Reciprocating type natural gas compressor unit suitable for various working conditions and control method

Abstract

The invention discloses a reciprocating type natural gas compressor unit suitable for multiple working conditions and a control method, and belongs to the technical field of natural gas conveying. The compressor unit comprises a first compressor assembly and a plurality of second compressor assemblies which are sequentially communicated, and the second compressor assembly at one end is suitable for being communicated with the first compressor assembly; the inlet and the outlet of the first compressor assembly are selectively communicated through the natural gas backflow assembly, and / or the inlet and the outlet of the second compressor assembly are selectively communicated through the natural gas backflow assembly; a second natural gas outlet pipe is arranged between every two adjacent second compressor assemblies. According to the compressor unit designed by the invention, natural gas compressed by each second compressor assembly can be independently discharged, so that a user can utilize the natural gas according to different requirements, the use range of the user on the natural gas is expanded, the user does not need to build a plurality of natural gas stations, the use cost of the user on the natural gas is reduced, and the user experience is improved. And the satisfaction degree of the user is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of natural gas transportation, and in particular relates to a reciprocating natural gas compressor unit suitable for various working conditions and a control method. Background Art

[0002] In the related technology, natural gas can be used for gas lifting, storage, pressurized gathering and transportation or reinjection through natural gas stations. In the prior art, after being processed by natural gas stations, natural gas can only be used for gas lifting, storage, pressurized gathering and transportation or reinjection. If the user needs to have multiple application requirements for natural gas, a corresponding number of natural gas stations must be built, resulting in high cost of natural gas utilization for users. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the present invention is to propose a reciprocating natural gas compressor unit suitable for various working conditions. According to the reciprocating natural gas compressor unit suitable for various working conditions designed by the present invention, the natural gas compressed by each second compressor assembly can be discharged separately, so that users can use natural gas according to different needs, expand the scope of users' use of natural gas, avoid users from building multiple natural gas stations, reduce users' use costs of natural gas, and improve users' satisfaction.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] The present invention provides a reciprocating natural gas compressor unit suitable for various working conditions, comprising: a first compressor assembly, the first compressor assembly is suitable for being connected to the natural gas inlet pipe; a second compressor assembly, the second compressor assembly is constructed as a plurality of components connected in sequence, the second compressor assembly at one end is suitable for being connected to the first compressor assembly, and the second compressor assembly at the other end is suitable for being connected to the first natural gas outlet pipe; a natural gas reflux assembly, the natural gas reflux assembly can selectively connect the inlet and outlet of the first compressor assembly, and / or the natural gas reflux assembly can selectively connect the inlet and outlet of the second compressor assembly; wherein a second natural gas outlet pipe is respectively arranged between any two adjacent second compressor assemblies, and the natural gas discharged from the first natural gas outlet pipe and the plurality of the second natural gas outlet pipes are respectively suitable for reinjection, gas lifting, storage or pressurized gathering and transportation.

[0006] According to the reciprocating natural gas compressor unit suitable for various working conditions of the present invention, the natural gas compressed by each second compressor assembly can be discharged separately, so that users can use the natural gas according to different needs, thereby expanding the scope of users' use of natural gas, avoiding users from building multiple natural gas stations, reducing users' natural gas use costs, and improving users' satisfaction.

[0007] Further, the natural gas reflux assembly includes: a first reflux assembly, which can selectively connect the natural gas inlet pipe and the outlet of the second compressor assembly at one end; a second reflux assembly, which is constructed to correspond one to one with multiple second natural gas outlet pipes, and the second reflux assembly can selectively connect the inlet and outlet of the second compressor assembly adjacent to the second natural gas outlet pipe downstream.

[0008] Furthermore, it also includes: a pressure relief component, which is suitable for communicating with the natural gas inlet pipe, the first compressor component and / or the second compressor component, and the pressure relief component is suitable for balancing the pressure of the natural gas when the pressure of the natural gas exceeds a preset value.

[0009] Further, the second compressor assembly includes a second washing tank, a second compressor and a second cooler which are connected in sequence; wherein the pressure relief assembly is connected to the outlet of the second compressor.

