Control circuit and control system of pneumatic anti-blocking four-way distributor

Abstract

The embodiment of the utility model provides a pneumatic anti-blocking four-way distributor control circuit and a control system, and belongs to the technical field of material conveying. The control circuit comprises a first field controllable switch, a first field and remote change-over switch, a first relay, a second relay, a first field switch, a first contactor and a first contact of the first contactor. According to the utility model, distribution and distribution of materials are realized, the materials of a cement production line are input from one feed port and are distributed to three different discharge ports, the number of valves used during material distribution is reduced, control of a plurality of distribution channels is realized, the control integration level is improved, the cost is reduced, and the design of the valves is facilitated.

Description

Technical Field

[0001] The utility model relates to the technical field of material conveying, in particular to a pneumatic anti-blocking four-way distributor control circuit and a control system. Background Art

[0002] Material splitting in cement production lines is a common process requirement. Traditional cement production lines usually use two-way valves and three-way valves for material splitting. When multiple two-way valves or three-way valves are used for multi-channel control, a large number of valves are required, making the design and installation of valves more difficult. Therefore, it is urgent to introduce four-way valves to split materials in cement production lines to improve the control integration of valves. However, so far, there is no corresponding control circuit for four-way valves in cement production lines. Utility Model Content

[0003] The purpose of the embodiment of the utility model is to provide a pneumatic anti-blocking four-way distributor control circuit and control system, which solves the problem of low control integration and difficult design caused by a large number of valves used in material distribution of a cement production line.

[0004] In order to achieve the above-mentioned purpose, the embodiment of the utility model provides a pneumatic anti-blocking four-way distributor control circuit, and the control circuit includes:

[0005] A first field-controllable switch, one end of which is connected to a phase line of the AC bus;

[0006] a first on-site and remote switching switch, one end of which is connected to the other end of the first on-site controllable switch;

[0007] a first relay, one end of which is connected to a remote end of the first on-site and remote switching switch;

[0008] a second relay, one end of which is connected to the remote end of the first on-site and remote switching switch;

[0009] A first field switch, one end of which is connected to the field end of the first field and remote switching switch;

[0010] a first contactor, one end of the first contactor being connected to the other end of the second relay;

[0011] The first contact of the first contactor, one end of the first contact of the first contactor is connected to one end of the first field switch, and the other end of the first contact of the first contactor is connected to the other end of the first relay.

[0012] Optionally, the control circuit includes:

[0013] a second field-controllable switch, one end of which is connected to a phase line of the AC bus;

[0014] a second on-site and remote switching switch, one end of the second on-site and remote switching switch being connected to the other end of the second on-site controllable switch;

[0015] a third relay, one end of the third relay being connected to the remote end of the second on-site and remote switching switch;

[0016] a fourth relay, one end of the fourth relay being connected to the remote end of the second on-site and remote switching switch;

[0017] A second field switch, one end of which is connected to the field end of the second field and remote switching switch;

[0018] a second contactor, one end of the second contactor being connected to the other end of the third relay;

[0019] A first contact of the second contactor, one end of the first contact of the second contactor is connected to one end of the second field switch, and the other end of the first contact of the second contactor is connected to the other end of the third relay.

[0020] Optionally, the control circuit includes:

[0021] a third field-controllable switch, one end of which is connected to a phase line of the AC bus;

[0022] A third-site and remote switching switch, one end of which is connected to the other end of the third-site controllable switch;

[0023] a fifth relay, one end of which is connected to the remote end of the third on-site and remote switching switch;

[0024] a sixth relay, one end of which is connected to the remote end of the third on-site and remote switching switch;

[0025] A third field switch, one end of which is connected to the field end of the third field and remote switching switch;

[0026] a third contactor, one end of the third contactor being connected to the other end of the fifth relay;

[0027] A first contact of the third contactor, one end of the first contact of the third contactor is connected to one end of the second field switch, and the other end of the first contact of the third contactor is connected to the other end of the fifth relay.

[0028] Optionally, the control circuit includes:

[0029] A first operation indicator light, one end of which is connected to the other end of the second relay, and the other end of which is connected to the neutral line of the AC bus;

[0030] a second operation indicator light, one end of the second operation indicator light being connected to the other end of the fourth relay, and the other end of the second operation indicator light being connected to the neutral line of the AC bus;

[0031] A third operation indicator light, one end of the third operation indicator light is connected to the other end of the sixth relay, and the other end of the third operation indicator light is connected to the neutral line of the AC bus.

