Gas hydrate stable storage device, system and method

Abstract

The present invention relates to a gas hydrate stable storage device, system and method, comprising: an upper shell, which has a first cylinder and a top cover, the bottom of the first cylinder is open and is equipped with a switch valve; a piston, which reciprocates inside the first cylinder, a first pressure chamber is defined between one side of the piston and the first cylinder, 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, a first channel and a second channel are provided inside the piston, and a spray head is provided at the bottom of the second channel; a lower shell, which has a second cylinder and a bottom plate located on the second cylinder, the top of the second cylinder is open and is detachably connected to the switch valve, pressurized liquid is injected into the second pressure chamber to drive the piston to move to an 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.

Description

Technical Field

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

[0002] Gas hydrates are a type of gas hydrate that is stably stored within hydrogen-bonded cages of water molecules via van der Waals forces. Hydrate storage technology enables efficient, convenient, and safe storage of gases such as methane, propane, carbon dioxide, and hydrogen. These technologies offer high gravimetric and volumetric gas storage densities, making them energy-efficient, efficient, and safe. However, achieving stable storage of gas hydrates with high gas storage densities currently requires high pressures. This not only places stringent demands on storage equipment but also increases costs and the difficulty of safely storing and transporting gas hydrates, hindering their industrial application. Despite this, the slow formation rate and difficulty in stably storing gas hydrates remain major challenges limiting their industrial application. While current approaches have attempted to increase the formation rate of gas hydrates by increasing the gas-liquid contact area (e.g., bubbling, spraying, mechanical stirring) and the gas-solid contact area (e.g., ice powder grinding), and to achieve stable storage through compression molding and coating, these approaches often present operational conflicts between increasing the formation rate and achieving stable storage. For example, most equipment used for rapid gas hydrate formation lacks the compression molding capability to improve stability, while equipment that does have compression molding capabilities lacks the kinetics to increase the formation rate. This, to a certain extent, restricts the continuous and efficient production of gas hydrate technology. Therefore, the development of a new type of device for the stable preservation of gas hydrates is an urgent problem that needs to be solved. Summary of the Invention

[0003] In response to the technical problems existing in the prior art, the first purpose of the present invention is to provide a gas hydrate stable storage device, which 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 gas hydrate generation rate, but also can be directly compressed and molded after the synthesis is completed, thereby enhancing the stability of the gas hydrate, so that the gas hydrate can be stably stored for a long time under relatively mild conditions.

[0004] A second objective of the present invention is to provide a gas hydrate stabilization storage system, comprising a gas storage device, a liquid storage device, a data acquisition device, a gas-liquid separation device, and a gas hydrate stabilization storage device, designed to enable the continuous synthesis and efficient storage of gas hydrates. This system is not only suitable for the synthesis and storage of a variety of gas hydrates, but also enables the synthesis of gas hydrates under high pressure and their stable storage under low pressure, while maintaining a high gas storage density, thereby reducing gas hydrate storage and transportation costs.

[0005] The third object of the present invention is to provide a method for stabilizing the storage of gas hydrates, by injecting gas and atomized liquid into a gas hydrate stabilization storage device to synthesize gas hydrates, and then compressing the gas hydrates into shape and storing them at low pressure through piston movement.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] 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 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 hydrate 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 There is a first channel for receiving the gas to be synthesized and a second channel for receiving the liquid to be synthesized. The bottom of the second channel is provided with a spray head for atomizing the liquid and spraying it into the first pressure chamber; the lower shell is arranged vertically, and 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.

[0008] 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. The outer surface of the piston head is roughly adjacent to the inner surface of the first cylinder. The piston head defines a second pressure chamber and a first pressure chamber arranged vertically inside the first cylinder.

[0009] 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.

[0010] Furthermore, heating layers are provided on the inner walls of the first channel and the second channel; and temperature regulating layers are provided on the outer surfaces of the upper shell and the lower shell.

