CN210689364U

CN210689364U - Sluicing control system

Info

Publication number: CN210689364U
Application number: CN201920877421.0U
Authority: CN
Inventors: 张丽虎
Original assignee: China Shenhua Energy Co Ltd; Shenhua Shendong Power Co Ltd
Current assignee: China Shenhua Energy Co Ltd; Shenhua Shendong Power Co Ltd
Priority date: 2019-06-11
Filing date: 2019-06-11
Publication date: 2020-06-05
Anticipated expiration: 2029-06-11

Abstract

The utility model discloses a sluicing control system. Wherein, this system includes: the collecting equipment is used for collecting the operating parameters of the indirect cooling tower; the DCS is connected with the acquisition equipment and used for generating a control instruction according to the operation parameters, wherein the control instruction is used for indicating the action of the water drainage mechanism; and the water draining mechanism is connected with the DCS distributed control system and is used for executing the action indicated by the control command. The utility model provides a indirect cooling tower have the technical problem of sluicing valve maloperation.

Description

Sluicing control system

Technical Field

The utility model relates to a control field particularly, relates to a sluicing control system.

Background

More than 350MW thermal power generating units in the north and the domestic adopt indirect cooling towers to cool circulating water. The emergency water drain valve of the indirect cooling tower is an important facility for protecting the heat exchange elements of the cooling tower from safe operation in winter, and can drain cooling water in all sectors in time after protection is triggered to prevent the heat exchange elements from being frozen and cracked.

At present, an emergency water escape valve of an indirect cooling tower is usually controlled by a PLC (programmable logic controller) on site through collection, but the PLC fault protection is caused by the severe environment in the indirect cooling tower or misoperation.

Aiming at the problem that the water drain valve of the indirect cooling tower is in misoperation, an effective solution is not provided at present.

SUMMERY OF THE UTILITY MODEL

An embodiment of the utility model provides a sluicing control system to there is the technical problem of sluicing valve maloperation in solving indirect cooling tower at least.

According to an aspect of the embodiments of the present invention, there is provided a drain control system, including: the collecting equipment is used for collecting the operating parameters of the indirect cooling tower; the DCS distributed control system is connected with the acquisition equipment and used for generating a control instruction according to the operation parameters, wherein the control instruction is used for indicating the action of the water drainage mechanism; and the water draining mechanism is connected with the DCS distributed control system and is used for executing the action indicated by the control command.

Further, the water discharge mechanism includes: a water drain valve; and the hydraulic mechanism is respectively arranged between the DCS distributed control system and the water release valve and is used for responding to the control instruction and opening or closing the water release valve.

Further, the water discharge mechanism further includes: and the oil pump is respectively connected with the DCS distributed control system and the water release valve and is used for responding to the control instruction, adjusting the hydraulic pressure in the hydraulic mechanism and controlling the hydraulic mechanism to act.

Further, the hydraulic mechanism includes: and the electromagnetic valves are respectively connected with the oil pump and the DCS distributed control system and are used for responding to the control instruction, opening or disconnecting a passage between the hydraulic mechanism and an oil inlet of the oil pump, opening or disconnecting a passage between the hydraulic mechanism and an oil return port of the oil pump and adjusting the hydraulic pressure in the hydraulic mechanism.

Further, the solenoid valve is a plurality of, includes: a first solenoid valve, a second solenoid valve, a third solenoid valve and a fourth solenoid valve; the oil inlet is communicated with a first end of the first electromagnetic valve and a first end of the second electromagnetic valve respectively, a second end of the first electromagnetic valve is communicated with a second end of the second electromagnetic valve and a first end of the third electromagnetic valve respectively, a second end of the second electromagnetic valve is communicated with a first end of the fourth electromagnetic valve, and a second end of the third electromagnetic valve and a second end of the fourth electromagnetic valve are communicated with the oil return port.

Further, the hydraulic mechanism further includes: and the needle valve is connected between the oil inlet and the oil return port.

