Gas station oil tank pressure balance environmental protection system

Abstract

The invention relates to the technical field of environmental protection, in particular to a gas station oil tank pressure balance environmental protection system which comprises an ORVR oil gun, an oil gas recovery coaxial rubber pipe, an oil tank, an oil pump, a first oil gas pipeline, a second oil gas pipeline, a PV valve, a floating ball valve, a first ball valve, a connecting flange and a balancing device. According to the technical scheme, pressure balance of the oil tank in the oil inlet / outlet process can be achieved through the balancing device, oil gas volatilization is reduced, and zero emission is basically achieved. The system is free of power parts, free of power connection, easy to install, capable of achieving zero energy consumption, low in building cost and low in maintenance cost.

Description

Technical Field

[0001] This application relates to the field of environmental protection technologies, and particularly to an environmental protection system for pressure balance of oil tanks at gas stations. Background Art

[0002] During the refueling process at a gas station, the oil product moves from the oil tank to the vehicle fuel tank, and the oil and gas in the fuel tank will be released into the atmosphere, polluting the environment; during the process of injecting oil into the oil tank, the oil product will also volatilize, and these VOCs (Volatile Organic Compounds) will pollute the environment.

[0003] In the prior art, generally, a secondary oil and gas recovery gun is used to recover the oil and gas generated during the oil injection process. Although the secondary oil and gas recovery gun will recover the oil and gas, the volume of the recovered oil and gas is often greater than the volume of gasoline injected into the vehicle, which leads to a gradual increase in the air pressure in the oil tank, and then causes the PV valve to open, resulting in oil and gas volatilization.

[0004] When the oil truck unloads oil into the oil tank, gas-liquid exchange will be carried out according to the requirements of primary oil and gas recovery. However, due to reasons such as liquid phase changes, there will be oil and gas volatilization. The volume of the volatilized gas is about 10% of the volume of the unloaded liquid. The short-term oil and gas volatilization will cause the pressure in the oil tank to rise within a very short period of time, and then cause the PV valve to open, resulting in oil and gas volatilization. Summary of the Invention

[0005] To at least overcome to some extent the problem that pressure imbalance occurs during both the oil inlet / outlet process of the oil tank in the related art, resulting in oil and gas volatilization, this application provides an environmental protection system for pressure balance of oil tanks at gas stations.

[0006] The solution of this application is as follows: An environmental protection system for pressure balance of oil tanks at gas stations, comprising: ORVR (Onboard Refueling Vapor Recovery) gun, oil and gas recovery coaxial hose, oil tank, oil pump, first oil and gas pipeline, second oil and gas pipeline, PV (Pressure / Vacuum Valve) valve, float valve, first ball valve, connecting flange and balance device; The oil delivery pipeline of the oil and gas recovery coaxial hose is connected to the ORVR gun and the oil pump; the oil and gas recovery pipeline of the oil and gas recovery coaxial hose is connected to the ORVR gun and the top of the oil tank; The oil pump is arranged at the bottom of the oil tank; The first end of the first oil and gas pipeline is connected to the top of the oil tank, and the second end is provided with the PV valve; The first end of the second oil and gas pipeline is connected to the middle section of the first oil and gas pipeline, and the second end is connected to the balancing device through the connecting flange; The float valve and the first ball valve are arranged inside the second oil and gas pipeline, and the float valve is close to the first end of the second oil and gas pipeline, and the first ball valve is close to the second end of the second oil and gas pipeline; The balancing device includes: A balancing tank, an air bag, a breathing pipeline and a breathing valve; The air bag is arranged inside the balancing pipe and forms a cavity with the balancing tank; The breathing valve is arranged inside the breathing pipeline; Wherein, the first connection mode of the balancing device is: The second end of the second oil and gas pipeline is connected to the air bag through the connecting flange; The breathing pipeline is connected to the cavity; The second connection mode of the balancing device is: The second end of the second oil and gas pipeline is connected to the cavity through the connecting flange; The breathing pipeline is connected to the air bag.

[0007] In an implementable manner of the present application, the gas station oil tank pressure balancing and environmental protection system further includes: a second ball valve and a drain plug; The second oil and gas pipeline includes: a first branch pipe, a second branch pipe, a third branch pipe, a fourth branch pipe, a fifth branch pipe and a sixth branch pipe; The first oil and gas pipeline is vertically arranged; the first branch pipe is horizontally arranged; the second branch pipe is vertically arranged; the third branch pipe is horizontally arranged; the fourth branch pipe is vertically arranged; the fifth branch pipe is horizontally arranged; the sixth branch pipe is vertically arranged; The first end of the first branch pipe is connected to the middle section of the first oil and gas pipeline through a quick connector assembly, and the second end is connected to the first end of the second branch pipe through an L-shaped elbow; The second end of the second branch pipe is connected to the first end of the third branch pipe through an L-shaped elbow; The second end of the third branch pipe is connected to the first end of the fourth branch pipe through an L-shaped elbow; The middle section of the fourth branch pipe is connected to the first end of the fifth branch pipe, and the second end is provided with the drain plug; The second end of the fifth branch pipe is connected to the first end of the sixth branch pipe through an L-shaped elbow; The second end of the sixth branch pipe is connected to the balancing device through the connecting flange; The float valve is arranged inside the second branch pipe; The first ball valve is arranged inside the fifth branch pipe; The second ball valve is arranged inside the fourth manifold pipe.

