Double-air-bag storage tank

Abstract

The utility model discloses a storage tank with double air bags, which is used for storing light oil products and at least comprises a tank body, a floating disc capable of moving up and down is arranged in the tank body, a liquid phase space is arranged below the floating disc, and a gas phase space is arranged above the floating disc; an isolation plate is arranged at the position, close to the tank top, of the tank body, the space between the isolation plate and the floating disc is an oil gas space, and the space between the isolation plate and the tank top is a tank top space; the main air bag is hermetically arranged in the oil-gas space, the bottom of the main air bag is fixed on the floating disc, and an opening of the main air bag hermetically penetrates through the isolation plate and the tank top and is communicated with the atmosphere; the auxiliary air bag is arranged in the tank top space in a sealed mode and communicates with the oil-gas space; and the tank top space is provided with an air vent communicated with the atmosphere. The two relatively isolated spaces are arranged on the upper portion of the floating disc, the main air bag and the auxiliary air bag are arranged in the two spaces respectively, zero emission of VOCs waste gas of the storage tank can be achieved, pressure balance of the gas phase space can be effectively adjusted in the large breathing process and the small breathing process, and the structure is simple and practical.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of environmental protection and energy saving technology, especially to a double air bag storage tank. BACKGROUND

[0002] As an important storage device in the petroleum and chemical industry, the storage tank stores a large amount of VOCs in the crude oil and gasoline, etc. These VOCs have strong volatility, and during the "breathing" process of the storage tank, i.e. the internal pressure changes caused by the liquid level changes or temperature fluctuations, the gas will be released into the atmosphere in large quantities. This not only causes great waste of resources, but also causes serious pollution to the environment and affects human health. The "breathing" of the storage tank mainly includes two types: large breathing and small breathing. Large breathing refers to the gas emission caused by the rapid fluctuation of internal pressure due to the rapid change of liquid level during the receiving and sending operation of the storage tank. Small breathing refers to the gas emission caused by the temperature change in the tank body due to the diurnal temperature difference or climate change in the static storage state. These two "breathing" actions are the main sources of VOCs emission.

[0003] In order to reduce the VOCs emission of the storage tank, the traditional storage tank design usually adopts a floating roof design, i.e. a floating partition is added above the stored liquid to cover the liquid surface, so as to reduce the contact area between the liquid and the gas. However, this design can only reduce the volatilization of VOCs to a certain extent, but cannot fundamentally solve the emission problem caused by the "breathing" action. In addition, in order to prevent the storage tank from introducing too much oxygen during inhalation and causing safety hazards and oil oxidation, the storage tank is usually provided with a nitrogen sealing system to supplement nitrogen to the tank body to isolate air during inhalation. However, although this method can improve the safety of the storage tank, it also increases the maintenance cost of the storage tank.

[0004] At present, there are also storage tanks that use air bags for "breathing" in the prior art. For example, Chinese patent application CN114435780A discloses an energy-saving and emission-reducing storage tank, which comprises a shell, an internal air bag located inside the shell, an air bag support and a U-shaped oil and gas conduit. The internal air bag comprises an outer air bag and an inner air bag, and the outer air bag and the inner air bag share an air bag top, and the air bag top is provided with a vent hole. The outer air bag has no air bag bottom, and is fixed on the air bag support and can move up and down along the support. The lower part of the outer air bag extends below the upper surface of the oil product. One end of the U-shaped oil and gas conduit is located in the space surrounded by the outer air bag and the shell, and the other end is located in the space surrounded by the outer air bag, the inner air bag and the oil product. This scheme realizes the pressure balance and automatic volume adjustment of the oil and gas gas phase space in the inner and outer air bags of the storage tank, and the storage tank does not emit volatile oil and gas into the atmosphere, thereby realizing zero emission of storage tank exhaust gas.

[0005] Although the scheme can realize low emission of the waste gas of the storage tank, the structure is relatively complex, and the pressure balance of the gas phase space for small breathing is not easy to control.

