阅读说明：本技术 一种使用旋转活塞泵对槽车轻油进行卸车的自动控制系统及其控制方法 (Automatic control system for unloading tank car light oil by using rotary piston pump and control method thereof ) 是由 于金宁 武珊珊 张昌运 牟洪祥 何春宏 王建明 于 2018-06-06 设计创作，主要内容包括：本发明提供了一种使用旋转活塞泵对槽车轻油进行卸车的自动控制系统,包括连接有人机交互界面的交换机、可编程逻辑控制器、液位监控仪、卸车鹤管、旋转活塞泵、气液分离罐和离心泵,卸车吸油管的底部固定设置有两段式液位探头,两段式液位探头与液位监控仪连接,过滤器出口连接旋转活塞泵,旋转活塞泵出口管线连接气液分离罐,两段式液位探头、气液分离罐上设置的气液分离罐液位计连接至可编程逻辑控制器,旋转活塞泵和离心泵分别通过一个变频控制器连接至可编程逻辑控制器。采用该使用旋转活塞泵对槽车轻油进行卸车的自动控制系统的控制方法,能实时监控液位变化,无需卸车工作人员接触有毒有害物质,液位变化实现自动化控制,液位稳定,提高了卸车效率。(The invention provides an automatic control system for unloading light oil from a tank car by using a rotary piston pump, which comprises a switch connected with a human-computer interaction interface, a programmable logic controller, a liquid level monitor, an unloading oil filling riser, a rotary piston pump, a gas-liquid separation tank and a centrifugal pump, wherein a two-section liquid level probe is fixedly arranged at the bottom of an unloading oil suction pipe and is connected with the liquid level monitor, an outlet of a filter is connected with the rotary piston pump, an outlet pipeline of the rotary piston pump is connected with the gas-liquid separation tank, the two-section liquid level probe and a gas-liquid separation tank liquid level meter arranged on the gas-liquid separation tank are connected to the programmable logic controller, and the rotary piston pump and the centrifugal pump are respectively connected to the programmable logic controller through a variable. By adopting the control method of the automatic control system for unloading the light oil from the tank car by using the rotary piston pump, the liquid level change can be monitored in real time, the unloading workers are not required to contact toxic and harmful substances, the automatic control of the liquid level change is realized, the liquid level is stable, and the unloading efficiency is improved.)

1. An automatic control system for unloading light oil from a tank car by using a rotary piston pump is characterized by comprising a switch, a programmable logic controller, a liquid level monitor, an unloading oil filling pipe, the rotary piston pump, a gas-liquid separation tank and a centrifugal pump which are connected with a human-computer interaction interface, wherein an unloading oil suction pipe and a sweeping oil suction pipe are vertically arranged in the unloading oil filling pipe of a sleeve type structure, a two-section liquid level probe is fixedly arranged at the bottom of the unloading oil suction pipe and is connected with the liquid level monitor, the unloading oil suction pipe and the sweeping oil suction pipe are respectively communicated with an oil conveying pipeline through an unloading pipeline and a sweeping pipeline and are connected to an inlet of a filter, an outlet of the filter is connected with the rotary piston pump, an outlet pipeline of the rotary piston pump is connected with the gas-liquid separation tank, the two-section liquid level probe and a liquid level meter of the gas-liquid separation tank are connected to the programmable logic controller, a discharge pipeline of the gas-liquid separation tank is connected with an inlet of a centrifugal pump, and the rotary piston pump and the centrifugal pump are respectively connected to a programmable logic controller through a variable frequency controller; the outlet pipeline of the centrifugal pump is divided into two branches, wherein one branch is connected to the storage tank through an oil pipeline, and the other branch is used as an oil supplementing pipe of the rotary piston pump and is communicated with the inlet pipeline of the rotary piston pump.

2. The automatic control system for unloading light oil from tank cars of claim 1, wherein said unloading line and said sweeping compartment line are provided with unloading electric valves and sweeping compartment electric valves, respectively.

3. The automatic control system for unloading light oil from tank car by using rotary piston pump according to claim 1, characterized in that two branch lines of said centrifugal pump outlet line are respectively equipped with electric valve for centrifugal pump outlet and electric valve for rotary piston pump oil-supplementing pipe.