[0008] In an implementable manner of the present application, the pressure balance environmental protection system for a gas station oil tank further includes: A first drain pipe, a drain hose, a third ball valve, an auxiliary mechanical diaphragm pump, and a three-way pipe fitting; The drain hose is arranged inside the airbag, and the first end of the drain hose communicates with the first end of the first drain pipe, and the second end contacts the bottom of the airbag; The second end of the first drain pipe is connected to the drain plug through the three-way pipe fitting; The third ball valve and the auxiliary mechanical diaphragm pump are arranged inside the first drain pipe; When draining the airbag, the first ball valve and the second ball valve are closed, and the drain plug, the third ball valve, and the auxiliary mechanical diaphragm pump are opened, and the accumulated liquid inside the airbag is pumped out through the drain hose and the first drain pipe in sequence.

[0009] In an implementable manner of the present application, the pressure balance environmental protection system for a gas station oil tank further includes: A second drain pipe and a fourth ball valve; The first end of the second drain pipe communicates with the cavity; The fourth ball valve is arranged inside the second drain pipe; When draining the cavity, the first ball valve, the second ball valve, and the third ball valve are closed, and the drain plug and the fourth ball valve are opened, and the accumulated liquid inside the cavity is discharged through the second drain pipe.

[0010] In an implementable manner of the present application, when refueling the oil tank, the first ball valve is opened, and the second ball valve, the third ball valve, and the fourth ball valve are closed; If the balancing device is in the first connection mode, the oil and gas inside the oil tank enter the airbag in sequence through the first oil and gas pipe, the second oil and gas pipe, and the connecting flange; The air in the cavity is discharged through the breathing pipe; If the balancing device is in the second connection mode, the oil and gas inside the oil tank enter the cavity in sequence through the first oil and gas pipe, the second oil and gas pipe, and the connecting flange; The air in the airbag is discharged through the breathing pipe.

[0011] In an implementable manner of the present application, when refueling a vehicle through an ORVR oil gun, the first ball valve is opened, the first ball valve is opened, the second ball valve, the third ball valve, and the fourth ball valve are closed; the oil and gas recovery coaxial rubber hose recovers the oil and gas generated during refueling and introduces the oil and gas into the oil tank. If the balancing device is in the first connection mode, the oil and gas in the airbag enter the oil tank successively through the connecting flange, the second oil and gas pipeline, and the first oil and gas pipeline; The cavity inhales air through the breathing pipeline; If the balancing device is in the second connection mode, the oil and gas in the cavity enter the oil tank successively through the connecting flange, the second oil and gas pipeline, and the first oil and gas pipeline; The airbag inhales air through the breathing pipeline.

[0012] In an implementable manner of the present application, the breathing pipeline includes a breathing vertical pipe and a breathing horizontal pipe; The first end of the breathing vertical pipe communicates with the airbag or the cavity, and the second end communicates with the first end of the breathing horizontal pipe; Wherein, the second end of the breathing horizontal pipe is in an inclined cut shape, and the upper layer is longer than the lower layer; Or, an L-shaped elbow is provided at the second end of the breathing horizontal pipe.

[0013] In an implementable manner of the present application, the pressure balancing and environmental protection system for a gas station oil tank further includes: A balance tank support structure; The balance tank support structure is arranged at the bottom of the balance tank and is used for bearing the weight of the balance tank and maintaining the balance tank suspended.

[0014] In an implementable manner of the present application, the pressure balancing and environmental protection system for a gas station oil tank further includes: A balance tank positioning structure; The balance tank positioning structure is arranged outside the balance tank support structure and is used for spatially fixing the balance tank.

[0015] In an implementable manner of the present application, the oil tank is arranged underground; The balancing device is arranged on the ground surface.

[0016] The technical solution provided by the present application may include the following beneficial effects: In this technical solution, an ORVR oil gun is used to refuel a vehicle. When the ORVR oil gun refuels the vehicle, the air-liquid ratio needs to be maintained below 0.5, that is, the volume of gasoline refueled into the vehicle is more than twice the volume of the recovered oil gas. At this time, the volume of oil discharged from the oil tank is greater than the volume of the recovered gas, and the pressure in the oil tank gradually drops below the atmospheric pressure. When refueling the oil tank through an oil truck, the pressure in the oil tank will gradually rise above the atmospheric pressure. Both of these situations require pressure balancing.

