CN118836375A - Compressed air supply system and control method - Google Patents

Abstract

The present invention relates to the technical field of compressed air, and provides a compressed air supply system and control method, the system comprising: a dryer, an air inlet pipeline and an air outlet pipeline, and also comprising: a controller, a first bypass and a first pressure transmitter, one end of the first bypass is connected to the air inlet pipeline, and the other end is connected to the air outlet pipeline, a first solenoid valve is provided on the first bypass, and a first pressure transmitter is provided on the air outlet pipeline, and a second solenoid valve and a third solenoid valve are provided at the air inlet end and the air outlet end of the dryer respectively; the controller is connected to the first pressure transmitter, the first solenoid valve, the second solenoid valve and the third solenoid valve; the first pressure transmitter sends the monitored outlet pressure on the outlet pipeline to the controller, and the controller controls the first solenoid valve to open, and the second solenoid valve and the third solenoid valve to close when the outlet pressure is less than the first preset air pressure threshold. In the present invention, the first bypass can be automatically opened when the outlet pressure is reduced, and air can be supplied to the back-end equipment in a timely and sufficient manner.

Description

Compressed air supply system and control method

Technical Field

The present invention relates to the technical field of air compression, and in particular to a compressed air supply system and a control method.

Background Art

The existing compressed air supply system, as shown in FIG1, has certain requirements for air dryness in the back-end equipment when the system is supplying air normally. Therefore, the compressed air enters the dryer 101 through the pipeline from the air inlet end, is dried by the dryer 101, and the dried compressed air is output to the workshop that needs compressed air through the air outlet pipeline. If the dryer 101 suddenly fails, such as: the dryer 101 is blocked internally, it will affect the reduction of the compressed air supply pressure, that is, the pressure transmitter 102 detects the reduction of the outlet pressure and alarms, causing the workshop equipment to shut down due to insufficient compressed air pressure, affecting production. After the pressure transmitter 102 alarms, the relevant staff opens the manual bypass valve 103 to ensure the air supply pressure at the air outlet.

However, the manual bypass valve 103 needs to be opened manually, and the manual bypass valve 103 may not be opened in time, resulting in insufficient gas supply pressure at the gas outlet. Even if the gas supply pressure is insufficient in a short period of time, it will affect the subsequent production rhythm.

Summary of the invention

The present invention provides a compressed air supply system and a control method, which are used to solve the problem in the prior art that a manual bypass valve is not opened in time, resulting in insufficient air supply pressure at an air outlet, thus affecting the subsequent production rhythm.

The present invention provides a compressed air supply system, comprising: a dryer, an air inlet pipeline connected to an air inlet end of the dryer and an air outlet pipeline connected to an air outlet end of the dryer, and further comprising: a controller, a first bypass and a first pressure transmitter, wherein one end of the first bypass is connected to the air inlet pipeline and the other end is connected to the air outlet pipeline, a first solenoid valve is arranged on the first bypass, the first pressure transmitter is arranged on the air outlet pipeline, and a second solenoid valve and a third solenoid valve are respectively arranged on the air inlet end and the air outlet end of the dryer;

The controller is connected to the first pressure transmitter, the first solenoid valve, the second solenoid valve and the third solenoid valve;

The first pressure transmitter is used to monitor the outlet pressure on the outlet pipeline and send the outlet pressure to the controller. The controller is used to control the first solenoid valve to open and the second solenoid valve and the third solenoid valve to close when the outlet pressure is less than a first preset pressure threshold.

A compressed air supply system provided according to the present invention also includes: a second bypass connected in parallel with the first bypass, one end of the second bypass is connected to the air inlet pipeline, and the other end is connected to the air outlet pipeline, a fourth solenoid valve is provided on the second bypass, and the fourth solenoid valve is connected to the controller, the first solenoid valve is used to feed back an opening state signal to the controller after opening, and the controller is also used to control the fourth solenoid valve to open when the opening state signal of the first solenoid valve is not received within a preset time.

According to a compressed air supply system provided by the present invention, the fourth solenoid valve is used to feed back an opening status signal to the controller after opening, and the controller is also used to issue a warning when the opening status signal of the fourth solenoid valve is not received within a preset time.

According to a compressed air supply system provided by the present invention, the air inlet end and the air outlet end of the dryer are respectively provided with an air inlet manual valve and an air outlet manual valve, the second solenoid valve is used to feed back a closing state signal to the controller after closing, and the controller is also used to issue a warning to prompt the closing of the air inlet manual valve when the closing state signal of the second solenoid valve is not received within a preset time; the third solenoid valve is used to feed back a closing state signal to the controller after closing, and the controller is also used to issue a warning to prompt the closing of the air outlet manual valve when the closing state signal of the third solenoid valve is not received within a preset time.

