Volumetric hydrogen compressor cylinder body structure and hydrogen compressor system

Abstract

The invention discloses a volume type hydrogen compressor cylinder body structure and a hydrogen compressor system, and belongs to the technical field of compressors, the compressor system comprises the cylinder body structure, the cylinder body structure comprises a cylinder body, piston assemblies and a piston rod, and the piston assemblies comprise the first piston assembly and the second piston assembly; each of the first piston assembly and the second piston assembly comprises a piston ring and a guide ring; an air guide hole is formed in the piston rod, an annular groove is formed between the first piston assembly and the second piston assembly, and one end of the air guide hole communicates with the annular groove; the pressure sampling device further comprises a pressure sampling cylinder, a cavity is formed in the pressure sampling cylinder, and when the piston assembly is in the gas compression stroke, the other end of the gas guide hole is communicated with the cavity. And the pressure sensor is used for measuring the pressure in the cavity. According to the structural design provided by the scheme, online monitoring of the sealing condition of the piston assembly and the air cylinder wall can be achieved, and compared with technologies based on vibration monitoring, sound wave monitoring and the like, adverse effects of the data extraction and analysis process on the monitoring result can be avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of compressors, in particular to a positive displacement hydrogen compressor cylinder structure and a hydrogen compressor system. BACKGROUND

[0002] A hydrogen compressor is a compressor for compressing hydrogen. Compared with an air compressor, the performance characteristics of a hydrogen compressor include not only the ability to resist hydrogen embrittlement (usually achieved by material selection and heat treatment), but also higher anti-leakage performance, compressor temperature control performance, etc. At the same time, according to the use of the product gas after hydrogen is compressed, in a hydrogen compressor based on a piston for compression, the lubrication methods used include oil lubrication and oil-free lubrication. Oil-free lubrication is used in application fields with high requirements for product gas purity, such as fuel cell fields. For the anti-leakage performance of the contact position between the piston and the cylinder wall of an oil-free lubricated hydrogen compressor, in the prior art, the piston is provided with a sealing ring (piston ring) made of a self-lubricating material and a support ring. The self-lubricating materials include PTFE and PEEK, etc. Although these materials have ideal self-lubricating properties, in the working process of a hydrogen compressor, due to the heat generated by the friction pair and the rapid temperature rise during hydrogen compression, the influence of temperature on the sealing performance of the contact position is mainly as follows: when the temperature of the sealing ring rises, the thermal expansion generated by the sealing ring is greater than the expansion amount of the cylinder, which increases the contact force between the piston ring and the cylinder wall, further increases the temperature of the friction pair position, and under the influence of temperature, the significant decrease in the strength and hardness of the sealing ring leads to a decrease in the sealing pressure of the friction pair, which increases the axial leakage of the piston position in the cylinder; the wear rate increases due to the decrease in the wear resistance of the softened sealing ring, which greatly affects the service life of the piston ring; the temperature rise destroys the transfer film formed by the self-lubricating material of the piston ring on the cylinder wall, which increases the wear rate.

[0003] To monitor the axial leakage of the piston position, in the patent application No. CN202511159761.6, entitled "Intelligent monitoring method and system for sealing performance of liquid-driven compressor", a technical solution based on data processing methods such as friction sound signals is provided to monitor the sealing performance, and a technical solution based on vibration signal analysis is mentioned to evaluate the sealing performance of the compressor. Regarding the axial leakage monitoring, conventional methods also include methods based on exhaust volume and pressure analysis, fixed-point temperature monitoring, sound wave monitoring, and shutdown inspection, etc.

[0004] During the working process of the oil-free lubrication hydrogen compressor, the axial leakage of the piston and the cylinder wall is relatively easy to occur, and the most direct influence of the axial leakage is the decrease of the exhaust volume and the exhaust pressure, and the decrease of the operation efficiency and the increase of the operation cost, so further optimizing the cylinder structure of the hydrogen compressor to facilitate the axial leakage monitoring has important significance for the further development of the hydrogen energy technology and the promotion of the hydrogen energy utilization. SUMMARY

[0005] In view of the above-mentioned problem of optimizing the cylinder structure of the hydrogen compressor, the purpose of the present application is to provide a positive displacement hydrogen compressor cylinder structure and a hydrogen compressor system, the structure design provided by the present application can not only realize online monitoring of the sealing condition of the piston assembly and the cylinder wall, but also can avoid the adverse effects of the data extraction and analysis process on the monitoring results compared with the monitoring schemes based on vibration monitoring, acoustic monitoring and the like.

[0006] The purpose of the present application is mainly realized by the following technical scheme: a positive displacement hydrogen compressor cylinder structure, comprising a cylinder body, a piston assembly installed in the cylinder body, and a piston rod connected with the piston assembly, the piston assembly comprises a first piston assembly and a second piston assembly, the first piston assembly and the second piston assembly are installed on the piston rod in a spaced manner, and the first piston assembly and the second piston assembly each comprise a piston ring and a guide ring. A gas guide hole is arranged on the piston rod, and an annular groove is formed between the first piston assembly and the second piston assembly, one end of the gas guide hole is communicated with the annular groove; Further comprising a pressure collecting cylinder, the pressure collecting cylinder is configured with a closed cavity, the piston rod passes through the pressure collecting cylinder and passes through the cavity, and the other end of the gas guide hole is configured to be communicated with the cavity when the piston assembly is in a gas compression stroke; Further comprising a pressure sensor installed on the pressure collecting cylinder for measuring the pressure in the cavity.

[0007] In the present application, the cylinder body is a cylinder barrel of the compressor cylinder structure, used to provide a piston cavity, the piston assembly is installed in the piston cavity of the cylinder body, when the compressor is working, the piston assembly moves with the piston rod to realize the compression of the gas in the piston cavity.