[0017] If the balancing device adopts the first connection method, when refueling a vehicle through an ORVR oil gun, the pressure in the oil tank gradually drops below atmospheric pressure. At this time, the oil and gas in the airbag enter the oil tank through the connecting flange, the second oil and gas pipeline, and the first oil and gas pipeline in sequence due to the action of air pressure, replenishing the negative pressure in the oil tank. Air is replenished through the breathing pipeline in the cavity to maintain the air pressure. When refueling the oil tank with an oil truck, the pressure in the oil tank gradually rises above atmospheric pressure. At this time, the oil and gas in the oil tank enter the airbag through the first oil and gas pipeline, the second oil and gas pipeline, and the connecting flange in sequence due to the action of air pressure. Air is discharged through the breathing pipeline in the cavity to maintain the air pressure.

[0018] If the balancing device adopts the second connection method, when refueling a vehicle through an ORVR oil gun, the pressure in the oil tank gradually drops below atmospheric pressure. At this time, the oil and gas in the cavity enter the oil tank through the connecting flange, the second oil and gas pipeline, and the first oil and gas pipeline in sequence due to the action of air pressure, replenishing the negative pressure in the oil tank. The airbag replenishes air through the breathing pipeline to maintain the air pressure. When refueling the oil tank with an oil truck, the pressure in the oil tank gradually rises above atmospheric pressure. At this time, the oil and gas in the oil tank enter the cavity through the first oil and gas pipeline, the second oil and gas pipeline, and the connecting flange in sequence due to the action of air pressure. The airbag discharges air through the breathing pipeline to maintain the air pressure.

[0019] Both of the above two structures of the pressure balancing and environmental protection system for a gas station oil tank in this technical solution can achieve pressure balance in the oil tank during the process of oil inlet / outlet, reduce oil and gas volatilization, and basically achieve zero emissions. This system has no power components, does not require power connection, is simple to install, can achieve zero energy consumption, has a low construction cost, and a low maintenance cost.

[0020] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit this application. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with this application, and are used together with the specification to explain the principles of this application.

[0022] Figure 1 is a schematic structural diagram of a pressure balancing and environmental protection system for a gas station oil tank provided by an embodiment of this application; Figure 2 is a schematic structural diagram of a pressure balancing and environmental protection system for a gas station oil tank provided by another embodiment of this application; Figure 3 is a schematic structural diagram of the first connection method of a balancing device provided by an embodiment of this application; Figure 4 is a schematic structural diagram of the second connection method of a balancing device provided by an embodiment of this application.

[0023] Reference Numerals: ORVR oil gun - 1; oil - gas recovery coaxial hose - 2; oil tank - 3; oil pump - 4; first oil - gas pipeline - 5; second oil - gas pipeline - 6; PV valve - 7; float valve - 8; first ball valve - 9; connecting flange - 10; balance tank - 1101; airbag - 1102; breathing pipeline - 1103; breathing valve - 1104; second ball valve - 12; drain plug - 13; first drain pipeline - 14; drain hose - 15; third ball valve - 16; tee fitting - 17; second drain pipeline - 18; fourth ball valve - 19; balance tank support structure - 20. Detailed Description of the Invention

[0024] Here, exemplary embodiments will be described in detail, and examples thereof are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0025] Figure 1 is a schematic structural diagram of an oil - tank 3 pressure - balancing environmental protection system for a gas station provided by an embodiment of the present application. Referring to Figure 1 , an oil - tank 3 pressure - balancing environmental protection system for a gas station includes: ORVR oil gun 1, oil - gas recovery coaxial hose 2, oil tank 3, oil pump 4, first oil - gas pipeline 5, second oil - gas pipeline 6, PV valve 7, float valve 8, first ball valve 9, connecting flange 10 and a balancing device; The oil - delivery pipeline of the oil - gas recovery coaxial hose 2 connects the ORVR oil gun 1 and the oil pump 4; the oil - gas recovery pipeline of the oil - gas recovery coaxial hose 2 connects the ORVR oil gun 1 and the top of the oil tank 3; The oil pump 4 is arranged at the bottom of the oil tank 3; The first end of the first oil - gas pipeline 5 is connected to the top of the oil tank 3, and the second end is provided with a PV valve 7; The first end of the second oil - gas pipeline 6 is connected to the middle section of the first oil - gas pipeline 5, and the second end is connected to the balancing device through a connecting flange 10; The float valve 8 and the first ball valve 9 are arranged inside the second oil - gas pipeline 6, and the float valve 8 is close to the first end of the second oil - gas pipeline 6, and the first ball valve 9 is close to the second end of the second oil - gas pipeline 6; The balancing device includes: balance tank 1101, airbag 1102, breathing pipeline 1103 and breathing valve 1104; The airbag 1102 is arranged inside the balance pipe and forms a cavity with the balance tank 1101; The breathing valve 1104 is arranged inside the breathing pipeline 1103; Among them, referring to Figure 3 , the first connection method of the balance device is: The second end of the second oil and gas pipeline 6 is connected to the airbag 1102 through the connecting flange 10; The breathing pipeline 1103 is connected to the cavity; Referring to Figure 4 , the second connection method of the balance device is: The second end of the second oil and gas pipeline 6 is connected to the cavity through the connecting flange 10; The breathing pipeline 1103 is connected to the airbag 1102.

