Automatic nitrogen protection system of buried methanol storage tank

Abstract

The utility model belongs to the technical field of automatic control, and particularly relates to an automatic nitrogen protection system of a buried methanol storage tank, which is characterized by comprising a nitrogen cylinder bundling device, a methanol storage tank, a nitrogen supply pipeline and a methanol output pipeline, the two methanol storage tanks and the two sets of nitrogen gas cylinder bundling devices form a switching loop controlled by a PLC (Programmable Logic Controller) through a nitrogen supply pipeline, the methanol storage tanks are connected with the nitrogen supply pipeline through tank side branches, the nitrogen gas cylinder bundling devices are connected with the nitrogen supply pipeline through collection side branches, and the two methanol storage tanks are respectively connected with methanol output pipelines. The device has the beneficial effects that the PLC control system is adopted, and the two paths of nitrogen sources are subjected to interlocking control, so that the timely switching of the pressure and the regulating valve is realized, and therefore, the problem of production stagnation caused by the fact that one path of nitrogen source is used up or the pressure is unstable and cannot be switched in time is solved, the continuous production is guaranteed, and the safety guarantee of the methanol storage tank is improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the automatic control technical field, especially relates to an automatic nitrogen protection system of buried methanol storage tank. BACKGROUND

[0002] Nitrogen is a kind of element formed by nitrogen, chemical formula N2.It is a kind of colorless and odorless gas at normal temperature and pressure, only under high temperature and high pressure and catalyst conditions can it react with hydrogen to generate ammonia, and under the condition of discharge, it can combine with oxygen to generate nitric oxide, even if Ca, Mg, Sr and Ba and other active metals can only react with it under heating condition.

[0003] The chemical property of nitrogen is very stable, generally does not react with other substances.This inert quality makes it can be widely used in many anaerobic environments, such as using nitrogen to displace the air in a specific container, plays the role of isolation, fire retardant, explosion-proof, anticorrosion, this technology is applied in light hydrocarbon device overhaul, LPG engineering, gas pipeline and liquefied gas pipe network purging and other industrial and civil aspects.Nitrogen can also be used as a cover gas in packaged processed food and medicine, seal cable, telephone line and pressurize inflatable rubber tires, etc.As a kind of anticorrosive agent, nitrogen is also replaced in the well to slow down the corrosion caused by the contact of pipe column and formation fluid.

[0004] When the buried methanol storage tank is protected by nitrogen, first, when the nitrogen source (nitrogen cylinder) is exhausted, the operator needs to manually close the exhausted nitrogen cylinder and replace the new one, which is very troublesome, sometimes the operator does not watch the pressure, resulting in gas supply interruption, and during the replacement process, the nitrogen source needs to be interrupted, which may cause the methanol storage tank to be without nitrogen protection for a short time, causing safety risk, second, the nitrogen pressure in the methanol storage tank is not accurate, which will cause the nitrogen pressure in the storage tank to be unstable, too high or too low, which will cause safety risk, therefore, it is necessary to develop a methanol storage tank nitrogen protection system which can automatically switch the gas source and automatically adjust the pressure. UTILITY MODEL CONTENT

[0005] The utility model aims at providing a kind of automatic nitrogen protection system of buried methanol storage tank, overcome the deficiency of prior art, adopt PLC control system to interlock control two-way nitrogen source, realize the switching of pressure and regulating valve, solve the problem of production stagnation caused by one-way nitrogen source exhaustion or unstable pressure and unable to switch in time, guarantee safety production.

[0006] To achieve the above object, the utility model realizes by the following technical scheme:

[0007] The application relates to an automatic nitrogen protection system for a buried methanol storage tank, which comprises a nitrogen cylinder cluster device, a methanol storage tank, a nitrogen supply pipeline and a methanol output pipeline, the methanol storage tank is connected with the nitrogen cylinder cluster device through the nitrogen supply pipeline, two sets of the nitrogen cylinder cluster device and the two methanol storage tanks are connected through the nitrogen supply pipeline to form a switching loop controlled by a PLC, the methanol storage tank is connected with the nitrogen supply pipeline through a tank side branch, the nitrogen cylinder cluster device is connected with the nitrogen supply pipeline through a cluster side branch, and each of the two methanol storage tanks is connected with the methanol output pipeline; the tank side branch comprises a first tank side branch and a second tank side branch, a one-way valve I, a low-pressure stop valve I, an electric regulating valve I and a high-pressure stop valve I are sequentially arranged on the first tank side branch, a pressure gauge I is connected to an outlet side branch of the electric regulating valve I, and the electric regulating valve I and the pressure gauge I are interlocked; a one-way valve II, a low-pressure stop valve II, an electric regulating valve II and a high-pressure stop valve II are sequentially arranged on the second tank side branch, a pressure gauge II is connected to an outlet side branch of the electric regulating valve II, and the electric regulating valve II and the pressure gauge II are interlocked; the cluster side branch comprises a first cluster side branch and a second cluster side branch, a high-pressure stop valve III, a pressure reducing valve I and a cut-off valve I are sequentially arranged on the first cluster side branch, a pressure gauge III is connected to an outlet side branch of the high-pressure stop valve III, and the cut-off valve I and the pressure gauge III are interlocked; a high-pressure stop valve IV, a pressure reducing valve II and a cut-off valve II are sequentially arranged on the second cluster side branch, a pressure gauge IV is connected to an outlet side branch of the high-pressure stop valve IV, and the cut-off valve II and the pressure gauge IV are interlocked.

[0008] Further, the two sets of nitrogen cylinder cluster devices are of the same specification, and the specification is matched with the volume of the two methanol storage tanks.

[0009] Further, a fire-resistant breather valve is arranged on the methanol output pipeline.

[0010] Further, the model of the PLC is S7-200.

[0011] Further, the pressure gauge I, the pressure gauge II, the pressure gauge III and the pressure gauge IV are all remote pressure gauges, the specification of the pressure gauge I and the pressure gauge II is 0-40kPa, and the specification of the pressure gauge III and the pressure gauge IV is 0-25MPa.

[0012] Further, the first tank side branch and the second tank side branch are respectively provided with emptying valves.

[0013] Further, the cluster side branch is connected with the nitrogen cylinder cluster device through a quick connector.

[0014] Compared with the prior art, the application has the following beneficial effects:

[0015] 1) using PLC control system to interlock control two-way nitrogen source, realizing timely switching of pressure and regulating valve, so as to solve the problem of production stagnation caused by failure to switch in time due to one-way nitrogen source being used up or unstable pressure, and guarantee continuous production;

[0016] 2) with remote pressure gauge monitoring function, which is conducive to realizing remote control and setting alarm loop in the control room, and further improving the safety guarantee of the methanol storage tank. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a structural schematic diagram of an embodiment of the utility model.

[0018] In the drawing: 1 - first nitrogen cylinder cluster device, 2 - second nitrogen cylinder cluster device, 3 - first methanol storage tank, 4 - second methanol storage tank, 5 - nitrogen supply pipeline, 6 - methanol output pipeline, 7 - first tank side branch, 8 - second tank side branch, 9 - one-way valve one, 10 - low-pressure stop valve one, 11 - electric regulating valve one, 12 - high-pressure stop valve one, 13 - one-way valve two, 14 - low-pressure stop valve two, 15 - electric regulating valve two, 16 - high-pressure stop valve two, 17 - first cluster side branch, 18 - second cluster side branch, 19 - high-pressure stop valve three, 20 - pressure reducing valve one, 21 - cut-off valve one, 22 - high-pressure stop valve four, 23 - pressure reducing valve two, 24 - cut-off valve two, 25 - flame arrestor breather valve, 26 - emptying valve, 31 - pressure gauge one, 32 - pressure gauge two, 33 - pressure gauge three, 34 - pressure gauge four, 35 - PLC controller. DETAILED DESCRIPTION

[0019] The technical solutions of the utility model will be described clearly and completely in combination with specific embodiments, obviously, the described embodiments are some embodiments of the utility model, rather than all the embodiments.

[0020] In order to more clearly illustrate the specific embodiments of the utility model or the technical solutions in the prior art, the specific embodiments needed in the specific embodiment or prior art description will be briefly introduced, obviously, the specific embodiments in the following description are some embodiments of the utility model, and other specific embodiments can also be obtained by those skilled in the art without creative labor.

