Gas hydrate stable preservation device and system

Abstract

The utility model relates to a gas hydrate stable preservation device and system, and the device comprises an upper housing which is provided with a first cylinder body and a top cover, and the bottom of the first cylinder body is open and is provided with a switch valve; the piston reciprocates in the first barrel, a first pressure cavity is defined between one side of the piston and the first barrel, a second pressure cavity is defined between the other side of the piston and the first barrel, the second pressure cavity contains pressurized liquid, a first channel and a second channel are formed in the piston, and a spraying head is arranged at the bottom of the second channel; the lower shell is provided with a second barrel and a bottom plate located on the second barrel, the top of the second barrel is open and detachably connected with the switch valve, pressurized liquid is injected into the second pressure cavity to drive the piston to move towards the extending position, and the gas hydrate in the first pressure cavity is compressed and formed under pressurization of the piston to obtain the solid gas hydrate. And then the switching valve is opened, and the solid gas hydrate is transferred to the lower shell for low-pressure storage.

Description

Technical Field

[0001] The utility model relates to the technical field of gas storage and transportation, and in particular to a gas hydrate stable storage device and system. Background Art

[0002] Gas hydrates are a type of gas hydrate that is stably stored in a hydrogen-bonded cage structure of water molecules through van der Waals forces. The hydrate method can be used to store gases such as methane, propane, carbon dioxide and hydrogen efficiently, conveniently and safely. It has a high mass and volumetric gas storage density and is an energy-saving, efficient and safe gas storage technology. However, the current stable storage of gas hydrates with high gas storage density usually requires the application of high pressure, which not only places strict requirements on gas storage devices, but also increases cost investment and the difficulty of safely storing and transporting gas hydrates, which is not conducive to industrial application. Despite this, the slow formation rate of gas hydrates and the difficulty of stable storage are still the main challenges restricting their industrial application. Although current technical solutions have attempted to increase the generation rate of gas hydrates by increasing the gas-liquid contact area (such as bubbling, spraying, mechanical stirring) and the gas-solid contact area (such as ice powder grinding), and by compressing and molding gas hydrates, coating and other means to achieve stable storage of gas hydrates, these methods often have operational conflicts between increasing the generation rate and achieving stable storage. For example, most of the equipment used for rapid generation of gas hydrates does not have the function of compression molding to improve stability, while the equipment with compression molding function lacks the kinetic means to increase the generation rate, which to a certain extent restricts the continuous and efficient production of gas hydrate technology. Therefore, how to develop a new type of stable storage device for gas hydrates is an urgent problem that needs to be solved. Utility Model Content

[0003] In view of the problems existing in the prior art, the first purpose of the utility model is to provide a gas hydrate stable storage device, including an upper shell, a switch valve, a piston and a lower shell. Through the technical combination of spray and piston, the integration of gas hydrate synthesis and compression molding functions is realized, which not only improves the generation rate of gas hydrates, but also can directly perform compression molding after the synthesis is completed, thereby enhancing the stability of gas hydrates, so that gas hydrates can be stably stored for a long time under relatively mild conditions.

[0004] The second purpose of the utility model is to provide a gas hydrate stable storage system, including a gas storage device, a liquid storage device, a data acquisition device, a gas-liquid separation device and a gas hydrate stable storage device, aiming to achieve continuous synthesis and efficient storage of gas hydrates. The system is not only suitable for the synthesis and storage of a variety of gas hydrates, but also can synthesize gas hydrates under high pressure conditions, stably store them under low pressure environments, and maintain a high gas storage density, so as to reduce the storage and transportation costs of gas hydrates.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A gas hydrate stable storage device comprises: a vertically arranged upper shell, the upper shell having a first cylinder and a top cover located on the first cylinder, the bottom of the first cylinder is open and is provided with a switch valve; a piston, the piston part is received inside the first cylinder for reciprocating between an extended position and a retracted position, a first pressure chamber is defined between one side of the piston and the first cylinder, the first pressure chamber is configured to receive gas hydrate therein, a second pressure chamber is defined between the other side of the piston and the first cylinder, the second pressure chamber receives pressurized liquid for driving the piston to move toward the extended position, wherein the piston has a There are a first channel for receiving the gas to be synthesized and a second channel for receiving the liquid to be synthesized, and the bottom of the second channel is provided with a spray head for atomizing the liquid and spraying it into the first pressure chamber; a vertically arranged lower shell, the lower shell having a second cylinder and a bottom plate located on the second cylinder, the top of the second cylinder is open and detachably connected to the switch valve, wherein pressurized liquid is injected into the second pressure chamber to drive the piston to move to the extended position, so that the gas hydrate in the first pressure chamber is compressed and formed under the pressure of the piston to obtain solid gas hydrate, and then the switch valve is opened to transfer the solid gas hydrate to the lower shell for low-pressure storage.