[0026] Furthermore, referring to Figures 2 - 4 , the pressure balance environmental protection system of the gas station oil tank 3 further includes: a second ball valve 12 and a drain plug 13; The second oil and gas pipeline 6 includes: a first branch pipe, a second branch pipe, a third branch pipe, a fourth branch pipe, a fifth branch pipe and a sixth branch pipe; The first oil and gas pipeline 5 is vertically arranged; the first branch pipe is horizontally arranged; the second branch pipe is vertically arranged; the third branch pipe is horizontally arranged; the fourth branch pipe is vertically arranged; the fifth branch pipe is horizontally arranged; the sixth branch pipe is vertically arranged; The first end of the first branch pipe is connected to the middle section of the first oil and gas pipeline 5 through a quick connector assembly, and the second end is connected to the first end of the second branch pipe through an L-shaped elbow; The second end of the second branch pipe is connected to the first end of the third branch pipe through an L-shaped elbow; The second end of the third branch pipe is connected to the first end of the fourth branch pipe through an L-shaped elbow; The middle section of the fourth branch pipe is connected to the first end of the fifth branch pipe, and the drain plug 13 is arranged at the second end; The second end of the fifth branch pipe is connected to the first end of the sixth branch pipe through an L-shaped elbow; The second end of the sixth branch pipe is connected to the balance device through the connecting flange 10; The float ball valve 8 is arranged inside the second branch pipe; The first ball valve 9 is arranged inside the fifth branch pipe; The second ball valve 12 is arranged inside the fourth branch pipe.

[0027] The oil pump 4 is arranged at the bottom of the oil tank 3 to ensure the oil pumping efficiency and can cooperate with the return oil and gas system to maintain the liquid-gas flow balance. It is used to transport the liquid oil product at the bottom of the oil tank 3 to the fueling gun through the oil-gas recovery coaxial rubber hose 2 to realize fueling the vehicle.

[0028] The ORVR nozzle is a vehicle-mounted oil and gas recovery technology, whose design goal is to prevent the oil and gas in the vehicle fuel tank from volatilizing into the atmosphere to the greatest extent during the refueling process and achieve the airtight recovery of oil and gas. The ORVR nozzle is connected to the oil and gas recovery channel of the coaxial hose for oil and gas recovery, guiding the oil and gas escaping from the vehicle fuel tank to the top of the oil tank instead of releasing it into the atmosphere.

[0029] According to the requirements of "Control and Limitation of Oil and Gas Emissions from Gasoline Stations DB11 / 208 - 2023", when refueling a vehicle with an ORVR system, the nozzle needs to maintain the air-liquid ratio below 0.5, and this function is achieved by the ORVR nozzle. When injecting fuel into the vehicle, the ORVR nozzle maintains the air-liquid ratio below 0.5, that is, the volume of gasoline injected into the vehicle is more than twice the volume of the recovered oil and gas. At this time, the volume of oil flowing out of the oil tank is greater than the volume of the recovered gas, and the pressure in the oil tank gradually drops below the atmospheric pressure.

[0030] The first oil and gas pipeline 5 serves as the main circulation pipeline for oil and gas and is connected to a PV valve 7. In special cases, it can direct the oil and gas to the PV valve 7 for safely releasing overpressure gas.

[0031] The second oil and gas pipeline 6 is used to guide the oil and gas to the pressure balancing device to buffer and regulate the pressure prior to the opening of the PV valve 7. It plays a role of shunting and slow release and is the key pipeline of the "oil and gas buffer circuit".

[0032] The connecting flange 10 serves as the sealing connection interface between the second oil and gas pipeline 6 and the balancing device, facilitating replacement and maintenance and also supporting two connection methods (airbag 1102 type or cavity type).

[0033] It should be noted that Figures 1 - 3 What is shown are all the first connection methods of the balancing device, Figure 4 What is shown is the second connection method of the balancing device.

[0034] It should be noted that Figures 1 - 4 only one achievable connection method is shown in [reference], and in specific practice, other pipeline connection methods can also be selected. For example, placing the balancing device horizontally can also achieve the effect of balancing pressure, and only minor adjustments to the pipeline are required.