4. The automatic control system for unloading light oil from tank car by using rotary piston pump according to claim 1, wherein the oil supply pipe of rotary piston pump is provided with electric valve for oil supply pipe of rotary piston pump, and the oil line for connecting storage tank is provided with storage tank feeding valve.

5. The automatic control system for unloading light oil from a tank car using a rotary piston pump of claim 1, wherein said programmable logic controller is further connected to an unloading line electric valve, a scavenging line electric valve, a centrifugal pump outlet electric valve, and a rotary piston pump oil supply line electric valve.

6. The automatic control system for unloading a light oil from a tank car using a rotary piston pump as claimed in claim 5, wherein said programmable logic controller is further connected to a two-stage level probe and a gas-liquid separation tank level gauge.

7. The automatic control system for unloading a light oil from a tank car using a rotary piston pump according to claim 1, wherein a gas line is further provided on the top of the gas-liquid separation tank, a gas discharge valve of the gas-liquid separation tank is provided on the gas line, and the discharged gas is introduced into a gas piping system or an oil-gas recovery apparatus.

8. A control method of an automatic control system for unloading light oil from a tank car using a rotary piston pump according to any one of claims 1 to 7, characterized by the steps of:

Firstly, an unloading electric valve and an exhaust valve of a gas-liquid separation tank are started, a rotary piston pump is started to pump oil, when the liquid level in the gas-liquid separation tank rises to reach a set high value, an outlet electric valve of a centrifugal pump and a centrifugal pump are automatically started after receiving a control instruction of a programmable logic controller, the liquid level in the gas-liquid separation tank is kept stable, and a two-section liquid level probe monitors the liquid level in a tank car in real time;

Secondly, when the liquid level in the tank car is reduced to a first section probe of the two-section liquid level probe, entering a bin sweeping operation stage, outputting a control signal by the programmable logic controller to automatically close an unloading line electric valve, opening a bin sweeping line electric valve and a rotary piston pump oil supplementing pipe electric valve, and simultaneously outputting a control signal to the two variable frequency controllers to synchronously reduce the frequency output of the rotary piston pump and the centrifugal pump so as to reduce the rotating speed of the pump to carry out bin sweeping operation;

and thirdly, when the liquid level is reduced to a second section of probe of the two-section type liquid level probe, the programmable logic controller outputs control signals to automatically close the rotary piston pump, the bin sweeping electric valve and the rotary piston pump oil supplementing pipe electric valve, and bin sweeping operation is finished.

9. The control method of an automatic control system for unloading light oil from a tank car by using a rotary piston pump according to claim 8, wherein when the liquid level in the gas-liquid separation tank is higher than a set value, the output of the variable frequency controller connected to the centrifugal pump is increased, and the opening of the electric valve at the outlet of the centrifugal pump is increased; when the liquid level is lower than the set low value, the output of the frequency conversion controller is reduced, the opening of the electric valve at the outlet of the centrifugal pump is reduced, and when the liquid level is lower than the minimum value, the electric valves at the outlet of the centrifugal pump and the centrifugal pump are closed.

Technical Field

the invention relates to the technical field of unloading oil products transported by a train tank car by a displacement pump, in particular to an automatic control system for unloading light oil of the tank car by using a rotary piston pump and a control method thereof.

Background

The positive displacement oil pump has strong self-absorption capacity, for example, a rotary piston pump can directly pump oil from a train tank car without oil guiding and pump filling, so the positive displacement oil pump is widely applied to tank car oil unloading in recent years. At present, due to the lack of a perfect unloading automatic control system and method, the existing rotary piston pump unloading process inevitably has the following problems: in the unloading process, unloading workers need to check the liquid level condition in the tank car timely, and as is known, the concentration of toxic and harmful substances in oil products is high, and the unloading workers are seriously harmed by frequent contact; in the unloading process, when the real-time discharge capacity of the rotary piston pump is not matched with that of the centrifugal pump, the liquid level in the gas-liquid separation tank can fluctuate greatly, so that a worker is required to frequently adjust the opening degree of each valve, the unloading labor intensity is increased, and the unloading efficiency is low.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides an automatic control system for unloading light oil from a tank car by using a rotary piston pump and a control method thereof, which can monitor the liquid level change in real time, do not need unloading workers to contact toxic and harmful substances, realize automatic control on the liquid level change, stabilize the liquid level and improve the unloading efficiency.