[0010] Furthermore, the working fluid of the second compressor is supercritical carbon dioxide.

[0011] Furthermore, it also includes: a sewage discharge component, which is suitable for communicating with the first compressor component and multiple second compressor components respectively, and the sewage discharge component is suitable for discharging dirt in the first compressor component and / or the second compressor component.

[0012] The invention also provides a control method.

[0013] The control method is applied to the reciprocating natural gas compressor unit suitable for multiple working conditions as described in any one of the above embodiments, and is characterized by comprising: obtaining the opening and closing information of the first natural gas outlet pipe and the second natural gas outlet pipe; controlling the operation of the natural gas reflux component according to the opening and closing information of the first natural gas outlet pipe and the second natural gas outlet pipe; wherein when the first natural gas outlet pipe is closed and one of the second natural gas outlet pipes is opened, the natural gas reflux component is controlled to operate so that the inlet and outlet of the second compressor component between the opened second natural gas outlet pipe and the first natural gas outlet pipe are connected.

[0014] Furthermore, when the reciprocating natural gas compressor unit suitable for various working conditions is started or shut down, the natural gas reflux component is controlled to operate so that the inlet and outlet of the first compressor component are connected, and / or the inlet and outlet of the second compressor component are connected.

[0015] Other advantages, objectives and features of the present invention will be described in the following description and will be apparent to those skilled in the art to some extent, or those skilled in the art may be taught from the practice of the present invention. The objectives and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention provides the following drawings for illustration:

[0017] Figure 1 is a schematic diagram of a case where the number of the second compressor assemblies of the present invention is 4;

[0018] Figure 2 A partial schematic diagram of the second compressor assembly of the present invention when the number of the second compressor assembly is 2 Figure 1 ;

[0019] Figure 3 A partial schematic diagram of the second compressor assembly of the present invention when the number of the second compressor assembly is 2 Figure 2 ;

[0020] Figure 4 A partial schematic diagram of the second compressor assembly of the present invention when the number of the second compressor assembly is 2 Figure 3 ;

[0021] Figure 5 It is a structural schematic diagram when the number of the second compressor components of the present invention is 2;

[0022] Figure 6 It is a schematic diagram of a control method of a compressor unit of the present invention.

[0023] The following are marked in the accompanying drawings:

[0024] 10. First compressor assembly; 11. First washing tank; 12. First compressor; 13. First cooler;

[0025] 20. Second compressor assembly; 21. Second washing tank; 22. Second compressor; 23. Second cooler;

[0026] 31. First reflux assembly; 32. Second reflux assembly;

[0027] 40. Pressure relief assembly; 50. Blowdown assembly;

[0028] 61. Natural gas inlet pipe; 62. First natural gas outlet pipe; 63. Second natural gas outlet pipe. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0030] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is apparent to one of ordinary skill in the art that these specific details are not necessarily employed to practice the present invention. In other instances, well-known structures, circuits, materials, or methods are not specifically described in order to avoid obscuring the present invention.

[0031] Throughout the specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment," "an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily all refer to the same embodiment or example. In addition, particular features, structures, or characteristics may be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. In addition, it will be appreciated by those of ordinary skill in the art that the figures provided herein are for illustrative purposes and that the figures are not necessarily drawn to scale. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0032] In the description of the present invention, it should be understood that the terms "front", "rear", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the scope of protection of the present invention.

[0033] Embodiment 1:

[0034] like Figure 1-Figure 6As shown, the present invention provides a reciprocating natural gas compressor unit suitable for various working conditions, including: a first compressor assembly 10, a second compressor assembly 20 and a natural gas reflux assembly, wherein the first compressor assembly 10 is suitable for being connected to a natural gas inlet pipe 61, and the second compressor assembly 20 is constructed as a plurality of components connected in sequence, wherein the second compressor assembly 20 at one end is suitable for being connected to the first compressor assembly 10, and the second compressor assembly 20 at the other end is suitable for being connected to a first natural gas outlet pipe 62, and the natural gas reflux assembly can selectively connect the inlet and outlet of the first compressor assembly 10, and / or the natural gas reflux assembly can selectively connect the inlet and outlet of the second compressor assembly 20; wherein a second natural gas outlet pipe 63 is respectively arranged between any two adjacent second compressor assemblies 20, and the natural gas discharged from the first natural gas outlet pipe 62 and the plurality of second natural gas outlet pipes 63 are respectively suitable for reinjection, gas lifting, storage or pressurized gathering and transportation.

