An LNG filling station and its filling equipment

Abstract

The present invention provides an LNG filling station and its filling equipment, which adds a temporary storage tank and a first electric control valve on the pressure relief pipeline above the pump pool, so that the vaporized LNG in the pump pool is stored in the temporary storage tank, and then the controller controls the opening of the first electric control valve under preset conditions to make the vaporized LNG stored in the temporary storage tank flow into the pump pool; compared with the prior art in which the vaporized LNG in the pump pool is directly released through a two-way safety valve, the present invention reduces the loss of the vaporized LNG in the pump pool and saves costs.

Description

Technical Field

[0001] The present invention relates to the technical field of LNG filling stations, and particularly to an LNG filling station and its filling equipment. Background Art

[0002] Submersible pumps are often installed in the pump pit of an LNG filling station to transfer the LNG in the pump pit to the dispenser through the submersible pumps; when the refueling vehicles are not continuous, the submersible pumps often stop intermittently, and the intermittent shutdown of the submersible pumps will cause the LNG in the pump pit to vaporize and increase the pressure. The LNG filling station releases the gas in the pump pit through a pressure relief method to ensure that the LNG in the storage tank is transferred to the pump pit; however, when the pressure in the pump pit is too low, LNG vaporization will occur in the pump pit again, and the vaporized LNG will cause a large amount of loss after being released through the pressure relief method. Summary of the Invention

[0003] In view of the above problems, the present invention is proposed to provide an LNG filling station and its filling equipment that can overcome or at least partially solve the above problems, which can solve the problem of excessive loss after LNG vaporization release and achieve the purpose of cost saving.

[0004] Specifically, the present invention provides a filling equipment for an LNG filling station, including:

[0005] A pressure sensor for monitoring the pressures of the pump pit, the temporary storage tank, and the input pipeline;

[0006] A temperature sensor for monitoring the ambient temperature;

[0007] A pump pit for storing and transferring LNG;

[0008] A temporary storage tank for storing the vaporized LNG in the pump pit. The vaporized LNG in the pump pit flows into the temporary storage tank through a first valve and a first check valve in sequence, and the gas in the temporary storage tank flows into the pump pit through a second check valve, a three-way valve, and a first electric control valve in sequence;

[0009] A first electric control valve connected between the temporary storage tank and the pump pit;

[0010] A controller connected to the pressure sensor, the temperature sensor, and the first electric control valve, configured to control the opening and closing of the first electric control valve according to the relationship between the pressure monitored by the pressure sensor, the temperature monitored by the temperature sensor, and the preset conditions.

[0011] Optionally, the temporary storage tank has four connection ports. The first connection port is connected to the first electric control valve through a second check valve and a three-way valve in sequence, the second connection port is connected to the pump pit through a first check valve and a first valve in sequence, the third connection port is connected to the second inlet of a two-way safety valve, and the fourth connection port is connected to a third pressure sensor.

[0012] Optionally, there are at least three of the pressure sensors, including:

[0013] A first pressure sensor, connected inside the pump chamber, for monitoring the pressure of the pump chamber, and the monitored pressure value is the first pressure value;

[0014] A second pressure sensor, connected at the inlet of the pump chamber, for monitoring the pressure of the input pipeline, and the monitored pressure value is the second pressure value;

[0015] A third pressure sensor, connected to the fourth connection port of the temporary storage tank, for monitoring the pressure of the temporary storage tank, and the monitored pressure value is the third pressure value.

[0016] The filling device further includes:

[0017] A second electromagnetic control valve, connected between the first inlet of the two-way safety valve and the pump chamber, and connected to the controller;

[0018] The controller is configured to:

[0019] Control the opening and closing of the second electromagnetic control valve according to the relationship between the pressure monitored by the pressure sensor, the temperature monitored by the temperature sensor and the preset conditions.

[0020] Optionally, the controller is configured to:

[0021] When the temperature monitored by the temperature sensor is higher than the first preset temperature and the second pressure value is not less than the first preset pressure value, control the first electromagnetic control valve to close and the second electromagnetic control valve to open; or,

[0022] When the temperature monitored by the temperature sensor is higher than the first preset temperature and the second pressure value is less than the second preset pressure value, control the first electromagnetic control valve to open and the second electromagnetic control valve to close; or,

[0023] When the temperature monitored by the temperature sensor is higher than the first preset temperature, the second electromagnetic control valve is open and the third pressure value continuously increases or remains at the maximum value, control the first electromagnetic control valve to open.

[0024] Optionally, when the temperature monitored by the temperature sensor is higher than the first preset temperature and the second pressure value is not less than the first preset pressure value, controlling the first electromagnetic control valve to close and the second electromagnetic control valve to open includes:

[0025] When the first pressure value remains unchanged within the first preset time, the controller controls the first electromagnetic control valve to open and controls the first preset pressure value to decrease by the third preset pressure value every first preset time; or,

[0026] Within a first preset time, the first pressure value increases, and the controller controls the first electric control valve to open.

