Boiler pneumatic check valve control loop

Abstract

The utility model discloses a boiler pneumatic check valve control loop which comprises two air cylinders (1), one-way throttle valves (2), electromagnetic valves (3) and a pressure reduction filter (5), two air inlet pipes of each air cylinder (1) are respectively provided with one one-way throttle valve (2), the speeds of the four air inlet pipes of the two air cylinders are independently adjusted, each air cylinder (1) is controlled by one electromagnetic valve (3), and the pressure reduction filter (5) is connected with the electromagnetic valves (3). The control ends of the two one-way throttle valves (2) of each air cylinder (1) are connected with an electromagnetic valve (3), and the input end of the electromagnetic valve (3) is connected with a pressure reduction filter (5). By means of the technical scheme, the problem that due to the fact that double air cylinders of the fan outlet check valve act asynchronously, the opening and closing time of the fan check valve is too long is solved. And the control loop is simple in design and high in reliability, and the safety and reliability of the unit are improved.

Description

Technical Field

[0001] The present invention relates to power generation equipment, and particularly to a control device for a check valve of a fan used in power generation equipment. Background Art

[0002] The main functions of a check valve are to prevent the reverse flow of media, prevent the reverse rotation of pumps and drive motors, and the release of container media.

[0003] The patent document with the publication number CN208518716U discloses a check valve system, which includes a check valve, a check valve cylinder, an intake pipe, and a test solenoid valve assembly. The check valve cylinder is connected to the check valve to drive the check valve to open or close; the intake pipe is connected to the check valve cylinder to supply gas to the check valve cylinder; the test solenoid valve assembly is arranged on the intake pipe to allow a predetermined amount of gas to enter the check valve cylinder when detecting the check valve cylinder, and determine whether the check valve cylinder is working properly according to the movement state of the piston in the check valve cylinder after a predetermined amount of gas enters the check valve cylinder. This technical solution solves the problem that the existing check valve system cannot determine whether the piston in the check valve cylinder can work properly.

[0004] Currently, it is necessary to control two pneumatic check valve driving cylinders simultaneously, so there will actually be problems such as asynchronous operation of the two cylinders and too long opening and closing times of the pneumatic check valve. Summary of the Invention

[0005] The technical problem to be solved by the present invention is how to ensure the synchronous operation of the two cylinders of the check valve at the fan outlet and that the opening and closing times of the fan check valve are not too long.

[0006] The present invention solves the above technical problem by the following technical means: A control circuit for a boiler pneumatic check valve includes a cylinder (1), a one-way throttle valve (2), a solenoid valve (3), and a pressure reducing filter (5). There are two cylinders (1), and one one-way throttle valve (2) is respectively arranged on the two intake pipes of each cylinder (1). The speeds of the four intake pipes of the two cylinders are independently adjusted. Each cylinder (1) is controlled by a solenoid valve (3). The control ends of the two one-way throttle valves (2) of each cylinder (1) are both connected to the solenoid valve (3), and the input end of the solenoid valve (3) is connected to the pressure reducing filter (5).

[0007] Further, the one-way throttle valve (2) is arranged in the electrical cabinet.

[0008] Further, the control circuit for the boiler pneumatic check valve further includes a muffler 4, and a muffler (4) is arranged on each solenoid valve (3).

[0009] Further, the electrical cabinet is placed at the position closest to the check valve to shorten the circuit pipeline.

[0010] Further, the input air source pipeline of the air cylinder (1) adopts a stainless steel pipe with a diameter greater than DN25, and the output air source pipeline of the air cylinder (1) adopts a stainless steel pipe with a diameter greater than DN20.

[0011] Further, the pneumatic check valve control circuit of the boiler includes an electrical control circuit, which includes a main power switch K, a "remote / local" control switch SB, a local manual open check valve switch SB1, a local manual close check valve switch SB2, two valve open coils VT1A and VT1B corresponding to two solenoid valves (3), two valve close coils VT2A and VT2B corresponding to two solenoid valves (3), a valve open in place relay K1, a valve close in place relay K2, open limit switches LS1A and LS1B corresponding to the valve open coils VT1A and VT1B respectively, and close limit switches LS2A and LS2B corresponding to the valve close coils VT2A and VT2B respectively.