According to a compressed air supply system provided by the present invention, a second pressure transmitter is further provided on the air outlet pipeline, and the second pressure transmitter is connected to the controller.

According to a compressed air supply system provided by the present invention, the controller is also used to control the first solenoid valve to close, the second solenoid valve and the third solenoid valve to open, when the first solenoid valve is opened, the second solenoid valve and the third solenoid valve are closed, and the outlet air pressure is greater than a second preset air pressure threshold, and the second preset air pressure threshold is greater than the first preset air pressure threshold.

According to a compressed air supply system provided by the present invention, a third pressure transmitter is also provided on the air intake pipeline, and the third pressure transmitter is connected to the controller. The third pressure transmitter sends the monitored air intake pressure to the controller, and the controller is also used to calculate the pressure difference between the air intake pressure and the air outlet pressure. When the pressure difference is greater than the pressure loss of the dryer, the first solenoid valve is controlled to open, and the second solenoid valve and the third solenoid valve are controlled to close.

According to a compressed air supply system provided by the present invention, a fourth pressure transmitter is further provided on the air intake pipeline, and the fourth pressure transmitter is connected to the controller.

The present invention also provides a compressed air supply control method, which is implemented based on any of the above-mentioned compressed air supply systems and applied to the controller, and the method comprises:

Obtaining the outlet pressure on the outlet pipeline monitored by the first pressure transmitter;

When the outlet pressure is less than the first preset pressure threshold, the first solenoid valve is controlled to open, and the second solenoid valve and the third solenoid valve are controlled to close.

According to a compressed air supply control method provided by the present invention, after controlling the first solenoid valve to open and the second solenoid valve and the third solenoid valve to close, the method further includes:

When the outlet pressure is greater than a second preset pressure threshold, the first solenoid valve is controlled to be closed, and the second solenoid valve and the third solenoid valve are controlled to be opened, and the second preset pressure threshold is greater than the first preset pressure threshold.

In the compressed air supply system and control method provided by the present invention, a first bypass connecting an air inlet pipeline and an air outlet pipeline is provided, a first solenoid valve is provided on the first bypass, a first pressure transmitter is provided on the air outlet pipeline, and a second solenoid valve and a third solenoid valve are provided at the air inlet end and the air outlet end of the dryer, respectively. The outlet pressure on the air outlet pipeline monitored by the first pressure transmitter is obtained by a controller, and when the outlet pressure is less than a first preset air pressure threshold, the first solenoid valve is controlled to open, and the second solenoid valve and the third solenoid valve are controlled to close, so that when the outlet pressure decreases, the first bypass is automatically opened, and the compressed air directly passes through the first bypass to the air outlet pipeline, so that the back-end system can be supplied with air in time, and the air supply pressure of the air outlet pipeline is guaranteed to meet the air pressure requirement of the back-end system to avoid affecting the subsequent production rhythm; and the second solenoid valve and the third solenoid valve are automatically closed to avoid compressed air entering the dryer to cause air pressure loss, so that the air outlet pipeline maintains a higher air supply pressure to ensure subsequent production needs.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG1 is a schematic structural diagram of an existing compressed air supply system;

FIG2 is a schematic structural diagram of a compressed air supply system provided by the present invention;

FIG3 is a schematic flow chart of the compressed air supply control method provided by the present invention.

DETAILED DESCRIPTION

In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

The compressed air supply system of the embodiment of the present invention, as shown in FIG2, comprises: a dryer 201 and an air inlet pipeline connected to the air inlet end of the dryer 201 and an air outlet pipeline connected to the air outlet end of the dryer 201. In the present embodiment, the dryer 201 is composed of at least two drying tanks arranged side by side, such as the dryer A tank and the dryer B tank in FIG2, and at least two drying tanks share the air inlet end and the air outlet end. The compressed air supply system of the present embodiment also comprises: a controller 202, a first bypass and a first pressure transmitter 203, one end of the first bypass is connected to the air inlet pipeline, and the other end is connected to the air outlet pipeline, and the first bypass is provided with a first solenoid valve 204, that is, the first bypass is arranged in parallel with the dryer 201. The first pressure transmitter 203 is arranged on the air outlet pipeline for monitoring the air outlet pressure, and the air inlet end and the air outlet end of the dryer 201 are respectively provided with a second solenoid valve 205 and a third solenoid valve 206.

