Gas recovery system and gas recovery method

Abstract

The application belongs to the technical field of resource conveying equipment, and particularly relates to a gas recovery system and a gas recovery method. The gas recovery system comprises: an air inlet mechanism, an air inlet end of the air inlet mechanism is communicated with a discharge end of a storage device storing to-be-recovered gas; a plurality of sequentially communicated gas compression components, an air inlet end of a gas compression component located at a head end is communicated with an air outlet end of the air inlet mechanism, and the plurality of gas compression components are respectively used for sequentially performing multi-stage compression on the to-be-recovered gas; a plurality of inter-stage coolers, the plurality of inter-stage coolers and the plurality of gas compression components are sequentially and alternately communicated and arranged, and the inter-stage coolers are used for cooling and transmitting the gas compressed by the gas compression components; and a storage mechanism, an air inlet end of the storage mechanism is communicated with an air outlet end of an inter-stage cooler located at a tail end and is used for storing the to-be-recovered gas after multi-stage compression and cooling. By using the above method, the to-be-recovered gas can be subjected to multi-stage compression and cooling, so that the to-be-recovered gas can be safely recovered.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of resource conveying equipment, and particularly relates to a gas recovery system and a gas recovery method. BACKGROUND

[0002] Fuel gas such as natural gas is a clean and high-calorific-value energy source, and is paid more and more attention. In recent years, with the continuous construction of domestic fuel gas long-distance pipelines, the venting amount of natural gas at pressure stations and various process pipelines along the pipeline increases year by year, the number of pipeline trunk and station reconstruction increases year by year, the venting amount of fuel gas at the fuel gas pipeline trunk and station is obviously high, and the venting fuel gas is basically treated in the form of burning a flare or direct emission. The above treatment methods cause serious resource waste and carbon emission.

[0003] There are some devices and methods for the secondary utilization of vented fuel gas in the prior art, but the venting amount of fuel gas during the reconstruction and overhaul is large, and the fuel gas needs to be compressed and then stored after compression. The fuel gas is flammable and explosive gas, and there is a safety hazard in the compression process of the fuel gas. If the fuel gas explodes due to too high temperature in the compression process, a serious safety accident will be caused. SUMMARY

[0004] The purpose of the present application is to provide a gas recovery system and a gas recovery method to solve the technical problem that the gas to be recovered is difficult to be safely compressed in the prior art.

[0005] In order to achieve the above purpose, the present application provides a gas recovery system, which comprises:

[0006] An air inlet mechanism, an air inlet end of the air inlet mechanism being in communication with a discharge end of a storage device storing the gas to be recovered;

[0007] A plurality of gas compression members in sequence, an air inlet end of a gas compression member located at a first end being in communication with an air outlet end of the air inlet mechanism, and the plurality of gas compression members being respectively used for sequentially performing multi-stage compression on the gas to be recovered;

[0008] A plurality of inter-stage coolers, the plurality of inter-stage coolers and the plurality of gas compression members being alternately arranged in sequence, and the inter-stage coolers being used for cooling and transmitting the gas compressed by the gas compression members;

[0009] A storage mechanism, an air inlet end of the storage mechanism being in communication with an air outlet end of an inter-stage cooler located at a last end and being used for storing the gas to be recovered after multi-stage compression and cooling.

[0010] In some embodiments, the gas compression component further has an exhaust end, the gas recovery system further comprises a plurality of exhaust pipelines, the gas inlet end of each of the plurality of exhaust pipelines is in communication with the exhaust end of one of the plurality of gas compression components, and the gas outlet end of each of the plurality of exhaust pipelines is in communication with the external atmosphere; the gas inlet mechanism comprises: a main pipeline, the gas inlet end of the main pipeline is in communication with the gas outlet end of the storage device, and the gas outlet end of the main pipeline is in communication with the gas inlet end of the gas compression component at the head end; and a storage container, the storage container stores nitrogen, and the gas outlet end of the storage container is in communication with the main pipeline, the nitrogen being used to replace air in the main pipeline, the plurality of gas compression components and the plurality of inter-stage coolers before the gas recovery.