[0012] The main power switch K is arranged at the control bus inlet of the whole control circuit. The "remote / local" control switch SB is a multi-way control switch, one end of which is connected to the control bus, and the other end is respectively connected to the local manual open check valve switch SB1 and the local manual close check valve switch SB2. The other end of the local manual open check valve switch SB1 is respectively connected to the two valve open coils VT1A and VT1B, and the other end of the local manual close check valve switch SB2 is respectively connected to the two valve close coils VT2A and VT2B. The open limit switches LS1A and LS1B are connected in series between the bus and the valve open in place relay K1, and the close limit switches LS2A and LS2B are connected in series between the bus and the valve close in place relay K2. The other ends of the two valve open coils VT1A and VT1B, the two valve close coils VT2A and VT2B, the valve open in place relay K1, and the valve close in place relay K2 are respectively connected to the power ground.

[0013] Further, the electrical control circuit of the pneumatic check valve control circuit of the boiler further includes a remote indicator light LM1, a local indicator light LM2, a valve close indicator light LM3, a valve open indicator light LM4, and a power indicator light LM5. The other end of the "remote / local" control switch SB is also connected to the remote indicator light LM1 and the local indicator light LM2. One end of the valve close indicator light LM3 is connected between the switch LS2B and the valve close in place relay K2, one end of the valve open indicator light LM4 is connected between the switch LS1B and the valve open in place relay K1, the power indicator light LM5 is connected to the bus, and the other ends of the remote indicator light, the local indicator light, the valve close indicator light, the valve open indicator light, and the power indicator light are respectively connected to the power ground.

[0014] Further, the electrical control circuit further includes a remote DCS. The control port 3 of the remote DCS is connected to the node between two valve opening coils VT1A and VT1B and the local manual opening check valve switch SB1. The control port 4 of the remote DCS is connected to the node between two valve closing coils VT2A and VT2B and the local manual closing check valve switch SB2. The control port 7 of the remote DCS is connected to the bus through a remote changeover switch. The wiring of the control ports 3 and 7 of the remote DCS represents the remote valve opening control command signal; the wiring of the control ports 4 and 7 of the remote DCS represents the remote valve closing control command signal.

[0015] Further, during use: (1) Close the main power switch K in the electrical cabinet, and the "remote / local" control changeover switch SB is closed. The check valve control cabinet is in the local control mode, and the valve opening and closing are controlled manually locally; (2) When the "remote / local" control changeover switch SB is opened, the check valve control cabinet is in the remote control mode, and the valve opening and closing are realized by receiving the remote DCS command.

[0016] Further, the step (1) of closing the main power switch K in the electrical cabinet and closing the "remote / local" control changeover switch SB, with the check valve control cabinet in the local control mode and manually controlling the valve opening and closing locally specifically includes:

[0017] 1) Press the local manual opening check valve switch SB1 to open the check valve button, and the two valve opening coils VT1A and VT1B are energized simultaneously, realizing the simultaneous opening on both sides of the check valve. After opening in place, the open limit switches LS1A and LS1B are closed simultaneously, the valve opening in-place relay K1 is energized, and the valve opening indicator light LM4 is lit.

[0018] 2) Press the local manual closing check valve switch SB2 to close the check valve button, and the two valve closing coils VT2A and VT2B are energized simultaneously, realizing the simultaneous closing on both sides of the check valve. After closing in place, the close limit switches LS2A and LS12B are closed simultaneously, the valve closing in-place relay K2 is energized, and the valve closing indicator light LM3 is lit.

[0019] The step (2) when the "remote / local" control changeover switch SB is opened, with the check valve control cabinet in the remote control mode and realizing the valve opening and closing by receiving the remote DCS command specifically includes:

[0020] 3) Receive the remote check valve opening command, and the two valve opening coils VT1A and VT1B are energized simultaneously, realizing the simultaneous opening on both sides of the check valve. After opening in place, the open limit switches LS1A and LS1B are closed simultaneously, the valve opening in-place relay K1 is energized, and the valve opening indicator light LM4 is lit.

[0021] 4) By receiving the remote non-return valve closing instruction, two valve closing coils VT2A and VT2B are energized simultaneously, achieving simultaneous closing on both sides of the non-return valve. After closing in place, the closing limit switches LS2A and LS12B are closed simultaneously, the valve closing in-place relay K2 is energized, and the valve closing indicator light LM3 lights up.

