Liquid storage system with pressure regulating function

Abstract

The utility model belongs to the technical field of flow batteries, and particularly relates to a liquid storage system with a pressure regulating function. The liquid storage system comprises a liquid storage tank, and an air bag is arranged in the liquid storage tank; the opening of the air bag can be communicated with the outside, so that the volume of the air bag can change along with the pressure in the liquid storage tank, and the pressure in the liquid storage tank is always equal to the outside atmospheric pressure. The air bag is arranged in the liquid storage tank, and the volume of the air bag changes along with the pressure in the liquid storage tank, so that the pressure in the liquid storage tank is always equal to the external atmospheric pressure. When the pressure in the liquid storage tank changes, air enters and exits from the air bag and does not make contact with the electrolyte in the liquid storage tank. Therefore, the conditions that when the negative pressure in the liquid storage tank exceeds the suction opening pressure of the breather valve, the breather valve is opened, the air directly enters the liquid storage tank, the air makes contact with the electrolyte, and the electrolyte is oxidized can be effectively prevented. In addition, nitrogen does not need to be supplemented at any time in the using process, and the nitrogen cost is saved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of liquid flow battery, specifically relates to a liquid storage system with pressure regulating function. BACKGROUND

[0002] The energy unit of the liquid flow battery energy storage system, electrolyte, is stored in a liquid storage tank made of insulating material. When designing the liquid storage tank, a certain amount of excess is generally considered to prevent electrolyte overflow caused by electrolyte deviation.

[0003] When the energy storage system is running, it will release some gas, and this part of gas will form a positive pressure in the liquid storage tank. When the pressure reaches a certain value, it will be discharged from the liquid storage tank through the breather valve.

[0004] In addition, the following situations may occur when the liquid flow battery energy storage system is running: (1) due to the entry of part of the electrolyte into the pipeline and the stack, the liquid level in the liquid storage tank will decrease, forming a negative pressure in the liquid storage tank; (2) due to the continuous deviation of the electrolyte in the positive and negative electrolyte storage tanks, a negative pressure will also be formed in one of the liquid storage tanks; (3) opening the balance valve in the positive and negative electrolyte storage tanks will cause the high liquid level in the liquid storage tank to move to the low liquid level, also causing one of the liquid storage tanks to form a negative pressure. These three situations may cause air to enter the liquid storage tank through the breather valve, oxidize the electrolyte, and affect the quality of the electrolyte. To prevent air from entering the liquid storage tank and affecting the electrolyte, nitrogen is generally continuously charged into the liquid storage tank to isolate air, but nitrogen is expensive, and if it is continuously supplemented, it will increase the cost of energy storage.

[0005] To solve the above problems, the present application is proposed. CONTENT OF THE UTILITY MODEL

[0006] When the liquid flow battery energy storage system is running, in order to prevent air from affecting the energy unit of the liquid flow energy storage system, electrolyte, a method of charging nitrogen into the storage tank is generally used to isolate air. This requires continuous supplementation of nitrogen in the storage tank. Nitrogen is a consumable and cannot be recycled, and it is expensive.

[0007] The present application provides a liquid storage system with pressure regulating function, which comprises: a liquid storage tank, wherein a gas bag is arranged in the liquid storage tank 1;

[0008] The opening of the gas bag 8 can communicate with the outside to change the volume of the gas bag 8 with the change of the pressure in the liquid storage tank 1, so that the pressure in the liquid storage tank 1 is always equal to the atmospheric pressure outside.

[0009] Preferably, the opening of the gas bag 8 communicates with the outside through a valve 9. Of course, the function of the present application can also be realized without setting the valve 9.

[0010] Preferably, the gas bag 8 is arranged at the upper part in the liquid storage tank 1.

[0011] Preferably, the upper part of the liquid storage tank 1 has a support structure 10, and the air bag 8 is arranged on the support structure 10.

[0012] Preferably, a pressure pipeline is connected to the upper part of the liquid storage tank 1, and a breathing valve 7 and a ball valve 6 are sequentially arranged on the pressure pipeline, and the ball valve 6 is arranged between the breathing valve and the liquid storage tank 1.