Further, the hydraulic mechanism further includes: the first power supply is connected with the first electromagnetic valve and the second electromagnetic valve and used for supplying power to the first electromagnetic valve and the second electromagnetic valve; the second power supply is connected with the third electromagnetic valve and the fourth electromagnetic valve and used for supplying power to the second electromagnetic valve and the fourth electromagnetic valve; wherein the first power supply and the second power supply are independent of each other.

Further, the hydraulic mechanism further includes: and the pressure monitoring element is connected with the DCS distributed control system and is used for monitoring the hydraulic pressure in the hydraulic mechanism.

Further, the acquisition device comprises: and the pressure switch is connected with the DCS distributed control system and used for transmitting a trigger signal to the DCS distributed control system according to the water pressure in the indirect cooling tower, wherein the trigger signal is used for representing the operation parameter.

Further, the pressure switch includes: the low-pressure switch is connected with the DCS distributed control system and used for transmitting a low-pressure trigger signal to the DCS distributed control system under the condition that the water pressure in the indirect cooling tower is lower than a preset low pressure; the high-pressure switch is connected with the DCS distributed control system and used for transmitting a high-pressure trigger signal to the DCS distributed control system under the condition that the water pressure in the indirect cooling tower is higher than a preset high pressure; wherein the trigger signal comprises the low voltage trigger signal and the high voltage trigger signal.

The embodiment of the utility model provides an in, gather the operating parameter of indirect cooling tower through collection equipment, and transmit this operating parameter to DCS distributed control system, generate control command by DCS distributed control system according to this operating parameter, and transmit this control command to sluicing mechanism, by the action that sluicing mechanism execution control command instructs, can reach the purpose that carries out remote control to sluicing mechanism through DCS distributed control system, avoid ground connection control's in-process to lead to the mistake of sluicing action to start because of the adverse circumstances in the indirect cooling tower, thereby realized reducing the maloperation risk of sluicing action, improve the technological effect of sluicing reliability, and then solved indirect cooling tower and had the technical problem of sluicing valve maloperation.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without undue limitation to the invention. In the drawings:

FIG. 1 is a schematic diagram of a bleed water control system according to an embodiment of the present invention;

fig. 2 is a schematic diagram of a solenoid valve distribution according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a cluster emergency water escape valve control logic in accordance with an embodiment of the present invention;

FIG. 4 is a schematic diagram of a unit emergency bleed-out valve oil pump control logic in accordance with an embodiment of the present invention;

fig. 5 is a schematic diagram of a solenoid control logic for a unit emergency drain valve according to an embodiment of the present invention.

Detailed Description

In order to make the technical solution of the present invention better understood, the technical solution of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts shall belong to the protection scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, system, article, or apparatus that comprises a list of elements is not necessarily limited to those elements explicitly listed, but may include other elements not expressly listed or inherent to such process, system, article, or apparatus.

Fig. 1 is a schematic diagram of a water discharge control system according to an embodiment of the present invention, as shown in fig. 1, the system includes the following steps:

the collecting device 11 is used for collecting the operating parameters of the indirect cooling tower; the DCS distributed control system 13 is connected with the acquisition equipment and used for generating a control instruction according to the operation parameters, wherein the control instruction is used for indicating the action of the water drainage mechanism; and the water draining mechanism 15 is connected with the DCS distributed control system and is used for executing the action indicated by the control command.

It should be noted that the distributed DCS control system is a new computer control system compared to the centralized control system, and is developed and evolved based on the centralized control system.

As an alternative embodiment, the acquisition device comprises: and the pressure switch is connected with the DCS distributed control system and used for transmitting a trigger signal to the DCS distributed control system according to the water pressure in the indirect cooling tower, wherein the trigger signal is used for representing the operation parameters.

The above-mentioned embodiment of the utility model, pressure switch can gather the water pressure in the indirect cooling tower to under the early warning pressure's that this water pressure is higher than this pressure switch settlement condition, to DCS distributed system transmission triggering signal, thereby DCS distributed system can know the operating parameter that this triggering signal instructed after receiving this triggering signal, and then control sluices the mechanism action.