[0007] Furthermore, the piston includes a piston rod and a piston head fixedly connected to the bottom of the piston rod. A telescopic opening for accommodating the piston rod is formed on the top cover. The piston head is located inside the first cylinder body. The outer surface of the piston head is substantially adjacent to the inner surface of the first cylinder body. The piston head defines a second pressure chamber and a first pressure chamber arranged vertically inside the first cylinder body.

[0008] Furthermore, a pressure sensor and a temperature sensor are also configured. The sensing part of the pressure sensor enters the first pressure chamber through the first channel. The piston also has a third channel inside for accommodating the temperature sensor. The sensing part of the temperature sensor enters the first pressure chamber through the third channel.

[0009] Furthermore, heating layers are disposed on the inner walls of the first channel and the second channel.

[0010] Furthermore, the outer surfaces of the upper shell and the lower shell are both provided with a temperature regulating layer.

[0011] Furthermore, a support frame and a lifting mechanism located at the bottom of the support frame are also configured, the upper part of the support frame is fixedly connected to the switch valve, the lower part of the support frame is configured with a fixed platform, the lower shell is located on the fixed platform, the lifting mechanism includes a lifting platform and a telescopic rod fixed at the bottom of the lifting platform, the fixed platform is provided with a lifting port, the lifting platform cooperates with the lifting port, the lifting platform abuts against the bottom of the lower shell, the bottom of the telescopic rod is connected to a power input part, and the lifting and lowering of the telescopic rod drives the lifting and lowering of the lower shell to connect or separate the lower shell and the switch valve.

[0012] Furthermore, the second cylinder includes a small cylinder and a large cylinder arranged up and down, the top of the small cylinder has a receiving port detachably connected to the switch valve, the diameter of the small cylinder is smaller than the diameter of the large cylinder, and the diameter of the small cylinder is equal to the diameter of the first cylinder.

[0013] Furthermore, the gas to be synthesized is one or more of methane, ethane, propane, carbon dioxide or hydrogen; the liquid to be synthesized is pure water, a kinetic additive or a thermodynamic additive, wherein the kinetic additive is a surfactant or an amino acid, and the thermodynamic additive is tetrahydrofuran, 1,3-dioxolane, 1,2-epoxycyclopentane or cyclopentane.

[0014] According to a system using the above-mentioned gas hydrate stable storage device, the system includes: a gas storage device, the gas storage device is located upstream of the gas hydrate stable storage device, so as to transport the gas to be synthesized to the first pressure chamber through the first channel; a liquid storage device, the liquid storage device is located upstream of the gas hydrate stable storage device, so as to transport the liquid to be synthesized to the first pressure chamber through the second channel; a data acquisition device, the data acquisition device is located downstream of the gas hydrate stable storage device, so as to collect and analyze the temperature and pressure in the gas hydrate stable storage device; a gas-liquid separation device, the gas-liquid separation device is respectively connected to the gas storage device , a liquid storage device and a gas hydrate stabilization storage device are connected to recover and separate the unreacted gas and liquid in the gas hydrate stabilization storage device through the first channel; a gas hydrate stabilization storage device, wherein the gas hydrate stabilization storage device is used to allow the gas and liquid to be synthesized to enter the first pressure chamber through the first channel and the second channel respectively to synthesize gas hydrates, and to inject pressurized liquid into the second pressure chamber to drive the piston to move to the extended position, so that the gas hydrate in the first pressure chamber is compressed and formed under the pressure of the piston to obtain solid gas hydrates, and then the switch valve is opened to transfer the solid gas hydrate to the lower shell under pressure for low-pressure storage.

[0015] Furthermore, a booster pump is arranged on the pipeline between the gas storage device and the gas hydrate stabilization storage device.

[0016] The utility model has the following advantages:

[0017] 1. The gas hydrate stable storage device of the utility model comprises an upper shell, a switch valve, a piston and a lower shell. Through the technical combination of spray and piston, the gas hydrate synthesis and compression molding functions are integrated, which not only improves the generation rate of gas hydrates, but also can be directly compressed and molded after the synthesis is completed, thereby enhancing the stability of gas hydrates, so that gas hydrates can be stably stored for a long time under relatively mild conditions.

[0018] 2. The gas hydrate stable storage system of the utility model includes a gas storage device, a liquid storage device, a data acquisition device, a gas-liquid separation device and a gas hydrate stable storage device, which is intended to achieve continuous synthesis and efficient storage of gas hydrates. The system is not only suitable for the synthesis and storage of a variety of gas hydrates, but also can synthesize gas hydrates under high pressure conditions and stably store them under low pressure environments, while maintaining a high gas storage density, so as to reduce the storage and transportation costs of gas hydrates. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a three-dimensional structural schematic diagram of the gas hydrate stable storage device of the utility model.