[0013] Preferably, the outlet of the liquid storage tank 1 is connected to the electrolyte inlet of the flow battery 4 through a liquid storage tank outlet pipeline 2.

[0014] The electrolyte outlet of the flow battery 4 is connected to the inlet of the liquid storage tank 1 through a liquid storage tank inlet pipeline 3.

[0015] Preferably, a pressure sensor 5 is arranged at the lower part of the liquid storage tank 1.

[0016] The second aspect of the present application provides a working method of a liquid storage system with pressure regulating function, which comprises the following steps:

[0017] When the pressure in the liquid storage tank 1 is less than the atmospheric pressure, the ambient air automatically enters the air bag 8, so that the pressure in the liquid storage tank 1 is equal to the atmospheric pressure.

[0018] When the pressure in the liquid storage tank 1 is greater than the atmospheric pressure, the gas in the liquid storage tank 1 compresses the volume of the air bag 8, so that the air in the air bag 8 is discharged to the outside, so that the pressure in the liquid storage tank 1 is equal to the atmospheric pressure.

[0019] The air bag 8 is made of pressure-sensitive, soft and air-tight material, such as rubber, polyester or polyurethane.

[0020] The principle of the present application is as follows:

[0021] The material of the liquid storage tank 1 is generally pph material. In addition to meeting the required liquid column pressure for work, the additional pressure range of the liquid storage tank made of this material should meet the requirements of 5kPa~-3 kPa stipulated in GB / T25197-2010, Static Atmospheric Pressure Welding Thermoplastic Plastic Storage Tank. When the flow battery works, the electrolyte flows to the flow battery 4 through the liquid storage tank outlet pipeline 2, and then returns to the liquid storage tank 1 through the liquid storage tank inlet pipeline 3, completes the charging and discharging, and a pressure sensor 5 is arranged at the lower part of the liquid storage tank for detecting the change of the liquid level in the liquid storage tank 1.

[0022] In order to ensure that the additional pressure in the gas tank is in the range of 5kPa~3 kPa, and to reasonably protect the liquid storage tank, a breather valve 7 is installed on the upper part of the liquid storage tank, and the breather valve 7 is separated by a ball valve 6, and the ball valve 6 is opened during operation. The opening pressure range of the breather valve 7 is +1735Pa and -295Pa. When the additional pressure in the gas tank exceeds this range, the breather valve 7 is automatically opened to balance the pressure inside and outside the liquid storage tank. The suction pressure value of the breather valve 7 is relatively low, according to the national standard, and in the current domestic breather valve 7 opening pressure grade table, there is only one kind of suction opening pressure, that is, -295Pa. When the additional pressure in the gas tank is not in the opening pressure range, the breather valve cannot be opened, and the pressure in the liquid storage tank is still unstable. In addition, if only the breather valve 7 is used, air will inevitably enter the liquid storage tank, affecting the quality of the electrolyte.

[0023] Therefore, the application adds a gas bag 8 in the liquid storage tank. The expansion and contraction of the gas bag 8 balance the pressure in the liquid storage tank. When negative pressure is formed in the liquid storage tank 1 due to the three reasons described in the background art, air enters the gas bag 8 through the valve 9 to balance the pressure inside and outside the gas bag 8, thereby making the pressure inside the liquid storage tank 1 equal to the atmospheric pressure. When the pressure in the gas tank 1 is positive, due to the increase of the pressure outside the gas bag 8, the volume of the gas bag 8 will be reduced, and the air in the gas bag 8 will be discharged, balancing the pressure inside and outside the gas bag 8 and the atmospheric pressure. The gas bag 8 is placed on the support 10.

[0024] The material of the gas bag 8 needs to be in contact with the electrolyte and will not affect the electrolyte, and the texture is soft and sensitive to pressure. For example, the material of the gas bag 8 is similar to the material of the automobile safety air bag, such as rubber, polyester or polyurethane, etc. The application still retains the breather valve 7 and the separating ball valve 6 to avoid damage to the liquid storage tank 1 when the gas bag 8 fails and the additional pressure in the liquid storage tank 1 is too large.

