Nitrogen sealing device for heavy oil product tank field

Abstract

The utility model discloses a nitrogen sealing device for a heavy oil product tank field. The nitrogen sealing device for the heavy oil product tank area comprises a storage tank, a nitrogen sealing device and a nitrogen sealing device, an outlet of the nitrogen pipeline is formed in the top or the side portion of the storage tank, and a check valve, a pressure regulating valve and a first expanding pipe are sequentially arranged on the nitrogen pipeline in the flowing direction of nitrogen; the pressure measuring device is arranged at the top of the storage tank, the pressure measuring device comprises a detection part and an execution part which are connected, the detection part is communicated with the top of the storage tank to detect the pressure in the storage tank, and the execution part is in control connection with the pressure regulating valve to control the pressure in the storage tank within a preset range. According to the nitrogen sealing device for the heavy oil tank area, the opening degree of the pressure regulating valve is accurately and directly controlled through the tank top pressure, the situation that the check valve cannot be opened at low pressure is avoided, and the overflowing requirement of nitrogen behind the pressure regulating valve and the safety of a nitrogen pipeline are guaranteed.

Description

Technical Field

[0001] The present application relates to the technical field of coal chemical industry, and particularly relates to a nitrogen sealing device for a heavy oil product tank area. Background Art

[0002] Heavy oil is the remaining heavy oil after gasoline and diesel are extracted from crude oil. It is characterized by a large molecular weight and high viscosity. The specific gravity of heavy oil is generally between 0.82 and 0.95, and the calorific value is between 10,000 and 11,000 kcal / kg. Its main components are hydrocarbons, and it also contains some sulfur and trace inorganic compounds. At present, in the coal chemical oil product tank area, considering the environmental protection requirements and reducing the escape and volatilization loss of oil products during storage, the storage tanks will be nitrogen-sealed. The density of nitrogen is lower than that of oil and gas, and it floats on the oil and gas, forming a nitrogen seal protection between the medium and the tank top. When exhaling, the main gas exhaled outside the tank is nitrogen; when the pressure in the storage tank decreases, nitrogen automatically replenishes the gas space in the tank, reducing evaporation loss and at the same time avoiding the oxidation of oil products when contacting air.

[0003] At present, there is a situation in the oil product tank area where some heavy oil product storage tanks are blocked by crystallization of the nitrogen-sealed self-operated regulating valve, affecting the use of the nitrogen seal valve; at the same time, due to the use of low-pressure nitrogen seal (generally 0.2 - 0.5 KPa) for the storage tanks, the pressure measurement of the storage tanks at low pressure is not accurate enough, resulting in the regulating valve not being sensitive enough in response, and the storage pressure of the storage tanks cannot be stably controlled during the production process. In addition, for some storage tanks, since the nitrogen seal pressure tapping point is on the nitrogen seal pipeline, there is a certain deviation between the actual storage tank pressure and the measured pressure, resulting in the nitrogen seal valve not being sensitive enough in operation; at the same time, in order to prevent gas backflow, check valves are often installed in the nitrogen seal pipeline, and the check valve in the pipeline has an opening pressure (generally > 2 KPaG). The general design is to place the check valve close to the storage tank. However, in actual production, it is found that due to the low pressure behind the nitrogen seal valve, the nitrogen gas flow cannot open the check valve, resulting in the failure of the nitrogen seal of the storage tank; in actual production, it is also found that the pipeline after the nitrogen seal valve is not correspondingly enlarged in diameter, resulting in the rapid pressurization of nitrogen gas in the pipeline, which cannot ensure the safety of the pipeline, and the nitrogen gas cannot smoothly pass through the pipeline into the storage tank, affecting the nitrogen seal effect. Summary of the Utility Model

[0004] The purpose of the solution of the present application is to provide a nitrogen sealing device for a heavy oil product tank area, which accurately and directly controls the opening of the pressure regulating valve by the tank top pressure, and avoids the situation that the check valve cannot be opened under low pressure.