in order to solve the problems, the technical measures adopted by the invention are as follows:

An automatic control system for unloading light oil from a tank car by using a rotary piston pump comprises a switch, a programmable logic controller, a liquid level monitor, an unloading oil filling pipe, a rotary piston pump, a gas-liquid separation tank and a centrifugal pump which are connected with a human-computer interaction interface, wherein an unloading oil suction pipe and a bin sweeping oil suction pipe are vertically arranged in the unloading oil filling pipe of a sleeve type structure, a two-section liquid level probe is fixedly arranged at the bottom of the unloading oil suction pipe and is connected with the liquid level monitor, the unloading oil suction pipe and the bin sweeping oil suction pipe are respectively communicated with an oil conveying pipeline through an unloading pipeline and a bin sweeping pipeline and are connected to an inlet of a filter, an outlet of the filter is connected with the rotary piston pump, an outlet pipeline of the rotary piston pump is connected with the gas-liquid separation tank, the two-section liquid level probe and a liquid level meter of the gas-liquid separation tank are connected to the programmable logic, a discharge pipeline of the gas-liquid separation tank is connected with an inlet of a centrifugal pump, and the rotary piston pump and the centrifugal pump are respectively connected to a programmable logic controller through a variable frequency controller; the outlet pipeline of the centrifugal pump is divided into two branches, wherein one branch is connected to the storage tank through an oil pipeline, and the other branch is used as an oil supplementing pipe of the rotary piston pump and is communicated with the inlet pipeline of the rotary piston pump.

preferably, the unloading pipeline and the bin sweeping pipeline are respectively provided with an unloading electric valve and a bin sweeping electric valve.

Preferably, two branch pipelines of the outlet pipeline of the centrifugal pump are respectively provided with an electric valve at the outlet of the centrifugal pump and an electric valve of an oil supplementing pipe of the rotary piston pump.

Preferably, an electric valve of the rotary piston pump oil supplementing pipe is arranged on the rotary piston pump oil supplementing pipe, and a storage tank feeding valve is arranged on an oil conveying pipeline connected with the storage tank.

Preferably, the programmable logic controller is further connected with an unloading line electric valve, a bin sweeping line electric valve, a centrifugal pump outlet electric valve and a rotary piston pump oil supplementing pipe electric valve.

Preferably, the programmable logic controller is further connected with a two-section type liquid level probe and a liquid level meter of the gas-liquid separation tank.

preferably, the top of the gas-liquid separation tank is also provided with a gas pipeline, the gas pipeline is provided with a gas-liquid separation tank exhaust valve, and discharged gas enters a gas pipeline network system or an oil-gas recovery device.

Preferably, an inlet valve of the gas-liquid separation tank is arranged on the inlet pipeline of the gas-liquid separation tank.

a control method of an automatic control system for unloading light oil from a tank car by using a rotary piston pump comprises the following control steps:

firstly, an unloading electric valve and an exhaust valve of a gas-liquid separation tank are started, a rotary piston pump is started to pump oil, when the liquid level in the gas-liquid separation tank rises to reach a set high value, an outlet electric valve of a centrifugal pump and a centrifugal pump are automatically started after receiving a control instruction of a programmable logic controller, the liquid level in the gas-liquid separation tank is kept stable, and a two-section liquid level probe monitors the liquid level in a tank car in real time;

Secondly, when the liquid level in the tank car is reduced to a first section probe of the two-section liquid level probe, entering a bin sweeping operation stage, outputting a control signal by the programmable logic controller to automatically close an unloading line electric valve, opening a bin sweeping line electric valve and a rotary piston pump oil supplementing pipe electric valve, and simultaneously outputting a control signal to the two variable frequency controllers to synchronously reduce the frequency output of the rotary piston pump and the centrifugal pump so as to reduce the rotating speed of the pump to carry out bin sweeping operation;

and thirdly, when the liquid level is reduced to a second section of probe of the two-section type liquid level probe, the programmable logic controller outputs control signals to automatically close the rotary piston pump, the bin sweeping electric valve and the rotary piston pump oil supplementing pipe electric valve, and bin sweeping operation is finished.

