Liquefied gas filling constant-pressure backflow system

Abstract

The utility model relates to the technical field of liquefied gas filling, and discloses a liquefied gas filling constant-pressure backflow system which comprises a liquid storage tank, the liquid storage tank is connected with a liquid inlet pipe and a hydrocarbon pump liquid suction pipe, the other end of the hydrocarbon pump liquid suction pipe is connected with a hydrocarbon pump, the hydrocarbon pump is connected with a hydrocarbon pump liquid discharge pipe, the tail end of the hydrocarbon pump liquid discharge pipe is connected with a filling table, and the filling table is used for filling liquefied gas bottles. The system further comprises a regulating valve, a pressure transmitter and a controller, the altitude of the regulating valve is higher than that of the filling table, the inlet end of the regulating valve is connected to the tail end of the hydrocarbon pump liquid discharge pipe, the outlet end of the regulating valve is connected with a main liquid return pipe through a pipeline, and the main liquid return pipe is communicated with the liquid inlet pipe. The pressure transmitter is arranged on the hydrocarbon pump liquid discharge pipe, a pressure sensing signal line is arranged between the pressure transmitter and the controller, and a valve control signal line and a valve feedback signal line are further arranged between the adjusting valve and the controller. The liquefied gas filling constant-pressure backflow system has the advantages of automatically exhausting gas to eliminate gas resistance and automatically stabilizing pressure, dividing and filling.

Description

Technical Field

[0001] The utility model relates to the technical field of liquefied gas filling, in particular to a liquefied gas filling constant pressure reflux system. Background Art

[0002] Liquefied gas filling refers to the process of filling liquefied gas into liquefied gas cylinders through specific equipment and processes. Liquefied gas is usually first stored in a liquid storage tank or a water-buried tank, and then the liquefied gas is passed into the filling station through a hydrocarbon pump, and then the liquefied gas is filled into each liquefied gas cylinder through multiple filling guns. However, the liquefied gas filling industry has the following characteristics:

[0003] 1. Liquefied gas / propane, which will vaporize at high temperatures, and the gas will accumulate in the pipeline;

[0004] 2. The underground tank / storage tank is low, the hydrocarbon pump is high, and the filling platform is even higher, so the gas will gather at high places;

[0005] 3. Hydrocarbon pumps / screw pumps basically stop working when encountering gas;

[0006] 4. When the liquid enters the bottle, the high pressure will liquefy the gas in the bottle. However, the gas cannot be liquefied once it enters the bottle, which means that the liquefied gas cannot be filled in. This is called gas resistance.

[0007] The conventional practice in the prior art is to connect the hydrocarbon pump return pipe to the hydrocarbon pump discharge pipe and perform reflux through manually controlled switches. This method cannot solve the gas problem of the filling station. In actual production, the gas problem is mainly solved by manually exhausting the gas toward the sky. However, there is another problem. The hydrocarbon pump has a stable output, but the bottles are not fixed. If a few bottles are suddenly full, the liquid with nowhere to go will impact the equipment and pipelines. It is also impossible to manually control the size of the switch, and the pressure is unstable. Utility Model Content

[0008] 1. Technical issues to be resolved

[0009] In view of the deficiencies in the prior art, the utility model provides a liquefied gas filling constant pressure reflux system, which has the advantages of automatic exhaust to eliminate gas blockage and automatic pressure-stabilizing shunt filling, solving the problems of gas blockage and pressure instability during the prior art liquefied gas filling.

[0010] (II) Technical solution

[0011] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0012] A liquefied gas filling constant pressure reflux system, comprising a liquid storage tank for storing liquefied gas, wherein the inlet and outlet of the liquid storage tank are respectively connected with a liquid inlet pipe and a hydrocarbon pump liquid suction pipe, the other end of the hydrocarbon pump liquid suction pipe is connected to the inlet of the hydrocarbon pump, the outlet of the hydrocarbon pump is connected to the hydrocarbon pump liquid discharge pipe, the end of the hydrocarbon pump liquid discharge pipe is connected to a filling platform, a plurality of filling guns for filling liquefied gas cylinders are arranged on the filling platform, and also comprises a regulating valve, a pressure transmitter and a controller, the regulating valve is at an altitude higher than the filling platform, the inlet end of the regulating valve is connected to the end of the hydrocarbon pump liquid discharge pipe through a pipeline, the outlet end of the regulating valve is connected to a main liquid return pipe through a pipeline, and the main liquid return pipe is connected to the liquid inlet pipe;