[0027] Optionally, when the temperature monitored by the temperature sensor is higher than a first preset temperature and the second pressure value is less than a second preset pressure value, controlling the first electric control valve to open and the second electric control valve to close includes:

[0028] Within a first preset time, if the third pressure value does not decrease and the first pressure value does not increase, the controller controls the second electric control valve to open and controls the second preset pressure value to decrease by a third preset pressure value every second preset time; or,

[0029] Within a first preset time, if the third pressure value does not decrease and the first pressure value increases, the controller controls the second preset pressure value to decrease by a fourth preset pressure value every second preset time; or,

[0030] Within a first preset time, if the third pressure value decreases and the second pressure value decreases, the controller controls the first electric control valve to close; or,

[0031] Within a first preset time, if the third pressure value decreases and the second pressure value does not decrease, the controller controls the second preset pressure value to increase by a fourth preset pressure value every second preset time.

[0032] Optionally, the controller is configured to:

[0033] When the temperature monitored by the temperature sensor is not higher than a first preset temperature and the second pressure value is not less than a fifth preset pressure value, the controller controls the first electric control valve to close and the second electric control valve to open; or,

[0034] When the temperature monitored by the temperature sensor is not higher than a first preset temperature and the second pressure value is less than a sixth preset pressure value, the controller controls the first electric control valve to open and the second electric control valve to close; or,

[0035] When the temperature monitored by the temperature sensor is not higher than a first preset temperature, the second electric control valve is open, and the third pressure value continuously increases or remains at the maximum value, the controller controls the first electric control valve to open.

[0036] Optionally, when the temperature monitored by the temperature sensor is not higher than a first preset temperature and the second pressure value is not less than a fifth preset pressure value, the controller controls the first electric control valve to close and the second electric control valve to open, including:

[0037] Within a first preset time, the first pressure value remains unchanged, and the controller controls the first electric control valve to open and controls the fifth preset pressure value to decrease by a third preset pressure value every first preset time; or,

[0038] Within a first preset time, the first pressure value increases, and the controller controls the first electric control valve to open.

[0039] Optionally, when the temperature monitored by the temperature sensor is not higher than a first preset temperature and the second pressure value is less than a sixth preset pressure value, the controller controls the first electric control valve to open and the second electric control valve to close, including:

[0040] Within a first preset time, when the third pressure value does not decrease and the first pressure value does not increase, the controller controls the second electric control valve to open and controls the sixth preset pressure value to decrease by a third preset pressure value every second preset time; or,

[0041] Within a first preset time, when the third pressure value does not decrease and the first pressure value increases, the controller controls the sixth preset pressure value to decrease by a fourth preset pressure value every second preset time; or,

[0042] Within a first preset time, when the third pressure value decreases and the second pressure value decreases, the controller controls the first electric control valve to close; or,

[0043] Within a first preset time, when the third pressure value decreases and the second pressure value does not decrease, the controller controls the sixth preset pressure value to increase by a fourth preset pressure value every second preset time.

[0044] Optionally, an LNG filling station includes:

[0045] A storage tank configured to store LNG;

[0046] A filling machine configured to output the LNG;

[0047] The filling device as described in any one of the above, which is connected between the storage tank and the filling machine.

[0048] The present invention provides an LNG filling station and its filling device, which adds a temporary storage tank and a first electric control valve on the pressure relief pipeline above the pump pool, so that the gasified LNG in the pump pool is stored in the temporary storage tank, and then the controller controls the opening of the first electric control valve under preset conditions, and the gasified LNG stored in the temporary storage tank flows into the pump pool; compared with the prior art in which the gasified LNG in the pump pool is directly released through a two-way safety valve, the present invention reduces the loss of the gasified LNG in the pump pool and saves costs.

[0049] From the following detailed description of specific embodiments of the present invention in conjunction with the accompanying drawings, those skilled in the art will become more clearly aware of the above and other objects, advantages and features of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Some specific embodiments of the present invention will be described in detail hereinafter with reference to the accompanying drawings in an exemplary but not limiting manner. The same reference numerals in the drawings denote the same or similar components or parts. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings:

[0051] Figure 1 is a schematic process diagram of an LNG filling station according to an embodiment of the present invention;

[0052] Figure 2 is Figure 1 a partial enlarged view of the filling equipment in

[0053] Figure 3 is a schematic structural diagram of a controller according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0054] The following will refer to Figures 1 to 3 to describe an LNG filling station and its filling equipment according to an embodiment of the present invention. In the description of this embodiment, it should be understood that the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features, that is, including one or more of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined. When a certain feature "includes or contains" a certain or certain features it covers, unless otherwise specifically described, this indicates that other features are not excluded and other features may be further included.

[0055] Unless otherwise clearly defined and limited, the terms "installed", "mounted", "connected", "coupled", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly limited. Those of ordinary skill in the art should be able to understand the specific meanings of the above terms in the present invention according to specific circumstances.

[0056] In addition, in the description of this embodiment, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but in contact through additional features therebetween. That is, in the description of this embodiment, the first feature being "above", "over", and "on top of" the second feature includes the first feature being directly above and diagonally above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "below", "beneath", or "underneath" the second feature may be the first feature being directly below and diagonally below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0057] In the description of this embodiment, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples.

[0058] Figure 1 is a schematic process diagram of an LNG filling station according to an embodiment of the present invention. The LNG filling station includes a storage tank 30 for storing LNG, a filling machine 40 for filling liquid into a vehicle, a filling device 50, and connecting pipelines therebetween. The filling device 50 is connected between the storage tank 30 and the filling machine 40, and there are multiple temperature sensors disposed at key positions of the LNG filling station.