[0006] Therefore, there is an urgent need for a double air bag storage tank which is not only simple in structure, but also has low requirements for the floating plate, and can effectively adjust the pressure balance of the gas phase space during large and small breathing.

[0007] The information disclosed in the background section is only intended to increase the understanding of the general background of the present application, and should not be considered as acknowledging or implying in any form that the information constitutes prior art known to those skilled in the art. Content of the application

[0008] The purpose of the present application is to provide a double air bag storage tank, which is simple in structure and practical, and can realize zero emission of VOCs waste gas of the storage tank, and effectively adjust the pressure balance of the gas phase space during large and small breathing, by providing two relatively isolated spaces on the upper part of the floating plate, and arranging a main air bag and an auxiliary air bag in the two spaces.

[0009] To achieve the above purpose, the present application provides a double air bag storage tank for storing light oil products, which at least comprises: a tank body, which is provided with a floating plate movable up and down inside, the space below the floating plate being a liquid phase space, and the space above the floating plate being a gas phase space; the tank body is provided with a partition plate near the tank top, the space between the partition plate and the floating plate being an oil gas space, and the space between the partition plate and the tank top being a tank top space; a main air bag, which is sealingly arranged in the oil gas space, the bottom of the main air bag being fixed on the floating plate, and the bag opening being sealingly penetrated through the partition plate and the tank top and being in communication with the atmosphere; an auxiliary air bag, which is sealingly arranged in the tank top space and is in communication with the oil gas space; and the tank top space is provided with a vent opening in communication with the atmosphere.

[0010] Further, in the above technical solution, a communication pipe can be arranged on the partition plate, and the bag opening of the auxiliary air bag can be in communication with the oil gas space through the communication pipe.

[0011] Further, in the above technical solution, a grid for protecting the auxiliary air bag can be arranged on the upper part of the communication pipe.

[0012] Further, in the above technical solution, an air bag lifting rope can be arranged on the upper part of the main body of the main air bag, for dispersing the weight of the main air bag and keeping the main air bag in an unfolded state at all times. The air bag lifting rope is preferably four and is uniformly spaced.

[0013] Further, in the above technical solution, a floating plate limiting column can be arranged in the tank body near the tank wall, the floating plate limiting column extending vertically from the tank bottom to the tank top and sealingly penetrating through the partition plate.

[0014] Further, in the above technical solution, in the receiving process of the large breathing of the storage tank, the internal space of the main gas bag is in the state of exhausting to the atmosphere, at the same time, the oil gas space is in the state of inflating to the auxiliary gas bag, and the tank top space is in the state of exhausting to the atmosphere.

[0015] Further, in the above technical solution, in the discharging process of the large breathing of the storage tank, the internal space of the main gas bag is in the state of inhaling from the atmosphere, at the same time, the oil gas space is in the state of inhaling from the auxiliary gas bag, and the tank top space is in the state of inhaling from the atmosphere.

[0016] Further, in the above technical solution, in the process of the temperature rise of the small breathing of the storage tank, the oil gas in the oil gas space expands due to heat, the oil gas space is in the state of inflating to the auxiliary gas bag, at the same time, the tank top space is in the state of exhausting to the atmosphere.

[0017] Further, in the above technical solution, in the process of the temperature drop of the small breathing of the storage tank, the oil gas in the oil gas space shrinks due to cold, the oil gas space is in the state of inhaling from the auxiliary gas bag, at the same time, the tank top space is in the state of inhaling from the atmosphere.