[0022] The advantages of the present invention are as follows: Through the technical solution of the present invention, the problem that the double cylinders of the non-return valve at the fan outlet act out of sync, resulting in too long opening and closing times of the fan non-return valve, is solved. Moreover, the control circuit of the present invention is simply designed and has strong reliability, improving the safety and reliability of the unit. Description of the Drawings

[0023] Figure 1 is the connection schematic diagram of a control circuit for a boiler pneumatic non-return valve in an embodiment of the present invention;

[0024] Figure 2 is the schematic diagram of the control electrical cabinet for starting the non-return valve. Detailed Embodiments

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts fall within the protection scope of the present invention.

[0026] Regarding the synchronization and time issues of the pneumatic non-return valve opening / closing, the driving cylinders of the pneumatic non-return valve act simultaneously and synchronously, consuming a large amount of compressed air and having a high flow rate. Through analysis of the on-site usage situation, the main reasons for the non-synchronization of the pneumatic non-return valve are as follows:

[0027] 1. A single solenoid valve controls two cylinders, and the opening and closing actions on both sides are carried out sequentially and cannot be synchronized, resulting in a relatively long overall opening and closing time of the non-return valve;

[0028] 2. The effective diameter of the air supply pipeline is small. For example, in a certain usage scenario, the outer diameter of the inlet / outlet air supply pipeline is φ14mm. After removing the wall thickness of the stainless steel pipe, the inner diameter is only about φ10mm, which is basically 1 / 6 of the required value;

[0029] 3. During on-site installation, the electrical cabinet is placed far away from the pneumatic non-return valve, and during construction, the air supply pipeline is routed relatively far, further aggravating the blockage of the already thin and poorly flowing air supply pipeline. As a result, the air supply flow rate to the cylinder is severely insufficient;

[0030] The above factors have greatly affected the speed and synchronization of opening and closing the door, failing to meet the design requirements.

[0031] The pneumatic check valve control circuit of the boiler in the present invention is a dual circuit. Refer to Figure 1 As shown, the pneumatic check valve control circuit of the boiler in the present invention includes a cylinder 1, a one-way throttle valve 2, a solenoid valve 3, a muffler 4, and a pressure reducing filter 5.

[0032] There are two cylinders 1. One one-way throttle valve 2 is respectively arranged on the two air inlet pipes of each cylinder 1, so that the speeds of the four air inlet pipes of the two cylinders can be independently adjusted to achieve the purpose of synchronous opening / closing. The one-way throttle valve 2 is installed in the electrical cabinet and does not need to climb onto the pneumatic check valve body for adjustment.

[0033] Each cylinder 1 is controlled by a solenoid valve 3. The control ends of the two one-way throttle valves 2 of each cylinder 1 are both connected to the solenoid valve 3, and the input end of the solenoid valve 3 is connected to the pressure reducing filter 5.

[0034] A muffler 4 is arranged on each solenoid valve 3.

[0035] The electrical cabinet is placed at the position closest to the check valve to shorten the loop pipeline, minimize the loss of compressed air to the greatest extent, and improve the reliability and safety of the pneumatic check valve.

[0036] Among them, the input air source pipeline of the cylinder 1 uses a stainless steel pipe larger than DN25 (1" pipe), and the output air source pipeline of the cylinder 1 uses a stainless steel pipe larger than DN20 (6 - branch pipe). After the pipeline connection is completed, all pipelines must undergo a purging process to ensure the internal cleanliness of the pipelines.

[0037] As Figure 2 As shown, starting from the schematic diagram of the check valve control electrical cabinet, the electrical control circuit of the pneumatic check valve control circuit of the boiler in the present invention includes a main power switch K, a "remote / local" control switch SB, a local manual open check valve switch SB1, a local manual close check valve switch SB2, two valve open coils VT1A and VT1B corresponding to the two solenoid valves 3, two valve close coils VT2A and VT2B corresponding to the two solenoid valves 3, a valve open in - place relay K1, a valve close in - place relay K2, open limit switches LS1A and LS1B corresponding to the valve open coils VT1A and VT1B respectively, close limit switches LS2A and LS2B corresponding to the valve close coils VT2A and VT2B respectively, a remote indicator light LM1, a local indicator light LM2, a valve close indicator light LM3, a valve open indicator light LM4, and a power indicator light LM5.

[0038] When the valve open-in-place relay K1 is energized, it indicates that the check valve is open in place and sends a signal to the DCS. When the valve close-in-place relay K2 is energized, it indicates that the check valve is closed in place and sends a signal to the DCS. When the remote indicator light LM1 is on, it indicates that the check valve is in the "remote control" state. When the local indicator light LM2 is on, it indicates that the check valve is in the "local control" state. When the valve closed indicator light LM3 is on, it indicates that the check valve is in the "closed" state. When the valve open indicator light LM4 is on, it indicates that the check valve is in the "open" state. When the power indicator light LM5 is on, it indicates that the electrical cabinet is powered on.