As an alternative embodiment, the pressure switch comprises: the low-pressure switch is connected with the DCS distributed control system and used for transmitting a low-pressure trigger signal to the DCS distributed control system under the condition that the water pressure in the indirect cooling tower is lower than a preset low pressure; the high-pressure switch is connected with the DCS distributed control system and used for transmitting a high-pressure trigger signal to the DCS distributed control system under the condition that the water pressure in the indirect cooling tower is higher than a preset high pressure; the trigger signal comprises a low-voltage trigger signal and a high-voltage trigger signal.

The above embodiment of the present invention, the pressure switch includes a low pressure switch and a high pressure switch, the low pressure switch is used for transmitting a low pressure trigger signal to the DCS distributed control system under the condition that the water pressure in the indirect cooling tower is lower than the predetermined low pressure, so that the DCS distributed control system can determine the operation parameters of the indirect cooling tower according to the low pressure trigger signal; the high-pressure switch is used for transmitting a high-pressure trigger signal to the DCS distributed control system under the condition that the water pressure in the indirect cooling tower is higher than the preset high pressure, so that the DCS distributed control system can determine the operation parameters of the indirect cooling tower according to the high-pressure trigger signal.

As an alternative embodiment, the water release mechanism includes: a water drain valve; and the hydraulic mechanism is respectively arranged between the DCS distributed control system and the water release valve and used for responding to the control instruction and opening or closing the water release valve.

The utility model discloses above-mentioned embodiment, sluicing mechanism includes sluicing valve and hydraulic pressure mechanism, and DCS distributed control system can realize opening or closing the sluicing valve through controlling hydraulic pressure mechanism.

The control command includes an open command and a close command, and the operation of the drain mechanism includes: and opening the control drain valve or closing the drain valve, wherein the opening instruction is used for indicating to open the control drain valve, and the closing instruction is used for indicating to close the drain valve.

Optionally, the DCS distributed control system may control the drain mechanism to open the control drain valve according to the low-voltage trigger signal; the drain mechanism can be controlled to close the drain valve according to the low-pressure trigger signal.

As an alternative embodiment, the water release mechanism further comprises: and the oil pump is respectively connected with the DCS distributed control system and the water release valve and used for responding to the control instruction, adjusting the hydraulic pressure in the hydraulic mechanism and controlling the hydraulic mechanism to act.

The utility model discloses above-mentioned embodiment, DCS distributed control system can adjust the hydraulic pressure in the hydraulic pressure mechanism through the oil pump to control the action of hydraulic pressure mechanism, realize opening or closing the sluice valve.

As an alternative embodiment, the hydraulic machine comprises: and the electromagnetic valves are respectively connected with the oil pump and the DCS distributed control system and used for responding to a control instruction, opening or disconnecting a passage between the hydraulic mechanism and an oil inlet of the oil pump, opening or disconnecting a passage between the hydraulic mechanism and an oil return port of the oil pump and adjusting the hydraulic pressure in the hydraulic mechanism.

The above embodiment of the utility model, the oil inlet and the oil return of oil pump can be connected to hydraulic pressure mechanism, supply liquid for hydraulic pressure mechanism through the oil inlet, thereby improve the hydraulic pressure in the hydraulic pressure mechanism, retrieve the liquid in the hydraulic pressure mechanism through the oil return, thereby reduce the hydraulic pressure in the hydraulic pressure mechanism, and still be equipped with the solenoid valve in the hydraulic pressure mechanism, open or break the route between the oil inlet of hydraulic pressure mechanism and oil pump by the solenoid valve, and the route of the oil return of hydraulic pressure mechanism and oil pump, thereby hydraulic pressure in the control hydraulic pressure mechanism, make the action of hydraulic pressure mechanism, realize opening or closing to the sluicing valve.