[0008] The present application provides a technical scheme for solving the online monitoring of the sealing condition of the piston assembly and the cylinder wall by designing the piston assembly, the gas guide hole and the pressure measurement, which can avoid the adverse effects of the data extraction and analysis process on the monitoring results compared with the existing monitoring schemes based on vibration monitoring, acoustic monitoring and the like.

[0009] Specifically, in the scheme, the piston assembly includes a first piston assembly and a second piston assembly, which are designed to cooperate with the cylinder wall to form an annular groove between the first piston assembly and the second piston assembly, the first piston assembly and the second piston assembly serve as axial sealing structures at different ends of the annular groove, and the first piston assembly and the second piston assembly form axial sealing surfaces with the cylinder wall of the cylinder body. When the first piston assembly and the second piston assembly can normally perform axial sealing functions, the annular groove and the piston cavities on both sides of the piston assembly are isolated from each other. For example, when the piston assembly is in a gas compression stroke, the pressure in the annular groove will not increase due to the increase in the pressure in the piston cavity on one side of the piston assembly. In this state, due to the change in the working temperature of the cylinder body structure, the internal pressure in the annular groove will change to a certain extent, but the change range of the internal pressure in the annular groove is relatively constant, and the change rate is also relatively constant. When the sealing ring on the first piston assembly or the second piston assembly deteriorates due to inevitable wear, the gas in the compression cavity in the piston cavity will be introduced into the annular groove through the leakage gap between the piston ring and the cylinder wall when the piston assembly is in a gas compression stroke. The gas introduced into the annular groove becomes an interference factor that interferes with the internal pressure in the annular groove, which will destroy the original pressure change rate of the annular groove and the maximum pressure of the annular groove. By collecting pressure data in the annular groove in real time, the sealing condition of the piston assembly and the cylinder wall can be determined.

[0010] Further, the present scheme realizes the communication between the annular groove and the upper cavity of the pressure cylinder by providing a gas guide hole on the piston rod. In this way, the gas guide hole is used as a communication hole between the annular groove and the upper cavity of the pressure cylinder, so that the internal pressure of the cavity and the internal pressure of the annular groove change synchronously. By installing a pressure sensor on the pressure cylinder, the internal pressure of the annular groove can be monitored. In this way, not only is the signal pickup interference and signal processing interference faced by the traditional online monitoring of the sealing performance of the piston assembly based on vibration and sound wave avoided, but also the problems of energy supply, detection result transmission, and the serious impact on the service life of the pressure sensor caused by the synchronization of the piston assembly movement are avoided. The temperature environment in the cylinder body also affects the accuracy of the pressure detection element.

[0011] As a person skilled in the art, since the pressure cylinder is arranged outside the cylinder body, the main path for the compression heat to be transferred to the pressure cylinder is the piston rod, which acts as a heat conduction bridge, resulting in the compression heat affecting the temperature of the gas in the annular groove and the gas guide hole. Therefore, in the gas cavity including the cavity, the annular groove and the gas guide hole, the pressure change and the pressure change rate of the gas cavity within the working cycle of the compressor are related to the heating capacity of the piston rod to the pressure cylinder, the heat dissipation capacity of the gas cavity, the volume of the cavity, the volume of the annular groove and the volume of the gas guide hole, etc. Therefore, when the compressor is in thermal equilibrium, and when the sealing performance of the piston assembly is good, the final pressure measured by the pressure sensor, or the pressure rise rate obtained from multiple monitoring results of the pressure sensor, is related to the specific design of the compressor and environmental factors. When the pressure detection result is used to determine the sealing performance of the piston assembly based on the pressure threshold and the pressure rise rate threshold, the specific threshold value should be determined according to the specific design of the compressor and the use environment. However, for a single compressor, when the operating environment factors are stable and the compressor is in thermal equilibrium, if there is no leakage between the piston assembly and the cylinder wall, the maximum pressure that can be measured by the pressure sensor is stable, and the pressure threshold can be used as a standard for judging the sealing performance of the piston assembly. If the measured pressure during the operation of the compressor exceeds the pressure threshold, it is determined that the sealing performance of the piston assembly has decreased, and the piston assembly has leaked with the cylinder wall. At the same time, after the leakage occurs, or in order to match the design of the compression amount of the gas, the service life design of the piston assembly, etc., there is always internal leakage at the exhaust pressure during the entire life cycle of the piston assembly. As long as the leakage speed is within the allowable range, i.e. after the pressure rise rate is obtained by continuously measuring the pressure value, if the pressure rise rate is less than the pressure rise rate threshold, it is determined that the piston assembly at this time still meets the sealing performance requirements, and the sealing performance of the piston assembly in this stage meets the requirements.

[0012] In specific applications, for hydrogen compression, according to the use occasion, the raw material gas can be normal pressure gas or pressurized gas, and the target pressure distribution range of the product gas is relatively wide, such as 20 MPa to 70 MPa, and the hydrogen compression process usually adopts multi-stage pressurization. For the present scheme, when it is used in the case where the cylinder exhaust pressure is greater than 5 MPa, if the initial pressure in the pressure collecting cylinder cavity is atmospheric pressure, because the pressure difference between the ring groove and the compression cavity is large, the sealing performance of the first piston assembly and the second piston assembly is required to be higher. In view of this problem, preferably, a pressure compensation hole for compensating the inner cavity of the pressure collecting cylinder is arranged on the pressure collecting cylinder, and the pressure compensation hole compensates the cavity based on the pressure compensation pipeline, so as to reduce the pressure difference on both sides of the first piston assembly and the second piston assembly (the pressure difference between the ring groove and the compression cavity), and achieve the purpose of simplifying the design of the first piston assembly and the second piston assembly. Further, when it is used in the case where there is internal leakage, the pressure in the pressure collecting cylinder cavity has a process of continuously rising, and when it reaches a certain value, the sealing ability of the piston assembly and the back pressure established in the ring groove will prevent the occurrence of internal leakage. In the subsequent operation process of the compressor, as the piston assembly is continuously worn and the sealing ability decreases, the pressure in the ring groove will continue to rise, so the detection result of the pressure sensor can still be used as an important indicator of the sealing performance of the piston assembly.