[0013] The pressure transmitter is arranged on the hydrocarbon pump discharge pipe, and a pressure sensing signal line for transmitting the pipeline pressure signal is arranged between the pressure transmitter and the controller. A valve control signal line for transmitting the valve control signal and a valve feedback signal line for transmitting the valve status signal are also arranged between the regulating valve and the controller. The valve feedback signal line converts the opening and closing state of the regulating valve into an electrical signal and transmits it to the controller. The controller controls the regulating valve in real time through the valve control signal line according to the pressure signal transmitted by the pressure sensing signal line and the valve status signal transmitted by the valve feedback signal line.

[0014] Preferably, the end of the hydrocarbon pump discharge pipe is connected to the main return pipe, and an emergency exhaust valve is provided between the hydrocarbon pump discharge pipe and the main return pipe, and the emergency exhaust valve is used to control the safe pressure relief reflux when the system fails.

[0015] Preferably, artificial valves are provided before and after the regulating valve to facilitate closing when the regulating valve fails or needs maintenance.

[0016] Preferably, a hydrocarbon pump reflux pipe is provided at the outlet end of the hydrocarbon pump or at one end of the hydrocarbon pump discharge pipe close to the hydrocarbon pump, the other end of the hydrocarbon pump reflux pipe is connected to the liquid inlet pipe, a safety valve is provided on the hydrocarbon pump reflux pipe, and the hydrocarbon pump reflux pipe is retained as the original reflux channel on the hydrocarbon pump.

[0017] Preferably, a mechanical pressure gauge is also provided at the end of the hydrocarbon pump discharge pipe, and the mechanical pressure gauge is convenient for manual direct observation of the pressure index.

[0018] Preferably, the controller is connected to an external power supply, and the controller is connected to a central control terminal wirelessly or by wire. The controller sends an alarm to the central control terminal when the pressure or valve is abnormal.

[0019] Preferably, the liquid storage tank is a water-buried tank, and the liquid storage tank is installed underground.

[0020] (III) Beneficial effects

[0021] Compared with the prior art, the utility model provides a liquefied gas filling constant pressure reflux system, which has the following beneficial effects:

[0022] 1. The liquefied gas filling constant pressure reflux system is connected to the main return liquid pipe by setting a regulating valve at the end of the hydrocarbon pump discharge pipe. In the preparation stage, the regulating valve is fully opened to discharge all the gas in the pipeline into the liquid storage tank through the regulating valve, the main return liquid pipe and the liquid inlet pipe in sequence, thereby eliminating the gas in the pipeline and avoiding the formation of gas blockage, making the filling of liquefied gas more efficient and convenient.

[0023] 2. The liquefied gas filling constant pressure reflux system sets the regulating valve at a higher altitude than the filling platform, so that the gas in the hydrocarbon pump discharge pipe is first gathered in the regulating valve at a higher altitude, so that the regulating valve can be fully opened during normal filling or in the preparation stage to discharge all the gas in the pipeline into the liquid storage tank, avoiding gas accumulation in the filling platform to form air blockage.

[0024] 3. The liquefied gas filling constant pressure reflux system is equipped with a pressure transmitter at the end of the hydrocarbon pump discharge pipe. The controller controls the regulating valve according to the pressure detected by the pressure transmitter. When multiple liquefied gas cylinders are filled at the filling station, the pressure transmitter detects a decrease in the pressure in the pipeline and automatically controls the regulating valve switch to reduce the opening, thereby increasing the filling pressure. When the number of liquefied gas cylinders filled at the filling station decreases, the pressure transmitter detects an increase in the pipeline pressure, and the controller controls the regulating valve to increase the opening, thereby reducing the filling pressure, thereby achieving stable pressure when filling different numbers of liquefied gas cylinders by diversion. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The figure is a schematic diagram of the process structure of liquefied gas filling in the prior art.