Fig. 2 is a schematic diagram of distribution of electromagnetic valves according to an embodiment of the present invention, as shown in fig. 2, the electromagnetic valves are multiple, including: a first solenoid valve V1, a second solenoid valve V2, a third solenoid valve V3, and a fourth solenoid valve V4; the oil inlet is communicated with a first end of a first electromagnetic valve V1 and a first end of a second electromagnetic valve V2 respectively, a second end of a first electromagnetic valve V1 is communicated with a second end of a second electromagnetic valve V2 and a first end of a third electromagnetic valve V3 respectively, a second end of a second electromagnetic valve V2 is communicated with a first end of a fourth electromagnetic valve V4, and a second end of the third electromagnetic valve V3 and a second end of the fourth electromagnetic valve V4 are communicated with the oil return port.

As an alternative embodiment, the hydraulic machine further comprises: and the needle valve K1 is connected between the oil inlet and the oil return port.

As an alternative embodiment, the hydraulic machine further comprises: the first power supply is connected with the first electromagnetic valve and the second electromagnetic valve and used for supplying power to the first electromagnetic valve and the second electromagnetic valve; the second power supply is connected with the third electromagnetic valve and the fourth electromagnetic valve and used for supplying power to the second electromagnetic valve and the fourth electromagnetic valve; wherein the first power supply and the second power supply are independent of each other.

As an alternative embodiment, the hydraulic machine further comprises: and the pressure monitoring element is connected with the DCS distributed control system and is used for monitoring the hydraulic pressure in the hydraulic mechanism.

Optionally, the pressure monitoring element comprises: the hydraulic control system comprises a high-pressure monitoring element and a low-pressure monitoring element, wherein the low-pressure monitoring element is triggered to transmit a low hydraulic instruction to the DCS distributed control system under the condition that the hydraulic pressure in the hydraulic mechanism is lower than a preset low hydraulic pressure, so that the DCS distributed control system can start an oil pump according to the low hydraulic instruction; and under the condition that the hydraulic pressure in the hydraulic mechanism is higher than the preset high hydraulic pressure, triggering the high-pressure monitoring element to transmit a high hydraulic pressure instruction to the DCS distributed control system, so that the DCS distributed control system can close the oil pump according to the high hydraulic pressure instruction.

The utility model provides a technical scheme, opening and closing of sluicing valve are realized through hydraulic actuator:

under the condition that a DCS (distributed control system) sends a control instruction for indicating to close the drain valve, if the electromagnetic valve is electrified and the hydraulic pressure of the hydraulic system (namely a hydraulic mechanism) is less than a fixed value (namely preset low hydraulic pressure), the oil pump is started; if the drain valve has reached the closed position and the hydraulic pressure (i.e., the predetermined high hydraulic pressure) of the hydraulic system (i.e., the hydraulic mechanism) is greater than the constant value, the oil pump is stopped.

Under the condition that a DCS distributed control system sends a control instruction for indicating opening and closing of the drain valve, a power supply of the electromagnetic valve is cut off to release hydraulic pressure, so that the heavy hammer falls down, and the valve is opened.

It should be noted that the maintenance of the closed position during normal operation of the drain valve is ensured by the hydraulic oil stored in the accumulator, and the oil pump is activated if the pressure monitoring element of the hydraulic system (i.e. the hydraulic unit) detects that the hydraulic pressure of the hydraulic system (i.e. the hydraulic unit) is too low.

As a preferred embodiment, the utility model also provides an indirect cooling tower emergency water escape valve hydraulic control device based on DCS control.

The utility model provides a technical scheme can use in power plant's indirect cooling tower generating set, can utilize DCS control outlet valve during the unit normal operating.

The utility model provides a technical scheme causes the unplanned shutdown of unit for preventing that the outlet valve is opened by mistake:

the control of the oil pump and the electromagnetic valve is remotely controlled by a DCS distributed control system, local PLC is cancelled, and PLC fault protection is prevented from being operated according to the operation or misoperation due to the severe environment in the indirect cooling tower.