[0013] The further technical scheme of the positive displacement hydrogen compressor cylinder structure is: The pressure collecting cylinder is a cylindrical structure with its axis parallel to the piston rod axis, end plates arranged at both ends, and a partition plate in the center, and the cavity includes a first pressure collecting cavity and a second pressure collecting cavity separated by the partition plate. The piston rod passes through the partition plate and the end plates at both ends of the pressure collecting cylinder, the partition plate is provided with a first sealing assembly for achieving the gap axial sealing between the hole on the partition plate and the piston rod, and the end plates are each provided with a second sealing assembly for achieving the gap axial sealing between the hole on the end plate and the piston rod. The first pressure collecting cavity and the second pressure collecting cavity are each provided with a pressure sensor for measuring the pressure in the respective cavity. The cylinder is provided with an air inlet and an exhaust port at both ends. The first pressure collecting cavity and the second pressure collecting cavity are configured such that, during the reciprocating movement of the piston assembly in the cylinder, when the piston assembly compresses the gas on one side of the cylinder, the gas guide hole communicates with one of the first pressure collecting cavity and the second pressure collecting cavity, and when the piston assembly compresses the gas on the other side of the cylinder, the gas guide hole communicates with the other of the first pressure collecting cavity and the second pressure collecting cavity.

[0014] The above provides a specific pressure cylinder implementation form and cylinder body setting form, both ends of the cylinder body are provided with air inlet and air outlet, that is, a double-acting cylinder body form: the piston cavities on both sides of the piston assembly are used as compression cavities, such an implementation form is high in efficiency and stable in exhaust pulsation, as the piston rod is compressed by the piston assembly during forward and backward movement, under such a cylinder body form, the scheme is provided with first and second pressure cavities, and separate pressure sensors are arranged for the first and second pressure cavities, so as to realize that, for example, when the piston assembly moves forward and the gas in the compression cavity in front of the first piston assembly is compressed, at this time, the annular groove is communicated with the second pressure cavity through the gas guide hole, when the piston assembly moves backward and the gas in the compression cavity in front of the second piston assembly is compressed, at this time, the annular groove is communicated with the first pressure cavity through the gas guide hole, when the sealing performance of the first piston assembly decreases, the pressure in the annular groove increases during the forward movement of the piston assembly, so that the pressure in the second pressure cavity increases and can be detected by the corresponding pressure sensor, when the piston assembly moves backward, although the pressure gas in the annular groove also pressurizes the first pressure cavity, in this process, if the sealing performance of the second piston assembly is good, the maximum pressure that can be reached by the first pressure cavity after pressurization is also less than the pressure of the second pressure cavity and lags behind the pressure rise of the second pressure cavity, therefore, compared with the pressure cylinder provided with only one pressure cavity, the sealing performance of the piston assembly can be judged based on the pressure monitoring results of the first and second pressure cavities, the sealing performance of the first and second piston assemblies can be judged, and the sealing performance of the piston assembly can be intuitively and finely obtained.

[0015] In the above scheme, the first sealing assembly is used to prevent direct internal leakage of the first and second pressure cavities, and the second sealing assembly is used to prevent external leakage of the gas at the end of the pressure cylinder, as the pressure difference on both sides of the sealing assembly at the position of the partition plate and the position of the end plate is obviously different, and the leakage at the position of the end plate has an impact on the environment, the second sealing assembly is required to have higher sealing performance, preferably, the first and second sealing assemblies adopt different sealing structures. The gas guide hole on the piston rod can be configured as a hole that is communicated with the pressure cylinder, when the piston assembly is located at the center of the movement track of the cylinder body, the hole is located at the position of the partition plate, and the hole can be configured as being communicated with the second pressure cavity when the piston rod moves forward and being communicated with the first pressure cavity when the piston rod moves backward.

[0016] The first sealing assembly is a sealing ring installed in the annular groove of the partition plate, the number of the sealing ring is greater than or equal to 3, and each sealing ring is provided with an independent annular groove; the second sealing assembly is a packing sealing assembly installed on the end plate, the packing sealing assembly comprises packing and a compression ring for compressing the packing, the packing is arranged in the packing box of the end plate, and the compression ring is connected to the end plate through a compression bolt, and the end of the compression ring acts on the packing.

[0017] The above provides a specific implementation form of the first sealing assembly and the second sealing assembly, as described above, the first sealing assembly aims to solve the internal leakage problem and the pressure difference on both sides of the sealing surface is small, so a plurality of sealing rings with simple structure and convenient assembly can be used to realize reliable sealing, and the sealing ring is an O-ring; the second sealing assembly aims to solve the external leakage problem and the pressure difference on both sides of the sealing surface may be relatively large, so a structure comprising packing and a compression ring is used to provide reliable sealing for the position, and the packing sealing assembly can adjust the sealing performance at any time by adjusting the compression ring through the compression bolt.

[0018] The first piston assembly and the second piston assembly are both configured to comprise a plurality of piston rings, the piston rings are stacked in the axial direction of the piston rod, the guide ring is fixed on the piston rod, both ends of the stacked structure formed by the stacked piston rings are provided with guide rings, and the stacked structure is clamped between the guide rings. The piston ring is a plate-shaped structure comprising an outer ring and an inner ring, the outer ring is a high polymer material ring, the inner ring is a metal plate with a center hole, the inner ring is sleeved on the piston rod through the center hole thereon, the outer ring is fixed on the outer edge of the inner ring, and the outer ring is in contact with the cylinder wall of the cylinder.