[0035] In some embodiments, there are multiple second compressor assemblies 20, and the multiple second compressor assemblies 20 are connected in sequence through connecting pipes. The inlet of the second compressor assembly 20 located at the head end is suitable for connecting with the outlet of the first compressor assembly 10, the outlet of the second compressor assembly 20 located at the end is suitable for connecting with the first natural gas outlet pipe 62, and the inlet of the first compressor assembly 10 is suitable for connecting with the natural gas inlet pipe 61.

[0036] A second natural gas outlet pipe 63 is disposed between any two adjacent second compressor assemblies 20 (ie, a second natural gas outlet pipe 63 is disposed in the connecting pipeline between any two adjacent second compressor assemblies 20), and the second natural gas outlet pipe 63 is suitable for being connected to a corresponding connecting pipeline.

[0037] In some embodiments, the natural gas return component may selectively connect the inlet and outlet of the first compressor component 10; or the natural gas return component may selectively connect the inlet and outlet of the second compressor component 20; or the natural gas return component may selectively connect the inlet and outlet of the first compressor component 10, and the natural gas return component may selectively connect the inlet and outlet of the second compressor component 20; or the natural gas return component may selectively connect the outlet of the second compressor component 20 at the head end with the inlet of the first compressor component 10, and the natural gas return component may selectively connect the inlet and outlet of the remaining second compressor components 20, which is not limited here.

[0038] In some embodiments, the number of the second compressor assemblies 20 can be configured as 2, 3 or 4, which is not limited here. When the number of the second compressor assemblies 20 is configured as 4, the 4 second compressor assemblies 20 are respectively a first-stage compressor assembly, a second-stage compressor assembly, a third-stage compressor assembly and a fourth-stage compressor assembly, and the first-stage compressor assembly, the second-stage compressor assembly, the third-stage compressor assembly and the fourth-stage compressor assembly are connected in sequence, the inlet of the first-stage compressor assembly is connected to the outlet of the first compressor assembly 10, and the outlet of the fourth-stage compressor assembly is connected to the first natural gas outlet pipe 62.

[0039] In the embodiment where the number of the second compressor assemblies 20 is four, the natural gas reflux assembly may selectively connect the outlet of the first compressor assembly with the inlet of the first compressor assembly 10, the natural gas reflux assembly may selectively connect the inlet and outlet of the second compressor assembly, the natural gas reflux assembly may selectively connect the inlet and outlet of the third compressor assembly, and the natural gas reflux assembly may selectively connect the inlet and outlet of the fourth compressor assembly.

[0040] During operation, natural gas enters the first compressor assembly 10 through the natural gas inlet pipe 61. The first compressor assembly 10 is suitable for preliminarily compressing the natural gas so that the natural gas can reach a preset pressure value (different sources of natural gas will result in different pressures of the natural gas discharged from the natural gas inlet pipe 61. The first compressor assembly 10 can compress the natural gas from the natural gas inlet pipe 61 to a preset range value, so as to facilitate the subsequent second compressor assembly 20 to control the compression ratio of the natural gas, thereby realizing the control of the pressure value of the natural gas discharged from any second compressor assembly 20). Subsequently, the natural gas enters the first compressor assembly, which can further compress the natural gas so that the natural gas discharged from the first compressor assembly can be used for gas lift work; then the natural gas can enter the second compressor assembly, which can recompress the natural gas so that the natural gas discharged from the second compressor assembly can be used for storage; the natural gas discharged from the second compressor assembly can then enter the third compressor assembly, and the natural gas compressed by the third compressor assembly can be used for pressurized gathering and transportation; after the natural gas discharged from the third compressor assembly enters the fourth compressor assembly, the fourth compressor assembly can further compress the natural gas so that the natural gas can be reinjected (injecting the natural gas underground for storage).

