air valve (23); a master controller (24) is provided in the air cold cabinet (2), and the signals of the temperature sensors (6) in each cabinet (1) are input To the master controller (24), the output terminal of the master controller (24) is connected to the damper (13), exhaust fan (16), fan (5) and cold air valve (23). 2. A heat dissipation control method of an electric cabinet, which adopts the electric cabinet as claimed in claim 1, is characterized in that comprising the following measures: a, the air conditioner (17) in the air-conditioning cabinet (2) cools the air in the air-conditioning cabinet (2), and the cold air passes through the cold air pipe (19) and the first pipeline (20) in each cabinet (1) directly Transported to the controller installation room (7), the first pipeline (20) is guaranteed to be unobstructed for a long time, and the cold air enters the controller installation room (7) to cool down the installed controller (22) while part of the cold air passes through the overflow hole (25) dissipate to reduce the temperature in the cabinet (1); the cold air valve (23) keeps shutting off the communication of the cold air pipe (19) and the cold air cover (8) at ordinary times; b. The dampers (13) at both ends of the air duct (9) are usually in an open state, the flow direction of the air in the air duct (9) is connected with the flow direction of the outdoor air, and the hot air in each cabinet (1) flows from the cooling pipe (12) The overflow enters the air duct (9) and finally escapes the air duct (9); c. The temperature sensor (6) in each cabinet (1) measures the temperature t1 in the cabinet (1) and inputs it to the master controller (24), where four temperatures are stored in advance in the master controller (24) Values ta, tb, tc and td, ta represents standard temperature, tb represents medium temperature, tc represents medium high temperature, td represents high temperature, after the temperature t1 of each cabinet (1) is input into the master controller (24), the master controller ( 24) Compare it with the four temperature values; When the number of cabinets (1) with t1 greater than ta accounts for half of the total, or when the number of cabinets (1) with t1 greater than tb accounts for one-third of the total, start the exhaust fan (16), close the damper (13 ), and last for a period of time T; When the temperature t1 of a certain cabinet (1) is greater than tc, the general controller (24) controls the cold air valve (23) in the cabinet (1) to open, so that the cold air pipe (19) communicates with the cold air cover (8) , the cold air is released through the air outlet (10) on the air-cooling cover (8) to reduce the temperature in the cabinet (1), and the cold air valve (23) is not closed until t1 in the cabinet (1) is less than tb; When the temperature t1 of a certain cabinet (1) is greater than td, the general controller (24) controls the fan (5) of the cabinet (1) to continue to work and close the cold air valve (23) of the cabinet (1), The fan (5) works until t1 of the cabinet (1) is less than tb.