[0025] Compared with the prior art, the application has the following beneficial effects:

[0026] 1. The application sets a gas bag 8 in the liquid storage tank 1, and the volume of the gas bag 8 changes with the pressure in the liquid storage tank 1 to maintain the stability of the pressure in the liquid storage tank 1.

[0027] 2. When the pressure in the liquid storage tank 1 changes, air enters and exits the gas bag 8 without contacting the electrolyte in the liquid storage tank 1. Therefore, the application can effectively prevent the situation that when the negative pressure in the liquid storage tank 1 exceeds the suction opening pressure of the breather valve, the breather valve is opened, air directly enters the liquid storage tank 1, and air contacts the electrolyte and causes oxidation of the electrolyte. In addition, the application does not need to supplement nitrogen at any time during use, saving the cost of nitrogen.

[0028] 3. The start of the breather valve has an opening pressure range. When the additional pressure in the gas tank is not within the opening pressure range, it cannot be opened, still causing the pressure in the liquid tank to be unstable. After using the air bag 8 of the present application, the air bag 8 can adapt to any slight pressure change in the gas tank 1, and the pressure in the liquid tank 1 can always remain stable.

[0029] 4. The range of pressure changes in the liquid tank 1 that the air bag 8 adjusts can be changed by changing the volume of the air bag 8, which is simple, convenient, and not limited. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 The structure diagram of the liquid storage system with pressure regulating function of the present application.

[0031] Figure 2 The position diagram of the air bag device 8, valve 9, and support structure 10 of the present application.

[0032] LIST OF REFERENCE NUMBERS

[0033] 1. Liquid tank, 2. Liquid tank outlet pipeline, 3. Liquid tank inlet pipeline, 4. Flow battery, 5. Pressure sensor, 6. Ball valve, 7. Breather valve, 8. Air bag device, 9. Valve, 10. Support structure. DETAILED DESCRIPTION

[0034] The present application will be further described in detail below with reference to examples.

[0035] Those skilled in the art will appreciate that the following examples are intended to be illustrative only and should not be viewed as limiting the scope of the present application. In the examples, unless otherwise specified, the techniques or conditions were carried out in accordance with the techniques or conditions described in the literature in the field or in accordance with the product instructions. In the examples, unless otherwise specified, the materials or equipment used were conventional products that can be obtained by purchase.

[0036] Those skilled in the art will appreciate that, unless specifically stated otherwise, the singular forms "a," "an," and "the" as used herein are intended to include plural forms. In the description of the present application, "a plurality of" means two or more, unless otherwise specified. It should be further understood that the word "comprising" as used in the specification of the present application means that the features, integers, steps, operations, elements, and / or components described therein are present, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when we say an element is "connected" to another element, it can be directly connected to the other element, or there can be intermediate elements. In addition, "connected" as used herein can include wireless connections.

[0037] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like indicate the orientation or positional relationship shown in the drawings based on the orientation or positional relationship, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0038] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0039] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be broadly understood, for example, it can be connected, or detachable, or integrated; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0040] In the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can include the first and second features directly contacting, or the first and second features not directly contacting but contacting through another feature between them. Moreover, the first feature "on", "above" and "above" the second feature includes the first feature directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "under", "below" and "below" the second feature includes the first feature directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0041] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like 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 the present specification, the illustrative description of the above terms should not be understood as necessarily referring 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. In addition, those skilled in the art can combine and combine different embodiments or examples described in the present specification.

[0042] Those skilled in the art can understand that, unless otherwise defined, all terms used herein, including technical terms and scientific terms, have the same meaning as the general understanding of those skilled in the art to which the present application belongs. It should also be understood that terms such as those defined in a general dictionary should be understood to have meanings consistent with those in the context of the prior art, and should not be interpreted with idealized or overly formal meanings unless defined as such.