[0020] Figure 2 It is a three-dimensional exploded view of the gas hydrate stable storage device of the utility model.

[0021] Figure 3 It is a cutaway view of the gas hydrate stable storage device of the utility model.

[0022] Figure 4 It is a three-dimensional cutaway view of the upper housing and the piston of the utility model.

[0023] Figure 5 It is a cutaway view of the upper housing and the piston of the utility model.

[0024] Figure 6 It is a three-dimensional structural schematic diagram of the piston of the utility model.

[0025] Figure 7 It is a three-dimensional structural schematic diagram of the lower shell of the utility model.

[0026] Figure 8 It is a three-dimensional structural schematic diagram of the support frame and the lifting mechanism of the utility model.

[0027] Fig. 9 It is a schematic diagram of the flow of the gas hydrate stable storage system of the utility model.

[0028] Among them, 1 is a gas hydrate stable storage device, 101 is an upper shell, 101a is a first cylinder, 101b is a top cover, 101b1 is a telescopic port, 101b2 is a liquid injection hole, 101c is a first pressure chamber, 101d is a second pressure chamber, 102 is a switch valve, 103 is a piston, 103a is a first channel, 103b is a second channel, 103c is a third channel, 103d is a spray head, 103e is a piston rod, 103f is a piston head, 104 is a lower shell, 104a is a second cylinder, 104a1 is a small cylinder, 104a2 is a large cylinder, 104a3 is a receiving port, 104b is a bottom plate, 105 is a support frame, 105a is a fixing table, 105a is a fixing table, 1 is a lifting port, 106 is a lifting mechanism, 106a is a lifting platform, 106b is a telescopic rod, 106c is a power input component, 2 is an air storage device, 2a is a pressure reducing valve, 2b is a first valve, 2c is a booster pump, 2d is a second valve, 3 is a liquid storage device, 3a is a third valve, 3b is a first injection pump, 3c is a fourth valve, 4 is a data acquisition device, 4a is a temperature gauge, 4b is a pressure gauge, 4c is a signal converter, 4d is a computer, 5 is a gas-liquid separation device, 5a is a fifth valve, 5b is a sixth valve, 5c is a three-way valve, 5d is a seventh valve, 5e is an eighth valve, 6 is a pressurized liquid storage device, 6a is a ninth valve, 6b is a second injection pump, and 6c is a tenth valve. DETAILED DESCRIPTION

[0029] The following description is essentially only exemplary and is not intended to limit the utility model, its application or use. It will be further understood that the term "include" and / or "comprising" specifies the existence of the features, wholes, steps, operations, elements and / or parts mentioned when used in this specification, but does not exclude the existence of one or more other features, wholes, steps, operations, elements, parts and / or its groups or add one or more other features, wholes, steps, operations, elements, parts and / or its groups. As used in this article, the term "and / or" includes any and all combinations of one or more of the associated listed items. It will be understood that when an element, component and / or part is referred to as "connected to another element, component and / or part", it can be directly connected to another element, component and / or part, or there can be an intermediate element. It will be understood that although the terms "first", "second" and the like can be used to describe various elements, components and / or parts in this article, these elements, components and / or parts should not be limited by these terms. These terms are only used to distinguish an element, component or part from another element, component or part. Therefore, the first element, component or part discussed below can be referred to as the second element, component or part without departing from the teaching of the utility model. Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meanings as those commonly understood by those of ordinary skill in the field to which the utility model belongs. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having meanings consistent with their meanings in the relevant field and / or the context of this specification, and will not be interpreted in an idealized or overly formal sense, unless explicitly defined as such in this article.

[0030] It should be understood that, in order to clearly show the contents therein, the drawings herein are not drawn to scale, and the same or similar reference numerals indicate the same or similar components or parts. In addition, it should be understood that any embodiments described in this application and the technical features included therein can be combined with each other.