[0018] Compared with the prior art, the utility model has the following beneficial effects:

[0019] 1) adopt the double gas bag storage tank of the utility model, through setting two relatively isolated spaces on the upper portion of the floating disc, and setting the main gas bag and the auxiliary gas bag in the two spaces respectively, not only can realize the zero emission of the VOCs waste gas of the storage tank, still can effectively adjust the pressure balance of the gas phase space in the large and small breathing process, and the structure is simple and practical;

[0020] 2) adopt the double gas bag storage tank of the utility model, through the isolation of the isolation plate and the communication of the auxiliary gas bag and the oil gas space, make the oil gas circulate in the oil gas space and the auxiliary gas bag no matter in the large breathing process or the small breathing process, will not enter the tank top space and then pollute the atmosphere, can effectively reduce the emission of VOCs;

[0021] 3) the cooperation of the main gas bag and the auxiliary gas bag of the utility model makes the pressure regulation of the gas phase space more flexible, can effectively improve the safety and stability of the storage tank;

[0022] 4) since the utility model adopts the main gas bag and the auxiliary gas bag in two relatively isolated spaces, therefore need not adopt the high efficiency sealing floating disc commonly used in prior art, simple floating disc only plays the role of isolating liquid phase and gas bag, can effectively simplify the structure and save the cost;

[0023] 5) the gas bag hanging rope of the utility model can help to disperse the weight of the main gas bag, and can also avoid the phenomenon that the space in the bag is insufficient after the gas bag shrinks in the use process;

[0024] 6)The utility model discloses a grid is provided on the upper portion of the communicating pipe, can protect the auxiliary air bag, make the auxiliary air bag avoid being destroyed when being sucked into the communicating pipe when completely shrinking.

[0025] The above description is only a summary of the technical scheme of the utility model, in order to more clearly understand the technical means of the utility model and can be implemented according to the content of the specification, at the same time, in order to make the above and other purposes, technical features and advantages of the utility model more easy to understand, one or more preferred embodiments are listed below, and the following is described in detail with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0026] Fig. 1 It is the first internal structure schematic view of the double air bag storage tank of the utility model (showing the material receiving process of the big breath of storage tank, the solid line arrow in the drawing is oil gas, and the dashed line arrow is air).

[0027] Fig. 2 It is the second internal structure schematic view of the double air bag storage tank of the utility model (showing the material discharging process of the big breath of storage tank, the solid line arrow in the drawing is oil gas, and the dashed line arrow is air).

[0028] Fig. 3 It is the third internal structure schematic view of the double air bag storage tank of the utility model (showing the temperature rising state of the small breath of storage tank, the solid line arrow in the drawing is oil gas, and the dashed line arrow is air).

[0029] Fig. 4 It is the fourth internal structure schematic view of the double air bag storage tank of the utility model (showing the temperature falling state of the small breath of storage tank, the solid line arrow in the drawing is oil gas, and the dashed line arrow is air).

[0030] Main figure mark explanation:

[0031] 1-main air bag, 11-main air bag bag mouth, 12-main air bag rope, 2-auxiliary air bag;

[0032] 100-storage tank body, 101-tank top, 102-tank bottom, 103-simple floating disc, 104-isolation plate, 105-ventilation pipe, 106-grid, 107-ventilation port, 108-floating disc limiting stand;

[0033] A-main air bag internal space, B-auxiliary air bag internal space, C-oil gas space, D-tank top space. DETAILED DESCRIPTION

[0034] The specific embodiments of the utility model are described in detail below in combination with the drawings, but it should be understood that the protection scope of the utility model is not limited by the specific embodiments.

[0035] Unless specifically stated otherwise, throughout the specification and claims, the term "comprise" or variations such as "comprises" or "comprising" will be understood to imply the inclusion of a stated element or group of elements but not the exclusion of any other element or group of elements.

[0036] In this document, relational terms such as "first," "second," and the like can be used solely to distinguish one entity or action from another, without necessarily implying a relationship or order between entities or actions. Such terms can include derivatives, unless context clearly indicates otherwise. Stated explicitly, such terminology is related to the disclosure herein and should not be considered as limiting. For example, without limitation, "first" and "second" are used interchangeably with "another," "another," and so forth. Such terminology can include derivatives. For example, if a certain component is referred to as "enclosing" another part, then another part can also be "enclosed" by the certain component, and so on.