The controller 202 can be a controller developed based on PLC or FPGA. The controller 202 is connected to the first pressure transmitter 203, the first solenoid valve 204, the second solenoid valve 205 and the third solenoid valve 206. It can be a wired connection or a wireless connection, which facilitates the interaction of signals and/or control instructions between the controller 202 and the first pressure transmitter 203, the first solenoid valve 204, the second solenoid valve 205 and the third solenoid valve 206 respectively.

The first pressure transmitter 203 is used to monitor the outlet pressure on the outlet pipeline and send the outlet pressure to the controller 202. The controller 202 is used to control the first solenoid valve 204 to open and the second solenoid valve 205 and the third solenoid valve 206 to close when the outlet pressure is less than the first preset pressure threshold.

When the compressed air supply system of the embodiment of the present invention works normally, the first solenoid valve 204 is closed, that is, the first bypass is closed, and the pipeline passing through the dryer 201 is in a conducting state. The compressed air enters the dryer 201 through the air inlet pipeline and is supplied to the back-end equipment through the air outlet pipeline after drying. The air path is shown by the arrow in Figure 2, and the controller 202 receives the monitored outlet pressure uploaded by the first pressure transmitter 203. During the operation of the compressed air supply, due to a failure of the dryer 201, for example, a blockage of the dryer 201 may cause the outlet pressure to drop. When the outlet pressure drops to less than the first preset pressure threshold, the first solenoid valve 204 is opened under the control of the controller 202, and then the first bypass is automatically opened. The compressed air directly passes through the first bypass to the outlet pipeline, which can supply air to the back-end system in a timely manner and ensure (as long as the air pressure of the compressed air at the air inlet end does not decrease) that the air supply pressure of the outlet pipeline meets the air pressure requirement of the back-end system to avoid affecting the subsequent production rhythm; and the second solenoid valve 205 and the third solenoid valve 206 are automatically closed to prevent part of the compressed air from entering the dryer 201 and causing air pressure loss, so that the outlet pipeline maintains a higher air supply pressure to ensure subsequent production needs.

The first preset pressure threshold can be pre-set in the controller 202 according to the pressure requirement of the back-end equipment of the air outlet pipeline. For example, the normal delivery pressure of the air outlet pipeline of the system is 0.8-0.85Mpa, which meets the minimum air pressure requirement of 0.7Mpa required by the back-end equipment. 0.7Mpa can be used as the first preset pressure threshold. When the dryer 201 is blocked, resulting in the outlet pressure being lower than 0.7Mpa, the controller 202 controls the first solenoid valve 204 to open, and the second solenoid valve 205 and the third solenoid valve 206 to close.

In some embodiments, the compressed air supply system further includes: a second bypass connected in parallel with the first bypass, one end of the second bypass is connected to the air inlet pipeline, and the other end is connected to the air outlet pipeline, and a fourth solenoid valve 207 is provided on the second bypass, and the fourth solenoid valve 207 is connected to the controller 202. In this embodiment, the first solenoid valve 204 is used to feed back an opening state signal to the controller 202 after opening, so as to confirm to the controller 202 that the first solenoid valve 204 has been opened and the first bypass has been conducted. After receiving the opening state signal of the first solenoid valve 204, the controller 202 does not act, and continues to receive the outlet pressure uploaded by the first pressure transmitter 203. In actual use, the first solenoid valve 204 may also fail to open, so the controller 202 is also used to control the fourth solenoid valve 207 to open when the opening state signal of the first solenoid valve 204 is not received within a preset time (for example: 2 to 3 seconds). After the fourth solenoid valve 207 is opened, the second bypass is automatically conducted, thereby avoiding the problem of failure to supply air normally due to failure of the first solenoid valve 204 to open. It can be understood that the second bypass serves as a backup bypass for the first bypass. When the controller 202 detects that the first solenoid valve 204 fails and cannot open the first bypass, the controller 202 controls the fourth solenoid valve 207 to open and open the second bypass, further ensuring that the back-end system can be supplied with air in a timely manner, and (as long as the air pressure of the compressed air at the air inlet end does not decrease) the air supply pressure of the air outlet pipeline meets the air pressure requirement of the back-end system.

In some embodiments, the fourth solenoid valve 207 is used to feed back an opening status signal to the controller 202 after opening. The controller 202 is also used to issue a warning to prompt the staff to handle it when the opening status signal of the fourth solenoid valve 207 is not received within a preset time, so as to avoid the situation where both the first solenoid valve 204 and the fourth solenoid valve 207 fail and cannot automatically open the bypass.