[0041] It is worth noting that the second natural gas outlet pipe 63 located between the first compressor assembly and the second compressor assembly can be selectively opened or closed. When the second natural gas outlet pipe 63 is opened, the user can use natural gas for gas lift work; when the second natural gas outlet pipe 63 is closed, natural gas can enter the second compressor assembly.

[0042] The second natural gas outlet pipe 63 between the secondary compressor assembly and the tertiary compressor assembly can be selectively opened or closed. When the second natural gas outlet pipe 63 is opened, users can use natural gas for storage; when the second natural gas outlet pipe 63 is closed, natural gas can enter the tertiary compressor assembly.

[0043] The second natural gas outlet pipe 63 located between the third-stage compressor assembly and the fourth-stage compressor assembly can be selectively opened or closed. When the second natural gas outlet pipe 63 is opened, the user can use the natural gas for pressurized gathering and transportation; when the second natural gas outlet pipe 63 is closed, the natural gas can enter the fourth-stage compressor assembly.

[0044] The first natural gas outlet pipe 62 can be selectively opened or closed. When the first natural gas outlet pipe 62 is opened, the user can inject the natural gas compressed by the four-stage compressor assembly back into the ground; when the first natural gas outlet pipe 62 is closed, the natural gas can be used for gas lifting, storage and / or pressurized gathering and transportation.

[0045] It is worth mentioning that the user can also open part or all of the second natural gas outlet pipes 63 at the same time according to actual needs, so as to realize adaptive utilization of natural gas. When part or all of the second natural gas outlet pipes 63 are opened at the same time, the first natural gas outlet pipe 62 can also be selectively opened or closed.

[0046] It should be noted that, only when the second natural gas outlet pipe 63 located between the first-stage compressor assembly and the second-stage compressor assembly is opened, the natural gas reflux assembly is suitable for connecting the inlet and outlet of the second-stage compressor assembly, the inlet and outlet of the third-stage compressor assembly, and the inlet and outlet of the fourth-stage compressor assembly, so as to avoid the second-stage compressor assembly, the third-stage compressor assembly and the fourth-stage compressor assembly from continuously pressurizing the natural gas, thereby ensuring the working safety of the compressor unit.

[0047] Under the premise that the first natural gas outlet pipe 62 is closed, and when the second natural gas outlet pipe 63 between the second-stage compressor assembly and the third-stage compressor assembly is opened, and / or when the second natural gas outlet pipe 63 between the first-stage compressor assembly and the second-stage compressor assembly is opened, the natural gas reflux assembly is suitable for connecting the inlet and outlet of the third-stage compressor assembly, and the inlet and outlet of the fourth-stage compressor assembly, so as to avoid the third-stage compressor assembly and the fourth-stage compressor assembly from continuously pressurizing the natural gas, thereby ensuring the working safety of the compressor unit.

[0048] Under the premise that the first natural gas outlet pipe 62 is closed, and when the second natural gas outlet pipe 63 between the third-stage compressor assembly and the fourth-stage compressor assembly is opened, the second natural gas outlet pipe 63 between the second-stage compressor assembly and the third-stage compressor assembly is opened, and / or the second natural gas outlet pipe 63 between the first-stage compressor assembly and the second-stage compressor assembly is opened, the natural gas reflux assembly is suitable for connecting the inlet and outlet of the fourth-stage compressor assembly to avoid the fourth-stage compressor assembly from continuously pressurizing the natural gas, thereby ensuring the working safety of the compressor unit.

[0049] It is worth mentioning that when the first natural gas outlet pipe 62 is closed, the natural gas reflux component needs to connect the inlet and outlet of the four-stage compressor component to prevent the four-stage compressor component from continuously pressurizing the natural gas, thereby ensuring the working safety of the compressor unit.