[0043] As Figure 1 The present application provides a liquid storage system with pressure regulating function, which comprises a liquid storage tank 1, wherein a gas bag 8 is arranged inside the liquid storage tank 1.

[0044] The opening of the gas bag 8 can communicate with the outside to make the volume of the gas bag 8 change with the pressure in the liquid storage tank 1, so as to maintain the pressure in the liquid storage tank 1 stable.

[0045] The opening of the gas bag 8 communicates with the outside through a valve 9. Preferably, the valve 9 is a ball valve. When the gas bag 8 is used, the valve 9 is opened. When the gas bag 8 is not used, the valve 9 is opened.

[0046] The gas bag 8 is arranged at the upper part of the liquid storage tank 1, preferably above the liquid level.

[0047] The upper part of the liquid storage tank 1 has a support structure 10, and the gas bag 8 is arranged on the support structure 10. Of course, the function of the present application can also be achieved without arranging the support structure 10, so that the gas bag 8 floats on the liquid level.

[0048] A pressure pipeline is communicated above the liquid storage tank 1, and a breather valve 7 and a ball valve 6 are sequentially arranged on the pressure pipeline, and the ball valve 6 is arranged between the breather valve and the liquid storage tank 1. This is to avoid the damage of the liquid storage tank caused by the excessive additional pressure in the liquid storage tank when the gas bag 8 fails. The ball valve 6 can also be replaced by any suitable one-way valve.

[0049] The outlet of the liquid storage tank 1 is connected to the electrolyte inlet of the flow battery 4 through the liquid storage tank outlet pipeline 2.

[0050] The electrolyte outlet of the flow battery 4 is connected to the liquid storage tank 1 inlet through the liquid storage tank inlet pipeline 3.

[0051] The lower part of the liquid storage tank 1 is connected to the pressure sensor 5.

[0052] The working method of the liquid storage system with pressure regulating function comprises the following steps:

[0053] When the pressure in the liquid storage tank 1 is less than the atmospheric pressure, the outside air automatically enters the air bag 8, so that the pressure in the liquid storage tank 1 is equal to the atmospheric pressure.

[0054] When the pressure in the liquid storage tank 1 is greater than the atmospheric pressure, the gas in the liquid storage tank 1 compresses the volume of the air bag 8, so that the air in the air bag 8 is discharged to the outside, so that the pressure in the liquid storage tank 1 is equal to the atmospheric pressure.

Claims

1. A liquid storage system with pressure regulating function, characterized in that, The liquid storage system includes: a liquid storage tank (1), and an airbag (8) is provided inside the liquid storage tank (1); The opening of the airbag (8) can communicate with the outside so that the volume of the airbag (8) can change with the pressure inside the liquid storage tank (1) so that the pressure inside the liquid storage tank (1) is always equal to the outside atmospheric pressure.

2. The liquid storage system with pressure regulating function according to claim 1, characterized in that, The opening of the airbag (8) is connected to the outside through a valve (9).

3. The liquid storage system with pressure regulating function according to claim 1, characterized in that, The airbag (8) is located in the upper part of the liquid storage tank (1).

4. The liquid storage system with pressure regulating function according to claim 1, characterized in that, The upper part of the liquid storage tank (1) has a support structure (10), and the airbag (8) is disposed on the support structure (10).

5. The liquid storage system with pressure regulating function according to claim 1, characterized in that, A pressure pipeline is connected above the storage tank (1), and a breather valve (7) and a ball valve (6) are installed in sequence on the pressure pipeline. The ball valve (6) is located between the breather valve and the storage tank (1).

6. The liquid storage system with pressure regulating function according to claim 1, characterized in that, The outlet of the storage tank (1) is connected to the electrolyte inlet of the flow battery (4) through the storage tank outlet pipeline (2); The electrolyte outlet of the flow battery (4) is connected to the inlet of the storage tank (1) through the storage tank inlet pipe (3).

7. The liquid storage system with pressure regulating function according to claim 1, characterized in that, A pressure sensor (5) is connected to the lower part of the liquid storage tank (1).

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