In the unloading process, the liquid level of the gas-liquid separation tank is a control condition, if the liquid level in the gas-liquid separation tank is higher than a set value, the output of a variable frequency controller connected with the centrifugal pump is increased, the rotating speed is accelerated, the opening of an electric valve at the outlet of the centrifugal pump is increased, and the discharge capacity of the centrifugal pump is increased; when the liquid level is lower than a set low value, the output of the variable frequency controller is reduced, the rotating speed is reduced, the opening of an electric valve at the outlet of the centrifugal pump is reduced, and the discharge capacity of the centrifugal pump is correspondingly reduced; and when the electric valve is lower than the set minimum value, closing the centrifugal pump and the electric valve at the outlet of the centrifugal pump.

The beneficial effect of the invention is that,

1. The liquid level monitoring instrument connected with the two-section type liquid level probe monitors the change of the liquid level data of the tank car in the unloading process in real time, and the automatic switching is realized in the unloading and bin sweeping operation process without the need of contacting toxic and harmful substances by unloading workers.

2. The liquid level change in the gas-liquid separation tank is used as the control condition of the automatic control system, and the liquid level stability of the gas-liquid separation tank is ensured through the variable frequency linkage control of the rotary piston pump and the centrifugal pump, so that the condition of large liquid level fluctuation is avoided, and the opening degree of each outlet valve does not need to be frequently adjusted by workers.

3. The full-automatic control of unloading and sweeping the bin is realized, the automation and centralization level of operation is improved, and the working efficiency is improved.

Drawings

FIG. 1 is a schematic structural view of the present invention;

In the figure, 1-human-computer interaction interface; 2-a programmable logic controller; 3-liquid level monitor; 4-two-section type liquid level probe; 5-sweeping bin line electric valve; 6-electric valve of unloading line; 7-a variable frequency controller; 8-a gas-liquid separation tank liquid level meter; 9-centrifugal pump outlet electric valve; 10-a tank feed valve; 11-electric valve of oil supply pipe of rotary piston pump; 12-unloading crane pipe; 13-unloading oil suction pipe; 14-a bin sweeping oil suction pipe; 15-a filter; 16-a rotary piston pump; 17-a gas-liquid separation tank; 18-a centrifugal pump; 19-a storage tank; 20-a gas line; 21-gas-liquid separation tank exhaust valve.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in figure 1, an automatic control system for unloading light oil from a tank car by using a rotary piston pump comprises a switch connected with a human-computer interaction interface 1, a programmable logic controller 2, a liquid level monitor 3, an unloading oil pipe 12, a rotary piston pump 16, a gas-liquid separation tank 17 and a centrifugal pump 18, wherein an unloading oil suction pipe 13 and a bin sweeping oil suction pipe 14 are vertically arranged in the unloading oil pipe 12 of a sleeve type structure, a two-section liquid level probe 4 is fixedly arranged at the bottom of the unloading oil suction pipe 13, the two-section liquid level probe 4 is connected with the liquid level monitor 3, the unloading oil suction pipe 13 and the bin sweeping oil suction pipe 14 are respectively communicated with an oil conveying pipeline through an unloading pipeline and a bin sweeping pipeline and are connected to an inlet of a filter 15, an outlet of the filter 15 is connected with the rotary piston pump 16, an outlet pipeline of the rotary piston pump 16 is connected with the gas-liquid separation tank 17, a gas-liquid level meter 8 of the gas-liquid separation tank 17 arranged on the, a discharge pipeline of the gas-liquid separation tank 17 is connected with an inlet of a centrifugal pump 18, and the rotary piston pump 16 and the centrifugal pump 18 are respectively connected to the programmable logic controller 2 through a variable frequency controller 7; the outlet line of the centrifugal pump 18 is divided into two branches, one of which is connected to the storage tank 19 through an oil pipeline, and the other of which is used as a rotary piston pump oil supplementing pipe and is communicated with the inlet line of the rotary piston pump 16.

