阅读说明：本技术 一种判断先导式安全阀起跳的方法 (Method for judging take-off of pilot operated safety valve ) 是由 张士刚 于 2020-04-07 设计创作，主要内容包括：本发明公开了一种判断先导式安全阀起跳的方法,该方法通过对先导式安全阀的相关压力点和工艺点进行监测,找出各监测点与先导式安全阀运行状态内在的逻辑判断关系,并通过DCS系统对信号进行逻辑组态,对各信号点进行监控判别,从而实时监控空分装置上塔先导式安全阀的工作状态,并实现对其频繁起跳的原因查找。有效避免先导式安全阀故障,充分保障空分装置的运行安全,并维护空分装置的连续生产。(The invention discloses a method for judging the tripping of a pilot operated safety valve, which comprises the steps of monitoring relevant pressure points and process points of the pilot operated safety valve, finding out the logic judgment relation between each monitoring point and the internal operation state of the pilot operated safety valve, carrying out logic configuration on signals through a DCS (distributed control system), and monitoring and judging each signal point, thereby monitoring the working state of the pilot operated safety valve on a tower of an air separation unit in real time and realizing the search of the reason of frequent tripping. The failure of the pilot safety valve is effectively avoided, the operation safety of the air separation plant is fully ensured, and the continuous production of the air separation plant is maintained.)

1. A method for judging the tripping of a pilot operated safety valve is characterized by comprising the following steps:

(1) respectively installing pressure transmitters on a pressure measuring pipeline of the pilot safety valve and an instrument air source pipe of a main valve piston cavity, and leading signals of the pressure transmitters to a DCS (distributed control system);

collecting a process monitoring pressure point of an upper tower in an air separation device, and introducing a process monitoring pressure signal to a DCS (distributed control system);

leading out signals of two electromagnetic valves on the pilot operated safety valve emergency opening device to a DCS (distributed control system);

(2) finishing the logic relation between each signal in the step (1) and the working state of the pilot operated safety valve through logic configuration, and presetting the logic relation in a DCS (distributed control system);

(3) the DCS judges the working state of the pilot operated safety valve by monitoring the real-time condition of each signal, and gives the reason of the tripping when the pilot operated safety valve trips.

2. The method for determining a takeoff of a pilot operated safety valve according to claim 1, wherein in the step (2), the logical relationship includes: when the pressure of the pressure measuring pipeline of the pilot operated safety valve is normal, the pressure at the air source pipe of the main valve piston cavity instrument is normal, the process monitoring pressure is normal, and signals of the two electromagnetic valves are power-off, the pilot operated safety valve is in a normal working state.

3. The method of determining a piloted safety valve trip as in claim 2, wherein the logical relationship further comprises: when the pressure of the pressure measuring pipeline of the pilot operated safety valve is abnormal, the pressure at the air source pipe of the main valve piston cavity instrument is normal, the process monitoring pressure is normal, and signals of the two electromagnetic valves are power off, the pilot operated safety valve jumps because the pressure measuring pipeline has an overpressure trend.

4. The method of determining a piloted safety valve trip as in claim 3, wherein the logical relationship further comprises: when the pressure of the pressure measuring pipeline is abnormal, the pressure at the air source pipe of the main valve piston cavity instrument is abnormal, the process monitoring pressure signal is normal, and the signals of the two electromagnetic valves are power off, the pilot operated safety valve jumps because the pressure measuring pipeline has overpressure failure.

5. The method of determining a piloted safety valve trip as in claim 3, wherein the logical relationship further comprises: when the pressure of a pressure measuring pipeline of the pilot operated safety valve is abnormal, the pressure at the air source pipe of the main valve piston cavity instrument is abnormal, a process monitoring pressure signal is abnormal, and signals of the two electromagnetic valves are power off, the pilot operated safety valve jumps due to overpressure of a pilot operated safety valve system.

Technical Field

The invention relates to a monitoring method for an auxiliary machine of a large compressor unit, in particular to a method for judging the take-off of a pilot operated safety valve.

Background

The upper tower of the air separation unit in the key equipment for production and supply of the oxygen plant is provided with a pilot operated safety valve. The safety valve is an indirect load type safety valve. Consisting of a main valve and a pilot valve (also called "secondary valve"), the main valve being driven by means of a medium discharged from the pilot valve. The pilot valve itself is also a direct load relief valve, taken alone. When the medium pressure reaches the opening pressure of the pilot valve, the pilot valve is opened in advance, and the discharged medium enters the main valve from the bypass pipe.

The failure of the pilot operated safety valve can cause the overpressure of the upper tower of the air separation device, the overpressure explosion of the upper tower and other accidents, and the leakage of the overpressure can cause the serious consequences of the deformation of the pipeline of the air separation device, the collapse and explosion of the pipeline and the fractionating tower device, and the like, thereby bringing great harm to the continuous production of the air separation device and seriously threatening the operation safety and the equipment safety of the air separation device. In the actual production process, the tripping phenomenon of the pilot operated safety valve is frequent when the unit operates, if the tripping reason of the pilot operated safety valve cannot be timely and effectively judged, the fault of the pilot operated safety valve occurs, the continuous production of the air separation plant can be influenced if the fault of the pilot operated safety valve occurs, and the operation safety of the air separation plant is seriously influenced

Disclosure of Invention

The purpose of the invention is as follows: in order to overcome the defects of the prior art, the invention provides a method for judging the tripping of a pilot operated safety valve, which can accurately judge the tripping reason of the pilot operated safety valve and monitor the working state of the pilot operated safety valve.

