Natural gas dispensing system

Abstract

This utility model belongs to the field of gas control technology, specifically disclosing a natural gas refueling system, including a controller, an inlet container, an inlet control component, an exhaust container, a frequency converter, a drive component, and a compression component. The compression component is divided into M groups, and each group starts independently. Each compression component includes m reciprocating compressors, which start simultaneously. The m reciprocating compressors correspond to two sets of first-stage branch pipes. When only one set of first-stage branch pipes is opened, only one inlet pipe on the reciprocating compressor injects natural gas into the working chamber. When both sets of second-stage branch pipes are opened simultaneously, both inlet pipes on the reciprocating compressor inject natural gas into the working chamber. Therefore, the amount of natural gas entering each reciprocating compressor can be determined by the number of solenoid valves opened, thereby achieving gas volume regulation and distribution.

Description

Technical Field

[0001] This utility model belongs to the field of gas control technology, and in particular relates to a natural gas refueling system. Background Technology

[0002] LNG (liquefied natural gas) is a clean and efficient energy source. Natural gas is increasingly favored as a clean energy source, and many countries have listed LNG as their preferred fuel, leading to a rapid increase in its proportion of energy supply. LNG vehicles, as a national clean energy vehicle, have experienced rapid development in recent years, and LNG refueling stations have sprung up on a large scale.

[0003] An LNG refueling machine is a device used to refuel liquefied natural gas (LNG) vehicles. It features high-performance gas delivery pipes and durable corrosion resistance. The main function of an LNG refueling machine is to inject liquefied natural gas into LNG-fueled vehicles to meet their operational needs. The working principle of the natural gas compressor is as follows: an electric motor drives the compressor crankshaft via a coupling, which in turn drives the connecting rod and crosshead, causing the piston to reciprocate within the cylinder. As the piston moves from the inner dead center, a low-pressure area forms outside the piston within the cylinder, causing the intake valve to open and allowing gas to enter. When the piston moves towards the inner dead center, the intake valve closes, and the gas within the cylinder is gradually compressed and its pressure increased. As the piston continues to move towards the inner dead center, the gas within the cylinder is gradually compressed and its pressure increased. Once the pressure exceeds the gas pressure outside the exhaust valve, the exhaust valve opens, and the compressed gas begins to be discharged. When the piston reaches the outer dead center, the exhaust process is complete, thus completing one working cycle. Through the continuous reciprocating motion of the piston, the compressor continuously produces compressed gas. The compressed gas is discharged through the exhaust valve, completing the entire working cycle.

[0004] Using only one compressor for compression results in low compression efficiency and a high compressor load. Currently, to increase compression efficiency, multiple compressors are typically used. These compressors are usually controlled independently or in combination. Independent control generally involves each compressor starting and stopping individually, while combined control involves multiple compressors starting and stopping simultaneously. When the volume of gas to be compressed is small, simultaneous operation of multiple compressors can lead to resource waste and prolonged compressor operating time. Furthermore, when each compressor is started and stopped individually, one compressor may be used excessively, while others remain idle, failing to make efficient use of the multiple compressors. Utility Model Content

[0005] The purpose of this invention is to provide a natural gas refueling system that controls the number of compressors to be started based on the gas volume, so that each compressor can be used rationally.