[0032] Optionally, the control circuit includes a ready indicator light, one end of the ready indicator light is connected to a phase line of the AC bus, and the other end of the ready indicator light is connected to a neutral line of the AC bus.

[0033] Optionally, a first circuit breaker, one end of which is connected to a phase line of the AC bus;

[0034] A first fuse, one end of the first fuse is connected to the other end of the first circuit breaker, and the other end of the first fuse is connected to one end of the first field switch.

[0035] Optionally, the control circuit includes:

[0036] A second circuit breaker, one end of the second circuit breaker is connected to one end of the single-phase AC power supply, and the other end of the second circuit breaker is respectively connected to the first contactor, the second contactor and the third contactor;

[0037] a second contact of the first contactor, wherein one end of the second contact of the first contactor is connected to the other end of the second circuit breaker;

[0038] a second contact of a second contactor, wherein one end of the second contact of the second contactor is connected to the other end of the second circuit breaker;

[0039] a second contact of a third contactor, one end of the second contact of the third contactor being connected to the other end of the second circuit breaker;

[0040] a first valve body, wherein a first end of the first valve body is connected to the other end of the second contact of the first contactor, a second end of the first valve body is connected to one end of the single-phase AC power supply, and a third end of the first valve body is grounded;

[0041] a second valve body, wherein a first end of the second valve body is connected to the other end of the second contact of the second contactor, a second end of the second valve body is connected to one end of the single-phase AC power supply, and a third end of the second valve body is grounded;

[0042] A third valve body, wherein a first end of the third valve body is connected to the other end of the second contact of the second contactor, a second end of the third valve body is connected to one end of the single-phase AC power supply, and a third end of the third valve body is grounded.

[0043] On the other hand, the utility model provides a control system, which includes a controller, and the controller is used to execute any control circuit as described above.

[0044] Through the above technical scheme, the utility model provides a pneumatic anti-blocking four-way distributor control circuit and control system, which realizes the control of the valve body remotely and on-site respectively by switching the first on-site and remote switching switch, the second on-site and remote switching switch and the third on-site and remote switching switch, and realizes the self-locking and unlocking of the control circuit and the main circuit through the contactor, and disconnects the first on-site controllable switch, the second on-site controllable switch and the third on-site controllable switch in an emergency to cut off the control circuit and make the first valve body, the second valve body and the third valve body lose power and stop respectively. Compared with the prior art, the utility model realizes the distribution and diversion of materials, and the materials of the cement production line are diverted from one feed port to three different discharge ports, which reduces the number of valves used in material distribution, realizes the control of multiple distribution channels, improves the control integration, reduces the cost, and facilitates the design of valves.

[0045] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The accompanying drawings are used to provide a further understanding of the embodiments of the present utility model and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present utility model, but do not constitute a limitation on the embodiments of the present utility model. In the accompanying drawings:

[0047] Figure 1 is a circuit diagram of a control loop according to an embodiment of the present utility model;

[0048] Figure 2 is a simplified circuit diagram of a control loop according to one embodiment of the utility model;

[0049] Figure 3 It is a circuit diagram of a main loop according to one embodiment of the utility model.

[0050] Description of Reference Numerals

[0051] S1, first site controllable switch S2, first site and remote switching switch

[0052] K1, first relay K2, second relay

[0053] S3, first field switch KM1, first contactor

[0054] KM2, first contact S4 of the first contactor, second field controllable switch

[0055] S5, second site and remote switch K3, third relay

[0056] K4, fourth relay S6, second field switch

[0057] KM3, second contactor KM4, first contact of the second contactor

[0058] S7, third-site controllable switch S8, third-site and remote switching switch

[0059] K5, fifth relay K6, sixth relay

[0060] S9, third field switch KM5, third contactor

[0061] KM6, first contact point L1 of the third contactor, first operating indicator light

[0062] L2, second operation indicator light L3, third operation indicator light

[0063] L4, ready indicator light Q1, first circuit breaker

[0064] FU, first fuse Q2, second circuit breaker

[0065] KM7, the second contact of the first contactor KM8, the second contact of the second contactor

[0066] KM9, the second contact point Y1 of the third contactor, the first valve body

[0067] Y2, second valve body Y3, third valve body DETAILED DESCRIPTION

[0068] The specific implementation of the embodiment of the utility model is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the embodiment of the utility model, and is not used to limit the embodiment of the utility model.