[0021] The components of the embodiments of the utility model described and shown in the specific embodiments herein can be arranged and designed in countless different configurations. Therefore, the following detailed description of the embodiments of the utility model provided in the specific embodiments is not intended to limit the scope of the claimed utility model, but only represents selected embodiments of the utility model.

[0022] SeeFigure 1 is a buried methanol storage tank automatic nitrogen protection system embodiment structure schematic diagram, including first nitrogen cylinder cluster device 1, second nitrogen cylinder cluster device 2, first methanol storage tank 3, second methanol storage tank 4, nitrogen supply pipeline 5 and methanol output pipeline 6, first methanol storage tank 3, second methanol storage tank 4 are connected with first nitrogen cylinder cluster device 1, second nitrogen cylinder cluster device 2 by nitrogen supply pipeline 5, two methanol storage tanks and two sets of nitrogen cylinder cluster device are connected by nitrogen supply pipeline 5 and form switching loop controlled by PLC, methanol storage tank and nitrogen supply pipeline 5 are connected by tank side branch, nitrogen cylinder cluster device and nitrogen supply pipeline 5 are connected by cluster side branch, two methanol storage tanks are respectively connected with methanol output pipeline 6.

[0023] Tank side branch includes first tank side branch 7 and second tank side branch 8, one-way valve one 9, low-pressure stop valve one 10, electric regulating valve one 11 and high-pressure stop valve one 12 are sequentially arranged on the first tank side branch 7, the outlet side branch of electric regulating valve one 11 is connected with pressure gauge one 31, electric regulating valve one 11 and pressure gauge one 31 are interlocked controlled, pressure regulation is realized;Second tank side branch 8 is sequentially provided with one-way valve two 13, low-pressure stop valve two 14, electric regulating valve two 15 and high-pressure stop valve two 16, the outlet side branch of electric regulating valve two 15 is connected with pressure gauge two 32, electric regulating valve two 15 and pressure gauge two 32 are interlocked controlled, pressure regulation is realized.Electric regulating valve and pressure gauge are respectively arranged on the first tank side branch 7 and the second tank side branch 8, which are low-pressure stop valves, and the emptying valve 26 is located between the low-pressure stop valve and the electric regulating valve on each tank side branch.The function of emptying valve 26 is to close the front and rear valves and empty the nitrogen in the pipeline for the maintenance of electric regulating valve and the verification of pressure remote transmission.

[0024] Cluster side branch includes first cluster side branch 17 and second cluster side branch 18, high-pressure stop valve three 19, pressure reducing valve one 20 and cut-off valve one 21 are sequentially arranged on the first cluster side branch 17, the outlet side branch of high-pressure stop valve three 19 is connected with pressure gauge three 33, cut-off valve one 21 and pressure gauge three 33 are interlocked controlled, pressure regulation is realized;Second cluster side branch 18 is sequentially provided with high-pressure stop valve four 22, pressure reducing valve two 23 and cut-off valve two 24, the outlet side branch of high-pressure stop valve four 22 is connected with pressure gauge four 34, cut-off valve two 24 and pressure gauge four 34 are interlocked controlled, pressure regulation is realized.

[0025] Two sets of nitrogen cylinder cluster devices (1 and 2) are the same size, and the size is matched with the volume of two methanol storage tanks (3 and 4).Fire-resistant breather valve 25 is arranged on two methanol output pipelines 6.

[0026] The model of the PLC controller 35 is S7-200. The pressure gauges one 31, two 32, three 33 and four 34 are all remote pressure gauges. The specifications of the pressure gauges one and two are 0-40kPa, and the specifications of the pressure gauges three and four are 0-25MPa.

[0027] The branch pipes (5 and 6) are connected with the nitrogen cylinder cluster devices (1 and 2) through the quick connectors 30, so that the nitrogen cylinder cluster devices can be quickly disassembled and replaced.