[0059] Figure 2 is Figure 1 a partial enlarged view of the filling device 50 in Figure 2 as shown in Figures 1 to 3, the present invention provides an LNG filling station and its filling equipment, which adds a temporary storage tank 2 and a first electric control valve 4 in the pressure relief pipeline above the pump pool 8, so that the temporary storage tank 2 stores a part of the vaporized LNG in the pump pool 8, reducing the loss of LNG vaporization; the pressure relief pipeline above the pump pool 8 is respectively connected to the first inlet and the second inlet of a two-way safety valve 12. The first inlet of the two-way safety valve 12 is sequentially connected to the pump pool 8 through a second electric control valve 3 and a second valve 11. The second inlet of the two-way safety valve 12 is sequentially connected to the output pipeline of the pump pool 8 through the temporary storage tank 2, a second one-way valve 5, a three-way valve 13, and a first electric control valve 4. Among them, the second inlet of the two-way safety valve 12 is connected to the third connection port of the temporary storage tank 2. The first connection port of the temporary storage tank 2 is connected to the second one-way valve 5, and the flow direction of the second one-way valve 5 is from the temporary storage tank 2 into the output pipeline of the pump pool 8; the second connection port of the temporary storage tank 2 is sequentially connected to the pump pool 8 through a first one-way valve 6 and a first valve 7. The flow direction of the first one-way valve 6 is from the pump pool 8 to the temporary storage tank 2, that is, the vaporized LNG in the pump pool 8 flows into the temporary storage tank 2 through the second one-way valve 6, and the vaporized LNG is reused to reduce the loss; the fourth connection port of the temporary storage tank 2 is connected to a third pressure sensor 14 to detect the pressure of the temporary storage tank; a second pressure sensor 10 is connected to the input pipeline at the inlet of the pump pool 8 to detect the pressure of the input pipeline; a first pressure sensor 9 is connected inside the pump pool 8 to detect the pressure inside the pump pool 8; the above three pressure sensors and the above two electric control valves are connected to a controller, and the controller controls the on-off of the first electric control valve 4 and the second electric control valve 3 under preset conditions according to the pressures detected by the first pressure sensor 9, the second pressure sensor 10, and the third pressure sensor 14 and the temperature of the surrounding environment, realizing the pressure relief of the high-pressure pump pool 8 and the storage of vaporized LNG.

[0060] In some embodiments of the present invention, a filling device 50 of an LNG filling station includes:

[0061] A pressure sensor for monitoring the pressures of the pump pool, the temporary storage tank, and the input pipeline;

[0062] A temperature sensor for monitoring the ambient temperature;

[0063] A pump pool 8 for storing and transporting LNG;

[0064] A temporary storage tank 2 for storing the vaporized LNG in the pump pool 8. The vaporized LNG in the pump pool 8 flows into the temporary storage tank 2 sequentially through a first valve 7 and a first one-way valve 6, and the gas in the temporary storage tank 2 flows into the pump pool 8 sequentially through a second one-way valve 5, a three-way valve 13, and a first electric control valve 4;

[0065] A first electric control valve 4 connected between the temporary storage tank 2 and the pump pool 8;

[0066] A controller 500, connected to the pressure sensor, the temperature sensor and the first electric control valve 4, is configured to control the opening and closing of the first electric control valve 4 according to the relationship between the pressure monitored by the pressure sensor, the temperature monitored by the temperature sensor and a preset condition.

[0067] A storage tank 2 and a first electric control valve 4 are added to the vent pipeline of the existing technical solution. Compared with the vent pipeline in the existing solution that directly releases the vaporized LNG in the pump sump 8 through the two-way safety valve 12, a storage tank 8 is added to the pressure relief pipeline, and the on-off of the circulation between the storage tank 2 and the pump sump 8 is controlled by the first electric control valve 4, so that the storage tank 2 stores some of the vaporized LNG in the pump sump 8, reducing LNG loss. The vaporized LNG in the pump sump 8 flows into the storage tank 2 successively through the first valve 7 and the first check valve 6. The storage tank stores the vaporized LNG flowing out of the pump sump; when the controller 500 controls the opening of the first electric control valve 4 according to the relationship between the pressure monitored by the pressure sensor, the temperature monitored by the temperature sensor and a preset condition, the gas in the storage tank 2 flows into the pump sump 8 successively through the second check valve 5, the three-way valve 13 and the first electric control valve 4, and the gas flowing out of the pump sump 8 is utilized again, reducing LNG loss and saving costs.

[0068] In some embodiments of the present invention, the storage tank 2 has four connection ports. The first connection port is connected to the first electric control valve 4 successively through the second check valve 5 and the three-way valve 13. The second connection port is connected to the pump sump 8 successively through the first check valve 6 and the first valve 7. The third connection port is connected to the second inlet of the two-way safety valve 12. The fourth connection port is connected to the third pressure sensor 14.