[0019] The above scheme provides a specific piston assembly implementation form. Specifically, the piston ring (also known as the sealing ring) is used to prevent leakage in the cylinder at the position of the piston assembly, and the gas blow-by that is not allowed to occur at the position of the piston assembly. The guide ring (also known as the support ring) is used as a support on the piston assembly to keep the piston assembly centered with the piston cavity, ensure that the piston assembly reciprocates on the center line of the piston cavity, prevent direct contact and eccentric wear between the piston ring and the cylinder wall, and provide lateral force support structure to ensure the stability of the piston assembly. In the present scheme, a plurality of piston rings are provided on the corresponding piston assembly to achieve: forming multiple levels of sealing in the axial leakage direction to gradually reduce the pressure in a step-by-step manner, avoiding or reducing leakage while ensuring the service life of each piston ring; the guide ring at both ends of the laminated structure aims to provide lateral support for the laminated structure at both ends to reduce or avoid eccentric wear or even radial shaking of the piston ring. The present scheme further provides that the piston ring includes an outer ring and an inner ring. The outer ring is made of a high polymer material and serves as an outer ring body of the piston ring. The specific material can be polyether ether ketone material which is mature, has good wear resistance, and has low friction coefficient. The inner ring is made of a metal material and serves as an inner ring body of the piston ring. The specific material can be austenitic stainless steel which has good thermal conductivity, low thermal expansion coefficient, excellent strength and rigidity, and good hydrogen brittleness resistance. The piston ring with the above structure can, on the one hand, support the outer ring with the inner ring and strengthen the heat dissipation capacity of the inner side of the outer ring, aiming to reduce the working temperature of the outer ring and reduce the influence of friction heat on the sealing performance and service life of the outer ring; on the other hand, from the overall perspective of the piston ring, the inner ring made of a metal material has a smaller thermal expansion amount than the high polymer material, so the contact force between the outer ring and the cylinder wall under the hot state of the compressor can be effectively reduced, that is, by maintaining a reasonable and relatively constant contact force between the outer ring and the cylinder wall, the purpose of prolonging the service life of the piston ring is achieved.

[0020] The laminated structure is configured such that, in the axial direction of the piston rod, the end faces of adjacent outer rings are in contact with each other, the end faces of adjacent inner rings are in contact with each other, and the inner end faces of the guide rings at both ends of the laminated structure are in contact with the outer rings and the inner rings.

[0021] The above provides a more specific piston assembly structure. In the present scheme, the outer rings are in contact with each other, the inner rings are in contact with each other, and the guide rings at the ends of the laminated structure are in contact with the outer rings and the inner rings, so that the first piston assembly and the second piston assembly are both multi-layer structures with stable relative positions between layers. Such a multi-layer structure can effectively ensure the performance reliability of the piston assembly from the perspectives of overall vibration and interlayer slip.

[0022] The inner ring includes a sleeve and a plurality of plate rings in the form of sheets. The central hole is a hole in the sleeve. The plate rings are arranged in a spaced manner in the axial direction of the sleeve and are welded to the sleeve by ring welds. The inner wall of the outer ring is provided with ring grooves in number consistent with the number of plate rings, the ring grooves are arranged at intervals on the axis of the outer ring, and the outer edge of the plate ring is embedded in the ring groove, each ring groove being matched with a plate ring.

[0023] The sleeve serves as a connecting framework on the inner side of the plate ring and provides a central hole for sleeving the inner ring on the piston rod, the plate ring serves as a support ring between the outer ring and the sleeve, and the ring weld is preferably formed by laser welding to ensure axial sealing of the welding position by welding quality and reduce the influence of welding heat on material reliability. In the scheme, compared with the length of the sleeve, the plate ring is a thin-walled ring on the inner ring, which is used to provide support for the inner side of the outer ring. When the temperature of the cylinder structure rises, the temperature of the plate ring rises synchronously. The thinner plate ring is more prone to conical deformation under the extrusion of the outer ring expansion and its own expansion. Compared with a single plate ring with the same thickness as the sleeve, the rigid constraint of the inner ring on the outer ring is smaller, thereby achieving the purpose of facilitating the control of the contact force between the outer ring and the cylinder wall. In the scheme, the plate ring is connected with the outer ring by embedding the outer side of the plate ring in the ring groove on the inner wall of the outer ring, which aims to achieve: not only the position constraint of the outer ring in the axial direction of the inner ring is realized by a simple structure, but also for hydrogen, a small leakage gap is easy to cause hydrogen leakage. By embedding the outer edge of the plate ring in the ring groove, the length of the gas leakage gap between the inner ring and the outer ring can be effectively increased, and the possibility of axial leakage of gas through the gap between the inner ring and the outer ring can be reduced.

[0024] The gap between the plate ring and the plate ring, and the gap between the plate ring and the guide ring are filled with a flexible filler layer.