[0035] It should be noted that the second oil and gas pipeline 6 includes: the first branch pipe, the second branch pipe, the third branch pipe, the fourth branch pipe, the fifth branch pipe, and the sixth branch pipe. In Figures 2 - 4 [reference], the first branch pipe, the second branch pipe, the third branch pipe, the fourth branch pipe, the fifth branch pipe, and the sixth branch pipe are connected in sequence from left to right.

[0036] The float valve 8 is used to prevent liquid oil products or liquid impurities from entering the gas pipeline or the balancing device by mistake, playing the role of preventing backflow and liquid intrusion. The float valve 8 is arranged inside the second branch pipe, and the second branch pipe is arranged vertically, which can enable the float valve 8 to play a better role.

[0037] The function of the third branch pipe is to redirect the oil and gas flow back to the parallel flow direction.

[0038] The functions of the fourth branch pipe include: 1. Support function Since the second oil and gas pipeline 6 as a whole tends to be a horizontal pipe, in order to enhance stability, in this embodiment, a fourth branch pipe is separated from the second oil and gas pipeline 6 to be grounded to support the second oil and gas pipeline 6.

[0039] 2. Maintenance function The design of the fourth branch pipe also facilitates the maintenance of the second oil and gas pipeline 6.

[0040] The first ball valve 9 and the second ball valve 12 play the role of manually / automatically controlling the on-off.

[0041] The balance tank 1101 serves as a buffer cavity, and together with the airbag 1102 or the cavity, it accommodates or releases gas to adjust the internal pressure of the oil tank 3.

[0042] The airbag 1102 serves as a telescopic gas storage unit, which can release gas when the oil tank 3 is under negative pressure and absorb part of the gas when the oil tank 3 is under positive pressure.

[0043] The breathing pipeline 1103 is connected to the balance tank 1101 to provide a pressure release or air intake channel for the airbag 1102 or the cavity.

[0044] The breather valve 1104 is used to control the inlet and outlet of gas in the breathing pipeline 1103, adjust the internal air pressure of the airbag 1102 or the cavity within a safe range, and prevent overpressure or over-absorption.

[0045] If the balancing device adopts the first connection method, when refueling a vehicle through the ORVR oil gun 1, the pressure inside the oil tank 3 gradually drops below the atmospheric pressure. At this time, the oil and gas in the airbag 1102 enter the oil tank 3 in sequence through the connecting flange 10, the second oil and gas pipeline 6, and the first oil and gas pipeline 5 due to the action of air pressure, supplementing the negative pressure of the oil tank 3, and air is replenished through the breathing pipeline 1103 in the cavity to maintain the air pressure. When refueling the oil tank 3 by an oil truck, the pressure inside the oil tank 3 gradually rises above the atmospheric pressure. At this time, the oil and gas in the oil tank 3 enter the airbag 1102 in sequence through the first oil and gas pipeline 5, the second oil and gas pipeline 6, and the connecting flange 10 due to the action of air pressure, and air is discharged through the breathing pipeline 1103 in the cavity to maintain the air pressure.

[0046] If the balancing device adopts the second connection method, when refueling a vehicle through the ORVR oil gun 1, the pressure in the oil tank 3 gradually drops below the atmospheric pressure. At this time, the oil and gas in the cavity enter the oil tank 3 successively through the connecting flange 10, the second oil and gas pipeline 6, and the first oil and gas pipeline 5 due to the action of air pressure, replenishing the negative pressure of the oil tank 3. The air bag 1102 replenishes air through the breathing pipeline 1103 to maintain the air pressure. When refueling the oil tank 3 with an oil truck, the pressure in the oil tank 3 gradually rises above the atmospheric pressure. At this time, the oil and gas in the oil tank 3 enter the cavity successively through the first oil and gas pipeline 5, the second oil and gas pipeline 6, and the connecting flange 10 due to the action of air pressure, and the air bag 1102 discharges air through the breathing pipeline 1103 to maintain the air pressure.

[0047] Both of the above two structures of the pressure balancing and environmental protection system for the gas station oil tank 3 in this technical solution can achieve pressure balance during the oil inlet / outlet process of the oil tank 3, reduce oil and gas volatilization, and basically achieve zero emissions. This system has no power components, does not require power connection, is simple to install, can achieve zero energy consumption, has low construction costs, and low maintenance costs.

[0048] Embodiment 2 Refer to Figures 2 - 4 , the pressure balancing and environmental protection system for the gas station oil tank 3 further includes: The first drain pipe 14, the drain hose 15, the third ball valve 16, the auxiliary mechanical diaphragm pump, and the tee fitting 17; The drain hose 15 is arranged inside the air bag 1102, and the first end of the drain hose 15 communicates with the first end of the first drain pipe 14, and the second end contacts the bottom of the air bag 1102; The second end of the first drain pipe 14 is connected to the drain plug 13 through the tee fitting 17; The third ball valve 16 and the auxiliary mechanical diaphragm pump are arranged inside the first drain pipe 14; When draining the air bag 1102, the first ball valve 9 and the second ball valve 12 are closed, and the drain plug 13, the third ball valve 16, and the auxiliary mechanical diaphragm pump are opened, and the accumulated liquid inside the air bag 1102 is pumped out successively through the drain hose 15 and the first drain pipe 14.