And the second electromagnetic valve adopts a four-out-of-two series-parallel connection mode (as shown in figure 2), and is powered by two independent power supplies.

And thirdly, adding a set of remote pressure transmitter (namely a pressure monitoring element) and a DCS distributed control system to the hydraulic oil station to be used as the pressure monitoring and alarming of the oil station (namely an oil pump or a hydraulic mechanism).

Optionally, control signals of the oil pump and the electromagnetic valve, and signals of the pressure transmitter (i.e., the pressure monitoring element) are all connected to the DCS distributed control system, and logic control is realized by the DCS distributed control system.

The utility model provides a technical scheme, the equipment that uses is simple easily operated, has cancelled PLC for the local control, has increased solenoid valve and pressure monitoring element's redundancy, has improved the reliability of equipment, has reduced the protection maloperation and has refused the risk of moving.

The control signals of an oil pump and an electromagnetic valve, the signals of a low-pressure switch, a high-pressure switch and a pressure transmitter of a certain power plant are all connected to a DCS system, logic control is realized by the DCS, and the logic is as follows:

fig. 3 is a schematic diagram of a unit emergency drain valve control logic according to an embodiment of the present invention, as shown in fig. 3, a V1 pin of the DSC module is used for receiving a signal indicating the opening of the emergency drain valve of the air-cooled inlet pipe; a V2 pin is used for receiving an instruction to close the emergency water drain valve of the air cooling water inlet pipe; the L0 pin is used for receiving a signal for indicating the fault of the emergency water drain valve system of the air-cooled water inlet pipe; the SD pin is used for receiving a signal for indicating the on-site/remote control of the emergency water drain valve of the air-cooled water inlet pipe; the DV pin is used for sending an emergency water drain valve instruction for opening the air-cooling water inlet pipe; the RV pin is used for sending an emergency water drain valve instruction for closing the cold water inlet pipe.

Fig. 4 is a schematic diagram of an oil pump control logic of a unit emergency drain valve according to an embodiment of the present invention, as shown in fig. 4, based on the unit emergency drain valve control logic shown in fig. 3, a remote sensing module RS is added, wherein a SET pin of the remote sensing module RS is used for receiving an instruction to open the emergency drain valve of the air-cooled water inlet pipe; a RESET1 pin is used for receiving an emergency water drain valve instruction for closing the air cooling water inlet pipe; a Q1 pin of the RS module is connected with a signal for indicating that the oil pressure of an emergency water drain valve of the air-cooled water inlet pipe is low, and is connected with an L6 pin of the DSC module through an AND logic circuit; and a Q1 pin of the RS module is connected with a signal for indicating that the oil pressure of the emergency water drain valve of the air cooling water inlet pipe is high, and is connected with an L7 pin of the DSC module through an AND logic circuit.

Fig. 5 is a schematic diagram of a control logic of a solenoid valve of a unit emergency drain valve according to an embodiment of the present invention, as shown in fig. 5, a SET pin of a remote sensing module RS is used for receiving an emergency drain valve command for opening an air-cooled water inlet pipe; a RESET1 pin is used for receiving an emergency water drain valve instruction for closing the air cooling water inlet pipe; a Q1 pin of the RS module outputs a plurality of signals which respectively indicate the closing of an emergency water drain valve electromagnetic valve 1 of the air-cooled water inlet pipe; the electromagnetic valve 2 of the emergency water drain valve of the air cooling water inlet pipe is indicated to be closed; the electromagnetic valve 3 of the emergency water drain valve of the air cooling water inlet pipe is indicated to be closed; and the electromagnetic valve 4 of the emergency water drain valve of the air cooling water inlet pipe is closed.

The above embodiment numbers of the present invention are only for description, and do not represent the advantages and disadvantages of the embodiments.

In the above embodiments of the present invention, the descriptions of the respective embodiments have respective emphasis, and for parts that are not described in detail in a certain embodiment, reference may be made to the related descriptions of other embodiments.