[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, 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 to 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. 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 that is 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] According to the system using the above-mentioned gas hydrate stable storage device, it includes: a gas storage device, which is located upstream of the gas hydrate stable storage device to transport the gas to be synthesized to the first pressure chamber through the first channel; a liquid storage device, which is located upstream of the gas hydrate stable storage device to transport the liquid to be synthesized to the first pressure chamber through the second channel; a data acquisition device, which is located downstream of the gas hydrate stable storage device to collect and analyze the temperature and pressure in the gas hydrate stable storage device; a gas-liquid separation device, which is connected to the gas storage device and the storage device respectively. The liquid device is connected to the gas hydrate stabilization storage device to recover and separate the unreacted gas and liquid in the gas hydrate stabilization storage device through the first channel; 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 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 hydrate, and then the switch valve is opened to transfer the solid gas hydrate to the lower shell under pressure for low-pressure storage.

[0014] Furthermore, a booster pump is provided on the pipeline between the gas storage device and the gas hydrate stabilization storage device.

[0015] The method applied to the above-mentioned gas hydrate stable preservation system includes the following steps: pumping the gas to be synthesized into the first pressure chamber through the gas storage device, stopping the pumping of the gas when the first pressure chamber reaches a certain pressure, and delivering the liquid to be synthesized in batches and atomizing it into the first pressure chamber through the liquid storage device. When the pressure in the first pressure chamber drops and reaches a certain value, the gas hydrate synthesis is completed; injecting pressurized liquid into the second pressure chamber, driving the piston to move to the extended position, so as to compress and mold the gas hydrate in the first pressure chamber to obtain solid gas hydrate; opening the switch valve, and transferring the compressed and molded gas hydrate to the lower shell under pressure for low-pressure storage.

[0016] Furthermore, in the process of the piston moving to the extended position to compress and form the gas hydrate in the first pressure chamber, the unreacted gas and liquid flow back to the gas-liquid separation device through the first channel to separate the unreacted gas and liquid.

[0017] The present invention has the following advantages:

[0018] 1. The gas hydrate stabilization storage device of the present invention comprises an upper shell, an on-off valve, a piston, and a lower shell. Through the technical combination of spraying and piston, it achieves the integration of gas hydrate synthesis and compression molding functions. This not only improves the gas hydrate generation rate, but also enables direct compression molding after synthesis, thereby enhancing the stability of the gas hydrates and allowing the gas hydrates to be stably stored for a long time under relatively mild conditions.

[0019] 2. The gas hydrate stabilization storage system of the present invention, comprising a gas storage device, a liquid storage device, a data acquisition device, a gas-liquid separation device, and a gas hydrate stabilization storage device, is designed to achieve continuous synthesis and efficient storage of gas hydrates. This system is not only suitable for the synthesis and storage of a variety of gas hydrates, but also enables synthesis of gas hydrates under high pressure and stable storage under low pressure, while maintaining a high gas storage density, thereby reducing gas hydrate storage and transportation costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the three-dimensional structure of the gas hydrate stable storage device of the present invention.

[0021] Figure 2 It is a three-dimensional exploded view of the gas hydrate stable storage device of the present invention.

[0022] Figure 3 It is a cross-sectional view of the gas hydrate stable storage device of the present invention.

[0023] Figure 4 It is a three-dimensional cutaway view of the upper housing and the piston of the present invention.

[0024] Figure 5It is a cutaway view of the upper housing and the piston of the present invention.

[0025] Figure 6 It is a schematic diagram of the three-dimensional structure of the piston of the present invention.

[0026] Figure 7 It is a schematic diagram of the three-dimensional structure of the lower shell of the present invention.

[0027] Figure 8 It is a schematic diagram of the three-dimensional structure of the support frame and the lifting mechanism of the present invention.

[0028] Figure 9 It is a schematic flow diagram of the gas hydrate stable storage system of the present invention.