[0049] Furthermore, the pressure balancing and environmental protection system for the gas station oil tank 3 further includes: The second drain pipe 18 and the fourth ball valve 19; The first end of the second drain pipe 18 communicates with the cavity; The fourth ball valve 19 is arranged inside the second drain pipe 18; When draining the cavity, the first ball valve 9, the second ball valve 12, and the third ball valve 16 are closed, and the drain plug 13 and the fourth ball valve 19 are opened, and the accumulated liquid inside the cavity is discharged through the second drain pipe 18.

[0050] It should be noted that due to temperature differences and other reasons, water vapor in the air may liquefy, or oil and gas may liquefy. In this embodiment, a first drainage pipe 14 is provided to drain the airbag 1102, and a second drainage pipe 18 is provided to drain the cavity.

[0051] The first drainage pipe 14 serves as the main channel for draining liquid from the interior of the airbag 1102. One end of the first drainage pipe is connected to the three-way pipe 17, and the other end is connected to the drainage hose 15, which cooperates with the mechanical diaphragm pump to suck and drain liquid.

[0052] The drainage hose 15 is arranged inside the airbag 1102. Because the liquid will be deposited and gathered at the bottom of the airbag 1102, the hose must extend to the bottom of the airbag 1102 to achieve complete drainage. The design of the hose is also to facilitate the deformation of the airbag 1102.

[0053] The auxiliary mechanical diaphragm pump provides negative pressure suction to actively extract the accumulated liquid from the drain hose 15. Compared with the electric pump, the mechanical diaphragm pump has the advantages of explosion-proof and adaptability to oil and gas environments. It is suitable for discharging condensed liquids with medium and low viscosity, and has self-priming function and gas-liquid coexistence suction capability.

[0054] The three-way pipe 17, the first drainage pipe 14, the second drainage pipe 18 and the drainage plug 13 form a confluence / lead-out node.

[0055] The drain plug 13 is the terminal control interface of the entire drain system. The plug is opened during draining and closed after draining is completed to ensure sealing.

[0056] The second drainage pipe 18 is specifically used to drain the liquid condensate in the cavity of the balance tank 1101 to prevent liquid accumulation in the cavity from affecting the pressure buffering performance or corroding the container, thereby realizing independent drainage control of the airbag 1102 and the cavity.

[0057] The third ball valve 16 and the fourth ball valve 19 play the role of manual / automatic control of on and off.

[0058] Based on the overall structure of this embodiment, the working process of the pressure balance environmental protection system of the gas station oil tank 3 is as follows: When filling the oil tank 3, the first ball valve 9 is opened, and the second ball valve 12, the third ball valve 16 and the fourth ball valve 19 are closed; If the balancing device is in the first connection mode, the oil and gas inside the oil tank 3 pass through the first oil and gas pipeline 5, the second oil and gas pipeline 6 and the connecting flange 10 in sequence and then enter the air bag 1102; The air in the cavity is exhausted through the breathing tube 1103; If the balancing device is in the second connection mode, the oil and gas inside the oil tank 3 enter the cavity after passing through the first oil and gas pipeline 5, the second oil and gas pipeline 6 and the connecting flange 10 in sequence; The air in the airbag 1102 is discharged through the breathing pipe 1103.

[0059] When refueling the vehicle through the ORVR oil gun 1, the first ball valve 9 is opened, and the second ball valve 12, the third ball valve 16, and the fourth ball valve 19 are closed; the oil-gas recovery coaxial rubber hose 2 recovers the oil and gas generated during refueling and introduces the oil and gas into the interior of the oil tank 3; If the balancing device is in the first connection mode, the oil and gas in the airbag 1102 enter the oil tank 3 successively through the connecting flange 10, the second oil-gas pipeline 6, and the first oil-gas pipeline 5; The cavity inhales air through the breathing pipe 1103; If the balancing device is in the second connection mode, the oil and gas in the cavity enter the oil tank 3 successively through the connecting flange 10, the second oil-gas pipeline 6, and the first oil-gas pipeline 5; The airbag 1102 inhales air through the breathing pipe 1103.

[0060] Embodiment III Refer to Figures 2 - 4 , the breathing pipe 1103 includes a breathing vertical pipe and a breathing horizontal pipe; The first end of the breathing vertical pipe communicates with the airbag 1102 or the cavity, and the second end communicates with the first end of the breathing horizontal pipe; Wherein, the second end of the breathing horizontal pipe is in an inclined cut shape, and the upper layer is longer than the lower layer; Or, an L-shaped elbow is provided at the second end of the breathing horizontal pipe.