[0050] According to the compressor unit of the present invention, the natural gas compressed by each second compressor assembly 20 can be discharged separately, so that users can use natural gas according to different needs, which expands the scope of users' use of natural gas, avoids users from building multiple natural gas stations, reduces users' natural gas use costs, and improves user satisfaction.

[0051] Embodiment 2:

[0052] In this embodiment, based on the first embodiment, the natural gas reflux component includes: a first reflux component 31 and a second reflux component 32. The first reflux component 31 can selectively connect the natural gas inlet pipe 61 and the outlet of the second compressor component 20 at one end. The second reflux component 32 is constructed to correspond one to one with multiple second natural gas outlet pipes 63. The second reflux component 32 can selectively connect the inlet and outlet of the second compressor component 20 adjacent to the downstream of the second natural gas outlet pipe 63.

[0053] In an embodiment where the number of the second compressor assemblies 20 is four, the first return assembly 31 can selectively connect the outlet of the first compressor assembly with the inlet of the first compressor assembly 10, the number of the second return assemblies 32 is constructed to be three and are respectively a secondary return assembly, a tertiary return assembly and a quaternary return assembly, the secondary return assembly can selectively connect the inlet and outlet of the secondary compressor assembly, the tertiary return assembly can selectively connect the inlet and outlet of the tertiary compressor assembly, and the quaternary return assembly can selectively connect the inlet and outlet of the quaternary compressor assembly.

[0054] It can be understood that, only when the second natural gas outlet pipe 63 between the first-stage compressor assembly and the second-stage compressor assembly is opened, the second-stage return assembly connects the inlet and outlet of the second-stage compressor assembly, and the third-stage return assembly connects the inlet and outlet of the third-stage compressor assembly, while the fourth-stage return assembly connects the inlet and outlet of the fourth-stage compressor assembly.

[0055] Under the premise that the first natural gas outlet pipe 62 is closed, and when the second natural gas outlet pipe 63 between the secondary compressor assembly and the tertiary compressor assembly is opened, and / or when the second natural gas outlet pipe 63 between the primary compressor assembly and the secondary compressor assembly is opened, the third-stage reflux assembly connects the inlet and outlet of the third-stage compressor assembly, and at the same time, the fourth-stage reflux assembly connects the inlet and outlet of the fourth-stage compressor assembly.

[0056] Under the premise that the first natural gas outlet pipe 62 is closed, and when the second natural gas outlet pipe 63 between the third-stage compressor assembly and the fourth-stage compressor assembly is opened, when the second natural gas outlet pipe 63 between the second-stage compressor assembly and the third-stage compressor assembly is opened, and / or when the second natural gas outlet pipe 63 between the first-stage compressor assembly and the second-stage compressor assembly is opened, the fourth-stage reflux assembly connects the inlet and outlet of the fourth-stage compressor assembly.

[0057] It is worth mentioning that when the first natural gas outlet pipe 62 is closed, the four-stage reflux assembly needs to connect the inlet and outlet of the four-stage compressor assembly to prevent the four-stage compressor assembly from continuously pressurizing the natural gas, thereby ensuring the safe operation of the compressor unit.

[0058] It is worth noting that when the compressor unit is started or stopped, the first reflux component 31 connects the outlet of the first compressor component to the inlet of the first compressor component 10, the second reflux component connects the inlet and outlet of the second compressor component, the third reflux component connects the inlet and outlet of the third compressor component, and the fourth reflux component connects the inlet and outlet of the fourth compressor component. Thus, the above-mentioned arrangement can ensure that the first compressor component 10, the first compressor component, the second compressor component, the third compressor component and the fourth compressor component start and stop at low load or even no load, thereby avoiding excessive start and stop current of the first compressor component 10, the first compressor component, the second compressor component, the third compressor component and the fourth compressor component, thereby avoiding overload, and further protecting the first compressor component 10, the first compressor component, the second compressor component, the third compressor component and the fourth compressor component.