[0026] Figure 2 It is a schematic diagram of the process of the liquefied gas filling constant pressure reflux system in the first embodiment of the present utility model.

[0027] Figure 3 The utility model is a partial flow chart of the controller part of the liquefied gas filling constant pressure reflux system.

[0028] In the figure: 11, liquid storage tank; 12, hydrocarbon pump; 13, filling station; 14, liquefied gas cylinder;

[0029] 21. Regulating valve; 22. Pressure transmitter; 23. Controller; 24. Central control terminal; 25. Power supply; 26. Mechanical pressure gauge; 27. Emergency exhaust valve;

[0030] 71. Pressure sensor signal line; 81. Valve feedback signal line; 82. Valve control signal line;

[0031] 91. Liquid inlet pipe; 92. Hydrocarbon pump liquid suction pipe; 93. Hydrocarbon pump liquid discharge pipe; 94. Main liquid return pipe; 95. Hydrocarbon pump reflux pipe. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0033] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0034] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0035] Embodiment 1:

[0036] This embodiment provides a liquefied gas filling constant pressure reflux system having the following technical features.

[0037] Please refer to Figure 1-3 A liquefied gas filling constant pressure reflux system, comprising a liquid storage tank 11 for storing liquefied gas, wherein the inlet and outlet of the liquid storage tank 11 are respectively connected with a liquid inlet pipe 91 and a hydrocarbon pump liquid suction pipe 92, the other end of the hydrocarbon pump liquid suction pipe 92 is connected to the inlet of the hydrocarbon pump 12, the outlet of the hydrocarbon pump 12 is connected to a hydrocarbon pump liquid discharge pipe 93, the end of the hydrocarbon pump liquid discharge pipe 93 is connected to a filling platform 13, a plurality of filling guns for filling liquefied gas cylinders 14 are arranged on the filling platform 13, and a regulating valve 21, a pressure transmitter 22 and a controller 23 are also included, the regulating valve 21 is at an altitude higher than the filling platform 13, the inlet end of the regulating valve 21 is connected to the end of the hydrocarbon pump liquid discharge pipe 93 through a pipeline, the outlet end of the regulating valve 21 is connected to a main liquid return pipe 94 through a pipeline, and the main liquid return pipe 94 is connected to the liquid inlet pipe 91;

[0038] The pressure transmitter 22 is arranged on the hydrocarbon pump discharge pipe 93. A pressure sensing signal line 71 for transmitting the pipeline pressure signal is arranged between the pressure transmitter 22 and the controller 23. A valve control signal line 82 for transmitting the valve control signal and a valve feedback signal line 81 for transmitting the valve status signal are also arranged between the regulating valve 21 and the controller 23. The valve feedback signal line 81 converts the valve opening and closing state of the regulating valve 21 into an electrical signal and transmits it to the controller 23. The controller 23 controls the regulating valve 21 in real time through the valve control signal line 82 according to the pressure signal transmitted by the pressure sensing signal line 71 and the valve status signal transmitted by the valve feedback signal line 81.

[0039] Further settings, such as Figure 2-3 As shown, the liquid inlet pipe 91 is used to fill the liquid storage tank 11 with liquefied gas, and the liquid inlet pipe 91 is also used to discharge other refluxed liquefied gas back into the liquid storage tank 11.

[0040] In an optional embodiment, if Figure 2-3 As shown, the end of the hydrocarbon pump discharge pipe 93 is connected to the main return pipe 94, and an emergency exhaust valve 27 is provided between the hydrocarbon pump discharge pipe 93 and the main return pipe 94. The emergency exhaust valve 27 is used to control the safe pressure relief reflux when the system fails.

[0041] In an optional embodiment, if Figure 2-3 As shown, artificial valves are provided before and after the regulating valve 21 to facilitate closing when the regulating valve 21 fails or is under maintenance.