Further, a third bypass (not shown in the figure) connected in parallel with the first bypass and the second bypass is provided, and a manual bypass valve is provided on the third bypass. When the dryer operates normally and the first solenoid valve 204 and the fourth solenoid valve 207 are both fault-free, the manual bypass valve is closed. During the operation of the compressed air supply, the outlet pressure drops due to the failure of the dryer 201. When the outlet pressure drops to less than the first preset air pressure threshold and the first solenoid valve 204 and the fourth solenoid valve 207 are both faulty, the manual bypass valve on the third bypass is opened. Specifically, the controller 202 is also used to issue a warning to prompt the staff to open the manual bypass valve when the first solenoid valve 204 and the fourth solenoid valve 207 cannot be controlled to open. According to the aforementioned embodiment, the controller 202 first controls the first solenoid valve 204 to open. When the controller 202 does not receive the opening state signal of the first solenoid valve 204 within the preset time, the controller 202 controls the fourth solenoid valve 207 to open. When the controller 202 does not receive the opening state signal of the second solenoid valve 207 within the preset time, the controller issues a warning to prompt the staff to open the manual bypass valve.

In some embodiments, the air inlet and air outlet ends of the dryer 201 are respectively provided with an air inlet manual valve 210 and an air outlet manual valve 211. When the system is operating normally, the air inlet manual valve 210 and the air outlet manual valve 211 are in a normally open state. The second solenoid valve 205 is used to feed back a closing state signal to the controller 202 after closing. The controller 202 is also used to issue a warning to prompt the closing of the air inlet manual valve 210 when the closing state signal of the second solenoid valve 205 is not received within a preset time. The third solenoid valve 206 is used to feed back a closing state signal to the controller 202 after closing. The controller 202 is also used to issue a warning to prompt the closing of the air outlet manual valve 211 when the closing state signal of the third solenoid valve 206 is not received within a preset time. In this embodiment, when the second solenoid valve 205 and/or the third solenoid valve 206 fail and cannot be closed, the controller 202 prompts to close the air inlet manual valve 210 and/or the air outlet manual valve 211 to ensure that all compressed air is transmitted to the air outlet pipeline through the bypass.

In some embodiments, a second pressure transmitter 212 is further provided on the air outlet pipeline, and the second pressure transmitter 212 is connected to the controller 202. In a non-faulty state, the outlet pressures measured by the first pressure transmitter 203 and the second pressure transmitter 212 are the same. The first pressure transmitter 203 and the second pressure transmitter 212 are backup for each other, so that after one of the pressure transmitters is disassembled for inspection, the other pressure transmitter can continue to support the operation of the entire compressed air supply system.

Since the reason for the reduction in the outlet pressure may also be the reduction in the air pressure of the air intake source (i.e., the air compressor), for example, due to short-term voltage instability, the air intake pressure is reduced, and the air intake pressure is restored after the voltage stabilizes, therefore, in some embodiments, the controller 202 is also used to control the first solenoid valve 204 to be closed, the second solenoid valve 205 and the third solenoid valve 206 to be opened, and the second solenoid valve 205 and the third solenoid valve 206 to be opened, when the first solenoid valve 204 is opened, the second solenoid valve 205 and the third solenoid valve 206 are closed (i.e., the air intake pressure is reduced for a short time, causing the outlet pressure to be reduced to the first preset air pressure threshold, so that the controller 202 opens the first solenoid valve 204, and the second solenoid valve 205 and the third solenoid valve 206 are closed), and the outlet pressure is greater than the second preset air pressure threshold, control the first solenoid valve 204 to be closed, the second solenoid valve 205 and the third solenoid valve 206 to be opened, that is, close the first bypass, so that the compressed air passes through the dryer 201 and then is transmitted to the back-end equipment to meet the air dryness requirement. Among them, the second preset air pressure threshold is greater than the first preset air pressure threshold. For example, the normal air pressure of the system's air outlet pipeline is 0.8-0.85 MPa, which meets the minimum air pressure requirement of 0.7 MPa of the back-end equipment. 0.7 MPa can be used as the first preset air pressure threshold, and the second preset air pressure threshold can be set to 0.9 MPa.