[0031] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0032] like Figure 1-8As shown, a gas hydrate stable storage device comprises: a vertically arranged upper shell 101, wherein the upper shell 101 has a first cylinder 101a and a top cover 101b located on the first cylinder 101a, the bottom of the first cylinder 101a is open and is provided with a switch valve 102, the upper shell 101 is made of stainless steel, and the top cover 101b is provided with a liquid injection hole 101b2, wherein the switch valve 102 is a gate valve or a ball valve. A piston 103, wherein the piston 103 is partially received inside the first cylinder 101a for reciprocating between an extended position and a retracted position, wherein the extended position of the piston 103 is a position where the piston 103 moves downward, and the retracted position of the piston 103 is a position where the piston 103 moves upward, a first pressure chamber 101c is defined between one side of the piston 103 and the first cylinder 101a, and the first pressure chamber 101c is configured to receive gas hydrates therein, and a second pressure chamber 101d is defined between the other side of the piston 103 and the first cylinder 101a, and the second pressure chamber 101d receives pressurized liquid injected through the injection hole 101b2 to drive the piston 103 to move toward the extended position, and the volumes of the first pressure chamber 101c and the second pressure chamber 101d increase or decrease accordingly with the movement of the piston 103, and in addition, the first cylinder 101a and the second cylinder 104a both have cylindrical inner surfaces. The piston 103 has a first channel 103a for receiving the gas to be synthesized and a second channel 103b for receiving the liquid to be synthesized. The bottom of the second channel 103b is provided with a spray head 103d for atomizing the liquid and spraying it into the first pressure chamber 101c. The bottom of the spray head 103d is at the same level as one side of the piston 103. The spray head 103d disperses the liquid in the form of a spray to increase the contact area between the gas and the liquid, thereby improving the synthesis efficiency of the gas hydrate. The spray head 103d can be a micro-pressure spray head, a low-pressure spray head, a medium-pressure spray head or a high-pressure spray head, etc. The upper shell 101, the piston 103 and the switch valve 102 are combined to form a piston-type high-pressure spray reactor. The vertically arranged lower shell 104 is used for pressure-maintaining transfer and stable storage of gas hydrates. The lower shell 104 has a second cylinder 104a and a bottom plate 104b located on the second cylinder 104a. The top of the second cylinder 104a is open and detachably connected to the switch valve 102. The lower shell 104 is made of stainless steel. The lower shell 104 is pre-loaded with water, cyclopentane, tetrahydrofuran and other liquids that can form ice shells or hydrate shells on the surface of gas hydrates, so as to improve the stability of gas hydrates stored under low pressure.

[0033] Among them, the gas and liquid to be synthesized are first injected into the first pressure chamber 101c from the first channel 103a and the second channel 103b respectively, and gas hydrates are synthesized under a certain pressure. Then, the pressurized liquid is injected into the second pressure chamber 101d to drive the piston 103 to move to the extended position, so that the gas hydrate in the first pressure chamber 101c is compressed and formed under the pressure of the piston 103 to obtain solid gas hydrates, and then the switch valve 102 is opened to transfer the solid gas hydrates to the lower shell 104 for low-pressure storage. The entire device realizes the continuous synthesis and efficient storage of gas hydrates, is suitable for the synthesis and storage of various gas hydrates, and significantly reduces the storage and transportation costs.

[0034] like Figure 1-6 As shown, the piston 103 includes a piston rod 103e and a piston head 103f fixedly connected to the bottom of the piston rod 103e, and a telescopic opening 101b1 for receiving the piston rod 103e is formed on the top cover 101b to guide the reciprocating motion of the piston rod 103e. The piston head 103f is located inside the first cylinder 101a, and the outer surface of the piston head 103f is substantially adjacent to the inner surface of the first cylinder 101a. The piston head 103f defines a second pressure chamber 101d and a first pressure chamber 101c arranged vertically inside the first cylinder 101a, ensuring that during the movement of the piston 103, the independent separation of the internal space of the first cylinder 101a is not affected. The upper surface of the piston head 103f, the inner surface of the first cylinder 101a and the lower surface of the top cover 101b together form a second pressure chamber 101d, and the piston rod 103e is located on the central axis of the second pressure chamber 101d, which ensures the stability of the movement of the piston 103 and helps to evenly distribute the pressure of the pressurized liquid. The lower surface of the piston head 103f, the inner surface of the first cylinder 101a and the top of the switch valve 102 together form a first pressure chamber 101c. During the downward movement of the piston 103, the volume of the first pressure chamber 101c gradually decreases, and the gas hydrate is compressed and formed under high pressure to form a solid gas hydrate. A driving member is also configured at the top of the piston rod 103e to drive the piston rod 103e to reciprocate.

[0035] In an embodiment not shown, a pressure sensor and a temperature sensor are also configured, and the sensing part of the pressure sensor enters the first pressure chamber 101c through the first channel 103a. The piston 103 also has a third channel 103c for receiving the temperature sensor, and the sensing part of the temperature sensor enters the first pressure chamber 101c through the third channel 103c. The pressure sensor and the temperature sensor are used to monitor the pressure and temperature of the gas phase space in real time, and the pressure sensor and the temperature sensor are both connected to the external data acquisition device 4 by signal. Among them, the first channel 103a, the second channel 103b and the third channel 103c are vertically penetrated from the top of the piston rod 103e to the bottom of the piston head 103f.