[0039] The main power switch K is set at the control bus inlet of the entire control loop. The "remote / local" control switch SB is a multi-way control switch. One end is connected to the control bus, and the other end is respectively connected to the local manual open check valve switch SB1, the local manual close check valve switch SB2, the remote indicator light LM1, and the local indicator light LM2. The other end of the local manual open check valve switch SB1 is respectively connected to two valve open coils VT1A and VT1B. The other end of the local manual close check valve switch SB2 is respectively connected to two valve close coils VT2A and VT2B. The open limit switches LS1A and LS1B are connected in series between the bus and the valve open-in-place relay K1. The close limit switches LS2A and LS2B are connected in series between the bus and the valve close-in-place relay K2. One end of the valve closed indicator light LM3 is connected between the switch LS2B and the valve close-in-place relay K2. One end of the valve open indicator light LM4 is connected between the switch LS1B and the valve open-in-place relay K1. The power indicator light LM5 is connected to the bus. The other ends of the two valve open coils VT1A and VT1B, the two valve close coils VT2A and VT2B, the valve open-in-place relay K1, the valve close-in-place relay K2, the remote indicator light, the local indicator light, the valve closed indicator light, the valve open indicator light, and the power indicator light are respectively connected to the power ground. The control port 3 of the remote DCS is connected to the node between the two valve open coils VT1A and VT1B and the local manual open check valve switch SB1. The control port 4 of the remote DCS is connected to the node between the two valve close coils VT2A and VT2B and the local manual close check valve switch SB2. The control port 7 of the remote DCS is connected to the bus through a remote switch. The wiring of the control ports 3 and 7 of the remote DCS represents the remote valve open control command signal; the wiring of the control ports 4 and 7 of the remote DCS represents the remote valve close control command signal. The wiring of the two terminals represents a set of control signals. The control port 7 of the remote DCS is the common terminal and is connected to the common line. The remote switch is linked with the "remote / local" control switch SB. When the "remote / local" control switch SB is closed, the remote switch is opened, and the control port 7 of the remote DCS is disconnected from the bus. When the "remote / local" control switch SB is opened, the remote switch is closed, and the control port 7 of the remote DCS is connected to the bus.

[0040] During use:

[0041] (1) Close the main power switch K in the electrical cabinet. The "remote / local" control switch SB is closed, and the check valve control cabinet is in the local control mode. Manually control the valve opening and closing locally:

[0042] 1) Press the local manual open check valve switch SB1 to open the check valve button. The two valve opening coils VT1A and VT1B are energized simultaneously, realizing the simultaneous opening of both sides of the check valve. After opening in place, the open limit switches LS1A and LS1B are closed simultaneously, and the valve open in-place relay K1 is energized, and the valve open indicator light LM4 lights up.

[0043] 2) Press the local manual close check valve switch SB2 to close the check valve button. The two valve closing coils VT2A and VT2B are energized simultaneously, realizing the simultaneous closing of both sides of the check valve. After closing in place, the close limit switches LS2A and LS12B are closed simultaneously, and the valve close in-place relay K2 is energized, and the valve close indicator light LM3 lights up.

[0044] (2) When the "remote / local" control switch SB is disconnected, the check valve control cabinet is in the remote control mode, and the valve opening and closing are realized by receiving the DCS remote instruction:

[0045] 3) Receive the remote check valve opening instruction. The two valve opening coils VT1A and VT1B are energized simultaneously, realizing the simultaneous opening of both sides of the check valve. After opening in place, the open limit switches LS1A and LS1B are closed simultaneously, and the valve open in-place relay K1 is energized, and the valve open indicator light LM4 lights up.

[0046] 4) Receive the remote check valve closing instruction. The two valve closing coils VT2A and VT2B are energized simultaneously, realizing the simultaneous closing of both sides of the check valve. After closing in place, the close limit switches LS2A and LS12B are closed simultaneously, and the valve close in-place relay K2 is energized, and the valve close indicator light LM3 lights up.

[0047] 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 foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A boiler pneumatic check valve control circuit, characterized in that: The invention comprises a cylinder (1), a one-way throttle valve (2), a solenoid valve (3) and a pressure reducing filter (5), wherein there are two cylinders (1), two intake pipes of each cylinder (1) are respectively provided with a one-way throttle valve (2), the speeds of the four intake pipes of the two cylinders are independently adjusted, each cylinder (1) is controlled by a solenoid valve (3), the control ends of the two one-way throttle valves (2) of each cylinder (1) are connected to the solenoid valve (3), and the input end of the solenoid valve (3) is connected to the pressure reducing filter (5).