[0011] In some embodiments, the gas inlet mechanism further comprises: a first flow detection component, which is installed on the main pipeline and used to detect the gas flow of the main pipeline; a first pressure detection component, which is installed on the main pipeline and used to detect the gas pressure of the main pipeline; and a gas regulating valve, which is in communication with the main pipeline and used to regulate the gas pressure and the gas flow of the main pipeline.

[0012] In some embodiments, each of the gas compression components and the inter-stage coolers is in communication through a branch pipeline, one end of the branch pipeline is in communication with the gas outlet end of the gas compression component, the other end of the branch pipeline is in communication with the gas inlet end of the inter-stage cooler, a safety valve is installed on the branch pipeline, and the safety valve is arranged on the branch pipeline and used to limit the maximum pressure in the branch pipeline.

[0013] In some embodiments, the gas inlet end of the inter-stage cooler is provided with a first temperature detection component, the gas outlet end of the inter-stage cooler is provided with a second temperature detection component, the gas inlet end of each of the gas compression components is in communication with a gas filter, and the gas recovery system further comprises an exhaust pipeline, the exhaust pipeline is in communication with the exhaust end of the inter-stage cooler, and the exhaust pipeline is used to remove impurities obtained after the to-be-recovered gas is cooled.

[0014] In some embodiments, the storage mechanism comprises: an outlet pipeline, the gas inlet end of the outlet pipeline is in communication with the gas outlet end of the inter-stage cooler at the tail end; a storage component, the gas inlet end of the storage component is in communication with the gas outlet end of the outlet pipeline and used to store the to-be-recovered gas after treatment; and a filter, which is arranged on the outlet pipeline and used to filter impurities in the to-be-recovered gas.

[0015] The second aspect of the present application provides a gas recovery method, which is applied to the above-mentioned gas recovery system, and the gas recovery method comprises the following steps:

[0016] The gas in the gas recovery system is replaced by nitrogen;

[0017] The gas inlet end of the gas inlet mechanism is opened, and the to-be-recovered gas is introduced into the gas recovery system;

[0018] The plurality of gas compression components and the plurality of inter-stage coolers are started to perform multi-stage compression and cooling on the to-be-recovered gas;

[0019] The storage mechanism is opened to store the to-be-recovered gas after multi-stage compression and cooling.

[0020] In some embodiments, the gas inlet mechanism comprises a storage container storing nitrogen, and the gas recovery system further comprises a plurality of evacuation pipelines. The step of replacing the gas in the gas recovery system with nitrogen comprises: opening the storage container and the plurality of evacuation pipelines to replace the air in the gas recovery system with nitrogen and to discharge the air from the evacuation pipelines; and after a first preset time period, determining that the replacement of nitrogen is completed and closing the storage container.

[0021] In some embodiments, the step of opening the gas inlet end of the gas inlet mechanism and introducing the to-be-recovered gas into the gas recovery system comprises: opening the gas inlet end of the gas inlet mechanism to replace the nitrogen with the to-be-recovered gas, and the nitrogen is discharged from the evacuation pipelines; and after a second preset time period, determining that the replacement of the to-be-recovered gas is completed.

[0022] In some embodiments, the gas inlet mechanism further comprises a main pipeline, and a first flow detection member, a first pressure detection member, and a gas regulating valve installed on the main pipeline. The gas recovery method further comprises the following steps: after opening the gas inlet end of the gas inlet mechanism, observing the flow detection value of the first flow detection member and the pressure detection value of the first pressure detection member; in the case that the flow detection value is greater than a preset maximum flow threshold value, adjusting the gas regulating valve to reduce the flow of the main pipeline; and in the case that the pressure detection value is greater than a preset maximum pressure threshold value, adjusting the gas regulating valve to reduce the pressure of the main pipeline.