[0006] To achieve the above objectives, the technical solution of this utility model is as follows: a natural gas refueling system, comprising a controller, an inlet container, an inlet control component, an exhaust container, a frequency converter, a drive component, and a compression component; the controller is connected to the inlet control component, the frequency converter, the drive component, and the compression component; the inlet of the inlet container is connected to external natural gas, the outlet of the inlet container is connected to the inlet of the compression component through the inlet control component, the outlet of the compression component is connected to the inlet of the exhaust container, and the outlet of the exhaust container is connected to an exhaust pipe; the inlet control component includes a main pipe, a first-stage branch pipe assembly, a second-stage branch pipe assembly, and a solenoid valve; the first-stage branch pipe assembly is provided in n groups, each group of first-stage branch pipe assemblies includes two groups of first-stage branch pipes, and each group of first-stage branch pipes is provided with a set of the solenoid valves for opening and closing the connection of the first-stage branch pipes; the inlet ends of the first-stage branch pipes are respectively connected to the main pipe, each group of first-stage branch pipes corresponds to a group of second-stage branch pipe assemblies, and each group of second-stage branch pipe assemblies includes m groups of second-stage branch pipe assemblies. The system comprises a first-stage branch pipeline, the outlet of which is connected to the inlet of m groups of second-stage branch pipelines; the compression assembly comprises M groups, each group including m groups of reciprocating compressors; the intake port of each group of reciprocating compressors is connected to two intake pipes, each intake pipe having a pneumatic intake valve, and the intake port communicating with two working chambers of the reciprocating compressor; the two working chambers correspond to two outlets; the two intake pipes are connected to two groups of second-stage branch pipelines, and the two groups of second-stage branch pipelines are connected to different first-stage branch pipelines; the drive assembly is used to start and stop the compression assembly, and the frequency converter is used to adjust the drive frequency of the drive assembly; the start and stop of the drive assembly and the compression assembly are controlled by a controller or manually, and the controller stores A gears, where A = 2n; the first gear starts only one solenoid valve and the reciprocating compressor corresponding to that solenoid valve, the second gear starts two solenoid valves and the reciprocating compressors corresponding to those two solenoid valves, and so on, with the last gear starting all solenoid valves and all reciprocating compressors.

[0007] Furthermore, the drive assembly includes electric motors, and the number of electric motors is the same as the number of reciprocating compressors and corresponds one-to-one.

[0008] Furthermore, the drive assembly includes electric motors, the number of which is the same as the number of compressor assemblies, with each electric motor used to simultaneously start m reciprocating compressors.

[0009] Furthermore, a first pressure transmitter is connected inside the air intake container, and a second pressure transmitter is connected inside the exhaust container. The first pressure transmitter is connected to the frequency converter. The frequency converter adjusts the frequency of the motor according to the pressure value transmitted by the first pressure transmitter.

[0010] The working principle of this technical solution is as follows: During compression, each component is opened, and the number of solenoid valves and motors opened and closed is selected according to the gas volume. The frequency converter adjusts the output frequency according to the pressure value transmitted by the first pressure transmitter. The natural gas in the intake container enters the first-stage branch pipe through the main pipeline, where the solenoid valve is opened. Then, it enters the second-stage branch pipe through the first-stage branch pipe. The natural gas in the second-stage branch pipe opens the corresponding pneumatic intake valve and enters the suction port, thus flowing into the two working chambers of the reciprocating compressor. The reciprocating compressor compresses the natural gas in the two working chambers through reciprocating motion. The compressed natural gas is then discharged into the exhaust container for storage through the exhaust port.

[0011] The beneficial effects of this technical solution are as follows:

[0012] ① In this technical solution, the compression assembly is divided into M groups, and each group of M compression assemblies starts independently. Each group of compression assemblies includes m reciprocating compressors, so these m reciprocating compressors start simultaneously. The m reciprocating compressors correspond to two sets of first-stage branch pipes. When only one set of first-stage branch pipes is opened, only one intake pipe on the reciprocating compressor will inject natural gas into the working chamber. When both sets of second-stage branch pipes are opened simultaneously, both intake pipes on the reciprocating compressor will inject natural gas into the working chamber. Therefore, the amount of natural gas entering each reciprocating compressor can be determined by the number of solenoid valves opened, thereby achieving the regulation and distribution of gas volume.

[0013] ②This technical solution divides the compressor control into A levels according to the amount of gas to be compressed, so that multiple compressors can be started and stopped reasonably and the amount of gas can be distributed. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the natural gas refueling system of this utility model;

[0015] Figure 2 for Figure 1 Schematic diagram of the intake control assembly and compression assembly;

[0016] Figure 3 This is a diagram showing the air volume regulation and allocation for the compression component. Detailed Implementation

[0017] The following detailed description illustrates the specific implementation method:

[0018] The reference numerals in the accompanying drawings include: frequency converter 1, electric motor 2, air inlet container 3, exhaust container 4, air inlet control assembly 5, first pressure transmitter 6, second pressure transmitter 7, solenoid valve 8, main pipeline 9, first-stage branch pipeline 10, second-stage branch pipeline 11, reciprocating compressor 12, and pneumatic air inlet valve 13.