In the embodiments provided in the present application, it should be understood that the disclosed technology can be implemented in other ways. The above-described embodiments of the apparatus are merely illustrative, and for example, the division of the units may be a logical division, and in actual implementation, there may be another division, for example, multiple units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, units or modules, and may be in an electrical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to perform all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a removable hard disk, a magnetic or optical disk, and other various media capable of storing program codes.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. A bleed control system, comprising:

the collecting equipment is used for collecting the operating parameters of the indirect cooling tower;

the DCS distributed control system is connected with the acquisition equipment and used for generating a control instruction according to the operation parameters, wherein the control instruction is used for indicating the action of the water drainage mechanism;

and the water draining mechanism is connected with the DCS distributed control system and is used for executing the action indicated by the control command.

2. The system of claim 1, wherein the drainage mechanism comprises:

a water drain valve;

and the hydraulic mechanism is respectively arranged between the DCS distributed control system and the water release valve and is used for responding to the control instruction and opening or closing the water release valve.

3. The system of claim 2, wherein the drainage mechanism further comprises:

and the oil pump is respectively connected with the DCS distributed control system and the water release valve and is used for responding to the control instruction, adjusting the hydraulic pressure in the hydraulic mechanism and controlling the hydraulic mechanism to act.

4. The system of claim 3, wherein the hydraulic mechanism comprises:

and the electromagnetic valves are respectively connected with the oil pump and the DCS distributed control system and are used for responding to the control instruction, opening or disconnecting a passage between the hydraulic mechanism and an oil inlet of the oil pump, opening or disconnecting a passage between the hydraulic mechanism and an oil return port of the oil pump and adjusting the hydraulic pressure in the hydraulic mechanism.

5. The system of claim 4, wherein the plurality of solenoid valves comprises:

a first solenoid valve, a second solenoid valve, a third solenoid valve and a fourth solenoid valve;

the oil inlet is communicated with a first end of the first electromagnetic valve and a first end of the second electromagnetic valve respectively, a second end of the first electromagnetic valve is communicated with a second end of the second electromagnetic valve and a first end of the third electromagnetic valve respectively, a second end of the second electromagnetic valve is communicated with a first end of the fourth electromagnetic valve, and a second end of the third electromagnetic valve and a second end of the fourth electromagnetic valve are communicated with the oil return port.

6. The system of claim 5, wherein the hydraulic mechanism further comprises:

and the needle valve is connected between the oil inlet and the oil return port.

7. The system of claim 5, wherein the hydraulic mechanism further comprises:

the first power supply is connected with the first electromagnetic valve and the second electromagnetic valve and used for supplying power to the first electromagnetic valve and the second electromagnetic valve;

the second power supply is connected with the third electromagnetic valve and the fourth electromagnetic valve and used for supplying power to the second electromagnetic valve and the fourth electromagnetic valve;

wherein the first power supply and the second power supply are independent of each other.

8. The system according to any one of claims 2-7, wherein the hydraulic mechanism further comprises:

and the pressure monitoring element is connected with the DCS distributed control system and is used for monitoring the hydraulic pressure in the hydraulic mechanism.

9. The system of claim 1, wherein the acquisition device comprises:

and the pressure switch is connected with the DCS distributed control system and used for transmitting a trigger signal to the DCS distributed control system according to the water pressure in the indirect cooling tower, wherein the trigger signal is used for representing the operation parameter.

10. The system of claim 9, wherein the pressure switch comprises:

the low-pressure switch is connected with the DCS distributed control system and used for transmitting a low-pressure trigger signal to the DCS distributed control system under the condition that the water pressure in the indirect cooling tower is lower than a preset low pressure;

the high-pressure switch is connected with the DCS distributed control system and used for transmitting a high-pressure trigger signal to the DCS distributed control system under the condition that the water pressure in the indirect cooling tower is higher than a preset high pressure;

wherein the trigger signal comprises the low voltage trigger signal and the high voltage trigger signal.