[0059] At the same time, a large amount of heat is generated during the natural gas compression process. If the compressor is immediately operated at full load, the internal temperature of the first compressor assembly 10 and / or the second compressor assembly 20 may rise sharply, affecting the performance of the lubricating oil, aggravating the wear of the first compressor assembly 10 and / or the second compressor assembly 20, and even triggering the thermal protection device to shut down the first compressor assembly 10 and / or the second compressor assembly 20. Low-load startup can gradually increase the temperature, leaving enough preheating and heat dissipation time for the compressor unit to ensure the safe operation of the compressor unit.

[0060] At the same time, direct full-load startup may cause sudden changes in the compressor unit pressure, causing impacts on pipelines, valves and other accessories, and increasing the risk of leakage in the compressor unit. Therefore, the above settings can be used to achieve low-load startup to gradually build up pressure, thereby achieving smooth changes in the internal pressure of the compressor unit and reducing the impact on the entire natural gas transmission network.

[0061] Embodiment three:

[0062] In this embodiment, based on the second embodiment, the compressor unit further includes: a pressure relief assembly 40, the pressure relief assembly 40 is suitable for being connected to the natural gas inlet pipe 61, the first compressor assembly 10 and / or the second compressor assembly 20, and the pressure relief assembly 40 is suitable for balancing the pressure of the natural gas when the pressure of the natural gas exceeds a preset value.

[0063] In some embodiments, the pressure relief assembly 40 may be connected to the natural gas inlet pipe 61; the pressure relief assembly 40 may be connected to the first compressor assembly 10; the pressure relief assembly 40 may be connected to the second compressor assembly 20; or the pressure relief assembly 40 may be connected to the natural gas inlet pipe 61, the first compressor assembly 10 and the second compressor assembly 20 respectively.

[0064] The pressure relief assembly 40 is suitable for detecting the natural gas pressure in the natural gas inlet pipe 61, the first compressor assembly 10 and / or the second compressor assembly 20, and the pressure relief assembly 40 is suitable for communicating with the external environment (or an exhaust device) when the natural gas pressure in the natural gas inlet pipe 61, the first compressor assembly 10 and / or the second compressor assembly 20 exceeds a preset value, thereby reducing the natural gas pressure inside the natural gas inlet pipe 61, the first compressor assembly 10 and / or the second compressor assembly 20, and then balancing the pressure in the natural gas inlet pipe 61, the first compressor assembly 10 and / or the second compressor assembly 20, thereby ensuring the safe operation of the compressor unit.

[0065] Embodiment 4:

[0066] In this embodiment, based on the third embodiment, the second compressor assembly 20 includes a second washing tank 21 , a second compressor 22 and a second cooler 23 which are connected in sequence; wherein the pressure relief assembly 40 is connected to the outlet of the second compressor 22 .

[0067] In some embodiments, the first compressor assembly 10 includes a first washing tank 11, a first compressor 12, and a first cooler 13 which are connected in sequence. The first washing tank 11 is suitable for being connected to the natural gas inlet pipe 61. The first washing tank 11 can filter the oil, water, and solid impurities mixed in the natural gas to ensure the cleanliness of the natural gas entering the first compressor 12. The natural gas can enter the first cooler 13 for cooling after being compressed by the first compressor 12 (the temperature of the natural gas will increase after compression, and the first cooler 13 can cool the natural gas). It is worth noting that the outlet of the first compressor 12 is connected to the pressure relief device. When the pressure of the natural gas compressed by the first compressor 12 exceeds the preset value, the pressure relief assembly 40 works to balance the pressure of the natural gas, thereby controlling the pressure of the natural gas, and can ensure the pressure of the natural gas entering the first cooler 13, avoiding damage to the first cooler 13 due to excessive natural gas pressure.

[0068] The outlet of the first cooler 13 is connected to the second washing tank 21. After the natural gas is compressed by the first compressor 12, impurities such as oil and water mixed in the natural gas will precipitate. Therefore, the second washing tank 21 can further filter the impurities such as oil and water mixed in the natural gas, and the natural gas can enter the second cooler 23 for cooling after being compressed by the second compressor 22. It is worth noting that the outlet of the second compressor 22 is connected to the pressure relief device. When the pressure of the natural gas compressed by the second compressor 22 exceeds the preset value, the pressure relief assembly 40 works to balance the pressure of the natural gas, thereby achieving the control of the pressure of the natural gas.