If when the outlet pressure is less than the first preset pressure threshold, the first solenoid valve 204 cannot be opened due to a fault, and the fourth solenoid valve 207 of the second bypass is opened, then in this embodiment, the controller 202 is also used to control the fourth solenoid valve 207 to close, the second solenoid valve 205 and the third solenoid valve 206 to open, that is, to close the second bypass when the fourth solenoid valve 207 is opened, the second solenoid valve 205 and the third solenoid valve 206 are closed, and the outlet pressure is greater than the second preset pressure threshold.

In this embodiment, the first bypass is provided with a first bypass manual valve 208, which is arranged in series with the first solenoid valve 204, and the second bypass is provided with a second bypass manual valve 209, which is arranged in series with the fourth solenoid valve 204. When the system starts to work and the dryer 201 is normal, the first bypass manual valve 208 and the second bypass manual valve 209 are in a normally open state. When the first solenoid valve 204 is open, the second solenoid valve 205 and the third solenoid valve 206 are closed, and the outlet pressure is greater than the second preset pressure threshold, if the controller 202 cannot control the first solenoid valve 204 or the fourth solenoid valve 207 to close (the first solenoid valve 204 or the fourth solenoid valve 207 is faulty), a warning is issued to prompt the first bypass manual valve 208 or the second bypass manual valve 209 to be manually closed.

In some embodiments, a third pressure transmitter 213 is further provided on the air intake pipeline, and the third pressure transmitter 213 is connected to the controller 202. The third pressure transmitter 213 sends the monitored air intake pressure to the controller 202. The controller 202 is also used to calculate the pressure difference between the air intake pressure and the air outlet pressure. When the pressure difference is greater than the pressure loss of the dryer 201, the first solenoid valve 204 is controlled to be opened, and the second solenoid valve 205 and the third solenoid valve 206 are controlled to be closed. The pressure loss of the dryer 201 is an indicator for judging whether the dryer 201 is blocked. For example, if the pressure loss is 0.2Mpa, if the pressure difference is greater than 0.2Mpa, it means that the dryer 201 is blocked. Even if the current air outlet pressure is not less than the first preset air pressure threshold, the controller 202 controls the first solenoid valve 204 to be opened, and the second solenoid valve 205 and the third solenoid valve 206 to be closed, so as to avoid the occurrence of a trend of decreasing air outlet pressure. Moreover, the dryer 201 absorbs moisture from the air. One of the reasons for the blockage is that it absorbs too much moisture. The blockage caused by the high humidity inside the dryer 201 has little effect on drying the compressed air. The controller 202 controls the first solenoid valve 204 to open, opens the first bypass, and closes the second solenoid valve 205 and the third solenoid valve 206 to ensure the air supply pressure to the back-end equipment in a more timely manner.

In some embodiments, a fourth pressure transmitter 214 is further provided on the air intake pipeline, and the fourth pressure transmitter 214 is connected to the controller 202. In a non-faulty state, the third pressure transmitter 213 and the fourth pressure transmitter 214 respectively measure the same air intake pressure. The third pressure transmitter 213 and the fourth pressure transmitter 214 are backup for each other, so that after one of the pressure transmitters is disassembled for inspection, the other pressure transmitter can continue to support the operation of the entire compressed air supply system.

The present invention further provides a compressed air supply control method, which is implemented based on the compressed air supply system of any of the above embodiments and applied to the controller 202. The method flow is shown in FIG3 and includes:

Step S310: obtaining the outlet pressure on the outlet pipeline monitored by the first pressure transmitter 203 .

Step S320: When the outlet pressure is less than the first preset pressure threshold, the first solenoid valve 204 is controlled to open, and the second solenoid valve 205 and the third solenoid valve 206 are controlled to close.

The compressed air supply control method of the present embodiment is implemented based on a compressed air supply system. When the outlet pressure drops to less than a first preset pressure threshold, the first solenoid valve 204 is opened under the control of the controller 202, and then the first bypass is automatically opened. The compressed air directly passes through the first bypass to the outlet pipeline, so as to supply air to the back-end system in time and ensure (as long as the air pressure of the compressed air at the air inlet end does not decrease) that the air supply pressure of the outlet pipeline meets the air pressure requirement of the back-end system to avoid affecting the subsequent production rhythm; and automatically close the second solenoid valve 205 and the third solenoid valve 206 to prevent part of the compressed air from entering the dryer 201 and causing air pressure loss, so that the outlet pipeline maintains a higher air supply pressure to ensure subsequent production needs.