[0069] Figure 1 is a circuit diagram of a control loop according to an embodiment of the utility model, Figure 2It is a simplified circuit diagram of a control circuit according to an embodiment of the utility model. In the figure, the control circuit includes a first field controllable switch S1, a first field and remote switching switch S2, a first relay K1, a second relay K2, a first field switch S3, a first contactor KM1 and a first contact KM2 of the first contactor. Among them, one end of the first field controllable switch S1 is connected to the phase line of the AC bus, one end of the first field and remote switching switch S2 is connected to the other end of the first field controllable switch S1, one end of the first relay K1 is connected to the remote end of the first field and remote switching switch S2, one end of the second relay K2 is connected to the remote end of the first field and remote switching switch S2, one end of the first field switch S3 is connected to the field end of the first field and remote switching switch S2, one end of the first contactor KM1 is connected to the other end of the second relay K2, one end of the first contact of the first contactor KM1 is connected to one end of the first field switch S3, and the other end of the first contact KM2 of the first contactor is connected to the other end of the first relay K1. The first field controllable switch S1 of the field button box is activated. When the first field controllable switch S1 is closed and the first field and remote switch S2 are switched to the automatic position, the first relay K1 is energized and its normally open contact is closed. The DCS system starts to send a drive signal to energize the second relay K2, and its normally open contact of the control circuit is closed to energize the control circuit, thereby energizing the first contactor KM1. The first contactor KM1 is closed at the normally open contact of the control circuit, i.e., the first contactor KM2, to achieve self-locking of the control circuit. The first field controllable switch S1 of the field button box is activated. When the first field controllable switch S1 is closed and the first field and remote switch S2 are switched to the manual position, the field button box is activated to close the first field switch S3, and the control circuit is energized, thereby energizing the first contactor KM1. The first contactor KM1 is closed at the normally open contact of the control circuit, i.e., the first contactor KM2, to achieve self-locking of the control circuit. At this time, the DCS system cannot be started but can monitor all its states. Furthermore, once an emergency occurs, the on-site button box is pressed again to disconnect the first on-site controllable switch S1, the control circuit loses power, the first contactor KM1 loses power, and the first contact KM2 of the first contactor is disconnected, thereby unlocking the control circuit.

[0070] In one embodiment of the utility model, the specific composition of the control circuit can be various known to those skilled in the art. In a preferred example of the utility model, the control circuit can include a second field controllable switch S4, a second field and remote switching switch S5, a third relay K3, a fourth relay K4, a second field switch S6, a second contactor KM3, and a first contact KM4 of the second contactor. Among them, one end of the second field controllable switch S4 is connected to the phase line of the AC bus, one end of the second field and remote switching switch S5 is connected to the other end of the second field controllable switch S4, one end of the third relay K3 is connected to the remote end of the second field and remote switching switch S5, one end of the fourth relay K4 is connected to the remote end of the second field and remote switching switch S5, one end of the second field switch S6 is connected to the field end of the second field and remote switching switch S5, one end of the second contactor KM3 is connected to the other end of the fourth relay K4, one end of the second contact of the second contactor KM3 is connected to one end of the second field switch S6, and the other end of the second contact KM8 of the second contactor is connected to the other end of the third relay K3. The second field controllable switch S4 of the field button box is activated. When the second field controllable switch S4 is closed and the second field and remote switching switch S5 is switched to the automatic position, the third relay K3 is energized and its normally open contact is closed. The DCS system starts to send a drive signal to energize the fourth relay K4, and its normally open contact of the control circuit is closed to energize the control circuit, thereby energizing the second contactor KM3. The second contactor KM3 is closed at the normally open contact of the control circuit, i.e., the first contact KM4 of the second contactor, and the control circuit is self-locking. The second field controllable switch S4 of the field button box is activated. When the second field controllable switch S4 is closed and the second field and remote switching switch S5 is switched to the manual position, the field button box is activated to close the second field switch S6, and the control circuit is energized, thereby energizing the second contactor KM3. The second contactor KM3 is closed at the normally open contact of the control circuit, i.e., the first contact KM4 of the second contactor, and the control circuit is self-locking. At this time, the DCS system cannot be started but can monitor all its states. Furthermore, once an emergency occurs, the on-site button box is pressed again to disconnect the second on-site controllable switch S4, the control circuit loses power, the second contactor KM3 loses power, and the second contact KM8 of the second contactor is disconnected, thereby unlocking the control circuit.