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] The basic implementation examples are as follows: Figure 1-3 The diagram shows a natural gas refueling system, including a controller, an inlet container 3, an inlet control component 5, an exhaust container 4, a frequency converter 1, a drive component, and a compression component. The controller is connected to the inlet control component 5, the frequency converter 1, the drive component, and the compression component. The inlet of the inlet container 3 is connected to external natural gas, and the outlet of the inlet container 3 is connected to the inlet of the compression component via the inlet control component 5. The outlet of the compression component is connected to the inlet of the exhaust container 4, and the outlet of the exhaust container 4 is connected to an exhaust pipe.

[0021] like Figure 2 As shown, the intake control component 5 includes a main pipe 9, a first-stage branch pipe assembly, a second-stage branch pipe assembly, and a solenoid valve 8. The first-stage branch pipe assembly has n groups (n is 2 in this embodiment). Each group of first-stage branch pipe assemblies includes two groups of first-stage branch pipes 10. Each group of first-stage branch pipes 10 is equipped with a solenoid valve 8 for opening and closing the connection of the first-stage branch pipes 10. The solenoid valve 8 is connected to the controller. The intake end of the first-stage branch pipes 10 is connected to the main pipe 9. Each group of first-stage branch pipes 10 corresponds to a group of second-stage branch pipe assemblies. Each group of second-stage branch pipe assemblies includes m groups of second-stage branch pipes 11 (m is 2 in this embodiment). The exhaust end of the first-stage branch pipes 10 is connected to the intake end of the m groups of second-stage branch pipes 11. The compression assembly is provided with M groups (M is 2 in this embodiment), and each compression assembly includes m groups of reciprocating compressors 12; the suction port of each reciprocating compressor 12 is connected to two intake pipes, and each intake pipe is provided with a pneumatic intake valve 13. The suction port is connected to the two working chambers of the reciprocating compressor 12 respectively; the two working chambers correspond to two outlets respectively; the two intake pipes are connected to two groups of second-level branch pipes 11 respectively, and the two groups of second-level branch pipes 11 are connected to different first-level branch pipes 10.

[0022] That is, in this embodiment, the first-level branch pipe assembly is provided in 2 groups, and each group of the first-level branch pipe assembly includes two groups of first-level branch pipes 10, that is, there are a total of 4 groups of first-level branch pipes 10. Each group of first-level branch pipes 10 corresponds to 2 groups of second-level branch pipes 11, and the reciprocating compressor 12 has a total of 4 groups.

[0023] The drive assembly is used to start and stop the compression assembly, and the frequency converter 1 is used to adjust the drive frequency of the drive assembly. The drive assembly includes motors 2, the number of which can be the same as the number of reciprocating compressors 12 and correspond one-to-one, or the number of compressor assemblies can be the same. Each motor 2 is used to simultaneously start m reciprocating compressors 12. A first pressure transmitter 6 is connected inside the intake container 3, and a second pressure transmitter 7 is connected inside the exhaust container 4. The first pressure transmitter 6 is connected to the frequency converter 1; the frequency converter 1 adjusts the frequency of the motors 2 according to the pressure value transmitted by the first pressure transmitter 6. The frequency adjustment range of the frequency converter 1 is 30-50 Hz.

[0024] The opening and closing of the drive assembly and the compression assembly are controlled by the controller or manually. The controller stores A gears, where A = 2n. The first gear starts only one of the solenoid valves 8 and the reciprocating compressor 12 corresponding to that solenoid valve 8. The second gear starts two of the solenoid valves 8 and the reciprocating compressor 12 corresponding to those two solenoid valves 8, and so on. The last gear starts all the solenoid valves 8 and all the reciprocating compressors 12.