[0037] In this document, the terms "first," "second," and the like can be used to distinguish between two different elements or portions, and are not intended to define a particular position or relative relationship. In other words, in some embodiments, the terms "first," "second," and the like can be interchangeable with each other.

[0038] As Figs. 1 to 4 The utility model provides a kind of double air bag storage tank, it can be used to store light oil product, it is especially suitable for the storage tank for storing crude oil, gasoline and other light oil products in petrochemical industry.The double air bag storage tank at least includes tank body 100, main air bag 1 and auxiliary air bag 2.Wherein, tank body 100 is equipped with the simple float 103 that can move up and down.Here it needs to be explained: since the main air bag 1 and auxiliary air bag 2 in two relative isolation spaces are used in the utility model, it is not necessary to use the commonly used high-efficiency sealing float, and the simple float 103 can only play the role of isolating liquid phase and air bag.The liquid phase space below float 103, the gas phase space (i.e. including main air bag internal space A, auxiliary air bag internal space B, oil gas space C and tank top space D) above float 103.Tank body 100 is equipped with isolation plate 104 near tank top 101, and the space between isolation plate 104 and float 103 is oil gas space C, and the space between isolation plate 104 and tank top 101 is tank top space D.The isolation plate 104 of the utility model can isolate the gas phase (oil gas, i.e. VOCs waste gas) volatilized by liquid phase (such as crude oil, gasoline and other light oil products) below isolation plate 104, and oil gas cannot enter tank top space D communicated with atmosphere except in the process of "breathing" can enter auxiliary air bag internal space B.Isolation plate 104 can use metal plate or plastic plate.

[0039] Further as Figs. 1 to 4As shown, the main gas bag 1 is sealingly arranged in the oil-gas space C, the bottom of the main gas bag 1 is fixed on the floating plate 103, and the bag opening 11 of the main gas bag 1 sealingly penetrates the isolation plate 104 and the tank top 101 and is in communication with the atmosphere. The main gas bag bag opening 11 sealingly penetrates the isolation plate 104 means that a dynamic seal is made at the part of the main gas bag penetrating the isolation plate, so as to avoid the oil and gas in the oil-gas space C entering the tank top space D when the main gas bag 1 expands or shrinks. The weight of the main gas bag 1 of the utility model is about 200-500 kg, on the one hand, the buoyancy generated by the floating plate 103 needs to be greater than the gravity of the main gas bag, and on the other hand, in order to disperse the weight of the main gas bag and always keep the expanded state, the main body upper portion of the main gas bag 1 is preferably provided with a gas bag lifting rope 12, which can help disperse the weight of the gas bag, and can also avoid the phenomenon that the space in the bag is insufficiently utilized after the gas bag shrinks in the use process. The gas bag lifting rope 12 is preferably four and is uniformly and spacedly arranged.

[0040] Further as Figs. 1 to 4 shown, the auxiliary gas bag 2 is sealingly arranged in the tank top space D and is in communication with the oil-gas space C; the tank top space D is provided with a vent 107 in communication with the atmosphere. Specifically, the isolation plate 104 is provided with a communication pipe 105, and the bag opening of the auxiliary gas bag 2 is in communication with the oil-gas space C through the communication pipe 105. The interface between the bag opening of the auxiliary gas bag 2 and the communication pipe 105 is sealed, so as to avoid the oil and gas in the oil-gas space C or the internal space B of the auxiliary gas bag from leaking into the tank top space D and then being discharged into the atmosphere. Further, preferably but not limitedly, the upper portion of the communication pipe 105 can be provided with a grille 106 for protecting the auxiliary gas bag, that is, the auxiliary gas bag 2 is completely shrunk to avoid being sucked into the communication pipe 105.

[0041] Further as Figs. 1 to 4 shown, the tank body 100 is provided with a floating plate limiting stand 108 near the tank wall, the floating plate limiting stand 108 vertically extends from the tank bottom 102 to the tank top 101 and sealingly penetrates the isolation plate 104. In this way, the floating plate 103 can vertically and freely move under the guidance of the floating plate limiting stand 108 in the process of breathing in and breathing out of the material.