[0069] In the present invention, a temporary storage tank 2 is added to the exhaust gas pipeline of the prior art solution. The temporary storage tank 2 has four connection ports, which are respectively connected to different instruments to achieve different functions. The first connection port is successively connected to the first electric control valve 4 through the second one-way valve 5 and the three-way valve 13; the controller 500 controls the opening and closing of the first electric control valve 4 to control the on-off of the vaporized LNG in the temporary storage tank 2 inputting into the pump pool 8. The second one-way valve 5 can prevent the liquid in the pump pool 8 from entering the temporary storage tank 2 when transporting liquid to the liquid filling machine 40 through the output pipeline; the second connection port is successively connected to the pump pool 8 through the first one-way valve 6 and the first valve 7, so that the vaporized LNG in the pump pool 8 can flow into the temporary storage tank 2 through the first one-way valve 6. At the same time, the first one-way valve 6 prevents the gas in the temporary storage tank 2 from flowing back into the pump pool 8; the third connection port is connected to the second inlet of the two-way safety valve 12. When the sum of the pressures at the two inlets of the two-way safety valve 12 exceeds the threshold value of the two-way safety valve 12, the two-way safety valve 12 will open to release the excess vaporized LNG for pressure relief; the fourth connection port is connected to the third pressure sensor 14, which is used to monitor the pressure in the temporary storage tank 2 in real time, so that the controller 500 can control the opening and closing of the first electric control valve 4 and the second electric control valve 3 according to the relationship between the pressures monitored by the third pressure sensor 14, the first pressure sensor 9, the second pressure sensor 10 and the temperature of the current environment and the preset conditions, so as to realize the pressure relief of the pump pool 8 in the high-pressure state and store a part of the vaporized LNG in the temporary storage tank 2, and reuse the vaporized LNG.

[0070] In some embodiments of the present invention, there are at least three pressure sensors, including:

[0071] The first pressure sensor 9 is connected inside the pump pool 8 to monitor the pressure of the pump pool 8, and the monitored pressure value is the first pressure value;

[0072] The second pressure sensor 10 is connected at the inlet of the pump pool 8 to monitor the pressure of the input pipeline, and the monitored pressure value is the second pressure value;

[0073] The third pressure sensor 14 is connected to the fourth connection port of the temporary storage tank 2 to monitor the pressure of the temporary storage tank 2, and the monitored pressure value is the third pressure value.

[0074] The filling device 50 further includes:

[0075] The second electric control valve 3 is connected between the first inlet of the two-way safety valve 12 and the pump pool 8 and is connected to the controller 500;

[0076] The controller 500 is configured to:

[0077] Control the opening and closing of the second electric control valve 3 according to the relationship between the pressure monitored by the pressure sensor, the temperature monitored by the temperature sensor and the preset conditions.

[0078] It has the same connection relationship as the existing solution, but the timing of the controller to control the opening and closing of the second electric control valve is different, reducing the loss of vaporized LNG in the pump pool; the first inlet of the two-way safety valve 12 is successively connected to the pump pool 8 through the second electric control valve 3 and the second valve 11, so that when the pressure in the pump pool 8 is too high, the controller controls the second electric control valve 3 to open, allowing the two-way safety valve 12 to release the vaporized LNG in the pump pool 8 for pressure relief, so that the LNG in the storage tank 30 can flow into the pump pool 8 from the input pipeline; on the basis of the existing technical solution, a first pressure sensor and a third pressure sensor are added to monitor the pressures of the pump pool 8 and the temporary storage tank 2, so that the controller controls the opening and closing of the first electric control valve and the second electric control valve according to the relationship between the monitored pressures, the current ambient temperature and the preset conditions, reducing the loss of vaporized LNG and saving costs; among them, there are at least three pressure sensors to monitor the pressures at different positions; the first pressure sensor 9 is connected inside the pump pool 8 to monitor the pressure of the pump pool; the second pressure sensor 10 is connected at the inlet of the pump pool 8 to monitor the pressure of the input pipeline for the storage tank 30 to input LNG into the pump pool 8; the third pressure sensor 14 is connected to the fourth connection port of the temporary storage tank 2 to monitor the pressure of the temporary storage tank 2, so that the controller 500 can collect the pressure data of the pump pool 8, the temporary storage tank 2 and the input pipeline.

[0079] In some embodiments of the present invention, the controller 500 is configured to:

[0080] When the temperature monitored by the temperature sensor is higher than the first preset temperature and the second pressure value is not less than the first preset pressure value, control the first electric control valve 4 to close and the second electric control valve 3 to open; or,

[0081] When the temperature monitored by the temperature sensor is higher than the first preset temperature and the second pressure value is less than the second preset pressure value, control the first electric control valve 4 to open and the second electric control valve 3 to close; or,

[0082] When the temperature monitored by the temperature sensor is higher than the first preset temperature, the second electric control valve 3 is open and the third pressure value continues to increase or remains at the maximum value, control the first electric control valve 4 to open.

[0083] This embodiment elaborates on controlling the opening and closing of the first electric control valve 4 and the second electric control valve 3 according to the relationship between the pressures monitored by the pressure sensors, the temperature monitored by the temperature sensor and the preset conditions; according to the relationship between the monitored values of temperature and pressure and the preset conditions, control the opening and closing states of the first electric control valve 4 and the second electric control valve 3 to reduce the LNG loss. Taking the first preset temperature as 25 °C, the specific control method is:

[0084] When the temperature monitored by the temperature sensor is higher than 25°C and the second pressure value is not less than the first preset pressure value, control the first electric control valve 4 to close and the second electric control valve 3 to open, and the two-way safety valve 12 opens to release the vaporized LNG in the pump sump 8 connected to the first inlet; or, when the temperature monitored by the temperature sensor is higher than 25°C and the second pressure value is less than the second preset pressure value, control the first electric control valve 4 to open and the second electric control valve 3 to close, and the gas in the storage tank 2 flows into the pump sump 8 through the first electric control valve 4 and is reused by the pump sump 8 again to reduce LNG loss; or, when the temperature monitored by the temperature sensor is higher than 25°C, the second electric control valve 3 is open and the third pressure value continues to increase or remains at the maximum value, control the first electric control valve 4 to open, and the two-way safety valve 12 opens to release the vaporized LNG, and at the same time the gas in the storage tank 2 flows into the pump sump 8 through the first electric control valve 4 to relieve the pressure of the pump sump and ensure the safety of the gas filling station.