[0029] 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

[0030] The following description is essentially only exemplary and is not intended to limit the present invention, its application, or use. It will be further understood that the terms "comprise" and / or "comprising" specify the existence of the features, wholes, steps, operations, elements and / or parts described when used in this specification, but do not exclude the existence of one or more other features, wholes, steps, operations, elements, parts and / or their groups or add one or more other features, wholes, steps, operations, elements, parts and / or their groups. As used herein, 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 teachings of the present invention. Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as those commonly understood by those of ordinary skill in the art to which the present invention belongs. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning 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 herein.

[0031] 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.

[0032] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] like Figure 1-8As shown, a gas hydrate stable storage device includes: a vertically arranged upper shell 101, 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 equipped with a switch valve 102, the upper shell 101 is made of stainless steel, and the top cover 101b is equipped with a liquid injection hole 101b2, wherein the switch valve 102 is a gate valve or a ball valve. The piston 103 is partially received in the first cylinder 101a for reciprocating movement between an extended position and a retracted position, wherein the extended position of the piston 103 is the position where the piston 103 moves downward, and the retracted position of the piston 103 is the 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. 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. 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. 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. A spray head 103d is located at the bottom of the second channel 103b, atomizing the liquid and spraying it into the first pressure chamber 101c. The bottom of the spray head 103d is aligned with one side of the piston 103. The spray head 103d disperses the liquid in a spray form, increasing the gas-liquid contact area and thereby improving the efficiency of gas hydrate synthesis. The spray head 103d can be a micro-pressure nozzle, a low-pressure nozzle, a medium-pressure nozzle, or a high-pressure nozzle. The upper housing 101, the piston 103, and the on-off 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, which are used to improve the stability of gas hydrates stored under low pressure.

[0034] The gas and liquid to be synthesized are first injected into the first pressure chamber 101c through the first channel 103a and the second channel 103b, respectively, to form gas hydrates under a certain pressure. Then, pressurized liquid is injected into the second pressure chamber 101d, driving the piston 103 to its extended position. This compresses the gas hydrates in the first pressure chamber 101c under the pressure of piston 103 to form solid gas hydrates. The on-off valve 102 is then opened to transfer the solid gas hydrates to the lower housing 104 for low-pressure storage. The entire device achieves continuous synthesis and efficient storage of gas hydrates, is applicable to the synthesis and storage of a variety of gas hydrates, and significantly reduces storage and transportation costs.

[0035] 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. 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. 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 to ensure that the independent separation of the internal space of the first cylinder 101a is not affected during the movement of the piston 103. The upper surface of the piston head 103f, the inner surface of the first barrel 101a, and the lower surface of the top cover 101b collectively form a second pressure chamber 101d. The piston rod 103e is located on the central axis of the second pressure chamber 101d, ensuring the stability of the movement of the piston 103 and facilitating the uniform distribution of the pressure of the pressurized liquid. The lower surface of the piston head 103f, the inner surface of the first barrel 101a, and the top of the switch valve 102 collectively form a first pressure chamber 101c. As the piston 103 moves downward, the volume of the first pressure chamber 101c gradually decreases, and the gas hydrate is compressed and molded under high pressure to form a solid gas hydrate. The top of the piston rod 103e is also equipped with a drive member for driving the piston rod 103e to reciprocate.

[0036] In an unillustrated embodiment, a pressure sensor and a temperature sensor are also provided. The sensing portion of the pressure sensor enters the first pressure chamber 101c through the first channel 103a. The piston 103 also has a third channel 103c inside for receiving a temperature sensor, the sensing portion of which enters the first pressure chamber 101c through the third channel 103c. The pressure and temperature sensors are used to monitor the pressure and temperature of the gas phase in real time. Both the pressure and temperature sensors are signal-connected to an external data acquisition device 4. The first channel 103a, the second channel 103b, and the third channel 103c extend vertically downward from the top of the piston rod 103e to the bottom of the piston head 103f.