[0042] In an optional embodiment, if Figure 2-3 As shown, a hydrocarbon pump reflux pipe 95 is provided at the outlet of the hydrocarbon pump 12 or at one end of the hydrocarbon pump discharge pipe 93 close to the hydrocarbon pump 12 , and the other end of the hydrocarbon pump reflux pipe 95 is connected to the liquid inlet pipe 91 . A safety valve is provided on the hydrocarbon pump reflux pipe 95 .

[0043] It should be noted that the hydrocarbon pump reflux pipe 95 is retained as the original reflux passage of the hydrocarbon pump 12 .

[0044] In an optional embodiment, if Figure 2-3 As shown, a mechanical pressure gauge 26 is also provided at the end of the hydrocarbon pump discharge pipe 93. The mechanical pressure gauge 26 is convenient for manual direct observation of the pressure index.

[0045] It should be noted that the mechanical pressure gauge 26 and the pressure transmitter 22 are both arranged on the hydrocarbon pump discharge pipe 93 at the end position close to the filling station 13 .

[0046] In an optional embodiment, if Figure 2-3 As shown, the controller 23 is connected to an external power supply 25, and the controller 23 is connected to a central control terminal 24 wirelessly or by wire.

[0047] It should be noted that the central control terminal 24 displays the pipeline pressure in the hydrocarbon pump discharge pipe 93 and the opening and closing status of the regulating valve 21 in real time. The regulating valve 21 can also be remotely controlled to open and close at a scheduled time on the central control terminal 24. The controller 23 sends an alarm to the central control terminal 24 when the pressure or valve is abnormal.

[0048] In an optional embodiment, if Figure 2-3 As shown, the liquid storage tank 11 is an underground tank, and the liquid storage tank 11 is installed underground.

[0049] In an optional embodiment, if Figure 2-3 As shown, the diameter of the air pipe used by the regulating valve 21 is 8 mm.

[0050] In an optional embodiment, if Figure 2-3 As shown, three-way valves are provided between the hydrocarbon pump discharge pipe 93 and the hydrocarbon pump return pipe 95, between the hydrocarbon pump discharge pipe 93 and the regulating valve 21, between the regulating valve 21 and the main return pipe 94, between the main return pipe 94 and the liquid inlet pipe 91, and between the hydrocarbon pump return pipe 95 and the liquid inlet pipe 91 for connection.

[0051] Working principle: After standing for one night, the gas will gather upwards. At noon, when the temperature is high, the gas will also gather upwards. Once it is stuck and cannot be filled, new gas will be generated at the hydrocarbon pump, forming a vicious cycle, so exhaust is required in the morning and at noon. When preparing, the regulating valve 21 is automatically fully opened to allow the liquid to circulate and thoroughly clean the gas in the pipeline. It saves trouble and does not waste. The key is that it is not dangerous if it is not empty. When it is officially used, it will automatically divert and adjust the pressure according to the pipeline pressure detected by the pressure transmitter 22, which is particularly friendly to the pipeline / equipment. Electrically: it relies on the feedback of the filling pressure and PID adjusts the switch of the reflux valve. In terms of technology: it is to send the excess gas back to the storage tank. The regulating valve 21 is set at a position higher than the filling station 13. Since the gas flows upward, the other will not gather in the filling station 13, and will be discharged from the regulating valve 21 to the main return liquid pipe 94 to avoid the formation of gas blockage.

[0052] To summarize, the liquefied gas filling constant pressure reflux system is configured to connect the regulating valve 21 at the end of the hydrocarbon pump discharge pipe 93 to the main return pipe 94. In the preparation stage, the regulating valve 21 is fully opened to discharge all the gas in the pipeline into the liquid storage tank 11 through the regulating valve 21, the main return pipe 94 and the liquid inlet pipe 91 in sequence, thereby eliminating the gas in the pipeline and avoiding gas blockage, making the filling of liquefied gas more efficient and convenient.

[0053] The liquefied gas filling constant pressure reflux system sets the regulating valve 21 at a position with a higher altitude than the filling platform 13, so that the gas in the hydrocarbon pump discharge pipe 93 is first gathered in the regulating valve 21 at a higher altitude, so that the regulating valve 21 can be fully opened during normal filling or in the preparation stage to discharge all the gas in the pipeline into the liquid storage tank 11, thereby avoiding the gas from gathering in the filling platform 13 to form air blockage.