The technical scheme is as follows: the invention relates to a method for judging the take-off of a pilot operated safety valve, which comprises the following steps:

(1) respectively installing pressure transmitters on a pressure measuring pipeline of the pilot safety valve and an instrument air source pipe of a main valve piston cavity, and leading signals of the pressure transmitters to a DCS (distributed control system);

collecting a process monitoring pressure point of an upper tower in an air separation device, and introducing a process monitoring pressure signal to a DCS (distributed control system);

leading out signals of two electromagnetic valves on the pilot operated safety valve emergency opening device to a DCS (distributed control system);

(2) finishing the logic relation between each signal in the step (1) and the working state of the pilot operated safety valve through logic configuration, and presetting the logic relation in a DCS (distributed control system);

(3) the DCS judges the working state of the pilot operated safety valve by monitoring the real-time condition of each signal, and gives the reason of the tripping when the pilot operated safety valve trips.

Wherein, in the step (2), the logical relationship includes: when the pressure of the pressure measuring pipeline of the pilot operated safety valve is normal, the pressure at the air source pipe of the main valve piston cavity instrument is normal, the process monitoring pressure is normal, and signals of the two electromagnetic valves are power-off, the pilot operated safety valve is in a normal working state.

The logical relationship further comprises: when the pressure of the pressure measuring pipeline of the pilot operated safety valve is abnormal, the pressure at the air source pipe of the main valve piston cavity instrument is normal, the process monitoring pressure is normal, and signals of the two electromagnetic valves are power off, the pilot operated safety valve jumps because the pressure measuring pipeline has an overpressure trend.

The logical relationship further comprises: when the pressure of the pressure measuring pipeline is abnormal, the pressure at the air source pipe of the main valve piston cavity instrument is abnormal, the process monitoring pressure signal is normal, and the signals of the two electromagnetic valves are power off, the pilot operated safety valve jumps because the pressure measuring pipeline has overpressure failure.

The logical relationship further comprises: when the pressure of a pressure measuring pipeline of the pilot operated safety valve is abnormal, the pressure at the air source pipe of the main valve piston cavity instrument is abnormal, a process monitoring pressure signal is abnormal, and signals of the two electromagnetic valves are power off, the pilot operated safety valve jumps due to overpressure of a pilot operated safety valve system.

Has the advantages that: the method can monitor the working state of the pilot operated safety valve on the upper tower of the air separation unit in real time by monitoring the relevant pressure points and process points of the pilot operated safety valve, logically configuring the signals of each monitoring point and monitoring and distinguishing through a DCS (distributed control system), and realize the search of the reason of frequent take-off. The failure of the pilot safety valve is effectively avoided, the operation safety of the air separation plant is fully ensured, and the continuous production of the air separation plant is maintained.

Detailed Description

A method for judging the jump of pilot-operated safety valve includes such steps as installing two pressure transducers to the pilot-operated safety valve on site, and installing pressure measuring pipeline and pressure measuring tube of main valve piston cavity on the instrument gas source tube for monitoring the pressure of pressure measuring pipeline and pressure of instrument gas source tube in main valve piston cavity.

And then collecting the upper tower process monitoring pressure points in the air separation unit, taking out relevant process parameters, and mainly monitoring the actual operation condition of each air separation unit.

And two electromagnetic valve signals on the pilot operated safety valve emergency opening device are led out, and the electromagnetic valve signals on the emergency opening device are mainly monitored.

And finally, introducing signals of the field pressure transmitter, related signal points of the air separation unit system and a signal point of the electromagnetic valve of the emergency opening device to the DCS system to participate in logic configuration, exciting a screen to flash and alarm, and finishing analysis and search for judging the tripping reason of the pilot operated safety valve. And in the later stage, the DO point can be connected out as required to carry out flash alarm of the equipment.

The specific logic is as follows:

the system runs in a normal state if the pressure of a pressure measuring pipeline of the pilot operated safety valve is normal, the pressure at the air source pipe of the main valve piston cavity instrument is normal, the process monitoring pressure signal is normal and the signals of the two electromagnetic valves are power-off;

the pressure of a pressure measuring pipeline is abnormal, the pressure at the air source pipe of a main valve piston cavity instrument is normal, a process monitoring pressure signal is normal, and signals of two electromagnetic valves are power-off, so that the reason of tripping is that the pressure measuring pipeline has an overpressure trend;

the pressure of a pressure measuring pipeline is abnormal, the pressure at the air source pipe of a main valve piston cavity instrument is abnormal, process monitoring pressure signals are normal, and signals of two electromagnetic valves are power-off, so that the reason of tripping is that the pressure measuring pipeline has overpressure failure;

the pressure of a pressure measuring pipeline of the pilot operated safety valve is abnormal, the pressure at the air source pipe of the main valve piston cavity instrument is abnormal, process monitoring pressure signals are abnormal, and the signals of the two electromagnetic valves are power-off, so that the tripping reason is the overpressure of the system.