[0071] In one embodiment of the utility model, the specific composition of the control circuit can be various known to those skilled in the art. In a preferred example of the utility model, the control circuit can include a third field controllable switch S7, a third field and remote switching switch S8, a fifth relay K5, a sixth relay K6, a third field switch S9, a third contactor KM5 and a first contact KM6 of the third contactor. Among them, one end of the third field controllable switch S7 is connected to the phase line of the AC bus, one end of the third field and remote switching switch S8 is connected to the other end of the third field controllable switch S7, one end of the fifth relay K5 is connected to the remote end of the third field and remote switching switch S8, one end of the sixth relay K6 is connected to the remote end of the third field and remote switching switch S8, one end of the third field switch S9 is connected to the field end of the third field and remote switching switch S8, one end of the third contactor KM5 is connected to the other end of the sixth relay K6, one end of the first contact KM6 of the third contactor is connected to one end of the third field switch S9, and the other end of the first contact KM6 of the third contactor is connected to the other end of the third relay K3. The third field controllable switch S7 of the field button box is activated. When the third field controllable switch S7 is closed and the third field and remote switch S8 is switched to the automatic position, the fifth relay K5 is energized and its normally open contact is closed. The DCS system starts to send a drive signal to energize the sixth relay K6, and its normally open contact of the control circuit is closed to energize the control circuit, thereby energizing the third contactor KM5. The third contactor KM5 is closed at the normally open contact of the control circuit, i.e., the first contact KM6 of the third contactor, to achieve self-locking of the control circuit. The third field controllable switch S7 of the field button box is activated. When the third field controllable switch S7 is closed and the third field and remote switch S8 are switched to the manual position, the field button box is activated to close the third field switch S9, and the control circuit is energized, thereby energizing the third contactor KM5. The third contactor KM5 is closed at the normally open contact of the control circuit, i.e., the first contact KM6 of the third contactor, to achieve self-locking of the control circuit. At this time, the DCS system cannot be started but can monitor all its states. Furthermore, once an emergency occurs, the on-site button box is pressed again to disconnect the third on-site controllable switch S7, the control circuit loses power, the third contactor KM5 loses power, the third contact of the third contactor KM5 is disconnected, and the control circuit is unlocked.

[0072] In order to understand the state and fault condition of the control circuit, in one embodiment of the utility model, the control circuit may include an indicator light. The number of indicator lights may be multiple as known to those skilled in the art, such as 1, 2, 3, etc. In a preferred example of the utility model, the indicator lights may be 3, namely, a first operation indicator light L1, a second operation indicator light L2, and a third operation indicator light L3. Among them, one end of the first operation indicator light L1 is connected to the other end of the second relay K2, the other end of the first operation indicator light L1 is connected to the neutral line of the AC bus, one end of the second operation indicator light L2 is connected to the other end of the fourth relay K4, the other end of the second operation indicator light L2 is connected to the neutral line of the AC bus, one end of the third operation indicator light L3 is connected to the other end of the sixth relay K6, the other end of the third operation indicator light L3 is connected to the neutral line of the AC bus, and the first operation indicator light L1, the second operation indicator light L2, and the third operation indicator light L3 jointly detect whether the control circuit is operating normally.

[0073] In one embodiment of the present invention, the types of indicator lights in the control circuit may be various types known to those skilled in the art. In one embodiment of the present invention, the control circuit further includes a ready indicator light L4. One end of the ready indicator light L4 is connected to the phase line of the AC bus, and the other end of the ready indicator light L4 is connected to the neutral line of the AC bus, for detecting whether the power supply is in a ready state.

[0074] In one embodiment of the utility model, in view of the need to prevent damage caused by current overload in the control circuit, the control circuit also includes a first circuit breaker Q1 and a first fuse FU. One end of the first circuit breaker Q1 is connected to the phase line of the AC bus, one end of the first fuse FU is connected to the other end of the first circuit breaker Q1, and the other end of the first fuse FU is connected to one end of the first field switch S3. When the current in the circuit exceeds the set rated value, the first circuit breaker Q1 will automatically trip and cut off the circuit, thereby protecting the electrical equipment and circuit from damage. When the current of the control circuit exceeds the rated value, the first fuse FU will melt and cut off the circuit to prevent the current from continuing to flow, thereby protecting the circuit and equipment.