[0005] A nitrogen sealing device for a heavy oil storage tank provided by the technical solution of this application includes: a storage tank for storing heavy oil; a nitrogen pipeline, the outlet of which is arranged at the top or side of the storage tank, and a check valve, a pressure regulating valve and a first diameter-expanding pipe are sequentially arranged on the nitrogen pipeline along the flowing direction of nitrogen; a pressure measuring device, which is arranged at the top of the storage tank and includes a detection part and an execution part connected to each other. The detection part is communicated with the top of the storage tank to detect the pressure in the storage tank, and the execution part is connected to the pressure regulating valve in a control manner to control the pressure in the storage tank within a preset range.

[0006] Optionally, the nitrogen sealing device for the heavy oil storage tank further includes a bypass pipeline, which is connected in parallel to the nitrogen pipeline. A control valve is also arranged on the nitrogen pipeline. The pressure regulating valve and the control valve are connected in parallel to the nitrogen pipeline, and a stop valve is installed on the bypass pipeline.

[0007] Optionally, a flow-limiting orifice plate is further installed on the bypass pipeline, and the flow-limiting orifice plate is located downstream of the stop valve.

[0008] Optionally, a second diameter-expanding pipe is installed on the bypass pipeline, and the second diameter-expanding pipe is located downstream of the flow-limiting orifice plate.

[0009] Optionally, the stop valve is a manual control valve.

[0010] Optionally, a first pressure gauge is further installed on the nitrogen pipeline, and the first pressure gauge is located upstream of the check valve. The first pressure gauge is communicatively connected to the control end to transmit the detected pressure value to the control end for display.

[0011] Optionally, a second pressure gauge is further installed on the nitrogen pipeline, and the second pressure gauge is located downstream of the bypass pipeline.

[0012] Optionally, the storage tank is provided with a coil for heating the heavy oil.

[0013] Optionally, a breather valve is installed on the storage tank.

[0014] Optionally, the pressure regulating valve is a pneumatic pressure regulating valve.

[0015] Adopting the above technical solution, the following beneficial effects are achieved:

[0016] The nitrogen sealing device for heavy oil storage tanks provided by this application transports nitrogen into the storage tank through a nitrogen pipeline to achieve nitrogen sealing. The check valve is arranged upstream of the pressure regulating valve. The pressure at the position of the check valve on the nitrogen pipeline has not decreased and is relatively high, avoiding the situation where the check valve cannot be opened under low pressure and preventing the risk of nitrogen sealing failure. The pressure measuring device accurately and directly takes pressure from the top of the tank and controls the opening of the pressure regulating valve through the pressure value, increasing the adjustment accuracy. The nitrogen passing through the pressure regulating valve expands the size of the nitrogen pipeline through the first diameter-expanding pipe, ensuring that the inner diameter of the nitrogen pipeline downstream of the pressure regulating valve meets the over-flow requirements after the increase in nitrogen volume and ensuring the safety of the nitrogen pipeline. Description of the Drawings

[0017] Figure 1 It is a schematic structural diagram of the nitrogen sealing device for heavy oil storage tanks in an embodiment of this application.

[0018] Reference Numerals in the Drawings

[0019] 1 - Storage tank.

[0020] 2 - Nitrogen pipeline, 20 - Check valve, 21 - Pressure regulating valve, 22 - First diameter-expanding pipe, 23 - Control valve, 24 - First pressure gauge, 25 - Second pressure gauge.

[0021] 3 - Pressure measuring device, 30 - Detection part, 31 - Execution part.

[0022] 4 - Bypass pipeline, 40 - Shut-off valve, 41 - Flow-limiting orifice plate, 42 - Second diameter-expanding pipe.

[0023] 5 - Coiled pipe.

[0024] 6 - Breather valve. Detailed Embodiment

[0025] The following further describes the detailed embodiment of the present utility model with reference to the drawings.

[0026] It is easily understood that according to the technical solution of the present utility model, without changing the essence of the present utility model, there are various structural ways and implementation ways that can be mutually replaced by those of ordinary skill in the art. Therefore, the following detailed embodiment and drawings are only exemplary descriptions of the technical solution of the present utility model, and should not be regarded as the whole of the present utility model or as a limitation or restriction on the technical solution of the utility model.