In some embodiments, after controlling the first solenoid valve 204 to open and the second solenoid valve 205 and the third solenoid valve 206 to close, the method further includes:

When the outlet pressure is greater than the second preset pressure threshold, the first solenoid valve 204 is controlled to be closed, and the second solenoid valve 205 and the third solenoid valve 206 are controlled to be opened, and the second preset pressure threshold is greater than the first preset pressure threshold.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (10)

1. A compressed air supply system, comprising: a dryer, an air inlet pipeline connected to an air inlet end of the dryer, and an air outlet pipeline connected to an air outlet end of the dryer, characterized in that it also comprises: a controller, a first bypass and a first pressure transmitter, one end of the first bypass is connected to the air inlet pipeline, and the other end is connected to the air outlet pipeline, a first solenoid valve is arranged on the first bypass, the first pressure transmitter is arranged on the air outlet pipeline, and a second solenoid valve and a third solenoid valve are respectively arranged on the air inlet end and the air outlet end of the dryer; The controller is connected to the first pressure transmitter, the first solenoid valve, the second solenoid valve and the third solenoid valve; The first pressure transmitter is used to monitor the outlet pressure on the outlet pipeline and send the outlet pressure to the controller. The controller is used to control the first solenoid valve to open and the second solenoid valve and the third solenoid valve to close when the outlet pressure is less than a first preset pressure threshold. 2. The compressed air supply system according to claim 1 is characterized in that it also includes: a second bypass connected in parallel with the first bypass, one end of the second bypass is connected to the air inlet pipeline, and the other end is connected to the air outlet pipeline, a fourth solenoid valve is provided on the second bypass, and the fourth solenoid valve is connected to the controller, the first solenoid valve is used to feed back an opening state signal to the controller after opening, and the controller is also used to control the fourth solenoid valve to open when the opening state signal of the first solenoid valve is not received within a preset time. 3. The compressed air supply system according to claim 2 is characterized in that the fourth solenoid valve is used to feed back an opening status signal to the controller after opening, and the controller is also used to issue a warning when the opening status signal of the fourth solenoid valve is not received within a preset time. 4. The compressed air supply system according to claim 1 is characterized in that the air inlet end and the air outlet end of the dryer are respectively provided with an air inlet manual valve and an air outlet manual valve, and the second solenoid valve is used to feed back a closing state signal to the controller after closing, and the controller is also used to issue a warning to prompt the closing of the air inlet manual valve when the closing state signal of the second solenoid valve is not received within a preset time; the third solenoid valve is used to feed back a closing state signal to the controller after closing, and the controller is also used to issue a warning to prompt the closing of the air outlet manual valve when the closing state signal of the third solenoid valve is not received within a preset time. 5. The compressed air supply system according to claim 1, characterized in that a second pressure transmitter is also provided on the air outlet pipeline, and the second pressure transmitter is connected to the controller. 6. The compressed air supply system according to claim 1 is characterized in that the controller is also used to control the first solenoid valve to close, the second solenoid valve and the third solenoid valve to open, when the first solenoid valve is opened, the second solenoid valve and the third solenoid valve are closed, and the outlet air pressure is greater than a second preset air pressure threshold, and the second preset air pressure threshold is greater than the first preset air pressure threshold. 7. The compressed air supply system according to any one of claims 1 to 6 is characterized in that a third pressure transmitter is also provided on the intake pipeline, the third pressure transmitter is connected to the controller, the third pressure transmitter sends the monitored intake pressure to the controller, and the controller is also used to calculate the pressure difference between the intake pressure and the outlet pressure, and when the pressure difference is greater than the pressure loss of the dryer, the first solenoid valve is controlled to open, and the second solenoid valve and the third solenoid valve are controlled to close. 8. The compressed air supply system according to claim 6, characterized in that a fourth pressure transmitter is also provided on the air intake pipeline, and the fourth pressure transmitter is connected to the controller. 9. A compressed air supply control method, characterized in that it is implemented based on the compressed air supply system according to any one of claims 1 to 8 and applied to the controller, the method comprising: Obtaining the outlet pressure on the outlet pipeline monitored by the first pressure transmitter; When the outlet pressure is less than the first preset pressure threshold, the first solenoid valve is controlled to open, and the second solenoid valve and the third solenoid valve are controlled to close. 10. The compressed air supply control method according to claim 9, characterized in that after controlling the first solenoid valve to open and the second solenoid valve and the third solenoid valve to close, it further comprises: When the outlet pressure is greater than a second preset pressure threshold, the first solenoid valve is controlled to be closed, and the second solenoid valve and the third solenoid valve are controlled to be opened, and the second preset pressure threshold is greater than the first preset pressure threshold.