[0061] It should be noted that the above design of the breathing pipe 1103 can prevent rainwater from entering the balance tank 1101 through the breathing pipe 1103.

[0062] The inclined cut structure makes it easier for raindrops to slide down along the trend to the outside, rather than entering the pipe interior. The upper layer extends to form a natural shielding angle, similar to a rain shelter or a water baffle. Even if the rainwater flows to the pipe orifice along the trend, it will drip along the lower edge due to gravity and is not likely to flow back into the pipe reversely.

[0063] The L-shaped elbow structure is the same. When rainwater falls from top to bottom, it is difficult to enter the inner bending channel.

[0064] Embodiment IV Refer to Figures 2 - 4 , the pressure balance environmental protection system for the oil tank 3 of the gas station further includes: A balance tank support structure 20; The balance tank support structure 20 is arranged at the bottom of the balance tank 1101 and is used to carry the weight of the balance tank 1101 and keep the balance tank 1101 suspended.

[0065] Furthermore, it further includes: A balance tank positioning structure; The balance tank positioning structure is arranged outside the balance tank support structure 20 and is used for spatially fixing the balance tank 1101.

[0066] The balance tank support structure 20 is arranged at the bottom of the balance tank 1101 and is in direct contact with the balance tank 1101, mainly playing a bearing role to support the self-weight of the entire balance tank 1101 as well as the weight of the internal gas and possibly existing liquid, and avoiding the equipment from sinking or being damaged due to the action of gravity.

[0067] The balance tank support structure 20 keeps the balance tank 1101 suspended above the ground, which helps to install / replace the bottom pipeline and reduces the contact area between the bottom of the tank body and the ground, preventing corrosion or waterlogging erosion.

[0068] The balance tank positioning structure is arranged outside the balance tank support structure 20 to wrap, restrain or anchor the whole device. The balance tank positioning structure can resist displacement caused by wind force, vibration, ground settlement or operation collision, and ensure that the balance tank 1101 maintains a static position without deviation during long-term operation.

[0069] Preferably, the oil tank 3 is arranged underground; The balance device is arranged on the ground surface.

[0070] The oil tank 3 is arranged underground, which is a conventional layout for gas stations. The oil tank 3 is located underground to save ground space, reduce the fire risk and keep the liquid level stable.

[0071] The balance device needs to be in a position convenient for observation, maintenance, liquid drainage and ventilation, so it is arranged above the ground.

[0072] It can be understood that the same or similar parts in the above embodiments can be referred to each other, and the internal content not detailed in some embodiments can be referred to the same or similar internal content in other embodiments.

[0073] It should be noted that in the description of the present application, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present application, unless otherwise specified, the meaning of "a plurality" refers to at least two.

[0074] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0075] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. An environmental protection system for pressure balance of oil tanks at gas stations, characterized in that, Including: ORVR oil gun, coaxial oil-gas recovery hose, oil tank, oil pump, first oil-gas pipeline, second oil-gas pipeline, PV valve, float valve, first ball valve, connecting flange and balancing device; The oil delivery pipeline of the coaxial oil-gas recovery hose is connected to the ORVR oil gun and the oil pump; the oil-gas recovery pipeline of the coaxial oil-gas recovery hose is connected to the ORVR oil gun and the top of the oil tank; The oil pump is arranged at the bottom of the oil tank; The first end of the first oil-gas pipeline is connected to the top of the oil tank, and the PV valve is arranged at the second end; The first end of the second oil-gas pipeline is connected to the middle section of the first oil-gas pipeline, and the second end is connected to the balancing device through the connecting flange; The float valve and the first ball valve are arranged inside the second oil-gas pipeline, and the float valve is close to the first end of the second oil-gas pipeline, and the first ball valve is close to the second end of the second oil-gas pipeline; The balancing device includes: Balancing tank, airbag, breathing pipeline and breathing valve; The airbag is arranged inside the balancing pipe and forms a cavity with the balancing tank; The breathing valve is arranged inside the breathing pipeline; Wherein, the first connection mode of the balancing device is: The second end of the second oil-gas pipeline is connected to the airbag through the connecting flange; The breathing pipeline is connected to the cavity; The second connection mode of the balancing device is: The second end of the second oil-gas pipeline is connected to the cavity through the connecting flange; The breathing pipeline is connected to the airbag.