[0023] In the above technical solution, the gas recovery system comprises a gas inlet mechanism, a plurality of sequentially connected gas compression members, a plurality of inter-stage coolers, and a storage mechanism. The gas inlet mechanism can receive the to-be-recovered gas and transmit the gas to the gas compression members and the inter-stage coolers. The gas compression members can compress the gas, and the temperature of the pressurized gas will increase. High-temperature transportation of the to-be-recovered gas has a potential safety hazard. Therefore, the inter-stage cooler is arranged at the gas outlet end of the gas compression member. The inter-stage cooler can cool and transmit the compressed to-be-recovered gas. After the to-be-recovered gas is compressed and cooled multiple times, it can be safely transmitted to the storage mechanism for storage. The above gas recovery system can compress and cool the to-be-recovered gas multiple times, strictly control the temperature of the to-be-recovered gas before and after compression, and avoid the occurrence of safety accidents.

[0024] Other features and advantages of the embodiments of the present application will be described in detail in the following detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0025] The accompanying drawings are included to provide a further understanding of embodiments of the application, and are incorporated in and constitute a part of this specification, illustrate embodiments of the application, and together with the description serve to explain embodiments of the application. The drawings provided herein are for illustrative purposes only and, as such, do not limit the scope of the application. In the drawings:

[0026] Figure 1 A schematic diagram of a gas recovery system according to an embodiment of the application;

[0027] Figure 2 A flow chart of a gas recovery method according to an embodiment of the application.

[0028] BRIEF DESCRIPTION OF DRAWINGS

[0029] 1 storage container

[0030] 2 main pipe

[0031] 3 first flow detecting member

[0032] 4 first pressure detecting member

[0033] 5 gas filtering member

[0034] 6 compressing member

[0035] 7 safety valve

[0036] 8 check valve

[0037] 9 second pressure detecting member

[0038] 10 first temperature detecting member

[0039] 11 inter-stage cooler

[0040] 12 second temperature detecting member

[0041] 13 vent pipe

[0042] 14 blowdown pipe

[0043] 15 gas outlet pipe

[0044] 17 filter

[0045] 18 second flow detecting member

[0046] 19 gas regulating valve

[0047] 20 branch pipe DETAILED DESCRIPTION

[0048] The specific embodiments of the present application are described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely intended to illustrate and explain the present application, and are not intended to limit the present application.

[0049] The gas recovery system and the gas recovery method provided by the embodiments of the present application are described below with reference to the accompanying drawings.

[0050] As shown in Figure 1 , it is a schematic diagram of the gas recovery system provided by the embodiments of the present application. The gas recovery system comprises:

[0051] an air inlet mechanism, an air inlet end of the air inlet mechanism being in communication with an air outlet end of a storage device storing the gas to be recovered;

[0052] a plurality of gas compression members 6 in sequence, an air inlet end of the gas compression member 6 located at the head end being in communication with an air outlet end of the air inlet mechanism, and the plurality of gas compression members 6 being respectively used for sequentially performing multi-stage compression on the gas to be recovered;

[0053] a plurality of inter-stage coolers 11, the plurality of inter-stage coolers 11 and the plurality of gas compression members 6 being arranged in alternation in sequence, and the inter-stage cooler 11 being used for cooling and transmitting the gas compressed by the gas compression member 6;

[0054] a storage mechanism, an air inlet end of the storage mechanism being in communication with an air outlet end of the inter-stage cooler 11 located at the tail end and being used for storing the gas to be recovered after multi-stage compression and cooling.

[0055] The fuel gas exhausted to the atmosphere will cause a large amount of carbon emission and resource waste, and therefore, it is necessary to recover the fuel gas in the pipeline. However, the gas pressure in the pipeline is low, and if the gas is recovered, the gas needs to be compressed. During the compression process, the temperature of the fuel gas will be increased, which is easy to ignite and explode the fuel gas, and safety accidents will occur. The embodiments of the present application provide a gas recovery system to solve the above problems.