[0037] In an embodiment not shown, heating layers are provided on the inner walls of the first channel 103a and the second channel 103b. A heating layer is also provided within the piston rod 103e. These heating layers correspond to the first channel 103a, the second channel 103b, and the third channel 103c. When hydrate or ice blockage occurs within the channel, the heating layers can quickly initiate the heating process, effectively unblocking the blockage by raising the temperature within the channel, thereby preventing the liquid from undergoing a phase transition 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 temperature-regulating layers to maintain a constant temperature for the gas hydrates within them and to prevent the external environment from adversely affecting the temperature of the gas hydrates within them.

[0038] 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 further 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. The lifting platform 106a cooperates with the lifting port 105a1. The lifting platform 106a abuts against the bottom of the lower shell 104. The bottom of the telescopic rod 106b is connected to a power input member 106c. 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. The support frame 105 comprises four vertical support columns and a cross brace connecting two of the columns. A mounting opening for mounting and transferring the lower housing 104 is formed between the two support columns and the cross brace. A fixing platform 105a is fixed to the bottom of the four support columns. The ends of the on-off valve 102 are fixed to two opposing cross braces. The fixing platform 105a is positioned at a distance from the ground to accommodate the lifting mechanism 106. To assemble the lower housing 104 and the on-off valve 102, the lifting platform 106a is first aligned with the fixing platform 105a, and then the lower housing 104 is placed on the lifting platform 106a. To assemble the lower housing 104 and the on-off valve 102, the power input 106c drives the telescopic rod 106b, raising the lifting platform 106a until it firmly abuts the bottom of the lower housing 104, preventing leakage of gas hydrates. In the assembled state, the lifting platform 106a is higher than the fixing platform 105a, providing sufficient space for the connection between the lower housing 104 and the on-off valve 102. When the lower housing 104 loaded with gas hydrates needs to be disassembled and transferred, the power input member 106c can be reversed to retract the telescopic rod 106b, driving the lifting platform 106a to descend to a position flush with the fixed platform 105a, and the lower housing 104 can be removed. In an embodiment not shown, the lower housing 104 and the switch valve 102 are connected by a threaded connection. The bottom of the switch valve 102 has an internal threaded hole, and the top of the lower housing 104 is configured with a corresponding external thread. The telescopic rod 106b also has a rotation function. During the process of lifting the telescopic rod 106b, it can rotate simultaneously, so that the external thread of the lower housing 104 can be screwed into the internal threaded hole of the switch valve 102, which not only enhances the stability of the connection but also ensures the sealing of the connection.

[0039] like Figure 3 and Figure 7As shown, the second cylinder 104a includes a small cylinder 104a1 and a large cylinder 104a2 arranged vertically. 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 that of the large cylinder 104a2, resulting in a convex cross-section of the small and large cylinders 104a1 and 104a2. The interior of the large cylinder 104a2 provides more space to accommodate and store multiple columnar solid gas hydrates. The diameter of the small cylinder 104a1 is equal to that of the first cylinder 101a, allowing the solid gas hydrates to pass smoothly and avoid clogging or blocking.

[0040] like Figure 9 As shown, according to the system using the above-mentioned gas hydrate stable storage device, it includes:

[0041] Gas storage device 2, located upstream of gas hydrate stabilization and storage device 1, transports the gas to be synthesized through first channel 103a to first pressure chamber 101c. The gas to be synthesized enters first pressure chamber 101c from first channel 103a. A pressure reducing valve 2a, a first valve 2b, a booster pump 2c, and a second valve 2d are sequentially disposed on the pipeline between gas storage device 2 and gas hydrate stabilization and storage device 1. The gas to be synthesized in gas storage device 2 is one or more of methane, ethane, propane, carbon dioxide, or hydrogen.

[0042] A liquid storage device 3 is located upstream of the gas hydrate stabilization and storage device 1 to transport the liquid to be synthesized into the first pressure chamber 101c through the second channel 103b. A third valve 3a, a first injection pump 3b, and a fourth valve 3c are sequentially arranged on the pipeline between the liquid storage device 3 and the gas hydrate stabilization and storage device 1. The liquid to be synthesized in the liquid storage device 3 is a solution containing pure water or other mixed dynamic or thermodynamic additives. Dynamic additives include surfactants and amino acids, while thermodynamic additives include tetrahydrofuran, 1,3-dioxolane, 1,2-epoxycyclopentane, and cyclopentane. The volume of the liquid storage device 3 ranges from 1L to 100L.