[0085] In some embodiments of the present invention, when the temperature monitored by the temperature sensor is higher than the first preset temperature and the second pressure value is not less than the first preset pressure value, controlling the first electric control valve 4 to close and the second electric control valve 3 to open includes:

[0086] When the first pressure value remains unchanged within the first preset time, the controller 500 controls the first electric control valve 4 to open and controls the first preset pressure value to decrease by the third preset pressure value every first preset time; or, when the first pressure value increases within the first preset time, the controller 500 controls the first electric control valve 4 to open.

[0087] Taking the first preset time as thirty minutes and the third preset pressure value as 0.2 KPa as an example; in the state where the temperature monitored by the temperature sensor is higher than the first preset temperature, the second pressure value is not less than the first preset pressure value, the first electric control valve 4 is closed, and the second electric control valve 3 is open, in the first case: within thirty minutes, if the pressure in the pump sump 8 remains unchanged, the controller 500 controls the first electric control valve 4 to open and controls the first preset pressure value to decrease by 0.2 KPa every thirty minutes so that the controller 500 can more accurately control the first electric control valve 4 and the second electric control valve 3; in the second case: within thirty minutes, when the pressure in the pump sump 8 increases, the controller 500 controls the first electric control valve 4 to open, releases the vaporized LNG in the pump sump 8 from the two-way safety valve 12, and at the same time allows the gas in the storage tank 2 to flow to the pump sump 8. The storage tank 2 and the pump sump 8 form a cycle to reduce the pressure of the pump sump 8 and the storage tank 2.

[0088] In some embodiments of the present invention, when the temperature monitored by the temperature sensor is higher than the first preset temperature and the second pressure value is less than the second preset pressure value, controlling the first electric control valve 4 to open and the second electric control valve 3 to close includes:

[0089] Within the first preset time, when the third pressure value does not decrease and the first pressure value does not increase, the controller 500 controls the second electric control valve 3 to open and controls the second preset pressure value to decrease by a third preset pressure value every second preset time; or,

[0090] Within the first preset time, when the third pressure value does not decrease and the first pressure value increases, the controller 500 controls the second preset pressure value to decrease by a fourth preset pressure value every second preset time; or,

[0091] Within the first preset time, when the third pressure value decreases and the second pressure value decreases, the controller 500 controls the first electric control valve 4 to close; or,

[0092] Within the first preset time, when the third pressure value decreases and the second pressure value does not decrease, the controller 500 controls the second preset pressure value to increase by a fourth preset pressure value every second preset time.

[0093] Taking the first preset temperature as 25°C, the first preset time as thirty minutes, the third preset pressure value as 0.2 KPa, the fourth preset pressure value as 0.1 KPa, and the second preset time as ten minutes as an example; when the temperature monitored by the temperature sensor is higher than 25°C and the second pressure value is less than the second preset pressure value, and the first electric control valve 4 is open and the second electric control valve 3 is closed, in the first case: within thirty minutes, when the pressure of the storage tank 2 does not decrease and the pressure of the pump pool 8 does not increase, the controller controls the second electric control valve 3 to open, and at the same time controls the second preset pressure value to decrease by 0.2 KPa every ten minutes to adjust the second preset pressure value so that the controller 500 can control the opening and closing of the first electric control valve 4 and the second electric control valve 3 more precisely; in the second case: within thirty minutes, when the pressure of the storage tank 2 does not decrease and the pressure of the pump pool 8 increases, the controller 500 controls the second preset pressure value to decrease by 0.1 KPa every ten minutes so that the controller 500 can control the opening and closing of the first electric control valve 4 and the second electric control valve 3 more precisely; in the third case: within thirty minutes, when the pressure of the storage tank 2 decreases and the pressure of the input pipeline decreases, the controller 500 controls the first electric control valve 4 to close to keep the pressure of the pump pool 8 within a suitable range; in the fourth case: within thirty minutes, when the pressure of the storage tank 2 decreases and the pressure of the input pipeline does not decrease, the controller 500 controls the second preset pressure value to increase by 0.1 KPa every ten minutes to adjust the second preset pressure value to make the controller 500 control the opening and closing of the first electric control valve 4 and the second electric control valve 3 more precisely.

[0094] In some embodiments of the present invention, the controller is configured to:

[0095] When the temperature monitored by the temperature sensor is not higher than the first preset temperature and the second pressure value is not less than the fifth preset pressure value, the controller 500 controls the first electric control valve 4 to close and the second electric control valve 3 to open; or,

[0096] When the temperature monitored by the temperature sensor is not higher than the first preset temperature and the second pressure value is less than the sixth preset pressure value, the controller 500 controls the first electric control valve 4 to open and the second electric control valve 3 to close; or,

[0097] When the temperature monitored by the temperature sensor is not higher than the first preset temperature, the second electric control valve 3 is open, and the third pressure value continuously increases or remains at the maximum value, the controller 500 controls the first electric control valve 4 to open.