[0025] In the above scheme, on the one hand, the flexible filler layer is used to fill the gap at the corresponding position, so that the side surface of the piston ring has support from the flexible filler, so that the flexible filler layer can effectively constrain the vibration occurring on the piston ring during the reciprocating motion and variable speed motion of the piston assembly, thereby achieving the purpose of optimizing the stability of the piston ring; on the other hand, the flexible filler layer is used to fill part of the space in the gap to reduce the air gap in the gap, so as to reduce the influence of the expansion and contraction of the gas in the air gap on the structural stability and sealing reliability of the piston assembly. Preferably, due to the working temperature of the cylinder structure, the flexible filler layer itself will also expand to a certain extent, in order to avoid the influence of thermal expansion on the overall form of the piston assembly and the contact force with the cylinder wall, the flexible filler layer is arranged to fill part of the space in the gap and / or the flexible filler layer is made of a material with internal voids. With this scheme, the gap not filled by the flexible filler layer forms an air gap and serves as an expansion space for the flexible filler layer, and the voids allow the flexible filler layer to be compressed. Preferably, the flexible filler layer preferably uses flexible graphite material or expanded PTFE material with good resilience and long-term reliability at the working temperature range of the cylinder structure, and the flexible filler layer is not suitable for rubber material which is prone to failure under high temperature and hydrogen influence.

[0026] The cylinder has a double-layer structure with a liner on the inner side and an outer cylinder on the outer side, and a cold water groove for introducing cooling water into the cylinder is formed between the outer wall of the liner and the inner wall of the outer cylinder.

[0027] The above scheme provides a specific cylinder form, and in the specific scheme, the liner is made of a hydrogen embrittlement resistant material and provides a smooth cylinder wall, and the cold water groove is specifically used to control the temperature of the cylinder structure by introducing circulating cooling water into it. The double-layer cylinder facilitates the formation of a cold water groove in a spiral structure.

[0028] The present scheme also relates to a positive displacement hydrogen compressor system, which includes a driving motor, a middle body, and a cylinder structure. The driving motor is connected to the piston rod of the cylinder structure through the middle body, the middle body is used to convert the rotary motion of the driving motor into the linear reciprocating motion of the piston rod, and the cylinder structure is the cylinder structure according to any one of the above.

[0029] The above compressor system is a specific application of the cylinder structure, that is, the compressor system includes the cylinder structure. As a person skilled in the art, the driving motor serves as the power source of the system, the power output by the driving motor is transmitted to the piston rod through the middle body and drives the piston rod to perform linear reciprocating motion, and the gas is compressed in the cylinder structure.

[0030] The further technical scheme of the positive displacement hydrogen compressor cylinder structure is: The connecting disc comprises a connecting plate and a plurality of strips arranged in the circumferential direction of the connecting plate, and the open end of the pressure cylinder is bolted to the connecting plate through the flange plate on the outer side of the open end. The processing module is configured to: collect the pressure measurement result of the pressure sensor, and compare the pressure measurement result with a preset pressure threshold value and a preset pressure rise rate threshold value; when it is determined that the pressure measurement result is greater than or equal to the pressure threshold value or the pressure rise rate is greater than or equal to the pressure rise rate threshold value, an abnormal wear determination result of the piston assembly is output.

[0031] The above scheme provides a specific pressure cylinder connection mode. Specifically, for the pressure cylinder implementation form in which the first pressure chamber and the second pressure chamber are separated by the partition plate, the open end of the pressure cylinder is used to complete the configuration and maintenance of the first sealing assembly. Regarding the end plate, the bottom plate serves as the end plate of one end of the pressure cylinder, and the second sealing assembly of the end plate is arranged on the outer side of the bottom plate. The connecting plate serves as the end plate of the other end of the pressure cylinder, and the second sealing assembly of the end plate is arranged on the outer side of the connecting plate. The connecting disc serves as the intermediate connecting structure of the pressure cylinder and the middle body, and is provided with a plurality of strips arranged in the circumferential direction of the connecting plate. The space between the strips is used to debug and maintain the second sealing assembly on the outer side of the connecting plate. The processing module is used to collect the pressure measurement result of the pressure sensor, and determine whether the piston assembly has an abnormal wear based on the pressure threshold value and the pressure rise rate threshold value.

[0032] Compared with the prior art, the beneficial effects of the present application are as follows: The present scheme provides a technical scheme for solving the online monitoring of the sealing condition of the piston assembly and the cylinder wall by designing the piston assembly, the gas guide hole and the pressure measurement, which can avoid the adverse effects of data extraction and analysis process on the monitoring results compared with the existing monitoring schemes based on vibration monitoring and sound wave monitoring. BRIEF DESCRIPTION OF DRAWINGS

[0033] The accompanying drawings used to provide further understanding of the embodiments of the present application, constitute a part of the present application, and do not constitute a limitation of the embodiments of the present application. In the drawings: Figure 1 It is a partial structure schematic diagram of a specific embodiment of the volumetric hydrogen compressor system described in the present application, which is a partial sectional view; Figure 2 It is a partial structure schematic diagram of a specific embodiment of the volumetric hydrogen compressor system described in the present application, which is a partial sectional view; Figure 1 It is a partial enlarged view of part A. Figure 3 For Figure 1 A partial enlarged view of the middle A part, compared to Figure 2 , Figure 3 The structure is provided with a flexible filler layer; Figure 4 For Figure 3 A partial enlarged view of B part shown; Figure 5 For Figure 1 A partial enlarged view of C part shown; Figure 6 In a specific embodiment of the volumetric hydrogen compressor cylinder structure described in this scheme, the structure diagram of the inner ring; The figure marks are respectively: 1, cylinder, 2, piston assembly, 21, first piston assembly, 22, second piston assembly, 3, piston rod, 4, pressure cylinder, 5, middle body, 6, exhaust port, 7, inlet, 8, pressure sensor, 9, first pressure cavity, 10, second pressure cavity, 11, gas guide hole, 12, ring groove, 13, bushing, 14, cold water tank, 15, piston ring, 16, metal plate, 17, guide ring, 18, flexible filler layer, 19, partition, 20, ring, 23, connecting disc, 24, sleeve. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical scheme and advantages of the present application more clear and obvious, the present application will be further described in detail below, combined with examples and drawings, the schematic embodiment of the present application and its description are only used to explain the present application, and not as a limitation to the present application.