[0075] In one embodiment of the present invention, considering the need to prevent damage caused by current overload in the main circuit, the control circuit further includes a second circuit breaker Q2. Figure 3As shown, one end of the second circuit breaker Q2 is connected to one end of the single-phase AC power supply, and the other end of the second circuit breaker Q2 is connected to the first contactor KM1, the second contactor KM3 and the third contactor KM5 respectively. Further, in order to ensure the self-locking of the main circuit, the second contact KM7 of the first contactor, the second contact KM8 of the second contactor and the second contact KM9 of the third contactor are also included. When the first contactor KM1, the second contactor KM3 and the third contactor KM5 are powered, the second contact KM7 of the first contactor, the second contact KM8 of the second contactor and the second contact KM9 of the third contactor are changed from normally open to normally closed. In case of an emergency, the on-site button box is activated to disconnect the first on-site controllable switch S1, and the second contact KM7 of the first contactor, the second contact KM8 of the second contactor and the second contact KM9 of the third contactor are changed from normally closed to normally open, thereby realizing the unlocking of the main circuit. In addition, the control circuit also includes a first valve body Y1, a second valve body Y2 and a third valve body Y3. The first end of the first valve body Y1 is connected to the other end of the second contact KM6 of the first contactor, the second end of the first valve body Y1 is connected to one end of the single-phase AC power supply, the third end of the first valve body Y1 is grounded, the first end of the second valve body Y2 is connected to the other end of the second contact KM7 of the second contactor, the second end of the second valve body Y2 is connected to one end of the single-phase AC power supply, the third end of the second valve body Y2 is grounded, the first end of the third valve body Y3 is connected to the other end of the second contact KM8 of the third contactor, the second end of the third valve body Y3 is connected to one end of the single-phase AC power supply, and the third end of the third valve body Y3 is grounded. When the first on-site and remote switching switch S2, the second on-site and remote switching switch S5 or the third on-site and remote switching switch S8 is switched to the automatic position, the start and stop of the valve body can be remotely controlled, and when the first on-site and remote switching switch S2, the second on-site and remote switching switch S5 or the third on-site and remote switching switch S8 is switched to the manual position, the start and stop of the valve body can be controlled on-site. Specifically, the first valve body Y1, the second valve body Y2 and the third valve body Y3 are respectively energized when the first contactor KM1, the second contactor KM3 and the third contactor KM5 are energized, and the second contact KM7 of the first contactor, the second contact KM8 of the second contactor and the second contact KM9 of the third contactor change from normally open to normally closed, and they are energized and stop running when the first contactor KM1, the second contactor KM3 and the third contactor KM5 are de-energized, and the second contact KM7 of the first contactor, the second contact KM8 of the second contactor and the second contact KM9 of the third contactor change from normally closed to normally open. By starting and stopping the above three valve bodies, the three-way discharge can be realized, thereby controlling the material.

[0076] On the other hand, the utility model provides a control system, which includes a controller, and the controller is used to execute any control circuit as described above.

[0077] Through the above technical scheme, the utility model provides a pneumatic anti-blocking four-way distributor control circuit and control system, which realizes the control of the valve body remotely and on-site respectively by switching the first on-site and remote switching switch, the second on-site and remote switching switch and the third on-site and remote switching switch, and realizes the self-locking and unlocking of the control circuit and the main circuit through the contactor, and disconnects the first on-site controllable switch, the second on-site controllable switch and the third on-site controllable switch in an emergency to cut off the control circuit and make the first valve body, the second valve body and the third valve body lose power and stop respectively. Compared with the prior art, the utility model realizes the distribution and diversion of materials, and the materials of the cement production line are diverted from one feed port to three different discharge ports, which reduces the number of valves used in material distribution, realizes the control of multiple distribution channels, improves the control integration, reduces the cost, and facilitates the design of valves.

[0078] The optional implementation modes of the utility model examples are described in detail above in conjunction with the accompanying drawings. However, the implementation modes of the utility model are not limited to the specific details in the above implementation modes. Within the technical concept of the implementation modes of the utility model, various simple modifications can be made to the technical solutions of the implementation modes of the utility model. These simple modifications all belong to the protection scope of the implementation modes of the utility model.

[0079] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the various possible combinations of the embodiments of the present utility model will not be described separately.

[0080] In addition, various different embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed in the embodiments of the present invention.