[0025] The specific implementation process is as follows:

[0026] During compression, all components are opened, and the number of times solenoid valves 8 and motors 2 are opened and closed is selected according to the gas volume. The frequency converter 1 adjusts the output frequency according to the pressure value transmitted by the first pressure transmitter 6. The natural gas in the intake container 3 enters the first-stage branch pipe 10 through the main pipe 9, which opens the solenoid valve 8, and then enters the second-stage branch pipe 11 through the first-stage branch pipe 10. The natural gas in the second-stage branch pipe 11 will open the corresponding pneumatic intake valve 13 and enter the suction port, thus flowing into the two working chambers of the reciprocating compressor. The reciprocating compressor 12 compresses the natural gas in the two working chambers through reciprocating motion. The compressed natural gas is discharged into the exhaust container 4 through the exhaust port for storage.

[0027] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0028] The above descriptions are merely embodiments of this utility model. Commonly known structures and characteristics are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are knowledgeable of all existing technologies in that field, and possess the ability to apply conventional experimental methods prior to that date. Therefore, those skilled in the art can, based on the guidance provided in this application, improve and implement this solution in conjunction with their own capabilities. Typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of this utility model. These modifications and improvements should also be considered within the scope of protection of this utility model, and will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A natural gas refueling system, characterized in that: The system includes a controller, an intake container, an intake control assembly, an exhaust container, a frequency converter, a drive assembly, and a compression assembly. The controller is connected to the intake control assembly, the frequency converter, the drive assembly, and the compression assembly. The intake port of the intake container is connected to external natural gas, the outlet of the intake container is connected to the intake port of the compression assembly via the intake control assembly, the outlet of the compression assembly is connected to the inlet of the exhaust container, and the outlet of the exhaust container is connected to an exhaust pipe. The intake control assembly includes a main pipe, a first-stage branch pipe assembly, a second-stage branch pipe assembly, and a solenoid valve. The first-stage branch pipe assembly has n groups, each group including two groups of first-stage branch pipes. Each group of first-stage branch pipes has a set of the solenoid valves for opening and closing the connection of the first-stage branch pipes. The intake ends of the first-stage branch pipes are connected to the main pipe. Each group of first-stage branch pipes corresponds to a group of second-stage branch pipe assemblies, and each group of second-stage branch pipe assemblies includes m groups of second-stage branch pipes. The outlet is connected to the inlet of m sets of second-stage branch pipes; the compression assembly has M sets, each set including m sets of reciprocating compressors; the intake port of each set of reciprocating compressors is connected to two intake pipes, each intake pipe is equipped with a pneumatic intake valve, and the intake port is connected to two working chambers of the reciprocating compressor; the two working chambers correspond to two outlets; the two intake pipes are connected to two sets of second-stage branch pipes, and the two sets of second-stage branch pipes are connected to different first-stage branch pipes; the drive assembly is used to start and stop the compression assembly, and the frequency converter is used to adjust the drive frequency of the drive assembly; the start and stop of the drive assembly and the compression assembly are controlled by a controller or manually, and the controller stores A gears, A=2n; the first gear starts only one solenoid valve and the reciprocating compressor corresponding to that solenoid valve, the second gear starts two solenoid valves and the reciprocating compressors corresponding to those two solenoid valves, and so on, and the last gear starts all solenoid valves and all reciprocating compressors.

2. The natural gas refueling system according to claim 1, characterized in that: The drive assembly includes electric motors, and the number of electric motors is the same as the number of reciprocating compressors and corresponds one-to-one.

3. The natural gas refueling system according to claim 1, characterized in that: The drive assembly includes electric motors, the number of which is the same as the number of compression assemblies, with each motor used to simultaneously start m reciprocating compressors.

4. The natural gas refueling system according to claim 2 or 3, characterized in that: A first pressure transmitter is connected inside the air intake container, and a second pressure transmitter is connected inside the exhaust container. The first pressure transmitter is connected to the frequency converter. The frequency converter adjusts the frequency of the motor according to the pressure value transmitted by the first pressure transmitter.

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