[0069] In some embodiments, the first cooler 13 and the second cooler 23 may be configured as a water cooler or an air cooler, etc., which is not limited here. The first compressor 12 and the second compressor 22 may be configured as a reciprocating compressor, respectively.

[0070] Embodiment five:

[0071] In this embodiment, on the basis of the third embodiment, the working fluid of the second compressor 22 is supercritical carbon dioxide. It can be understood that the supercritical carbon dioxide is constructed to have the characteristics of neither a typical liquid nor a typical gas. The working fluid of the second compressor 22 of the present application adopts supercritical carbon dioxide, so that the second compressor 22 has a higher compression efficiency while reducing the energy consumption of the second compressor 22.

[0072] At the same time, using supercritical carbon dioxide as the working fluid of the second compressor 22 can make the volume of the second compressor 22 smaller, facilitate the layout of other components of the compressor unit, and reduce the volume of the entire compressor unit, thereby reducing the installation space occupied by the compressor unit. At the same time, using supercritical carbon dioxide as the working fluid of the second compressor 22 can make the working stability of the second compressor 22 better, thereby ensuring the working stability of the compressor unit.

[0073] It is worth noting that the working fluid of the first compressor 12 can also be supercritical carbon dioxide, which is not limited here.

[0074] Embodiment six:

[0075] In this embodiment, based on the first embodiment, the compressor unit further includes: a sewage discharge component 50, which is respectively suitable for being connected to the first compressor component 10 and the plurality of second compressor components 20, and is suitable for discharging dirt in the first compressor component 10 and / or the second compressor component 20.

[0076] It can be understood that when there is a lot of accumulation of oil, water and fixed impurities in the first washing tank 11 and / or the second washing tank 21, the sewage discharge component 50 can discharge the oil, water and fixed impurities in the first washing tank 11 and / or the second washing tank 21 to avoid the accumulation of oil, water and fixed impurities in the first washing tank 11 and / or the second washing tank 21, thereby ensuring the normal operation of the first washing tank 11 and / or the second washing tank 21, and further ensuring the normal operation of the compressor unit.

[0077] Embodiment seven:

[0078] This embodiment further proposes a control method based on any of the above embodiments, and the control method is applied to the reciprocating natural gas compressor unit suitable for multiple working conditions described in any of the above embodiments, including: obtaining the opening and closing information of the first natural gas outlet pipe 62 and the second natural gas outlet pipe 63; controlling the operation of the natural gas reflux component according to the opening and closing information of the first natural gas outlet pipe 62 and the second natural gas outlet pipe 63; wherein when the first natural gas outlet pipe is closed and one of the second natural gas outlet pipes is opened, the natural gas reflux component is controlled to operate so that the inlet and outlet of the second compressor component between the opened second natural gas outlet pipe and the first natural gas outlet pipe are connected.

[0079] According to some embodiments of the present invention, when a reciprocating natural gas compressor unit suitable for various working conditions is started or shut down, the natural gas reflux component is controlled to connect the inlet and outlet of the first compressor component 10 and / or the inlet and outlet of the second compressor component 20.

[0080] According to some embodiments of the present invention, see Figure 2-Figure 5 The second compressor assembly 20 is constructed as two, one is a primary compressor assembly and the other is a secondary compressor assembly. The outlet of the primary compressor assembly is connected to the inlet of the secondary compressor assembly. The inlet of the primary compressor assembly is suitable for connecting to the outlet of the first compressor assembly 10. The outlet of the secondary compressor assembly is connected to the first natural gas outlet pipe. The second natural gas outlet pipe 63 is constructed as one and is suitable for connecting to the outlet of the primary compressor assembly. The first reflux assembly 31 is suitable for connecting the outlet of the primary compressor assembly to the inlet of the first compressor assembly 10. The second reflux assembly 32 is constructed as one and is a secondary reflux assembly. The secondary reflux assembly is suitable for connecting the inlet and outlet of the secondary compressor assembly.