[0098] This embodiment describes the control of the opening and closing of the first electric control valve 4 and the second electric control valve 3 according to the relationship between the pressure monitored by the pressure sensor, the temperature monitored by the temperature sensor, and the preset conditions; according to the relationship between the monitored values of temperature and pressure and the preset conditions, the opening and closing states of the first electric control valve 4 and the second electric control valve 3 are controlled to reduce LNG loss. Taking the first preset temperature as 25°C, the specific control method is as follows:

[0099] When the temperature monitored by the temperature sensor is not higher than 25°C and the pressure of the input pipeline is not less than the fifth preset pressure value, the controller 500 controls the first electric control valve 4 to close and the second electric control valve 3 to open, so that the two-way safety valve 12 relieves the pressure of the pump pool 8; or, when the temperature monitored by the temperature sensor is not higher than 25°C and the pressure of the input pipeline is less than the sixth preset pressure value, the controller 500 controls the first electric control valve 4 to open and the second electric control valve 3 to close, so that the gas in the storage tank 2 flows into the pump pool 8, and the vaporized LNG is reused to reduce LNG loss; or, when the temperature monitored by the temperature sensor is not higher than 25°C, the second electric control valve 3 is open, and the pressure of the storage tank 2 continuously increases or remains at the maximum value, the controller 500 controls the first electric control valve 4 to open to reduce the pressure of the storage tank 2.

[0100] In some embodiments of the present invention, when the temperature monitored by the temperature sensor is not higher than the first preset temperature and the second pressure value is not less than the fifth preset pressure value, the controller 500 controls the first electric control valve 4 to close and the second electric control valve 3 to open, including:

[0101] Within the first preset time, when the first pressure value remains unchanged, the controller 500 controls the first electric control valve 4 to open and controls the fifth preset pressure value to decrease by the third preset pressure value every first preset time; or,

[0102] Within the first preset time, when the first pressure value increases, the controller 500 controls the first electric control valve 4 to open.

[0103] Taking 25°C as an example for the first preset temperature, 30 minutes as an example for the first preset time, and 0.2 KPa as an example for the third preset pressure value; in the state where the temperature monitored by the temperature sensor is not higher than 25°C, the pressure of the input pipeline is not less than the fifth preset pressure value, the first electromagnetic control valve 4 is closed, and the second electromagnetic control valve 3 is opened, there are two cases: In the first case, within 30 minutes, if the pressure of the pump sump 8 remains unchanged, the controller 500 controls the first electromagnetic control valve 4 to open and controls the fifth preset pressure value to decrease by 0.2 KPa every 30 minutes, so that the controller 500 can control the opening and closing of the first electromagnetic control valve 4 and the second electromagnetic control valve 3 more precisely; In the second case, within 30 minutes, if the pressure of the pump sump 8 increases, the controller 500 controls the second electromagnetic control valve 3 to open, so that the storage tank 2 and the pump sump 8 form a cycle to reduce the pressure of the pump sump 8.

[0104] In some embodiments of the present invention, when the temperature monitored by the temperature sensor is not higher than the first preset temperature and the second pressure value is less than the sixth preset pressure value, the controller 500 controls the first electromagnetic control valve 4 to open and the second electromagnetic control valve 3 to close, including:

[0105] Within the first preset time, if the third pressure value does not decrease and the first pressure value does not increase, the controller 500 controls the second electromagnetic control valve 3 to open and controls the sixth preset pressure value to decrease by the third preset pressure value every second preset time; or,

[0106] Within the first preset time, if the third pressure value does not decrease and the first pressure value increases, the controller 500 controls the sixth preset pressure value to decrease by the fourth preset pressure value every second preset time; or,

[0107] Within the first preset time, if the third pressure value decreases and the second pressure value decreases, the controller 500 controls the first electromagnetic control valve 4 to close; or,

[0108] Within the first preset time, if the third pressure value decreases and the second pressure value does not decrease, the controller 500 controls the sixth preset pressure value to increase by the fourth preset pressure value every second preset time.

[0109] Taking 25°C as an example for the first preset temperature, 30 minutes as an example for the first preset time, 0.2 KPa as an example for the third preset pressure value, 0.1 KPa as an example for the fourth preset pressure value, and 10 minutes as an example for the second preset time; in a state where the temperature monitored by the temperature sensor is not higher than 25°C, the pressure of the input pipeline is less than the sixth preset pressure value, the first electric control valve 4 is opened, and the second electric control valve 3 is closed, there are the following three situations: In the first situation, within 30 minutes, the pressure of the storage tank 2 does not decrease, and the pressure of the pump sump 8 does not increase. The controller 500 controls the second electric control valve 3 to open and controls the sixth preset pressure value to decrease by 0.2 KPa every 10 minutes to adjust the sixth preset pressure value, so that the controller 500 can control the opening and closing of the first electric control valve 4 and the second electric control valve 3 more precisely. In the second situation, within 30 minutes, the pressure of the storage tank 2 does not decrease, and the pressure of the pump sump 8 increases. The controller 500 controls the sixth preset pressure value to decrease by 0.1 KPa every 10 minutes to adjust the sixth preset pressure value, so that the controller 500 can control the opening and closing of the first electric control valve 4 and the second electric control valve 3 more precisely. In the third situation, within 30 minutes, the pressure of the storage tank 2 decreases, and the pressure of the input pipeline decreases. The controller 500 controls the first electric control valve 4 to close to keep the pressure of the pump sump 8 within a suitable pressure range and reduce the generation amount of vaporized LNG. When the pressure of the storage tank 2 decreases within 30 minutes and the pressure of the input pipeline does not decrease, the controller 500 controls the sixth preset pressure value to increase by 0.1 KPa every 10 minutes to adjust the sixth preset pressure value, so that the controller 500 can control the opening and closing of the first electric control valve 4 and the second electric control valve 3 more precisely.