[0036] In an embodiment not shown, a heating layer is disposed on the inner wall of the first channel 103a and the second channel 103b, wherein a heating layer is also disposed inside the piston rod 103e, and the heating layer corresponds to the first channel 103a, the second channel 103b and the third channel 103c. When hydrate or ice blockage occurs in the channel, the heating layer can quickly start the heating process and effectively remove the blockage by increasing the temperature in the channel, thereby preventing the liquid from undergoing a phase transition in the channel to form a solid and causing channel blockage. The outer surfaces of the upper shell 101 and the lower shell 104 are both provided with a temperature regulating layer to keep the temperature of the gas hydrates inside constant, and to prevent the external environment from having an adverse effect on the temperature of the internal gas hydrates.

[0037] like Figure 1 , 2As shown in Figure 8, a support frame 105 and a lifting mechanism 106 located at the bottom of the support frame 105 are also configured. The upper part of the support frame 105 is fixedly connected to the switch valve 102, and the lower part of the support frame 105 is configured with a fixed platform 105a. The lower shell 104 is located on the fixed platform 105a. The lifting mechanism 106 includes a lifting platform 106a and a telescopic rod 106b fixed to the bottom of the lifting platform 106a. The fixed platform 105a is provided with a lifting port 105a1, and the lifting platform 106a cooperates with the lifting port 105a1. The lifting platform 106a is in contact with the bottom of the lower shell 104. The bottom of the telescopic rod 106b is connected with a power input member 106c, and the lifting and lowering of the telescopic rod 106b drives the lifting and lowering of the lower shell 104 to connect or separate the lower shell 104 and the switch valve 102. Among them, the support frame 105 includes four vertically arranged support columns and a cross brace connected between two support columns, and a mounting port for installing and transferring the lower shell 104 is formed between the two support columns and the cross brace. The fixed platform 105a is fixed at the lower part of the four support columns, and the two ends of the switch valve 102 are fixed on two opposite cross braces. The fixed platform 105a has a certain distance from the ground for receiving the lifting mechanism 106. When it is necessary to engage, the lifting platform 106a is first kept flush with the fixed platform 105a, and then the lower shell 104 is placed on the lifting platform 106a. When it is necessary to engage the lower shell 104 and the switch valve 102, the telescopic rod 106b is driven by the power input member 106c to drive the lifting platform 106a to rise until the lifting platform 106a is tightly abutted against the bottom of the lower shell 104 to prevent the leakage of gas hydrates. In the engaged state, the height of the lifting platform 106a will be higher than the fixed platform 105a, so as to provide enough space for the connection between the lower shell 104 and the switch valve 102. When the lower shell 104 loaded with gas hydrate needs to be disassembled and transferred, it is only necessary to operate the power input member 106c in the reverse direction to retract the telescopic rod 106b, drive the lifting platform 106a to descend to a position flush with the fixed platform 105a, and then remove the lower shell 104. In an embodiment not shown, the connection between the lower shell 104 and the switch valve 102 is a threaded connection, the bottom of the switch valve 102 has an internal thread hole, and the top of the lower shell 104 is provided with a corresponding external thread. The telescopic rod 106b also has a rotation function. During the lifting process of the telescopic rod 106b, it can rotate at the same time, so that the external thread of the lower shell 104 can be screwed into the internal thread hole of the switch valve 102, which not only enhances the stability of the connection, but also ensures the sealing of the connection.

[0038] like Figure 3 and Figure 7As shown, the second cylinder 104a includes a small cylinder 104a1 and a large cylinder 104a2 arranged up and down, the top of the small cylinder 104a1 has a receiving port 104a3 that is detachably connected to the switch valve 102, the diameter of the small cylinder 104a1 is smaller than the diameter of the large cylinder 104a2, so that the combined cross-section of the small cylinder 104a1 and the large cylinder 104a2 is a convex structure, and the large cylinder 104a2 provides more accommodation space inside, so that multiple columnar solid gas hydrates can be accommodated and placed. The diameter of the small cylinder 104a1 is equal to the diameter of the first cylinder 101a, so that the solid gas hydrate can pass smoothly and avoid blockage or stagnation.

[0039] like Fig. 9 As shown, according to the system using the above-mentioned gas hydrate stable storage device, it includes:

[0040] The gas storage device 2 is located upstream of the gas hydrate stabilization storage device 1 to transport the gas to be synthesized to the first pressure chamber 101c through the first channel 103a, and the gas to be synthesized enters the first pressure chamber 101c from the first channel 103a. The pipeline between the gas storage device 2 and the gas hydrate stabilization storage device 1 is sequentially provided with a pressure reducing valve 2a, a first valve 2b, a booster pump 2c and a second valve 2d, and the gas to be synthesized in the gas storage device 2 is one or more of methane, ethane, propane, carbon dioxide or hydrogen.