[0042] It should be noted that before using the dual-gas-bag storage tank of this invention, specifically in the initial stage before the large and small breathing processes, the oil-gas space C outside the main gas bag and the internal space B of the auxiliary gas bag need to be gas-replaced, that is, the air needs to be replaced with nitrogen, to avoid contact between the oil-gas and air during the large and small breathing processes. Therefore, this invention has a nitrogen inlet pipeline and an exhaust pipeline (not shown in the figure) on the side wall of the storage tank. The oil-gas space C outside the main gas bag and the internal space B of the auxiliary gas bag are filled with nitrogen. This nitrogen can flow between the internal space B of the auxiliary gas bag and the oil-gas space C as the floating plate rises and falls during the large and small breathing processes, without being discharged externally. Specifically, the nitrogen replacement inside the tank is completed before using the dual-gas-bag storage tank of this invention: the exhaust pump is started to extract the air from the internal space B of the auxiliary gas bag and the oil-gas space C, the main gas bag 1 is expanded to its maximum state, and there is almost no gas in the auxiliary gas bag 2; then nitrogen is introduced into the oil-gas space C and the internal space B of the auxiliary gas bag. The amount of nitrogen to be filled should be such that the main gas bag is in a natural vertical position, at which point the auxiliary gas bag is basically still in a gas-free state due to the weight.

[0043] The following is a detailed description of the "breathing" process of the double-airbag storage tank of this utility model under different states:

[0044] 1) The material receiving process during the large-scale breathing of the storage tank (reference) Fig. 1 The main gas bag's internal space A is in a state of venting to the atmosphere, while the oil and gas space C is in a state of filling the auxiliary gas bag's internal space B, and the tank top space D is in a state of venting to the atmosphere. Specifically, when the storage tank receives material, the floating roof 103 rises, and the gas (i.e., air) in space A is compressed by the floating roof 103 and discharged outward from the main gas bag opening 101, which is connected to the atmosphere. At the same time, space C is also compressed, and the oil and gas in space C are discharged into space B. The expansion of space B acts on space D, discharging the gas (i.e., air) from space D. When the auxiliary gas bag in space B is full, it is in direct contact with the inner wall of the tank top and no longer receives gas (i.e., oil and gas). At this time, venting can continue from space A.

[0045] 2) The discharge process of the large breathing tank (refer to) Fig. 2 The main air bag's internal space A is in a state of drawing air from the atmosphere, while the oil and gas space C is in a state of drawing air from the auxiliary air bag's internal space B, and the tank top space D is in a state of drawing air from the atmosphere. Specifically, when the storage tank discharges material, the floating roof 103 descends, and the air pressure in space C decreases. At this time, space A draws air inward, and the oil and gas in space B enters space C until it is blocked by the grille 106 located above the connecting pipe 105. At the same time, space D receives air from the tank top vent 107.

[0046] 3) When the temperature rises during the small breathing of the storage tank (reference) Fig. 3) : the oil and gas in the oil and gas space C is expanded by heat, the oil and gas space C is in the state of inflating the inner space B of the auxiliary air bag, and meanwhile, the tank top space D is in the state of exhausting to the atmosphere. It should be noted that, in the process of small breathing, when the pressure in the C space is increased (or decreased) by a small range, the auxiliary air bag 2 is automatically selected to breathe due to the large weight of the main air bag 1, and when the auxiliary air bag 2 is expanded to the maximum (or contracted to the minimum) and still cannot balance the pressure, the main air bag 1 participates in breathing (that is, when the temperature is increased by a large range, the main air bag 1 participates in exhaust; when the temperature is decreased by a large range, the main air bag 1 participates in inhalation). Specifically, in the process of small breathing (temperature rise), the storage tank has no material in and out, at this time, the temperature rises, small exhalation starts, the oil and gas in the C space is expanded due to the temperature rise, the oil and gas enters the B space from the C space, and the air in the D space is exhausted out of the tank, until the B space is filled with oil and gas and contacts the inner wall of the D space, at this time, the A space can exhaust to the outside.