[0043] The data acquisition device 4 is located downstream of the gas hydrate stabilization and storage device 1 to collect and analyze the temperature and pressure in the gas hydrate stabilization and 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, and 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.

[0044] 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 booster 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 to transport the separated liquid to the liquid storage device 3. The second section of the pipeline is equipped with a fifth valve 5a. The third section of the pipeline is connected to the second channel 103b of the gas hydrate stabilization storage device 1, and the pipeline is equipped with a sixth valve 5b, a three-way valve 5c and a seventh valve 5d in sequence. 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 sequence to reach the second channel 103b. When it is necessary to recover unreacted gas and liquid in the gas hydrate stabilization storage device 1, a recovery pipeline is also configured on the pipeline between the seventh valve 5d and the second channel 103b. 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 equipped with an eighth valve 5e. During the compression molding process of the gas hydrate, the unreacted gas and liquid will be squeezed and expelled into 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 be recovered 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 out 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.

[0045] A gas hydrate stabilization 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 for low-pressure storage.

[0046] A pressurized liquid storage device 6 is also provided upstream of the gas hydrate stabilization and storage device 1. This device injects pressurized liquid into the second pressure chamber 101d, driving the piston 103 toward its extended position and achieving compression molding of the gas hydrates. Specifically, the pipeline between the pressurized liquid storage device 6 and the gas hydrate stabilization and storage device 1 is sequentially equipped with a ninth valve 6a, a second injection pump 6b, and a tenth valve 6c.

[0047] The method applied to the above-mentioned gas hydrate stabilization storage system comprises the following steps:

[0048] Gas hydrate synthesis: The gas to be synthesized is pumped into the first pressure chamber 101c via the gas storage device 2. When the first pressure chamber 101c reaches a certain pressure, gas pumping is stopped. The liquid to be synthesized is delivered in batches via the liquid storage device 3 and atomized into the first pressure chamber 101c. When the pressure in the first pressure chamber 101c drops and reaches a certain value, gas hydrate synthesis is completed. Specifically, the gas to be synthesized is pumped into the first pressure chamber 101c via the gas storage device 2. When the pressure in the first pressure chamber 101c reaches 5-200 MPa, gas pumping is stopped. The liquid to be synthesized is delivered in batches to the spray head 103d via the first liquid injection pump 3b using the liquid storage device 3 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, gas hydrate synthesis is completed.

[0049] Compression molding of gas hydrates: pressurized liquid is injected into the second pressure chamber 101d, and the piston 103 is driven to move toward the extended position 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 toward 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 judged by the pressure gauge 4b. After compression molding, the reading of the pressure gauge 4b ​​will rise sharply, indicating that there is no space left to be compressed in the first pressure chamber 101c, 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 shape of the solid gas hydrate can be 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.

[0050] Low-pressure storage: Open the on-off valve 102 to transfer the compressed gas hydrate to the lower shell under pressure for low-pressure storage. Specifically, open the on-off 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 the 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, prevent the gas hydrate from decomposing during the formation process, and increase the gas storage capacity.

[0051] By repeating the above steps, gas hydrates can be continuously synthesized and stored at low pressure.

[0052] In the process of the piston 103 moving to the extended position to compress and form 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.

[0053] Among them, the working volume of the first pressure chamber 101c in the gas hydrate stable storage device 1 is 0.1L-1L, the working pressure is 0.1MPa-200MPa, and the working temperature is 253K-298K.

[0054] In general, the gas hydrate stable storage device of the present invention 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 and allowing gas hydrates to be stably stored for a long time under relatively mild conditions. The gas hydrate stable storage system of the present invention 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, aiming to achieve continuous synthesis and efficient storage of gas hydrates. The system is not only suitable for the synthesis and storage of various 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 help reduce the storage and transportation costs of gas hydrates.