[0110] In some embodiments of the present invention, an LNG filling station includes:

[0111] A storage tank 30 configured to store LNG;

[0112] A filling machine 40 configured to output the LNG;

[0113] The filling device 50 as described in any one of the above is connected between the storage tank 30 and the filling machine 40.

[0114] In the LNG filling station, there is a storage tank 30 for storing LNG, a filling machine 40 for filling liquid into a vehicle, and a filling device 50 connected between the two; the LNG in the storage tank 30 flows into the pump sump 8 through an input pipeline, and the liquid in the pump sump 8 is pressurized and conveyed to the filling machine 40 by a submersible pump 1 arranged therein, so that the filling machine 40 can fill the vehicle with liquid.

[0115] In some embodiments of the present invention, the controller 500 includes a memory 520 and a processor 510. The memory 520 stores a machine-executable program 410. When the machine-executable program 410 is executed by the processor 510, it controls the opening and closing of the first electronically controlled valve 4 and / or the second electronically controlled valve 3. The memory 520 stores the data monitored by the first pressure sensor 9, the second pressure sensor 10, the third pressure sensor 14, and the temperature sensor. After comparing the data stored in the memory 520 with the corresponding data in the preset conditions by the processor 510, it controls the opening and closing of the first electronically controlled valve 4 and / or the second electronically controlled valve 3, and its processing process is carried out by executing the machine-executable program 410.

[0116] In some embodiments of the present invention, currently, the intermittent shutdown of the submersible pump 1 will cause the LNG in the pump sump 8 to vaporize, resulting in an increase in the internal pressure of the pump sump 8. The pump sump 8 needs to be depressurized to prevent the air pressure in the pump sump from being too high to receive the liquid in the storage tank 30. However, when the pressure in the pump sump 8 is too low after the vaporized LNG is released, there will be a problem of excessive LNG vaporization, and the released vaporized LNG will increase the LNG loss.

[0117] Add a storage tank 2 to the pressure relief branch above the pump sump 8. The controller controls the on-off of the circulation between the storage tank 2 and the pump sump 8 by controlling the first electronically controlled valve 4. The measured value of the first pressure sensor 9 is P1, the measured value of the second pressure sensor 10 is P2, and the measured value of the third pressure sensor 14 is P3. When the ambient temperature is higher than 25°C, the initial value of the pressure threshold adopts the low-pressure thresholds Pamin and Pamax, Pamax is the first preset pressure value, and Pamin is the second preset pressure value. In this embodiment, the first preset temperature is 25°C as an example. When the ambient temperature is equal to or lower than 25°C, the initial value of the pressure threshold adopts the high-pressure thresholds Pbmin and Pbmax. The fifth preset pressure value is Pbmax, and the sixth preset pressure value is Pbmin. The third preset pressure value is 0.2 KPa as an example, and the fourth preset pressure value is 0.1 KPa as an example. Taking the ambient temperature higher than 25°C as an example, the controller is configured as:

[0118] When the ambient temperature is higher than 25°C,

[0119] (1) When P2 ≥ Pamax, open the second electronically controlled valve and close the first electronically controlled valve.

[0120] If P1 remains unchanged within 30 minutes, open the first electronically controlled valve and reduce Pamax by 0.2 KPa every 30 minutes.

[0121] If P1 increases within 30 minutes, keep the first electronically controlled valve open.

[0122] (2) When P2 < Pamin, close the second electric control valve and open the first electric control valve.

[0123] If within 30 minutes, P3 does not decrease and P1 does not increase, then open the second electric control valve and decrease Pamin by 0.2 KPa every 10 minutes.

[0124] If within 30 minutes, P3 does not decrease but P1 increases, then keep the second electric control valve closed and decrease Pamin by 0.1 KPa every 10 minutes.

[0125] If within 30 minutes, P3 decreases and P2 decreases, then close the first electric control valve and the second electric control valve.

[0126] If within 30 minutes, P3 decreases and P2 does not decrease, then keep the second electric control valve closed and increase Pamin by 0.1 KPa every 10 minutes.

[0127] (3) When the second electric control valve is open, if P3 continuously increases or remains at the maximum value, then open the first electric control valve.

[0128] At this point, those skilled in the art should recognize that although multiple exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications that conform to the principles of the present invention can still be directly determined or derived from the disclosed content of the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and recognized as covering all these other variations or modifications.

Claims

1. A refueling device for an LNG filling station, characterized in that, Comprising: A pressure sensor for monitoring the pressures of the pump pool, the storage tank, and the input pipeline; A temperature sensor for monitoring the ambient temperature; A pump pool for storing and transporting LNG; A storage tank for storing the vaporized LNG in the pump pool. The vaporized LNG in the pump pool flows into the storage tank successively through a first valve and a first check valve, and the gas in the storage tank flows into the pump pool successively through a second check valve, a three-way valve, and a first electric control valve; A first electric control valve connected between the storage tank and the pump pool; A controller connected to the pressure sensor, the temperature sensor, and the first electric control valve, configured to control the opening and closing of the first electric control valve according to the relationship between the pressure monitored by the pressure sensor, the temperature monitored by the temperature sensor, and a preset condition.