2. The pressure balance environmental protection system for gas station oil tanks according to claim 1, wherein It also includes: Second ball valve and drain plug; The second oil-gas pipeline includes: first branch pipe, second branch pipe, third branch pipe, fourth branch pipe, fifth branch pipe and sixth branch pipe; The first oil-gas pipeline is vertically arranged; the first branch pipe is horizontally arranged; the second branch pipe is vertically arranged; the third branch pipe is horizontally arranged; the fourth branch pipe is vertically arranged; the fifth branch pipe is horizontally arranged; the sixth branch pipe is vertically arranged; The first end of the first branch pipe is connected to the middle section of the first oil-gas pipeline through a quick connector assembly, and the second end is connected to the first end of the second branch pipe through an L-shaped elbow; The second end of the second branch pipe is connected to the first end of the third branch pipe through an L-shaped elbow; The second end of the third branch pipe is connected to the first end of the fourth branch pipe through an L-shaped elbow; The middle section of the fourth branch pipe is connected to the first end of the fifth branch pipe, and the drain plug is arranged at the second end; The second end of the fifth branch pipe is connected to the first end of the sixth branch pipe through an L-shaped elbow; The second end of the sixth branch pipe is connected to the balancing device through the connecting flange; The float valve is arranged inside the second branch pipe; The first ball valve is arranged inside the fifth branch pipe; The second ball valve is arranged inside the fourth branch pipe.

3. The pressure balance environmental protection system for a gas station oil tank according to claim 2, wherein It also includes: First drain pipeline, drain hose, third ball valve, auxiliary mechanical diaphragm pump and tee fitting; The drain hose is arranged inside the airbag, and the first end of the drain hose is connected to the first end of the first drain pipeline, and the second end contacts the bottom of the airbag; The second end of the first drain pipeline is connected to the drain plug through the tee fitting; The third ball valve and the auxiliary mechanical diaphragm pump are arranged inside the first drain pipeline; When draining the liquid in the airbag, the first ball valve and the second ball valve are closed, and the drain plug, the third ball valve and the auxiliary mechanical diaphragm pump are opened, and the accumulated liquid inside the airbag is pumped out successively through the drain hose and the first drain pipe.

4. The pressure balance environmental protection system for a gas station oil tank according to claim 3, characterized in that, It further includes: A second drain pipe and a fourth ball valve; The first end of the second drain pipe communicates with the cavity; The fourth ball valve is arranged inside the second drain pipe; When draining the liquid in the cavity, the first ball valve, the second ball valve and the third ball valve are closed, and the drain plug and the fourth ball valve are opened, and the accumulated liquid inside the cavity is discharged through the second drain pipe.

5. The pressure balance environmental protection system for a gas station oil tank according to claim 4, characterized in that, When injecting oil into the oil tank, the first ball valve is opened, and the second ball valve, the third ball valve and the fourth ball valve are closed; If the balance device is in the first connection mode, the oil and gas inside the oil tank enter the airbag successively through the first oil and gas pipe, the second oil and gas pipe and the connecting flange; The air in the cavity is discharged through the breathing pipe; If the balance device is in the second connection mode, the oil and gas inside the oil tank enter the cavity successively through the first oil and gas pipe, the second oil and gas pipe and the connecting flange; The air in the airbag is discharged through the breathing pipe.

6. The environmental protection system for pressure balance of oil tanks at gas stations according to claim 4, characterized in that When injecting oil into the vehicle through an ORVR oil gun, the first ball valve is opened, and the second ball valve, the third ball valve and the fourth ball valve are closed; the oil and gas recovery coaxial rubber hose recovers the oil and gas generated by oil injection and introduces the oil and gas into the oil tank; If the balance device is in the first connection mode, the oil and gas in the airbag enter the oil tank successively through the connecting flange, the second oil and gas pipe and the first oil and gas pipe; The cavity inhales air through the breathing pipe; If the balance device is in the second connection mode, the oil and gas in the cavity enter the oil tank successively through the connecting flange, the second oil and gas pipe and the first oil and gas pipe; The airbag inhales air through the breathing pipe.

7. The pressure balance environmental protection system for the oil tank of a gas station according to claim 1, characterized in that, The breathing pipe includes a breathing vertical pipe and a breathing horizontal pipe; The first end of the breathing vertical pipe communicates with the airbag or the cavity, and the second end communicates with the first end of the breathing horizontal pipe; Wherein, the second end of the breathing horizontal pipe is in an inclined cut shape, and the upper layer is longer than the lower layer; Or, an L-shaped elbow is arranged at the second end of the breathing horizontal pipe.

8. The pressure balance environmental protection system for the oil tank of a gas station according to claim 1, characterized in that It further includes: A balance tank support structure; The balance tank support structure is arranged at the bottom of the balance tank and is used for bearing the weight of the balance tank and maintaining the balance tank suspended.

9. The pressure balance environmental protection system for a gas station oil tank according to claim 8, characterized in that It further includes: A balance tank positioning structure; The balance tank positioning structure is arranged outside the balance tank support structure and is used for spatially fixing the balance tank.

10. The pressure balance environmental protection system for a gas station oil tank according to claim 1, characterized in that, The oil tank is arranged underground; The balance device is arranged on the ground surface.

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