[0055] The above embodiments are preferred implementations of the present invention, but the implementations of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A gas hydrate stable storage device, characterized in that: include: A vertically arranged upper shell having a first cylinder and a top cover located on the first cylinder, wherein the bottom of the first cylinder is open and is provided with an on-off valve; a piston, wherein the piston portion is received within the first cylinder for reciprocating movement 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 being 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 receiving pressurized liquid for driving the piston 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 vertically arranged 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. Pressurized liquid is injected into the second pressure chamber to drive the piston to an extended position, causing the gas hydrate in the first pressure chamber to be compressed and molded under the pressure of the piston to obtain solid gas hydrate. The switch valve is then opened to transfer the solid gas hydrate to the lower shell for low-pressure storage. The piston includes a piston rod and a piston head fixedly connected to the bottom of the piston rod. A telescopic opening for receiving the piston rod is formed on the top cover. The piston head is located inside the first cylinder. The outer surface of the piston head is substantially adjacent to the inner surface of the first cylinder. The piston head defines a second pressure chamber and a first pressure chamber arranged vertically inside the first cylinder. It is also equipped with a support frame and a lifting mechanism located at the bottom of the support frame. The upper part of the support frame is fixedly connected to the switch valve, and the lower part of the support frame is equipped 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 to 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. 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.

2. A gas hydrate stable storage device according to claim 1, characterized in that: A pressure sensor and a temperature sensor are also provided. 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 receiving the temperature sensor. The sensing part of the temperature sensor enters the first pressure chamber through the third channel.

3. The gas hydrate stable storage device according to claim 1, characterized in that: The inner walls of the first channel and the second channel are both provided with a heating layer; the outer surfaces of the upper shell and the lower shell are both provided with a temperature regulating layer.

4. The 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 that is detachably connected to the switch valve. The diameter of the small cylinder is smaller than that of the large cylinder and is equal to that of the first cylinder.

5. A gas hydrate stabilization storage system, using the gas hydrate stabilization storage device according to any one of the above claims, characterized in that: The system comprises: a gas storage device, the gas storage device being located upstream of the gas hydrate stabilization storage device, for transporting the gas to be synthesized into the first pressure chamber through the first channel; a liquid storage device, the liquid storage device being located upstream of the gas hydrate stabilization storage device, for transporting the liquid to be synthesized into the first pressure chamber through the second channel; A data acquisition device, 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, the gas-liquid separation device being connected to the gas storage device, the liquid storage device and the gas hydrate stabilization storage device, respectively, to recover and separate unreacted gas and liquid in the gas hydrate stabilization storage device through the first channel; A gas hydrate stabilization and preservation 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 preservation.

6. A gas hydrate stabilization storage system according to claim 5, characterized in that: A booster pump is provided on the pipeline between the gas storage device and the gas hydrate stabilization storage device.

7. A gas hydrate stabilization storage method, applied to the gas hydrate stabilization storage system according to claim 5, characterized in that: The method comprises the following steps: The gas to be synthesized is pumped into the first pressure chamber through the gas storage device. When the first pressure chamber reaches a certain pressure, the gas pumping is stopped. The liquid to be synthesized is delivered in batches and atomized into the first pressure chamber through the liquid storage device. When the pressure in the first pressure chamber drops and reaches a certain value, the gas hydrate synthesis is completed. injecting pressurized liquid into the second pressure chamber and driving the piston to move toward the extended position to compress and mold the gas hydrate in the first pressure chamber to obtain solid gas hydrate; The switch valve is opened to transfer the compressed gas hydrate to the lower shell for low-pressure storage.

8. The method for stabilizing gas hydrate storage according to claim 7, characterized in that: During the process of the piston moving to the extended position to compress and form the gas hydrate in the first pressure chamber, the unreacted gas and liquid flow back to the gas-liquid separation device through the first channel to separate the unreacted gas and liquid.

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