[0027] The orientation terms such as up, down, left, right, front, back, front side, back side, top, bottom, etc. mentioned or possibly mentioned in this specification are defined relative to the structures shown in the respective drawings. They are relative concepts and may change accordingly depending on their different positions and usage states. Therefore, these or other orientation terms should not be construed as restrictive terms.

[0028] This application provides a nitrogen sealing device for a heavy oil product tank area, including: a storage tank 1, a nitrogen pipeline 2, and a pressure measuring device 3.

[0029] The storage tank 1 is used for storing heavy oil products. The outlet of the nitrogen pipeline 2 is arranged at the top or side of the storage tank 1, as Figure 1 shown. A check valve 20, a pressure regulating valve 21, and a first enlarged diameter pipe 22 are sequentially arranged on the nitrogen pipeline 2 along the flow direction of nitrogen. The pressure measuring device 3 is arranged at the top of the storage tank 1. The pressure measuring device 3 includes a detection part 30 and an execution part 31 which are connected. The detection part 30 (which can be connected through a pipeline, and a valve can be arranged on the pipeline) is communicated with the top of the storage tank 1 to detect the pressure in the storage tank 1, and the execution part 31 is connected to the pressure regulating valve 21 for control to control the pressure in the storage tank 1 within a preset range.

[0030] In the embodiment of this application, the pressure measuring device 3 is arranged at the top of the storage tank 1. When the top of the storage tank 1 is Figure 1 the arc-shaped top as shown, the pressure measuring device 3 is arranged at the exact center of the arc-shaped top or a position close to the exact center; when the top of the storage tank 1 is a flat top, the pressure measuring device 3 is arranged at any position on the flat top. In the embodiment of this application, the pressure taking of the nitrogen pipeline 2 in the prior art is changed to take pressure from the top of the storage tank 1 (taking the gas phase space pressure at the tank top), so as to accurately and directly control the opening of the pressure regulating valve 21 by the tank top pressure.

[0031] In the embodiment of this application, the preset pressure value in the storage tank 1 can be selected between 0.2 Kpa and 0.5 Kpa. When the pressure value measured by the detection part 30 is less than 0.2 Kpa, after receiving this pressure value, the execution part 31 controls the opening of the pressure regulating valve 21 to increase to increase the nitrogen supply amount and raise the pressure value in the storage tank 1. When the pressure value measured by the detection part 30 is greater than 0.5 Kpa, after receiving this pressure value, the execution part 31 controls the opening of the pressure regulating valve 21 to decrease to reduce the pressure value in the storage tank 1. The pressure regulating valve 21 in the embodiment of this application has a better pressure regulating effect in the working condition where high-viscosity media are prone to blockage compared with the self-acting regulating valve commonly used in the prior art.

[0032] In the embodiment of this application, the diameter of the first enlarged diameter pipe 22 at the upstream is larger than that at the downstream, so that the inner diameter of the nitrogen pipeline 2 connected downstream of the first enlarged diameter pipe 22 on the nitrogen pipeline 2 is larger than the inner diameter of the nitrogen pipeline 2 connected upstream of the first enlarged diameter pipe 22, ensuring that the inner diameter of the nitrogen pipeline 2 downstream of the pressure regulating valve 21 meets the over-flow demand after the nitrogen amount increases, ensuring the safety of the nitrogen pipeline 2, and realizing intrinsic safety while meeting the nitrogen sealing demand.

[0033] In the embodiment of the present application, the check valve 20 prevents the process medium gas in the storage tank 1 from flowing back into the nitrogen system, avoiding the mutual mixing of the media in each storage tank 1 and the risk of group tank fires. The check valve 20 is arranged upstream of the pressure regulating valve 21. The pressure at the position of the check valve 20 on the nitrogen pipeline 2 has not decreased and the pressure value is relatively large, avoiding the situation where the check valve 20 cannot be opened under low pressure and preventing the risk of nitrogen seal failure.