2. The filling device according to claim 1, wherein: The storage tank has four connection ports. The first connection port is connected to the first electric control valve successively through a second check valve and a three-way valve. The second connection port is connected to the pump pool successively through a first check valve and a first valve. The third connection port is connected to the second inlet of a two-way safety valve. The fourth connection port is connected to a third pressure sensor.

3. The filling device according to claim 2, wherein: There are at least three pressure sensors, including: A first pressure sensor connected inside the pump pool for monitoring the pressure of the pump pool, and the monitored pressure value is a first pressure value; A second pressure sensor connected at the inlet of the pump pool for monitoring the pressure of the input pipeline, and the monitored pressure value is a second pressure value; A third pressure sensor connected to the fourth connection port of the storage tank for monitoring the pressure of the storage tank, and the monitored pressure value is a third pressure value; The filling device further comprises: A second electric control valve connected between the first inlet of the two-way safety valve and the pump pool and connected to the controller; The controller is configured to: Control the opening and closing of the second electric control valve according to the relationship between the pressure monitored by the pressure sensor, the temperature monitored by the temperature sensor, and a preset condition.

4. The filling device according to claim 3, wherein: The controller is configured to: When the temperature monitored by the temperature sensor is higher than a first preset temperature and the second pressure value is not less than a first preset pressure value, control the first electric control valve to close and the second electric control valve to open; or, When the temperature monitored by the temperature sensor is higher than a first preset temperature and the second pressure value is less than a second preset pressure value, control the first electric control valve to open and the second electric control valve to close; Or, When the temperature monitored by the temperature sensor is higher than a first preset temperature, the second electric control valve is open, and the third pressure value continuously increases or remains at the maximum value, control the first electric control valve to open.

5. The filling device according to claim 4, wherein: The controlling the first electric control valve to close and the second electric control valve to open when the temperature monitored by the temperature sensor is higher than a first preset temperature and the second pressure value is not less than a first preset pressure value includes: When the first pressure value remains unchanged within the first preset time, the controller controls the first electric control valve to open and controls the first preset pressure value to decrease by a third preset pressure value every first preset time; or, When the first pressure value increases within the first preset time, the controller controls the first electric control valve to open.

6. The filling device according to claim 4, wherein When the temperature monitored by the temperature sensor is higher than the first preset temperature and the second pressure value is less than the second preset pressure value, controlling the first electric control valve to open and the second electric control valve to close includes: When the third pressure value does not decrease and the first pressure value does not increase within the first preset time, the controller controls the second electric control valve to open and controls the second preset pressure value to decrease by a third preset pressure value every second preset time; or, When the third pressure value does not decrease and the first pressure value increases within the first preset time, the controller controls the second preset pressure value to decrease by a fourth preset pressure value every second preset time; or, When the third pressure value decreases and the second pressure value decreases within the first preset time, the controller controls the first electric control valve to close; or, When the third pressure value decreases and the second pressure value does not decrease within the first preset time, the controller controls the second preset pressure value to increase by a fourth preset pressure value every second preset time.

7. The filling device according to claim 3, characterized in that The controller is configured to: When the temperature monitored by the temperature sensor is not higher than the first preset temperature and the second pressure value is not less than the fifth preset pressure value, the controller controls the first electric control valve to close and the second electric control valve to open; Or, When the temperature monitored by the temperature sensor is not higher than the first preset temperature and the second pressure value is less than the sixth preset pressure value, the controller controls the first electric control valve to open and the second electric control valve to close; Or, When the temperature monitored by the temperature sensor is not higher than the first preset temperature, the second electric control valve is open, and the third pressure value continuously increases or remains at the maximum value, the controller controls the first electric control valve to open.

8. The filling device according to claim 7, wherein When the temperature monitored by the temperature sensor is not higher than the first preset temperature and the second pressure value is not less than the fifth preset pressure value, the controller controls the first electric control valve to close and the second electric control valve to open, including: When the first pressure value remains unchanged within the first preset time, the controller controls the first electric control valve to open and controls the fifth preset pressure value to decrease by a third preset pressure value every first preset time; or, When the first pressure value increases within the first preset time, the controller controls the first electric control valve to open.

9. The filling device according to claim 7, wherein When the temperature monitored by the temperature sensor is not higher than the first preset temperature and the second pressure value is less than the sixth preset pressure value, the controller controls the first electric control valve to open and the second electric control valve to close, including: Within the first preset time, if the third pressure value does not decrease and the first pressure value does not increase, the controller controls the second electric control valve to open and controls the sixth preset pressure value to decrease by a third preset pressure value every second preset time; or, Within the first preset time, if the third pressure value does not decrease and the first pressure value increases, the controller controls the sixth preset pressure value to decrease by a fourth preset pressure value every second preset time; or, Within the first preset time, if the third pressure value decreases and the second pressure value decreases, the controller controls the first electric control valve to close; or, Within the first preset time, if the third pressure value decreases and the second pressure value does not decrease, the controller controls the sixth preset pressure value to increase by a fourth preset pressure value every second preset time.

10. An LNG filling station, characterized in that, Comprising: A storage tank configured to store LNG; A liquid filling machine configured to output the LNG; The filling device according to any one of claims 1-9, which is connected between the storage tank and the liquid filling machine.

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