[0056] The gas recovery system comprises an intake mechanism, a plurality of gas compression components 6 connected in sequence, a plurality of inter-stage coolers 11 and a storage mechanism. The intake end of the intake mechanism is in communication with the discharge end of a storage device (such as a natural gas pipeline or a natural gas storage station device) storing the gas to be recovered. The gas to be recovered can be fuel gas such as natural gas. The plurality of gas compression components 6 connected in sequence can compress the gas to be recovered transmitted by the intake mechanism in multiple stages so as to facilitate storage and transportation of the gas to be recovered. The inter-stage cooler 11 can cool the compressed gas to be recovered to prevent safety accidents caused by excessively high temperature of the gas to be recovered. The storage mechanism can store the compressed and cooled gas to be recovered. In the gas recovery system, the transmission process of the gas to be recovered is as follows: the low-pressure gas to be recovered first enters the intake end of the intake mechanism, the first gas compression component 6 at the head end compresses the low-pressure gas to be recovered for the first time and transmits it to the inter-stage cooler 11 connected thereto. The temperature of the compressed gas to be recovered is relatively high, and the inter-stage cooler 11 can cool the gas to be recovered so as to facilitate secondary compression of the gas to be recovered. The gas to be recovered after one compression and one cooling is transmitted to the second gas compression component 6 for secondary compression. The gas to be recovered after multiple compression and cooling has high gas density and low temperature, which is convenient for storage and transportation. The storage mechanism stores the gas to be recovered after multiple compression and cooling.

[0057] In one embodiment, as shown in Figure 1 The gas compression component 6 also has a discharge end, and the gas recovery system further comprises a plurality of discharge pipelines 13, the intake ends of the plurality of discharge pipelines 13 are in one-to-one correspondence with the discharge ends of the plurality of gas compression components 6, and the discharge ends of the discharge pipelines 13 are in communication with the atmosphere. The intake mechanism comprises a main pipeline 2 and a storage container 1, the intake end of the main pipeline 2 is in communication with the discharge end of the storage device, and the discharge end of the main pipeline 2 is in communication with the intake end of the gas compression component 6 at the head end. The storage container 1 stores nitrogen, the discharge end of the storage container 1 is in communication with the main pipeline 2, and the nitrogen is used to replace air in the main pipeline 2, the plurality of gas compression components 6 and the plurality of inter-stage coolers 11 before the gas recovery.

[0058] When the gas to be recovered is fuel gas such as natural gas, direct compression and cooling of the gas to be recovered and air can easily cause explosion, and also can cause the compressed gas to be impure. Thus, it is necessary to replace the air in the gas recovery system by nitrogen. The gas recovery system provided by the embodiments of the present application comprises a plurality of evacuation pipelines 13, which are in communication with the evacuation end of the gas compression member 6. When gas replacement is performed, the gas in the gas recovery system can flow to the atmosphere from the evacuation pipelines 13, preventing explosion of the high-temperature gas to be recovered during compression. The gas inlet mechanism provided by the embodiments of the present application comprises a main pipeline 2 and a storage container 1. The gas inlet end of the main pipeline 2 is in communication with the gas outlet end of the storage device, and the gas outlet end of the main pipeline 2 is in communication with the gas inlet end of the gas compression member 6 located at the head end. The gas to be recovered can enter the gas compression member 6 through the main pipeline 2 for gas compression. The storage container 1 stores nitrogen, and the gas outlet end of the storage container 1 is in communication with the main pipeline 2. Before the gas to be recovered enters the main pipeline 2, the main pipeline 2 is in communication with the storage container 1, so that the nitrogen can enter the plurality of gas compression members 6, the plurality of inter-stage coolers 11 and the pipelines therebetween through the main pipeline 2, and the gas is evacuated through the evacuation pipelines 13 to complete gas replacement. By using the above-mentioned gas recovery system, the air in the gas recovery system can be replaced to prevent explosion accidents during gas compression.

[0059] In one embodiment, during the gas replacement process, the gas outlet end of the inter-stage cooler 11 located at the tail end is also in communication with the atmosphere to evacuate the air in the inter-stage cooler 11 located at the tail end.