[0041] The liquid storage device 3 is located upstream of the gas hydrate stable storage device 1 to transport the liquid to be synthesized to the first pressure chamber 101c through the second channel 103b. The pipeline between the liquid storage device 3 and the gas hydrate stable storage device 1 is sequentially provided with a third valve 3a, a first injection pump 3b and a fourth valve 3c. The liquid to be synthesized in the liquid storage device 3 is a solution of pure water or other mixed dynamic or thermodynamic additives. The dynamic additives include surfactants, amino acids, etc., and the thermodynamic additives include tetrahydrofuran, 1,3-dioxolane, 1,2-epoxycyclopentane, cyclopentane, etc. The volume of the liquid storage device 3 is 1L-100L.

[0042] The data acquisition device 4 is located downstream of the gas hydrate stable storage device 1 to collect and analyze the temperature and pressure in the gas hydrate stable storage device 1. The data acquisition device 4 includes a temperature meter 4a, a pressure meter 4b, a signal converter 4c and a computer 4d. The temperature meter 4a is connected to the temperature sensor signal, the pressure meter 4b is connected to the pressure sensor signal, the temperature meter 4a and the pressure meter 4b are respectively connected to the signal converter 4c, and the signal converter 4c is connected to the computer 4d.

[0043] The gas-liquid separation device 5 is respectively connected to the gas storage device 2, the liquid storage device 3 and the gas hydrate stabilization storage device 1 to recover and separate the unreacted gas and liquid in the gas hydrate stabilization storage device 1 through the first channel 103a. Among them, the gas-liquid separation device 5 has three sections of pipelines, the first section of the pipeline is connected to the pipeline between the first valve 2b and the boosting pump 2c, and is used to transport the separated gas back to the first channel 103a, the second section of the pipeline is connected to the liquid storage device 3, and the separated liquid is transported to the liquid storage device 3. The second section of the pipeline is equipped with a fifth valve 5a, and the third section of the pipeline is connected to the second channel 103b of the gas hydrate stable preservation device 1, and the sixth valve 5b, the three-way valve 5c and the seventh valve 5d are sequentially arranged on the pipeline. The liquid storage device 3 is connected to the three-way valve 5c pipeline. During the injection process, the liquid to be synthesized in the liquid storage device 3 passes through the third valve 3a, the first injection pump 3b, the fourth valve 3c, the three-way valve 5c and the seventh valve 5d in turn to reach the second channel 103b. When it is necessary to recover the unreacted gas and liquid in the gas hydrate stable storage device 1, a recovery pipeline is also configured on the pipeline between the seventh valve 5d and the second channel 103b, and the recovery pipeline is connected between the input pipeline of the first channel 103a and the input pipeline of the second channel 103b. The recovery pipeline is configured with an eighth valve 5e. During the compression molding process of the gas hydrate, the unreacted gas and liquid will be squeezed and expelled to the first channel 103a by the piston rod 103e, and then flow from the recovery pipeline through the eighth valve 5e, the seventh valve 5d, the three-way valve 5c and the sixth valve 5b in sequence to the gas-liquid separation device 5 for recycling and reuse. In an embodiment not shown, a high-pressure back pressure valve is also configured on the recovery pipeline to control the constant and non-constant pressure compression of the gas hydrate during the compression process. By configuring the gas-liquid separation device 5, the hydrate can be squeezed in time during the reaction process to filter out the unreacted liquid and gas without opening the first pressure chamber 101c for manual cleaning, thereby improving the synthesis efficiency.

[0044] A gas hydrate stable storage device 1 is used to allow the gas and liquid to be synthesized to enter the first pressure chamber 101c through the first channel 103a and the second channel 103b respectively to synthesize gas hydrates, and inject pressurized liquid into the second pressure chamber 101d to drive the piston 103 to move to the extended position, so that the gas and liquid in the first pressure chamber 101c are compressed and formed under the pressure of the piston 103 to obtain solid gas hydrates, and then open the switch valve 102 to transfer the solid gas hydrate to the lower shell 104 under pressure to store it at low pressure.

[0045] In addition, a pressurized liquid storage device 6 is also provided, and the pressurized liquid storage device 6 is located upstream of the gas hydrate stable storage device 1, so as to inject pressurized liquid into the second pressure chamber 101d to drive the piston 103 to move to the extended position, thereby realizing the compression molding of gas hydrates. Specifically, the pipeline between the pressurized liquid storage device 6 and the gas hydrate stable storage device 1 is sequentially provided with a ninth valve 6a, a second injection pump 6b and a tenth valve 6c.