[0035] Example 1:

[0036] As Figures 1 to 6 shown, the embodiment of the present application provides a volumetric hydrogen compressor cylinder structure, which comprises a cylinder 1, a piston assembly 2 installed in the cylinder 1, and a piston rod 3 connected with the piston assembly 2, the piston assembly 2 comprises a first piston assembly 21 and a second piston assembly 22, the first piston assembly 21 and the second piston assembly 22 are installed on the piston rod 3 in a spaced manner, and the first piston assembly 21 and the second piston assembly 22 each comprise a piston ring 15 and a guide ring 17; The piston rod 3 is provided with a gas guide hole 11, and a ring groove 12 is formed between the first piston assembly 21 and the second piston assembly 22, one end of the gas guide hole 11 communicates with the ring groove 12; It also includes a pressure cylinder 4, the pressure cylinder 4 is configured with a closed cavity, the piston rod 3 passes through the pressure cylinder 4 and passes through the cavity, the other end of the gas guide hole 11 is configured to: when the piston assembly 2 is in the gas compression stroke, the other end of the gas guide hole 11 communicates with the cavity; Also included is a pressure sensor 8 mounted on the pressure cylinder 4 for measuring the pressure in the cavity.

[0037] In the scheme, the cylinder 1 is the cylinder barrel of the compressor cylinder 1 structure, for providing a piston cavity, the piston assembly 2 is installed in the piston cavity of the cylinder 1, when the compressor works, the piston assembly 2 moves with the piston rod 3, realizing the compression of the gas in the piston cavity.

[0038] The scheme is aimed at the characteristics that the sealing of hydrogen itself is difficult, and the temperature has a significant influence on the sealing performance of the piston ring 15 during compression. A technical scheme is provided by designing the piston assembly 2, the gas guide hole 11 and the pressure measurement, which solves the online monitoring of the sealing condition of the piston assembly 2 and the cylinder wall. By directly measuring the pressure, compared with the existing monitoring schemes based on vibration monitoring and sound wave monitoring, the adverse effects of data extraction and analysis process on the monitoring results can be avoided.

[0039] Specifically, in the scheme, the piston assembly 2 includes a first piston assembly 21 and a second piston assembly 22, which are designed to cooperate with the cylinder wall to form an annular groove 12 between the first piston assembly 21 and the second piston assembly 22. The first piston assembly 21 and the second piston assembly 22 serve as axial sealing structures at different ends of the annular groove 12. The first piston assembly 21 and the second piston assembly 22 form axial sealing surfaces with the cylinder wall of the cylinder 1. When the first piston assembly 21 and the second piston assembly 22 can normally perform axial sealing, the annular groove 12 and the piston cavities on both sides of the piston assembly 2 are isolated from each other. For example, when the piston assembly 2 is in the gas compression stroke, the pressure in the annular groove 12 will not increase due to the increase of the pressure in the piston cavity on one side of the piston assembly 2. In this state, the inner pressure in the annular groove 12 will change due to the change of the working temperature of the cylinder 1 structure, but the change range and the change rate of the inner pressure in the annular groove 12 are relatively constant. When the sealing ring on the first piston assembly 21 or the second piston assembly 22 deteriorates due to inevitable wear, the gas in the compression cavity of the piston cavity will be introduced into the annular groove 12 through the leakage gap between the piston ring 15 and the cylinder wall when the piston assembly 2 is in the gas compression stroke. The gas introduced into the annular groove 12 becomes an interference factor that interferes with the inner pressure in the annular groove 12, which will destroy the original pressure change rate and the maximum pressure of the annular groove 12. By collecting the pressure data in the annular groove 12 in real time, the sealing condition of the piston assembly 2 and the cylinder wall can be determined.

[0040] Further, the scheme realizes the communication between the annular groove 12 and the upper cavity of the pressure cylinder 4 by setting the air guide hole 11 on the piston rod 3, so that the air guide hole 11 is used as the communication hole between the annular groove 12 and the upper cavity of the pressure cylinder 4, the pressure in the cavity and the pressure in the annular groove 12 are changed synchronously, the pressure sensor 8 is installed on the pressure cylinder 4, and the pressure in the annular groove 12 can be monitored. In this way, not only the signal pickup interference and signal processing interference faced by the traditional online monitoring of the sealing performance of the piston assembly 2 based on vibration and sound wave are avoided, but also the problems of energy supply, detection result transmission, and the influence of the temperature environment in the cylinder body 1 on the accuracy of the pressure detection element are avoided.

[0041] As a person skilled in the art, since the pressure cylinder 4 is arranged outside the cylinder body 1, the main path for the compression heat to be transferred to the pressure cylinder 4 is the piston rod 3, which acts as a heat conduction bridge, resulting in that the compression heat affects the temperature of the gas in the annular groove 12 and the gas guide hole 11, and therefore in the gas cavity including the cavity, the annular groove 12 and the gas guide hole 11, the pressure change and the pressure change rate of the gas cavity in the compressor working cycle have a relationship with the heating capacity of the piston rod 3 to the pressure cylinder 4, the heat dissipation capacity of the gas cavity, the volume of the cavity, the volume of the annular groove 12 and the volume of the gas guide hole 11, etc., and therefore when the compressor is in thermal equilibrium, when the piston assembly 2 has good sealing performance, the final pressure measured by the pressure sensor 8, or the pressure rise rate obtained from multiple monitoring results of the pressure sensor 8 are related to the specific design of the compressor and environmental factors, and when the pressure detection result is used to determine the sealing performance of the piston assembly 2 based on the pressure threshold and the pressure rise rate threshold, the specific threshold value should be determined according to the specific design of the compressor and the use environment, but for a single compressor, when the operating environmental factors are stable and the compressor is in thermal equilibrium, if there is no leakage between the piston assembly 2 and the cylinder wall, the maximum pressure that can be measured by the pressure sensor 8 is stable, and the pressure threshold can be used as a standard for judging the sealing performance of the piston assembly 2; if the measured pressure during the operation of the compressor exceeds the pressure threshold, it is judged that the sealing performance of the piston assembly 2 is decreased, and the piston assembly 2 and the cylinder wall have internal leakage; at the same time, after the internal leakage occurs, or in order to match the design of the compression amount of the gas, the service life design of the piston assembly 2, etc., there is internal leakage at the exhaust pressure in the entire life cycle of the piston assembly 2, as long as the internal leakage speed is within the allowable range, that is, after the pressure rise rate is obtained by continuously measuring the pressure value, if the pressure rise rate is less than the pressure rise rate threshold, it is determined that the piston assembly 2 at this time still meets the sealing performance requirement, and the sealing performance of the piston assembly 2 in this stage meets the requirement.