[0060] In one embodiment, as shown in Figure 1 The gas inlet mechanism further comprises a first flow detection member 3, a first pressure detection member 4 and a gas regulating valve 19. The first flow detection member 3 is installed on the main pipeline 2 and is used to detect the gas flow of the main pipeline 2. The first pressure detection member 4 is installed on the main pipeline 2 and is used to detect the gas pressure of the main pipeline 2. The gas regulating valve 19 is in communication with the main pipeline 2 and is used to regulate the gas pressure and gas flow of the main pipeline 2. During the gas inlet process of the gas to be recovered, it is necessary to strictly control the flow and pressure of the inlet gas to prevent the gas compression member 6 and the inter-stage cooler 11 from being overloaded due to too fast inlet flow and gas pressure, and to prevent element failure in the pipeline. In one embodiment, as shown in Figure 1As shown, each of the adjacent gas compression component 6 and inter-stage cooler 11 is connected through a branch pipeline 20, one end of the branch pipeline 20 is connected with the gas outlet of the gas compression component 6, the other end of the branch pipeline 20 is connected with the gas inlet of the inter-stage cooler 11, and a safety valve 7 is installed on the branch pipeline 20 to limit the maximum pressure in the branch pipeline 20. After the to-be-recovered gas is compressed by the gas compression component 6, the gas temperature is high and the gas pressure is large, which can easily cause the branch pipeline 20 to fail to withstand the gas pressure. Therefore, the safety valve 7 is arranged on the branch pipeline 20, and when the gas pressure exceeds the preset pressure threshold, the safety valve 7 is opened to discharge the gas, thereby reducing the gas pressure in the branch pipeline 20 and protecting the branch pipeline 20 to normally transmit the to-be-recovered gas to the inter-stage cooler 11 for a long time.

[0061] In one embodiment, as shown in Figure 1 The gas inlet of the inter-stage cooler 11 is provided with a first temperature detection component 10, the gas outlet of the inter-stage cooler 11 is provided with a second temperature detection component 12, and the gas inlet of each gas compression component 6 is connected with a gas filter 5. The gas recovery system further comprises a blowdown pipeline 14 connected with the blowdown end of the inter-stage cooler 11, and the blowdown pipeline 14 is used to discharge the impurities obtained after the to-be-recovered gas is cooled. The first temperature detection component 10 and the second temperature detection component 12 can detect the temperature difference of the to-be-recovered gas before and after entering the inter-stage cooler 11, and further determine the cooling effect of the to-be-recovered gas. The gas inlet of each gas compression component 6 is connected with a gas filter 5, which can filter the impurities in the pipeline to protect the gas compression component 6 and prolong the service life of the gas compression component 6. If the purity of the to-be-recovered gas is not high, part of the impurities such as liquid water and water vapor can be separated out during the cooling process. The impurities flow from the blowdown end of the gas recovery system to the blowdown pipeline 14 to discharge the impurities and improve the purity of the to-be-recovered gas.

[0062] In one embodiment, as shown in Figure 1 The storage mechanism comprises a gas outlet pipeline 15, a storage component (not shown in the figure) and a filter 17. The gas inlet of the gas outlet pipeline 15 is connected with the gas outlet of the inter-stage cooler 11 at the tail end, the gas inlet of the storage component is connected with the gas outlet of the gas outlet pipeline 15 and is used to store the to-be-recovered gas after treatment, and the filter 17 is arranged on the gas outlet pipeline 15 and is used to filter the impurities in the to-be-recovered gas. The gas outlet pipeline 15 can transmit the to-be-recovered gas after multi-stage compression and cooling to the storage component for storage, so as to facilitate the transmission and transportation of the to-be-recovered gas after multi-stage compression and cooling, and the filter 17 can filter the impurities in the to-be-recovered gas to improve the purity of the to-be-recovered gas.

[0063] In one embodiment, as shown in Figure 1As shown, the gas recovery system further comprises a check valve 8 installed on the branch pipeline 20, which is used to prevent the flow of the gas to be recovered into the inter-stage cooler 11 from flowing back to the gas compression element 6, and a second pressure detection element 9, which is used to detect the gas pressure at the gas inlet end of the inter-stage cooler 11, so as to prevent the gas pressure in the branch pipeline 20 from being too high.