[0046] The method applied to the above-mentioned gas hydrate stable storage system comprises the following steps:

[0047] Synthesis of gas hydrates: The gas to be synthesized is pumped into the first pressure chamber 101c through the gas storage device 2. When the first pressure chamber 101c reaches a certain pressure, the pumping of gas is stopped. The liquid to be synthesized is transported and atomized into the first pressure chamber 101c in batches through the liquid storage device 3. When the pressure in the first pressure chamber 101c drops and reaches a certain value, the synthesis of gas hydrates is completed. Specifically, the gas to be synthesized is pumped into the first pressure chamber 101c through the gas storage device 2. When the pressure in the first pressure chamber 101c reaches 5-200MPa, the pumping of gas is stopped. The liquid storage device 3 is used to transport the liquid to be synthesized in batches to the spray head 103d through the first injection pump 3b for atomization and spraying into the first pressure chamber 101c. When the pressure in the first pressure chamber 101c drops and reaches a stable state, the synthesis of gas hydrates is completed.

[0048] Compression molding of gas hydrates: Inject pressurized liquid into the second pressure chamber 101d, drive the piston 103 to move to the extended position, so as to compress and mold the gas hydrates in the first pressure chamber 101c to obtain solid gas hydrates. Specifically, the pressurized liquid is injected into the second pressure chamber 101d by the second injection pump 6b to push the piston 103 to move to the extended position, and the gas hydrates in the first pressure chamber 101c are compressed into a specific shape. Whether the gas hydrates are compressed and molded is mainly determined by the pressure gauge 4b. After compression molding, the reading of the pressure gauge 4b ​​will rise sharply, indicating that there is no space in the first pressure chamber 101c that can be compressed, that is, the compression molding of the gas hydrates is completed. At the same time, by continuously injecting liquid and observing the pressure gauge reading at the front end of the second injection pump 6b, the compression force is adjusted to ensure the stability of the hydrate block tablet. The solid gas hydrate may be in the shape of a cylinder, a sphere or a cube. The diameter of the cylinder is 10-600 mm and the height is 10-100 mm. The diameter of the sphere is 10-300 mm and the side length of the cube is 10-300 mm.

[0049] Low-pressure storage: Open the switch valve 102 to transfer the compressed gas hydrate to the lower shell for low-pressure storage. Specifically, open the switch valve 102 to transfer the compressed gas hydrate to the lower shell pre-filled with liquid. The liquid in the lower shell should be able to evenly form an ice shell or hydrate shell with a thickness of 1-30mm on the surface of the gas hydrate. After the surface of the gas hydrate is covered with an ice shell or hydrate shell, the pressure is gradually reduced to 0.1-10MPa through the exhaust holes on the wall of the lower shell. The temperature and pressure conditions are maintained for more than 6 hours to ensure the complete formation of the ice shell or protective shell, and to prevent the gas hydrate from decomposing during the formation process, thereby increasing the gas storage capacity.

[0050] By repeating the above steps, gas hydrates can be continuously synthesized and stored at low pressure.

[0051] In the process where the piston 103 moves to the extended position to compress and mold the gas hydrate in the first pressure chamber 101c, the unreacted gas and liquid flow back to the gas-liquid separation device 5 through the first channel 103a to separate the unreacted gas and liquid.

[0052] Among them, the working volume of the first pressure chamber 101c in the gas hydrate stable preservation device 1 is 0.1L-1L, the working pressure is 0.1MPa-200MPa, and the working temperature is 253K-298K.

[0053] In general, the gas hydrate stable preservation device of the utility model includes an upper shell, a switch valve, a piston and a lower shell. Through the technical combination of spray and piston, the gas hydrate synthesis and compression molding functions are integrated, which not only improves the generation rate of gas hydrates, but also can be directly compressed and molded after the synthesis is completed, thereby enhancing the stability of gas hydrates, so that gas hydrates can be stably preserved for a long time under relatively mild conditions. The gas hydrate stable preservation system of the utility model includes a gas storage device, a liquid storage device, a data acquisition device, a gas-liquid separation device and a gas hydrate stable preservation device, aiming to achieve continuous synthesis and efficient storage of gas hydrates. The system is not only suitable for the synthesis and preservation of various gas hydrates, but also can synthesize gas hydrates under high pressure conditions and stably preserve them under low pressure environments, while maintaining a high gas storage density, so as to reduce the storage and transportation costs of gas hydrates.