[0034] In the embodiment of the present application, nitrogen is transported into the storage tank 1 through the nitrogen pipeline 2 to achieve nitrogen seal. The check valve 20 is arranged upstream of the pressure regulating valve 21. The pressure at the position of the check valve 20 on the nitrogen pipeline 2 has not decreased and the pressure value is relatively large, avoiding the situation where the check valve 20 cannot be opened under low pressure and preventing the risk of nitrogen seal failure; the pressure measuring device 3 accurately and directly takes pressure from the top of the tank and controls the opening of the pressure regulating valve 21 through the pressure value, increasing the accuracy of regulation; the nitrogen after passing through the pressure regulating valve 21 expands the size of the nitrogen pipeline 2 through the first enlarged diameter pipe 22, ensuring that the inner diameter of the nitrogen pipeline 2 downstream of the pressure regulating valve 21 meets the flow-through requirements after the increase in nitrogen volume and ensuring the safety of the nitrogen pipeline 2.

[0035] In an alternative embodiment, the nitrogen seal device for the heavy oil product tank area further includes a bypass pipeline 4. The bypass pipeline 4 is connected in parallel to the nitrogen pipeline 2. A control valve 23 is also arranged on the nitrogen pipeline 2. The pressure regulating valve 21 and the control valve 23 are connected in parallel to the nitrogen pipeline 2. A stop valve 40 is installed on the bypass pipeline 4. In the embodiment of the present application, when the pressure regulating valve 21 fails and needs to be repaired, the stop valve 40 can be opened to achieve short-term nitrogen supply through the bypass pipeline 4, ensuring the nitrogen seal effect of the storage tank 1.

[0036] In an alternative embodiment, a flow-limiting orifice plate 41 is further installed on the bypass pipeline 4. The flow-limiting orifice plate 41 is located downstream of the stop valve 40. The flow-limiting orifice plate 41 in the embodiment of the present application plays a role in limiting the flow of nitrogen. Nitrogen enters the storage tank 1 after being limited in flow and reduced in pressure through the flow-limiting orifice plate 41 to achieve safe nitrogen seal. The flow-limiting orifice plate 41 is a single-stage flow-limiting orifice plate 41 or a multi-stage flow-limiting orifice plate 41. The flow-limiting orifice plate 41 can be a plate-like structure installed on the bypass pipeline 4 and provided with through holes. The flow-limiting orifice plate 41 can be single or at least two. At least two flow-limiting orifice plates 41 are arranged along the length direction of the bypass pipeline 4.

[0037] In an alternative embodiment, a second pipe expander 42 is installed on the bypass pipe 4, and the second pipe expander 42 is located downstream of the flow-limiting orifice plate 41. Similarly, the inner diameter of the bypass pipe 4 at the upstream of the second pipe expander 42 is larger than that at the downstream, so that the inner diameter of the bypass pipe 4 connected to the rear end of the second pipe expander 42 is larger than that of the bypass pipe 4 connected to the front end of the second pipe expander 42, ensuring that the inner diameter of the bypass pipe 4 downstream of the control valve 23 meets the over-flow demand after the nitrogen quantity increases, ensuring the safety of the bypass pipe 4 and achieving intrinsic safety.

[0038] In an alternative embodiment, the stop valve 40 is a manual control valve, which is convenient for the operator to accurately control the opening degree and avoid overpressure of the storage tank 1 caused by excessive nitrogen quantity allowed to pass through.

[0039] In an alternative embodiment, a first pressure gauge 24 is further installed on the nitrogen pipe 2. The first pressure gauge 24 is located upstream of the check valve 20, and the first pressure gauge 24 is communicatively connected to the control end to transmit the detected pressure value to the control end for display. The control end in the embodiment of the present application can be a remote PC terminal, and the PC terminal is provided with a display screen, and the display screen displays the pressure value on the nitrogen pipe 2 in real time, which is convenient for the operator to monitor the site in real time. As Figure 1 shown, the first pressure gauge 24 is connected to the nitrogen pipe 2 through a pipeline with a valve.

[0040] In an alternative embodiment, a second pressure gauge 25 is further installed on the nitrogen pipe 2. The second pressure gauge 25 is located downstream of the bypass pipe 4. The second pressure gauge 25 is close to the storage tank 1. When the bypass pipe 4 is opened, the operator visually observes the second pressure gauge 25 and reasonably controls the tank top pressure by manually adjusting the control valve 23 to avoid excessive nitrogen flushing into the storage tank 1 and causing overpressure of the storage tank 1. As Figure 1 shown, the second pressure gauge 25 is connected to the nitrogen pipe 2 through a pipeline with a valve.