[0028] The use method of the embodiment of the utility model is: 1) automatically switching gas source: two groups of full nitrogen cylinder cluster devices (1 and 2) are prepared and the outlet valves are opened, the interlocking values of the pressure gauges on each branch pipe and the corresponding cut-off valves are set through the PLC operation system, when the pressure is insufficient during the use of the nitrogen cylinder cluster device 1, the pressure gauge 31 detects that the pressure reaches the set value, the cut-off valve two 24 on the second branch pipe 6 where the nitrogen cylinder cluster device 2 is located is automatically opened, the nitrogen cylinder cluster device 1 is closed, the nitrogen cylinder cluster device 2 starts to supply gas, then the nitrogen cylinder cluster device 1 is replaced with full storage compartments, after the nitrogen in the nitrogen cylinder cluster device 2 is used up, the nitrogen cylinder cluster device 2 is automatically switched again, and the cycle is used. 2) automatically adjusting pressure: the interlocking values of the pressure gauges and the corresponding electric regulating valves are set through the PLC, the pressure value is detected through the pressure gauge, when the pressure is lower than the set value, the opening of the electric regulating valve is increased, when the pressure is higher than the set value, the opening of the electric regulating valve is reduced or closed; when the pressure is higher than the set pressure, the nitrogen is automatically discharged through the fire-resistant breather valve 20, when the pressure reaches the standard, the fire-resistant breather valve 20 is closed, so that the stable state of the methanol storage tank pressure is achieved.

[0029] Although the embodiments of the utility model have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the utility model, the scope of the utility model is defined by the appended claims and their equivalents.

Claims

1. An automatic nitrogen protection system for a buried methanol storage tank, characterized in that, The nitrogen cylinder cluster device, the methanol storage tank, the nitrogen supply pipeline and the methanol output pipeline are provided, the methanol storage tank is connected with the nitrogen cylinder cluster device through the nitrogen supply pipeline, two sets of the nitrogen cylinder cluster device and the methanol storage tank are connected through the nitrogen supply pipeline to form a switching circuit controlled by a PLC, the methanol storage tank is connected with the nitrogen supply pipeline through a tank branch, the nitrogen cylinder cluster device is connected with the nitrogen supply pipeline through a cluster branch, and the two methanol storage tanks are respectively connected with the methanol output pipeline; The tank branch includes a first tank branch and a second tank branch, the first tank branch is sequentially provided with a check valve one, a low-pressure stop valve one, an electric regulating valve one and a high-pressure stop valve one, the electric regulating valve one is connected with a pressure gauge one on an outlet side branch, and the electric regulating valve one and the pressure gauge one are interlocked controlled; the second tank branch is sequentially provided with a check valve two, a low-pressure stop valve two, an electric regulating valve two and a high-pressure stop valve two, the electric regulating valve two is connected with a pressure gauge two on an outlet side branch, and the electric regulating valve two and the pressure gauge two are interlocked controlled; The cluster branch includes a first cluster branch and a second cluster branch, the first cluster branch is sequentially provided with a high-pressure stop valve three, a pressure reducing valve one and a cut-off valve one, the high-pressure stop valve three is connected with a pressure gauge three on an outlet side branch, and the cut-off valve one and the pressure gauge three are interlocked controlled; the second cluster branch is sequentially provided with a high-pressure stop valve four, a pressure reducing valve two and a cut-off valve two, the high-pressure stop valve four is connected with a pressure gauge four on an outlet side branch, and the cut-off valve two and the pressure gauge four are interlocked controlled.

2. The automatic nitrogen protection system for a buried methanol tank according to claim 1, characterized in that, The two sets of the nitrogen cylinder cluster device are of the same specification, and the specification is matched with the volume of the two methanol storage tanks.

3. The automatic nitrogen protection system for a buried methanol tank according to claim 1, characterized in that, The methanol output pipeline is provided with a fire-resistant breather valve.

4. The automatic nitrogen protection system of a buried methanol storage tank according to claim 1, characterized in that, The model of the PLC is S7-200.

5. The automatic nitrogen protection system for a buried methanol tank according to claim 1, characterized in that, The pressure gauge one, the pressure gauge two, the pressure gauge three and the pressure gauge four are all remote pressure gauges, the specification of the pressure gauge one and the pressure gauge two is 0-40kPa, and the specification of the pressure gauge three and the pressure gauge four is 0-25MPa.

6. The automatic nitrogen protection system of a buried methanol storage tank according to claim 1, characterized in that, The first tank branch and the second tank branch are respectively provided with an emptying valve.

7. The automatic nitrogen protection system of a buried methanol storage tank according to claim 1, characterized in that, The cluster branch and the nitrogen cylinder cluster device are connected through a quick connector.

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