Combustible liquid loading backflow protection system

Abstract

The utility model relates to a combustible liquid loading backflow protection system which comprises an oil product bus connected with an outlet of a tank field and a backflow bus connected with a backflow opening of the tank field, and the oil product bus is connected with a plurality of oil product branch lines. Each oil product branch line is sequentially connected with an operating valve, a flow meter, a mass flow meter, a pressure gauge, an interlocking stop valve and a crane pipe in the liquid flowing direction, each oil product branch line is communicated with a backflow branch line, and each backflow branch line is sequentially connected with a check valve, a second service valve, a backflow adjusting valve and a first service valve in the liquid flowing direction. And an oil outlet of the backflow branch line is communicated with the backflow bus. According to the utility model, static accumulation caused by too fast flow speed is effectively avoided; and when the time exceeds the set threshold value for a long time, oil flowing can be automatically suspended, and it is ensured that the wind direction generated by static electricity is reduced to the minimum.

Description

Technical Field

[0001] The utility model belongs to the technical field of oil and chemical storage and transportation, and particularly relates to a return protection system for combustible liquid loading. Background Art

[0002] In the operation of combustible liquid loading, static electricity protection is the cornerstone to ensure safe operation. Especially in the process of oil product handling, there are many limitations in the traditional loading system in terms of flow rate control and static electricity management. For example, too high an oil product flow rate is one of the main reasons for static electricity accumulation, which not only increases the risks of fire and explosion, but also may cause equipment damage or personal injury due to sudden static electricity discharge. Summary of the Utility Model

[0003] To solve the problems of the existing technology, the utility model provides a return protection system for combustible liquid loading to solve the problem of static electricity accumulation caused by too high an oil product flow rate at present.

[0004] The purpose of the utility model and the solution to its technical problems are achieved by adopting the following technical solutions. A return protection system for combustible liquid loading according to the utility model includes an oil product main line connected to the outlet of the tank farm and a return main line connected to the return port of the tank farm. The oil product main line is connected with a plurality of oil product branch lines. Along the liquid flow direction, the oil product branch lines are sequentially connected with an operation valve, a flow meter, a mass flow meter, a pressure gauge, an interlock cut-off valve and a loading arm. Each of the oil product branch lines is communicated with a return branch line. Along the liquid flow direction, the return branch line is sequentially connected with a check valve and a return regulating valve. The outlet of the return branch line is communicated with the return main line. The flow meter and the return regulating valve are interlock controlled, and the flow meter, the mass flow meter and the interlock cut-off valve are level interlock controlled.

[0005] Further, a flow-limiting orifice plate is arranged in the oil product branch line, and the flow-limiting orifice plate is arranged between the flow meter and the mass flow meter.

[0006] The beneficial effect is that the flow-limiting orifice plate is used to stabilize the oil product flow rate in the oil product branch line, so as to facilitate the oil product flow rate to be stabilized at the set value.

[0007] Further, a standby line is also arranged on the return branch line, and a standby line valve is arranged on the standby line.

[0008] Further, a second maintenance valve is arranged at the inlet end of the return regulating valve, and a first maintenance valve is arranged at the outlet end.

[0009] Further, a liquid level probe is arranged on the loading arm.

[0010] Further, an oil product line cut-off valve is arranged at the inlet of the oil product main line, and a return line cut-off valve is arranged at the outlet of the return main line.

[0011] In summary, the utility model is provided with a flowmeter and a mass flowmeter to monitor the oil flow rate in the pipeline in real time and conduct real-time data feedback. When the flow rate exceeds the set threshold, the system automatically controls the oil flow rate through the diversion of the return branch line to keep it within the safe range, effectively avoiding the accumulation of static electricity caused by too fast flow rate. When the time exceeding the set threshold is relatively long, the oil flow can be automatically paused to ensure that the risk of static electricity generation is minimized. At the same time, a standby line is set up to always keep the return branch line in a flowing state, avoiding the inability to adjust the flow rate through the return branch line when the return regulating valve needs to be repaired or is damaged.

[0012] The above description is only an overview of the technical solution of the utility model. In order to understand the technical means of the utility model more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the utility model more obvious and understandable, the following specific preferred embodiments are given and described in detail in conjunction with the accompanying drawings as follows. Brief Description of the Drawings

[0013] Figure 1 It is a schematic structural diagram of the utility model.

[0014] Figure 2 It is a schematic diagram of a choke orifice plate. Detailed Description of the Preferred Embodiment

[0015] The following further describes the technical solution of the utility model in conjunction with the accompanying drawings and the preferred embodiments.

[0016] An embodiment of a return protection system for loading combustible liquids:

[0017] As Figure 1, a combustible liquid loading reflux protection system, which includes an oil product main line 1 connected to the tank farm outlet and a reflux main line 3 connected to the tank farm reflux port. An oil product line cut-off valve 2 is provided at the inlet of the oil product main line 1, and a reflux line cut-off valve 4 is provided at the outlet of the reflux main line 3. The oil product cut-off valve 2 and the reflux cut-off valve 4 are in an open state. The oil product main line 1 is connected with multiple oil product branch lines 5 (four oil product branch lines 5 in this embodiment). Along the liquid flow direction on the oil product branch line 5, an operation valve 6, a flowmeter 11, a mass flowmeter 17, a pressure gauge 18, an interlock cut-off valve 19 and a loading arm 8 are sequentially connected. The mass flowmeter 17 and the interlock cut-off valve 19 are under interlock control (that is, the mass flowmeter 17 is electrically connected to the controller, the controller is electrically connected to the interlock cut-off valve 19, and the controller controls the opening and closing of the interlock cut-off valve 19 according to the signal transmitted by the mass flowmeter 17). Each oil product branch line 5 is communicated with a reflux branch line 9, and the connection point of the reflux branch line 9 and the oil product branch line 5 is located between the operation valve 6 and the flowmeter 11. Along the liquid flow direction on the reflux branch line 9, a check valve 12, a second maintenance valve 14, a reflux regulating valve 10 and a first maintenance valve 13 are sequentially connected. The flowmeter 11, the mass flowmeter 17 and the reflux regulating valve 10 are under interlock control (that is, the flowmeter 11 is electrically connected to the controller, the reflux regulating valve 10 is electrically connected to the controller, and the controller controls the opening and closing of the reflux regulating valve 10 according to the signals transmitted by the flowmeter 11 and the reflux regulating valve 17). A standby line 16 is also provided on the reflux branch line 9, and the first connection point of the standby line 16 and the reflux branch line 9 is located between the check valve and the second maintenance valve 14, and the second connection point is located behind the first maintenance valve. A standby line valve 15 is provided on the standby line 16;

[0018] The flowmeter 11, the mass flowmeter 17, the pressure gauge 18, the interlock cut-off valve 19 and the loading arm 8 are conventional equipment and will not be described.

[0019] In this embodiment, a flow-limiting orifice plate 7 is provided in the oil product branch line 5. The flow-limiting orifice plate 7 is provided between the flowmeter 11 and the mass flowmeter 17. The limiting orifice plate 7 is in a circular plate structure. An installation hole is provided at the center of the limiting orifice plate 7, and several flow-limiting holes are provided around the installation hole. The flow-limiting holes are distributed in a circumferential manner. The limiting orifice plate 7 can inhibit the oil product flow rate. When the flowmeter 11 emits a signal and the mass flowmeter 17 does not emit a signal, the oil product flow rate does not need to be adjusted.

[0020] In this embodiment, a liquid level probe 20 is provided on the loading arm 8.

[0021] The working process of this embodiment: When one pump corresponds to multiple loading positions, the oil product enters the oil product branch line 5 through the oil product main line 1. When it is detected that the flowmeter 11 and the mass flowmeter 17 do not exceed the set value, the reflux regulating valve 10 is in a closed state, and the oil product is finally loaded through the loading arm 8;

[0022] When it is detected that both the flowmeter 11 and the mass flowmeter 17 exceed the set value, a signal will be sent to the reflux regulating valve 10, and the reflux regulating valve 10 will automatically open. The oil product will flow through the reflux branch line 9 and the reflux main line 3 to the tank farm. At the same time, the orifice plate 7 acts as an auxiliary to keep the oil flow rate in the oil product branch line 5 stable at the set value. If the values of the flowmeter 11 and the mass flowmeter 17 still exceed the set value and the time exceeds 5 minutes, the mass flowmeter 17 will send a signal to the interlock cut-off valve 19 to stop loading the vehicle;

[0023] Under normal circumstances, the first maintenance valve 13 and the second maintenance valve 14 are in the normally open state. When the reflux regulating valve 10 is damaged or being repaired, the two maintenance valves are closed, and at the same time, the bypass valve 15 is opened, and the bypass line 16 replaces the reflux branch line 9 to work.

[0024] The above are only the preferred embodiments of the present invention. Any person skilled in the art, without departing from the scope of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A flammable liquid loading reflux protection system, comprising an oil product main line (1) connected to the tank farm outlet and a reflux main line (3) connected to the tank farm reflux port, characterized in that: The oil product main line (1) is connected with a plurality of oil product branch lines (5). Along the liquid flow direction, the oil product branch lines (5) are sequentially connected with an operation valve (6), a flowmeter (11), a mass flowmeter (17), a pressure gauge (18), an interlock cut-off valve (19) and a loading arm (8). A reflux branch line (9) is communicated with each oil product branch line (5). Along the liquid flow direction, the reflux branch line (9) is sequentially connected with a check valve (12) and a reflux regulating valve (10). The oil outlet of the reflux branch line (9) is communicated with the reflux main line (3). The flowmeter (11) and the reflux regulating valve (10) are in interlock control, and the flowmeter (11), the mass flowmeter (17) and the interlock cut-off valve (19) are also in interlock control.

2. The flammable liquid loading reflux protection system according to claim 1, characterized in that: A choke orifice plate (7) is arranged in the oil product branch line (5), and the choke orifice plate (7) is arranged between the flowmeter (11) and the mass flowmeter (17).

3. The combustible liquid loading reflux protection system according to claim 1, characterized in that: A standby line (16) is further arranged on the reflux branch line (9), and a standby line valve (15) is arranged on the standby line (16).

4. A flammable liquid loading reflux protection system according to claim 1, characterized in that: A second maintenance valve (14) is arranged at the inlet end of the reflux regulating valve (10), and a first maintenance valve (13) is arranged at the outlet end.

5. The flammable liquid loading reflux protection system according to claim 1, wherein: A liquid level probe (20) is arranged on the loading arm (8).

6. The flammable liquid loading reflux protection system according to claim 1, wherein: An oil product line cut-off valve (2) is arranged at the oil inlet of the oil product main line (1), and a reflux line cut-off valve (4) is arranged at the oil outlet of the reflux main line (3).

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