[0047] 4) The temperature of the storage tank is decreased in the process of small breathing (refer to Fig. 4 ) : the oil and gas in the oil and gas space C is contracted by cold, the oil and gas space C is in the state of inhaling from the inner space B of the auxiliary air bag, and meanwhile, the tank top space D is in the state of inhaling from the atmosphere. Specifically, in the process of small breathing (temperature drop), the storage tank has no material in and out, at this time, the temperature drops, small inhalation starts, the oil and gas in the C space is contracted due to the temperature drop, the oil and gas enters the C space from the B space, and the D space inhales air from the outside of the tank, until the B space is contracted to the minimum, at this time, the A space can inhale to the inside.

[0048] The double-air-bag storage tank of the utility model, by setting two relatively isolated spaces on the upper part of the floating plate, and setting a main air bag and an auxiliary air bag in the two spaces respectively, not only can realize zero emission of VOCs waste gas of the storage tank, but also can effectively adjust the pressure balance of the gas phase space in the process of large and small breathing, and the structure is simple and practical. The double-air-bag storage tank of the utility model, by the isolation of the isolation plate and the communication of the auxiliary air bag and the oil and gas space, makes the oil and gas circulate in the oil and gas space and the auxiliary air bag in the process of large and small breathing, and will not enter the tank top space to pollute the atmosphere, and can effectively reduce the emission of VOCs; the cooperation of the main air bag and the auxiliary air bag makes the pressure regulation of the gas phase space more flexible, and can effectively improve the safety and stability of the storage tank.

[0049] The foregoing description of specific exemplary embodiments of the present application is intended to be illustrative only and is not intended to limit the application to the precise forms described. Many modifications and variations are possible in light of the above teachings without departing from the spirit or essential characteristics of the present application. The exemplary embodiments were chosen and described in order to explain the principles of the present application and its practical application and to allow others skilled in the art to understand the present application for various exemplary embodiments with various modifications as are suited to the particular use contemplated. Any simple modifications, equivalent changes, and modifications based on the above-described exemplary embodiments should fall within the scope of the present application.

Claims

1. A dual gas bag storage tank characterized by, The application relates to a storage device for light oil products, which comprises: a tank body, a floating plate movably arranged in the tank body, a liquid phase space below the floating plate, a gas phase space above the floating plate, an isolation plate arranged near the tank top, a space between the isolation plate and the floating plate being an oil-gas space, a space between the isolation plate and the tank top being a tank top space; a main gas bag sealed in the oil-gas space, the bottom of the main gas bag being fixed on the floating plate, the bag opening of the main gas bag being sealed and penetrating through the isolation plate and the tank top and being in communication with the atmosphere; an auxiliary gas bag sealed in the tank top space and in communication with the oil-gas space, the tank top space being provided with a vent hole in communication with the atmosphere.

2. The dual gas bag reservoir of claim 1, wherein, A communication pipe is arranged on the isolation plate, the bag opening of the auxiliary gas bag is in communication with the oil-gas space through the communication pipe.

3. The dual gas bag reservoir of claim 2, wherein, A grid for protecting the auxiliary gas bag is arranged on the upper part of the communication pipe.

4. The dual gas pocket reservoir of claim 1, wherein, A gas bag lifting rope is arranged on the upper part of the main body of the main gas bag, which is used for dispersing the weight of the main gas bag and keeping the main gas bag in an unfolded state.

5. The dual gas bag reservoir of claim 4, wherein, The gas bag lifting rope is four and is arranged in uniform intervals.

6. The dual gas pocket reservoir of claim 1, wherein, A floating plate limiting stand is arranged near the tank wall in the tank body, the floating plate limiting stand vertically extends from the tank bottom to the tank top and is sealed and penetrates through the isolation plate.

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