[0041] In an alternative embodiment, the storage tank 1 is provided with a coil 5 for heating heavy oil products. The coil 5 in the embodiment of the present application is used to heat heavy oil products.

[0042] In an alternative embodiment, a breather valve 6 is installed on the storage tank 1. The breather valve 6 in the embodiment of the present application can discharge part of the nitrogen in time when the pressure in the storage tank 1 is too high, so that the pressure value in the storage tank 1 is within a suitable range and the safety of the storage tank 1 is ensured.

[0043] In an alternative embodiment, the pressure regulating valve 21 is a pneumatic pressure regulating valve 21. The pneumatic pressure regulating valve 21 is a pressure balancing regulating valve, adopting a single-seat and sleeve structure, and equipped with a multi-spring pneumatic diaphragm actuator. The actuator has a low height, light weight and is easy to install. The valve core of the pneumatic pressure regulating valve 21 adopts a cage-type sleeve valve core, which converts the air source pressure into the linear displacement of the valve core, automatically controls the opening of the regulating valve, and achieves continuous regulation of the pressure of the fluid in the pipeline. The pneumatic pressure regulating valve 21 does not require other external energy sources such as power sources and air sources, and is driven only by the energy of the medium itself. It is intrinsically safe and does not require additional explosion-proof measures.

[0044] According to needs, the above technical solutions can be combined to achieve the best technical effect.

[0045] The above are only the principles and preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, based on the principle of the present invention, several other variants can also be made, which should also be regarded as the protection scope of the present invention.

Claims

1. A nitrogen sealing device for a heavy oil storage tank area, characterized in that Comprising: A storage tank for storing heavy oil products; A nitrogen pipeline, the outlet of which is arranged at the top or side of the storage tank, and a check valve, a pressure regulating valve and a first diameter-expanding pipe are successively arranged on the nitrogen pipeline along the flowing direction of nitrogen; A pressure measuring device arranged at the top of the storage tank, the pressure measuring device comprises a detection part and an execution part which are connected, the detection part is communicated with the top of the storage tank to detect the pressure in the storage tank, and the execution part is in control connection with the pressure regulating valve to control the pressure in the storage tank within a preset range.

2. The nitrogen sealing device for heavy oil product storage tank according to claim 1, characterized in that, The nitrogen sealing device for the heavy oil product tank area further comprises a bypass pipeline which is connected in parallel to the nitrogen pipeline, a control valve is further arranged on the nitrogen pipeline, the pressure regulating valve and the control valve are connected in parallel to the nitrogen pipeline, and a stop valve is installed on the bypass pipeline.

3. The nitrogen sealing device for heavy oil product storage tank according to claim 2, characterized in that, A flow-limiting orifice plate is further installed on the bypass pipeline, and the flow-limiting orifice plate is located downstream of the stop valve.

4. The nitrogen sealing device for heavy oil product tank farm according to claim 3, wherein, A second diameter-expanding pipe is installed on the bypass pipeline, and the second diameter-expanding pipe is located downstream of the flow-limiting orifice plate.

5. The nitrogen sealing device for heavy oil product storage tank according to claim 2, characterized in that, The stop valve is a manual control valve.

6. The nitrogen sealing device for heavy oil product storage tank according to claim 1, characterized in that, A first pressure gauge is further installed on the nitrogen pipeline, the first pressure gauge is located upstream of the check valve, and the first pressure gauge is in communication connection with a control end to transmit the detected pressure value to the control end for display.

7. The nitrogen sealing device for heavy oil product storage tank according to claim 2, characterized in that, A second pressure gauge is further installed on the nitrogen pipeline, and the second pressure gauge is located downstream of the bypass pipeline.

8. The nitrogen sealing device for heavy oil product storage tank according to any one of claims 1-7, characterized in that, The storage tank is provided with a coil for heating the heavy oil products.

9. The nitrogen sealing device for heavy oil product tank farm according to any one of claims 1-7, characterized in that, A breathing valve is installed on the storage tank.

10. The nitrogen sealing device for heavy oil product tank farm according to any one of claims 1-7, characterized in that, The pressure regulating valve is a pneumatic pressure regulating valve.

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