[0064] In one embodiment, as shown in Figure 1 As shown, the storage mechanism is further provided with a second flow detection element 18 for detecting the flow rate of the gas in the outlet pipeline 15, so as to prevent the flow rate from being too high and causing element failure.

[0065] In one embodiment, a gas recovery method is provided, which is applied to the above-mentioned gas recovery system, as shown in Figure 2 As shown, the gas recovery method provided by the embodiment of the present application is a flow chart. The gas recovery method comprises the following steps:

[0066] S101, replacing the gas in the gas recovery system with nitrogen.

[0067] S102, opening the gas inlet end of the gas inlet mechanism, and introducing the gas to be recovered into the gas recovery system.

[0068] S103, starting the plurality of gas compression elements 6 and the plurality of inter-stage coolers 11 to perform multi-stage compression and cooling on the gas to be recovered.

[0069] S104, opening the storage mechanism to store the gas to be recovered after multi-stage compression and cooling.

[0070] In the gas recovery process by the above-mentioned gas recovery system, the air in the gas recovery system is first replaced with nitrogen, so as to prevent the high-temperature mixed gas from causing explosion when the gas to be recovered is fuel gas such as natural gas. Subsequently, the gas inlet end of the gas inlet mechanism is opened, the gas to be recovered is introduced into the gas recovery system, and the plurality of gas compression elements 6 and the plurality of inter-stage coolers 11 are started to perform multi-stage compression and cooling on the gas to be recovered. Since the gas compression elements 6 and the inter-stage coolers 11 are arranged in one-to-one correspondence, the gas to be recovered is sequentially compressed and cooled in the gas recovery system, until the gas to be recovered is transmitted to the inter-stage cooler 11 at the tail end, and the inter-stage cooler 11 at the tail end transmits the gas to be recovered to the storage mechanism for storage. By using the above-mentioned gas recovery method, the gas to be recovered can be safely and efficiently compressed and cooled in multiple stages, and it is convenient for storage and transportation of the gas to be recovered.

[0071] In one embodiment, the gas inlet mechanism comprises a storage container 1 storing nitrogen, the gas recovery system further comprises a plurality of evacuation pipelines 13, and the step of replacing the gas in the gas recovery system with nitrogen comprises: opening the storage container 1 and the plurality of evacuation pipelines 13 to replace the air in the gas recovery system with nitrogen and discharge the air from the evacuation pipelines 13; after the first preset time period, determining that the replacement of nitrogen is completed and closing the storage container 1. In the process of replacing the air in the gas recovery system, the storage container 1 and the evacuation pipelines 13 need to be opened first to discharge the air in the gas recovery system with nitrogen. After the first preset time period, it can be determined that the replacement of nitrogen is completed, and the storage container 1 can be closed for the gas recovery step.

[0072] In one specific embodiment, the first preset time period is determined according to the following steps: after opening the storage container 1, the nitrogen concentration at the gas outlet of the evacuation pipeline 13 is detected in real time, and when the nitrogen concentration reaches a preset concentration threshold, it is determined that the air in the gas recovery system is completely replaced, and the time difference from opening the storage container 1 to the nitrogen concentration reaching the preset concentration threshold is determined as the first preset time period.

[0073] In one embodiment, the step of opening the gas inlet end of the gas inlet mechanism and introducing the gas to be recovered into the gas recovery system comprises: opening the gas inlet end of the gas inlet mechanism to replace the nitrogen with the gas to be recovered, and discharging the nitrogen from the evacuation pipeline 13; after the second preset time period, determining that the replacement of the gas to be recovered is completed. Before the gas is compressed and cooled, the nitrogen in the gas recovery system needs to be replaced to improve the purity of the recovered gas. Therefore, the gas inlet end of the gas inlet mechanism is first opened to replace the nitrogen with the gas to be recovered, and the nitrogen is discharged from the evacuation pipeline 13. After the second preset time period, it can be determined that the replacement of the gas to be recovered is completed. By using the above method, the purity of the gas to be recovered after recovery can be improved to improve the recovery quality.