Claims

1. A pneumatic anti-blocking four-way distributor control circuit, characterized in that: The control circuit comprises: A first field-controllable switch, one end of which is connected to a phase line of the AC bus; a first on-site and remote switching switch, one end of which is connected to the other end of the first on-site controllable switch; a first relay, one end of which is connected to a remote end of the first on-site and remote switching switch; a second relay, one end of which is connected to the remote end of the first on-site and remote switching switch; A first field switch, one end of which is connected to the field end of the first field and remote switching switch; a first contactor, one end of the first contactor being connected to the other end of the second relay; The first contact of the first contactor, one end of the first contact of the first contactor is connected to one end of the first field switch, and the other end of the first contact of the first contactor is connected to the other end of the first relay.

2. The control circuit according to claim 1, characterized in that: The control circuit comprises: a second field-controllable switch, one end of which is connected to a phase line of the AC bus; a second on-site and remote switching switch, one end of the second on-site and remote switching switch being connected to the other end of the second on-site controllable switch; a third relay, one end of the third relay being connected to the remote end of the second on-site and remote switching switch; a fourth relay, one end of the fourth relay being connected to the remote end of the second on-site and remote switching switch; A second field switch, one end of which is connected to the field end of the second field and remote switching switch; a second contactor, one end of the second contactor being connected to the other end of the third relay; A first contact of the second contactor, one end of the first contact of the second contactor is connected to one end of the second field switch, and the other end of the first contact of the second contactor is connected to the other end of the third relay.

3. The control circuit according to claim 2, characterized in that: The control circuit comprises: a third field-controllable switch, one end of which is connected to a phase line of the AC bus; A third-site and remote switching switch, one end of which is connected to the other end of the third-site controllable switch; a fifth relay, one end of which is connected to the remote end of the third on-site and remote switching switch; a sixth relay, one end of which is connected to the remote end of the third on-site and remote switching switch; A third field switch, one end of which is connected to the field end of the third field and remote switching switch; a third contactor, one end of the third contactor being connected to the other end of the fifth relay; A first contact of the third contactor, one end of the first contact of the third contactor is connected to one end of the second field switch, and the other end of the first contact of the third contactor is connected to the other end of the fifth relay.

4. The control circuit according to claim 3, characterized in that: The control circuit comprises: A first operation indicator light, one end of which is connected to the other end of the second relay, and the other end of which is connected to the neutral line of the AC bus; a second operation indicator light, one end of the second operation indicator light being connected to the other end of the fourth relay, and the other end of the second operation indicator light being connected to the neutral line of the AC bus; A third operation indicator light, one end of the third operation indicator light is connected to the other end of the sixth relay, and the other end of the third operation indicator light is connected to the neutral line of the AC bus.

5. The control circuit according to claim 1, characterized in that: The control circuit comprises a ready indicator light, one end of which is connected to the phase line of the AC bus, and the other end of which is connected to the neutral line of the AC bus.

6. The control circuit according to claim 4, characterized in that: The control circuit comprises: A first circuit breaker, one end of which is connected to a phase line of the AC bus; A first fuse, one end of the first fuse is connected to the other end of the first circuit breaker, and the other end of the first fuse is connected to one end of the first field switch.

7. The control circuit according to claim 6, characterized in that: The control circuit comprises: A second circuit breaker, one end of the second circuit breaker is connected to one end of the single-phase AC power supply, and the other end of the second circuit breaker is respectively connected to the first contactor, the second contactor and the third contactor; a second contact of the first contactor, wherein one end of the second contact of the first contactor is connected to the other end of the second circuit breaker; a second contact of a second contactor, wherein one end of the second contact of the second contactor is connected to the other end of the second circuit breaker; A second contact of the second contactor and one end of the second contact of the third contactor are connected to the other end of the second circuit breaker; a first valve body, wherein a first end of the first valve body is connected to the other end of the second contact of the first contactor, a second end of the first valve body is connected to one end of the single-phase AC power supply, and a third end of the first valve body is grounded; a second valve body, wherein a first end of the second valve body is connected to the other end of the second contact of the second contactor, a second end of the second valve body is connected to one end of the single-phase AC power supply, and a third end of the second valve body is grounded; A third valve body, wherein a first end of the third valve body is connected to the other end of the second contact of the second contactor, a second end of the third valve body is connected to one end of the single-phase AC power supply, and a third end of the third valve body is grounded.

8. A control system, characterized in that: The control system comprises a controller, and the controller is used to execute the control circuit according to any one of claims 1 to 7.

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