2. A boiler pneumatic check valve control circuit as claimed in claim 1, characterized in that: The one-way throttle valve (2) is arranged in an electrical cabinet.

3. A boiler pneumatic check valve control circuit as claimed in claim 1, characterized in that: It also includes a muffler (4), and each solenoid valve (3) is provided with a muffler (4).

4. A boiler pneumatic check valve control circuit as claimed in claim 1, characterized in that: The electrical cabinet is placed as close to the check valve as possible to shorten the loop pipeline.

5. A boiler pneumatic check valve control circuit as claimed in claim 1, characterized in that: The input gas source pipeline of the cylinder (1) adopts a stainless steel pipe with a diameter greater than DN25, and the output gas source pipeline of the cylinder (1) adopts a stainless steel pipe with a diameter greater than DN20.

6. A boiler pneumatic check valve control circuit as claimed in claim 1, characterized in that: It also includes an electrical control circuit, which includes a main power switch K, a "remote / local" control switch SB, a local manual check valve opening switch SB1, a local manual check valve closing switch SB2, two valve opening coils VT1A and VT1B corresponding to two solenoid valves (3), two valve closing coils VT2A and VT2B corresponding to the two solenoid valves (3), a valve opening relay K1, a valve closing relay K2, opening limit switches LS1A and LS1B corresponding to the valve opening coils VT1A and VT1B respectively, and closing limit switches LS2A and LS2B corresponding to the valve closing coils VT2A and VT2B respectively; The main power switch K is set at the control bus entrance of the entire control loop. The "remote / local" control switching switch SB is a multi-way control switch, one end of which is connected to the control bus, and the other end is connected to the local manual check door opening switch SB1 and the local manual check door closing switch SB2 respectively. The other end of the local manual check door opening switch SB1 is connected to the two valve opening coils VT1A and VT1B respectively, and the other end of the local manual check door closing switch SB2 is connected to the two valve closing coils VT2A and VT2B respectively. The open limit switches LS1A and LS1B are connected in series between the bus and the valve open position relay K1, and the close limit switches LS2A and LS2B are connected in series between the bus and the valve closed position relay K2. The other ends of the two valve open coils VT1A and VT1B, the two valve closed coils VT2A and VT2B, the valve open position relay K1, and the valve closed position relay K2 are connected to the power ground respectively.

7. A boiler pneumatic check valve control circuit as claimed in claim 6, characterized in that: The electrical control circuit of the boiler pneumatic check valve control loop also includes a remote indicator light LM1, a local indicator light LM2, a valve closed indicator light LM3, a valve open indicator light LM4 and a power indicator light LM5. The other end of the "remote / local" control switching switch SB is also connected to the remote indicator light LM1 and the local indicator light LM2. One end of the valve closed indicator light LM3 is connected between the switch LS2B and the valve closed position relay K2. One end of the valve open indicator light LM4 is connected between the switch LS1B and the valve open position relay K1. The power indicator light LM5 is connected to the bus. The other ends of the remote indicator light, the local indicator light, the valve closed indicator light, the valve open indicator light and the power indicator light are respectively connected to the power ground.

8. A boiler pneumatic check valve control circuit as claimed in claim 6, characterized in that: The electrical control circuit also includes a remote DCS, wherein a control port 3 of the remote DCS is connected to a node between two valve opening coils VT1A and VT1B and a local manually opened check valve switch SB1, a control port 4 of the remote DCS is connected to a node between two valve closing coils VT2A and VT2B and a local manually closed check valve switch SB2, a control port 7 of the remote DCS is connected to a bus via a remote switching switch, and the wiring of control ports 3 and 7 of the remote DCS represents a remote valve opening control command signal; the wiring of control ports 4 and 7 of the remote DCS represents a remote valve closing control command signal.

9. A boiler pneumatic check valve control circuit as claimed in claim 8, characterized in that: Turn on the main power switch K in the electrical cabinet, and the "remote / local" control switch SB is closed. The check valve control cabinet is in local control mode, and the valve is opened and closed manually on site; when the "remote / local" control switch SB is disconnected, the check valve control cabinet is in remote control mode, and the valve is opened and closed by receiving remote commands from the DCS.

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