[0074] In one specific embodiment, the second preset time period is determined according to the following steps: after opening the gas inlet mechanism, the concentration of the gas to be recovered at the gas outlet of the evacuation pipeline 13 is detected in real time, and when the concentration of the gas to be recovered reaches a preset concentration threshold, it is determined that the nitrogen in the gas recovery system is completely replaced, and the time difference from opening the gas inlet mechanism to the concentration of the gas to be recovered reaching the preset concentration threshold is determined as the second preset time period.

[0075] In one embodiment, the gas inlet mechanism further comprises a main pipeline 2, and a first flow detection member 3, a first pressure detection member 4 and a gas regulating valve 19 installed on the main pipeline 2, and the gas recovery method further comprises the following steps: observing the flow detection value of the first flow detection member 3 and the pressure detection value of the first pressure detection member 4 after opening the gas inlet end of the gas inlet mechanism; adjusting the gas regulating valve 19 to reduce the flow of the main pipeline 2 in the case that the flow detection value is greater than a preset maximum flow threshold value; adjusting the gas regulating valve 19 to reduce the pressure of the main pipeline 2 in the case that the pressure detection value is greater than a preset maximum pressure threshold value. When the gas pressure or the gas flow in the main pipeline 2 is too high, the gas flow and the gas pressure in the main pipeline 2 can be adjusted by the gas regulating valve 19 to prevent the gas compression member 6 and the inter-stage cooler 11 from being overloaded, and to protect the components in the gas recovery system.

[0076] In the description of the present application, it is to be understood that the terms "first", "second", "third" and the like, if any, are used merely to describe different features, and do not imply or imply relative importance or a specific number of the features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0077] In the present application, unless otherwise specifically defined and limited, the terms "installation", "connection", "connection", "fixation" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected or communicate with each other; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0078] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine the different embodiments or examples described in the present application and the features of the different embodiments or examples without contradiction.

[0079] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and that changes, modifications, substitutions and variations can be made by those skilled in the art without departing from the scope of the present application.

Claims

1. A gas recovery system characterized by, The gas recovery system comprises: an air inlet mechanism, an air inlet end of which is in communication with a discharge end of a storage device storing the gas to be recovered; a plurality of sequentially communicated gas compressors (6), an air inlet end of the gas compressor (6) located at the head end being in communication with an air outlet end of the air inlet mechanism, the plurality of gas compressors (6) being respectively used for sequentially performing multi-stage compression on the gas to be recovered, the gas compressor (6) further having a discharge end, the gas recovery system further comprising a plurality of discharge pipelines (13), air inlet ends of the plurality of discharge pipelines (13) being in one-to-one correspondence with the discharge ends of the plurality of gas compressors (6), air outlet ends of the discharge pipelines (13) being in communication with the outside atmosphere; a plurality of inter-stage coolers (11), the plurality of inter-stage coolers (11) and the plurality of gas compressors (6) being sequentially and alternately arranged in communication, the inter-stage cooler (11) being used for cooling and transmitting the gas compressed by the gas compressor (6); a storage mechanism, an air inlet end of the storage mechanism being in communication with an air outlet end of the inter-stage cooler (11) located at the tail end and being used for storing the gas to be recovered after multi-stage compression and cooling; a main pipeline (2), an air inlet end of the main pipeline (2) being in communication with a discharge end of the storage device, an air outlet end of the main pipeline (2) being in communication with an air inlet end of the gas compressor (6) located at the head end; a storage container (1), the storage container (1) storing nitrogen, an air outlet end of the storage container (1) being in communication with the main pipeline (2), the nitrogen being used for replacing air in the main pipeline (2), the plurality of gas compressors (6) and the plurality of inter-stage coolers (11) before gas recovery.