An unloading electric valve 6 and a bin sweeping electric valve 5 are respectively arranged on the unloading pipeline and the bin sweeping pipeline, and a centrifugal pump outlet electric valve 9 and a rotary piston pump oil supplementing pipe electric valve 11 are respectively arranged on two branch pipelines of an outlet pipeline of a centrifugal pump 18; the rotary piston pump oil supplementing pipe is provided with a rotary piston pump oil supplementing pipe electric valve 11, and an oil pipeline connected with a storage tank 19 is provided with a storage tank feeding valve 10.

The programmable logic controller 2 is also connected with an unloading line electric valve 6, a bin sweeping line electric valve 5, a centrifugal pump outlet electric valve 9 and a rotary piston pump oil supplementing pipe electric valve 11, and the programmable logic controller 2 controls the opening, closing and opening of the unloading line electric valve 6, the bin sweeping line electric valve 5, the centrifugal pump outlet electric valve 9 and the rotary piston pump oil supplementing pipe electric valve 11; the programmable logic controller 2 is also connected with a two-section liquid level probe 4 and a gas-liquid separation tank liquid level meter 8, the two-section liquid level probe 4 outputs the acquired tank car liquid level data signals to the programmable logic controller 2, and the gas-liquid separation tank liquid level meter also outputs the acquired liquid level data signals to the programmable logic controller 2.

The top of the gas-liquid separation tank 17 is also provided with a gas pipeline 20, the gas pipeline 20 is provided with a gas-liquid separation tank exhaust valve 21, and exhausted gas enters a gas pipeline network system or oil-gas recovery equipment; an inlet pipeline of the gas-liquid separation tank 17 is provided with a gas-liquid separation tank inlet valve.

A control method of an automatic control system for unloading light oil from a tank car by using a rotary piston pump comprises the following control steps:

Firstly, an unloading electric valve 6 and an exhaust valve 21 of a gas-liquid separation tank are started, a rotary piston pump 16 is started to pump oil, when the liquid level in the gas-liquid separation tank 17 rises to reach a set high value, a centrifugal pump 18 and an electric valve 9 at the outlet of the centrifugal pump are automatically started after receiving a control instruction of a programmable logic controller, the liquid level in the gas-liquid separation tank 17 is kept stable, and a two-section liquid level probe 4 monitors the liquid level in a tank car in real time;

secondly, when the liquid level in the tank car is reduced to a first section probe of the two-section liquid level probe 4, entering a bin sweeping operation stage, outputting a control signal by the programmable logic controller 2 to automatically close the unloading line electric valve 6, opening the bin sweeping line electric valve 5 and the rotary piston pump oil supplementing pipe electric valve 11, and simultaneously outputting a control signal to the two variable frequency controllers 7 to synchronously reduce the frequency output of the rotary piston pump 16 and the centrifugal pump 18 so as to reduce the rotating speed of the pumps for bin sweeping operation;

and thirdly, when the liquid level is reduced to the second section of the two-section liquid level probe 4, the programmable logic controller 2 outputs control signals to automatically close the rotary piston pump 16, the bin sweeping electric valve 5 and the rotary piston pump oil supplementing pipe electric valve 11, and the bin sweeping operation is finished.

In the unloading process, the liquid level of the gas-liquid separation tank 17 is a control condition, if the liquid level in the gas-liquid separation tank 17 is higher than a set value, the output of the variable frequency controller 7 connected with the centrifugal pump 18 is increased, the rotating speed is accelerated, the opening of the electric valve 9 at the outlet of the centrifugal pump is increased, and the discharge capacity of the centrifugal pump 18 is increased; when the liquid level is lower than the set low value, the output of the variable frequency controller 7 is reduced, the rotating speed is reduced, the opening of the electric valve 9 at the outlet of the centrifugal pump is reduced, and the discharge capacity of the centrifugal pump 18 is correspondingly reduced; when it is lower than the set minimum value, the centrifugal pump 18 and the centrifugal pump outlet electro valve 9 are closed.

it is to be understood that the above description is not intended to limit the present invention, and the present invention is not limited to the above examples, and those skilled in the art may make modifications, alterations, additions or substitutions within the spirit and scope of the present invention.

It is to be understood that the above description is not intended to limit the present invention, and the present invention is not limited to the above examples, and those skilled in the art may make modifications, alterations, additions or substitutions within the spirit and scope of the present invention.