[0054] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principle of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A gas hydrate stable storage device, characterized in that: include: A vertically arranged upper shell, the upper shell having a first cylinder and a top cover located on the first cylinder, the bottom of the first cylinder is open and is provided with a switch valve; A piston, wherein the piston portion is received in the first cylinder for reciprocating between an extended position and a retracted position, a first pressure chamber is defined between one side of the piston and the first cylinder, the first pressure chamber is configured to receive gas hydrates therein, and a second pressure chamber is defined between the other side of the piston and the first cylinder, the second pressure chamber receives pressurized liquid for driving the piston to move toward the extended position, wherein the piston has a first channel for receiving the gas to be synthesized and a second channel for receiving the liquid to be synthesized, and a spray head is disposed at the bottom of the second channel for atomizing the liquid and spraying it into the first pressure chamber; A lower shell is arranged vertically, wherein the lower shell has a second cylinder and a bottom plate located on the second cylinder, the top of the second cylinder is open and detachably connected to the switch valve, wherein pressurized liquid is injected into the second pressure chamber to drive the piston to move to the extended position, so that the gas hydrate in the first pressure chamber is compressed and formed under the pressure of the piston to obtain solid gas hydrate, and then the switch valve is opened to transfer the solid gas hydrate to the lower shell for low-pressure storage.

2. A gas hydrate stable storage device according to claim 1, characterized in that: The piston includes a piston rod and a piston head fixedly connected to the bottom of the piston rod. A telescopic opening for accommodating the piston rod is formed on the top cover. The piston head is located inside the first cylinder body. The outer surface of the piston head is substantially adjacent to the inner surface of the first cylinder body. The piston head defines a second pressure chamber and a first pressure chamber arranged vertically inside the first cylinder body.

3. A gas hydrate stable storage device according to claim 1, characterized in that: A pressure sensor and a temperature sensor are also configured. The sensing part of the pressure sensor enters the first pressure chamber through the first channel. The piston also has a third channel inside for accommodating the temperature sensor. The sensing part of the temperature sensor enters the first pressure chamber through the third channel.

4. A gas hydrate stable storage device according to claim 1, characterized in that: A heating layer is disposed on the inner walls of the first channel and the second channel.

5. A gas hydrate stable storage device according to claim 1, characterized in that: The outer surfaces of the upper shell and the lower shell are both provided with temperature regulating layers.

6. A gas hydrate stable storage device according to claim 1, characterized in that: A support frame and a lifting mechanism located at the bottom of the support frame are also configured. The upper part of the support frame is fixedly connected to the switch valve, and the lower part of the support frame is configured with a fixed platform. The lower shell is located on the fixed platform. The lifting mechanism includes a lifting platform and a telescopic rod fixed at the bottom of the lifting platform. The fixed platform is provided with a lifting port, and the lifting platform cooperates with the lifting port. The lifting platform abuts against the bottom of the lower shell. The bottom of the telescopic rod is connected to a power input piece, and the lifting and lowering of the telescopic rod drives the lifting and lowering of the lower shell to connect or separate the lower shell and the switch valve.

7. A gas hydrate stable storage device according to claim 1, characterized in that: The second cylinder includes a small cylinder and a large cylinder arranged up and down, the top of the small cylinder has a receiving port detachably connected to the switch valve, the diameter of the small cylinder is smaller than the diameter of the large cylinder, and the diameter of the small cylinder is equal to the diameter of the first cylinder.

8. The gas hydrate stable storage device according to claim 1, characterized in that: The gas to be synthesized is one or more of methane, ethane, propane, carbon dioxide or hydrogen; the liquid to be synthesized is pure water, a kinetic additive or a thermodynamic additive, wherein the kinetic additive is a surfactant or an amino acid, and the thermodynamic additive is tetrahydrofuran, 1,3-dioxolane, 1,2-epoxycyclopentane or cyclopentane.

9. A gas hydrate stable storage system, characterized in that: The system comprises: The gas hydrate stable storage device according to any one of claims 1 to 8; A gas storage device, the gas storage device being located upstream of the gas hydrate stabilization storage device, so as to transport the gas to be synthesized into the first pressure chamber through the first channel; A liquid storage device, the liquid storage device is located upstream of the gas hydrate stabilization storage device, so as to transport the liquid to be synthesized into the first pressure chamber through the second channel; A data acquisition device, the data acquisition device is located downstream of the gas hydrate stabilization storage device to collect and analyze the temperature and pressure in the gas hydrate stabilization storage device; A gas-liquid separation device, wherein the gas-liquid separation device is connected to the gas storage device, the liquid storage device and the gas hydrate stabilization storage device, respectively, so as to recover and separate the unreacted gas and liquid in the gas hydrate stabilization storage device through the first channel; The gas hydrate stable storage device is used to allow the gas and liquid to be synthesized to enter the first pressure chamber through the first channel and the second channel respectively to synthesize gas hydrates, and inject pressurized liquid into the second pressure chamber to drive the piston to move to the extended position, so that the gas hydrate in the first pressure chamber is compressed and formed under the pressure of the piston to obtain solid gas hydrates, and then open the switch valve to transfer the solid gas hydrate to the lower shell under pressure for low-pressure storage.

10. A gas hydrate stable storage system according to claim 9, characterized in that: A booster pump is arranged on the pipeline between the gas storage device and the gas hydrate stabilization storage device.

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