[0042] In specific applications, for hydrogen compression, according to the use occasion, the raw gas can be normal pressure gas or pressurized gas, and the target pressure distribution range of the product gas is relatively wide, such as 20 MPa to 70 MPa. At the same time, the hydrogen compression process usually adopts multi-stage pressurization. For this scheme, for example, when it is applied to the condition that the cylinder 1 exhaust pressure is greater than 5 MPa, if the initial pressure in the cavity of the pressure cylinder 4 is atmospheric pressure, because the pressure difference between the ring groove 12 and the compression cavity is large, higher requirements are put forward for the sealing performance of the first piston assembly 21 and the second piston assembly 22. In view of this problem, preferably, a pressure compensation hole is arranged on the pressure cylinder 4 to compensate the internal cavity, and the pressure compensation hole compensates the cavity based on the pressure compensation pipeline, so as to reduce the pressure difference between the two sides of the first piston assembly 21 and the second piston assembly 22 (the pressure difference between the ring groove 12 and the compression cavity), so as to achieve the purpose of simplifying the design of the first piston assembly 21 and the second piston assembly 22. Further, when it is applied to the scene where there is internal leakage, the pressure in the cavity of the pressure cylinder 4 has a process of continuously rising, and when it reaches a certain value, the sealing ability of the piston assembly 2 and the back pressure established in the ring groove 12 will prevent the occurrence of internal leakage. In the subsequent operation process of the compressor, as the piston assembly 2 is continuously worn and the sealing ability is reduced, the pressure in the ring groove 12 will continue to rise, so the detection result of the pressure sensor 8 can still be used as an important indicator of the sealing performance of the piston assembly 2.

[0043] Embodiment 2:

[0044] This embodiment is further refined on the basis of embodiment 1: The pressure cylinder 4 is a cylindrical structure with its axis parallel to the axis of the piston rod 3, end plates arranged at both ends, and a partition plate 19 in the center. The cavity includes a first pressure cavity 9 and a second pressure cavity 10 separated by the partition plate 19. The piston rod 3 passes through the partition plate 19 and the end plates at both ends of the pressure cylinder 4. The partition plate 19 is provided with a first sealing assembly for achieving axial sealing between the hole on it and the piston rod 3. The end plates are each provided with a second sealing assembly for achieving axial sealing between the hole on it and the piston rod 3. The first pressure cavity 9 and the second pressure cavity 10 are each provided with a pressure sensor 8 for measuring the pressure in the respective cavity. The cylinder 1 is provided with an air inlet 7 and an exhaust port 6 at both ends. The first pressure cavity 9 and the second pressure cavity 10 are configured such that, during the reciprocating movement of the piston assembly 2 in the cylinder 1, when the piston assembly 2 compresses the gas on one side of the cylinder 1, the gas guide hole 11 communicates with one of the first pressure cavity 9 and the second pressure cavity 10, and when the piston assembly 2 compresses the gas on the other side of the cylinder 1, the gas guide hole 11 communicates with the other of the first pressure cavity 9 and the second pressure cavity 10.

[0045] The above provides a specific pressure taking cylinder 4 implementation form and cylinder body 1 setting form, the cylinder body 1 is provided with an air inlet 7 and an exhaust port 6 at both ends, that is, a double-acting cylinder body 1 form: the piston cavity on both sides of the piston assembly 2 is used as a compression cavity, such an implementation form is high in efficiency and stable in exhaust pulsation, because the piston rod 3 is compressed by the piston assembly 2 during forward and backward movement, under such a cylinder body 1 form, the scheme is provided with a first pressure taking cavity 9 and a second pressure taking cavity 10 in the pressure taking cylinder 4, and a separate pressure sensor 8 is arranged for the first pressure taking cavity 9 and the second pressure taking cavity 10 respectively, aiming to realize: for example, when the piston assembly 2 moves forward and the gas in the compression cavity in front of the first piston assembly 21 is compressed, at this time, the annular groove 12 communicates with the second pressure taking cavity 10 through the gas guide hole 11, when the piston assembly 2 moves backward and the gas in the compression cavity in front of the second piston assembly 22 is compressed, at this time, the annular groove 12 communicates with the first pressure taking cavity 9 through the gas guide hole 11, when the sealing performance of the first piston assembly 21 decreases, the pressure in the annular groove 12 increases during the forward movement of the piston assembly 2, so that the pressure in the second pressure taking cavity 10 increases and can be detected by the corresponding pressure sensor 8, when the piston assembly 2 moves backward, although the pressure gas in the annular groove 12 also pressurizes the first pressure taking cavity 9, but in this process, if the sealing performance of the second piston assembly 22 is good, the maximum pressure that the first pressure taking cavity 9 can reach after pressurization is also less than the pressure of the second pressure taking cavity 10 and lags behind the pressure rise of the second pressure taking cavity 10, therefore, by adopting the scheme, compared with judging the overall sealing performance of the piston assembly 2 by arranging only one pressure taking cavity in the pressure taking cylinder 4, the sealing performance of the first piston assembly 21 and the second piston assembly 22 can be judged based on the pressure monitoring results of the first pressure taking cavity 9 and the second pressure taking cavity 10, so that the sealing performance of the piston assembly 2 can be intuitively and finely obtained.