[0081] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A reciprocating natural gas compressor unit suitable for various working conditions, characterized in that: include: A first compressor assembly (10), the first compressor assembly (10) being adapted to communicate with the natural gas inlet pipe (61); a second compressor assembly (20), wherein the second compressor assembly (20) is configured to be connected in sequence, wherein the second compressor assembly (20) at one end is adapted to be connected to the first compressor assembly (10), and the second compressor assembly (20) at the other end is adapted to be connected to the first natural gas outlet pipe (62); A natural gas return assembly, wherein the natural gas return assembly can selectively connect the inlet and outlet of the first compressor assembly (10), and / or the natural gas return assembly can selectively connect the inlet and outlet of the second compressor assembly (20); wherein A second natural gas outlet pipe (63) is provided between any two adjacent second compressor assemblies (20), and the natural gas discharged from the first natural gas outlet pipe (62) and the plurality of second natural gas outlet pipes (63) are respectively suitable for reinjection, gas lifting, storage or pressurized gathering and transportation.

2. The reciprocating natural gas compressor unit suitable for various working conditions according to claim 1, characterized in that: The natural gas reflux component comprises: a first reflux assembly (31), the first reflux assembly (31) selectively connecting the natural gas inlet pipe (61) and an outlet of the second compressor assembly (20) at one end; A second return assembly (32), wherein the second return assembly (32) is constructed to correspond one to one with a plurality of second natural gas outlet pipes (63), and the second return assembly (32) can selectively connect the inlet and outlet of the second compressor assembly (20) adjacent to the downstream of the second natural gas outlet pipe (63).

3. The reciprocating natural gas compressor unit suitable for various working conditions according to claim 2, characterized in that: Also includes: A pressure relief assembly (40) is provided, wherein the pressure relief assembly (40) is adapted to be connected to a natural gas inlet pipe (61), a first compressor assembly (10) and / or a second compressor assembly (20), and the pressure relief assembly (40) is adapted to balance the pressure of the natural gas when the pressure of the natural gas exceeds a preset value.

4. The reciprocating natural gas compressor unit suitable for various working conditions according to claim 3, characterized in that: The second compressor assembly (20) comprises a second washing tank (21), a second compressor (22) and a second cooler (23) which are connected in sequence; wherein The pressure relief assembly (40) is in communication with an outlet of the second compressor (22).

5. The reciprocating natural gas compressor unit suitable for various working conditions according to claim 3, characterized in that: The working fluid of the second compressor (22) is supercritical carbon dioxide.

6. The reciprocating natural gas compressor unit suitable for various working conditions according to claim 1, characterized in that: Also includes: A sewage discharge component (50), wherein the sewage discharge component (50) is respectively adapted to be connected to the first compressor component (10) and a plurality of the second compressor components (20), and the sewage discharge component (50) is adapted to discharge dirt in the first compressor component (10) and / or the second compressor component (20).

7. A control method, the control method being applied to the reciprocating natural gas compressor unit applicable to various working conditions as claimed in any one of claims 1 to 6, characterized in that: include: Acquiring opening and closing information of the first natural gas outlet pipe (62) and the second natural gas outlet pipe (63); Controlling the operation of the natural gas reflux component according to the opening and closing information of the first natural gas outlet pipe (62) and the second natural gas outlet pipe (63); in When the first natural gas outlet pipe (62) is closed and one of the second natural gas outlet pipes (63) is opened, the natural gas reflux component is controlled to operate so that the inlet and outlet of the second compressor component (20) between the opened second natural gas outlet pipe (63) and the first natural gas outlet pipe (62) are connected.

8. The control method according to claim 7, characterized in that: When the reciprocating natural gas compressor unit suitable for various working conditions is started or shut down, the natural gas reflux component is controlled to operate so that the inlet and outlet of the first compressor component (10) are connected, and / or the inlet and outlet of the second compressor component (20) are connected.

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