[0054] The liquefied gas filling constant pressure reflux system is configured by arranging a pressure transmitter 22 at the end of the hydrocarbon pump discharge pipe 93. The controller 23 controls the regulating valve 21 according to the pressure detected by the pressure transmitter 22. When a plurality of liquefied gas cylinders 14 are filled at the filling station 13, the pressure transmitter 22 detects a decrease in the pressure in the pipeline and automatically controls the regulating valve 21 to reduce its opening, thereby increasing the filling pressure. When the number of liquefied gas cylinders 14 filled at the filling station 13 decreases, the pressure transmitter 22 detects a rise in the pipeline pressure and the controller 23 controls the regulating valve 21 to increase its opening, thereby reducing the filling pressure and achieving stable pressure when filling different numbers of liquefied gas cylinders 14 by diversion.

[0055] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0056] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A liquefied gas filling constant pressure reflux system, comprising a liquid storage tank (11) for storing liquefied gas, wherein the inlet and outlet of the liquid storage tank (11) are respectively connected to a liquid inlet pipe (91) and a hydrocarbon pump liquid suction pipe (92), the other end of the hydrocarbon pump liquid suction pipe (92) is connected to the inlet of a hydrocarbon pump (12), the outlet of the hydrocarbon pump (12) is connected to a hydrocarbon pump liquid discharge pipe (93), the end of the hydrocarbon pump liquid discharge pipe (93) is connected to a filling platform (13), and a plurality of filling guns for filling liquefied gas cylinders (14) are arranged on the filling platform (13), It is characterized in that It also includes a regulating valve (21), a pressure transmitter (22) and a controller (23); the regulating valve (21) is located at an altitude higher than the filling platform (13); the inlet end of the regulating valve (21) is connected to the end of the hydrocarbon pump discharge pipe (93) through a pipeline; the outlet end of the regulating valve (21) is connected to the main liquid return pipe (94) through a pipeline; and the main liquid return pipe (94) is connected to the liquid inlet pipe (91); The pressure transmitter (22) is arranged on the hydrocarbon pump discharge pipe (93), a pressure sensing signal line (71) for transmitting a pipeline pressure signal is arranged between the pressure transmitter (22) and the controller (23), and a valve control signal line (82) for transmitting a valve control signal and a valve feedback signal line (81) for transmitting a valve status signal are also arranged between the regulating valve (21) and the controller (23).

2. A liquefied gas filling constant pressure reflux system according to claim 1, It is characterized in that The end of the hydrocarbon pump discharge pipe (93) is connected to the main return pipe (94), and an emergency exhaust valve (27) is provided between the hydrocarbon pump discharge pipe (93) and the main return pipe (94). The emergency exhaust valve (27) is used to control safe pressure relief and reflux when a system failure occurs.

3. A liquefied gas filling constant pressure reflux system according to claim 1, It is characterized in that Artificial valves are arranged before and after the regulating valve (21).

4. A liquefied gas filling constant pressure reflux system according to claim 1, It is characterized in that A hydrocarbon pump reflux pipe (95) is provided at the outlet end of the hydrocarbon pump (12) or at one end of the hydrocarbon pump discharge pipe (93) close to the hydrocarbon pump (12). The other end of the hydrocarbon pump reflux pipe (95) is connected to the liquid inlet pipe (91). A safety valve is provided on the hydrocarbon pump reflux pipe (95).

5. A liquefied gas filling constant pressure reflux system according to claim 1, It is characterized in that A mechanical pressure gauge (26) is also provided at the end of the hydrocarbon pump discharge pipe (93).

6. A liquefied gas filling constant pressure reflux system according to claim 1, It is characterized in that The controller (23) is connected to an external power supply (25), and the controller (23) is connected to a central control terminal (24) wirelessly or by wire. When the pressure or valve is abnormal, the controller (23) sends an alarm to the central control terminal (24).

7. A liquefied gas filling constant pressure reflux system according to claim 1, It is characterized in that The liquid storage tank (11) is an underground tank.

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