2. The gas recovery system of claim 1, wherein, The air inlet mechanism further comprises: a first flow detection member (3) installed on the main pipeline (2) and used for detecting the gas flow of the main pipeline (2); a first pressure detection member (4) installed on the main pipeline (2) and used for detecting the gas pressure of the main pipeline (2); a gas regulating valve (19) in communication with the main pipeline (2) and used for regulating the gas pressure and the gas flow of the main pipeline (2).

3. The gas recovery system of claim 1, wherein, Any adjacent gas compressor (6) and inter-stage cooler (11) are in communication through a branch pipeline (20), one end of the branch pipeline (20) being in communication with an air outlet end of the gas compressor (6), the other end of the branch pipeline (20) being in communication with an air inlet end of the inter-stage cooler (11), a safety valve (7) being installed on the branch pipeline (20) and being arranged on the branch pipeline (20) and used for limiting the maximum pressure in the branch pipeline (20).

4. The gas recovery system of claim 1, wherein, The gas recovery system further comprises a first temperature detecting element (10) installed at the gas inlet end of the inter-stage cooler (11), a second temperature detecting element (12) installed at the gas outlet end of the inter-stage cooler (11), a gas filtering element (5) communicated with the gas inlet end of each of the gas compressing elements (6), and a blowdown pipeline (14) communicated with the blowdown end of the inter-stage cooler (11), the blowdown pipeline (14) being used for discharging impurities obtained after the to-be-recovered gas is cooled.

5. The gas recovery system of claim 1, wherein, The storage mechanism comprises: an outlet pipeline (15) having a gas inlet end communicated with the gas outlet end of the inter-stage cooler (11) located at the tail end; a storage element having a gas inlet end communicated with the gas outlet end of the outlet pipeline (15) and used for storing the treated to-be-recovered gas; a filter (17) provided in the outlet pipeline (15) and used for filtering impurities in the to-be-recovered gas.

6. A gas recovery method characterized by, The gas recovery method applied to the gas recovery system of any one of claims 1 to 5 comprises the following steps: replacing the gas in the gas recovery system with nitrogen; opening the gas inlet end of the gas inlet mechanism and introducing the to-be-recovered gas into the gas recovery system; starting the plurality of gas compressing elements (6) and the plurality of inter-stage coolers (11) to perform multi-stage compression and cooling on the to-be-recovered gas; opening the storage mechanism to store the to-be-recovered gas after multi-stage compression and cooling.

7. The gas recovery method according to claim 6, characterized in that, The gas inlet mechanism comprises a storage container (1) storing the nitrogen, and the gas recovery system further comprises a plurality of evacuation pipelines (13), and the step of replacing the gas in the gas recovery system with nitrogen comprises: opening the storage container (1) and the plurality of evacuation pipelines (13) to replace the nitrogen with air in the gas recovery system and discharge the air from the evacuation pipelines (13); after a first preset time period, determining that the replacement of the nitrogen is completed and closing the storage container (1).

8. The gas recovery method according to claim 7, characterized by, The step of opening the gas inlet end of the gas inlet mechanism and introducing the to-be-recovered gas into the gas recovery system comprises: opening the gas inlet end of the gas inlet mechanism to replace the nitrogen with the to-be-recovered gas, the nitrogen being discharged from the evacuation pipelines (13); after a second preset time period, determining that the replacement of the to-be-recovered gas is completed.

9. The gas recovery method according to claim 6, characterized by, The gas inlet mechanism further comprises a main pipeline (2), and a first flow detecting element (3), a first pressure detecting element (4) and a gas adjusting valve (19) installed on the main pipeline (2), and the gas recovery method further comprises the following steps: after opening the gas inlet end of the gas inlet mechanism, observing the flow detection value of the first flow detecting element (3) and the pressure detection value of the first pressure detecting element (4); in the case that the flow detection value is greater than a preset maximum flow threshold value, adjusting the gas adjusting valve (19) to reduce the flow of the main pipeline (2); in the case that the pressure detection value is greater than a preset maximum pressure threshold value, adjusting the gas adjusting valve (19) to reduce the pressure of the main pipeline (2).

Images