[0046] In the above scheme, the first sealing assembly is used to prevent direct internal leakage of the first pressure taking cavity 9 and the second pressure taking cavity 10, and the second sealing assembly is used to prevent external leakage of the gas at the end of the pressure taking cylinder 4, because there is a significant difference in pressure difference on both sides of the sealing assembly at the position of the partition plate 19 and the end plate, and the leakage at the position of the end plate has an impact on the environment, so the second sealing assembly is required to have higher sealing performance, preferably, the first sealing assembly and the second sealing assembly adopt different sealing structures. The gas guide hole 11 on the piston rod 3 can be configured as a hole opening that communicates with the pressure taking cylinder 4: when the piston assembly 2 is located at the center of the movement track of the cylinder body 1, the hole opening is located at the position of the partition plate 19, and the hole opening can be configured as: when the piston rod 3 moves forward, the hole opening communicates with the second pressure taking cavity 10, and when the piston rod 3 moves backward, the hole opening communicates with the first pressure taking cavity 9.

[0047] Embodiment 3:

[0048] The embodiment is further refined based on the embodiment 2. The first sealing assembly is a sealing ring installed in the annular groove of the hole of the partition plate 19, the number of the sealing ring is greater than or equal to 3, and each sealing ring is provided with an independent annular groove; the second sealing assembly is a packing sealing assembly installed on the end plate, the packing sealing assembly comprises a packing and a pressing ring for pressing the packing, the packing is arranged in the packing box of the end plate, and the pressing ring is connected to the end plate through a pressing bolt, and the end of the pressing ring acts on the packing.

[0049] The above provides a specific implementation form of the first sealing assembly and the second sealing assembly, as described above, the first sealing assembly aims to solve the internal leakage problem and the pressure difference on both sides of the sealing surface is small, so a plurality of sealing rings with simple structure and convenient assembly can be used to realize reliable sealing, and the sealing ring uses an O-ring; the second sealing assembly aims to solve the external leakage problem and the pressure difference on both sides of the sealing surface may be relatively large, so a structure comprising a packing and a pressing ring is used to provide reliable sealing for the position, and the packing sealing assembly can adjust the sealing performance at any time through the pressing bolt adjusting the pressing ring.

[0050] Embodiment 4:

[0051] The embodiment is further refined based on the embodiment 1: The first piston assembly 21 and the second piston assembly 22 are both configured to comprise a plurality of piston rings 15, the piston rings 15 are stacked in the axial direction of the piston rod 3, the guide ring 17 is fixed on the piston rod 3, both ends of the stacked structure formed by the stacked piston rings 15 are provided with the guide ring 17, and the stacked structure is clamped between the guide rings 17. The piston ring 15 is a plate-shaped structure comprising an outer ring and an inner ring, the outer ring is a high polymer material ring, the inner ring is a metal plate 16 with a center hole, the inner ring is sleeved on the piston rod 3 through the center hole thereon, the outer ring is fixed on the outer edge of the inner ring, and the outer ring is in contact with the cylinder wall of the cylinder body 1.

[0052] The above scheme provides a specific piston assembly 2 implementation form, specifically, the piston ring 15 (also known as the sealing ring) is used to prevent leakage in the cylinder 1 at the position of the piston assembly 2, and the blow-by gas that is not allowed to occur at the position of the piston assembly 2, the guide ring 17 (also known as the support ring) is provided on the piston assembly 2, which is used to support the piston assembly 2 to be centered with the piston cavity, ensures that the piston assembly 2 reciprocates on the center line of the piston cavity, prevents the piston ring 15 from directly contacting and eccentric wear with the cylinder wall, and guarantees the lateral force supporting structure of the piston assembly 2. In the scheme, a plurality of piston rings 15 are provided on the corresponding piston assembly 2, which aims to form a multi-stage seal in the axial leakage direction, so as to gradually reduce the pressure in a step-by-step manner, avoid or reduce leakage while ensuring the service life of each piston ring 15; The guide ring 17 at both ends of the laminated structure aims to provide lateral support for the laminated structure at both ends of the laminated structure, so as to reduce or avoid eccentric wear or even radial shaking of the piston ring 15. The scheme is further provided with the piston ring 15 including an outer ring and an inner ring, the outer ring is a high polymer material and serves as an external ring body of the piston ring 15, and the specific material can use a mature polyether ether ketone material with good wear resistance and low friction coefficient, the inner ring is a metal material and serves as an inner ring body of the piston ring 15, and the specific material can use austenitic stainless steel with good thermal conductivity, low thermal expansion coefficient, excellent strength and rigidity, and good hydrogen embrittlement resistance. The piston ring 15 in the above structure form, on the one hand, for the friction heat generated by the friction between the outer ring and the cylinder wall, the inner ring is used to support the outer ring and strengthen the heat dissipation capacity of the inner side of the outer ring, aiming to reduce the working temperature of the outer ring and reduce the influence of friction heat on the sealing performance and service life of the outer ring; on the other hand, from the overall perspective of the piston ring 15, the inner ring made of metal material has a smaller thermal expansion amount than the high polymer material, so that the contact force between the outer ring and the cylinder wall under the hot state of the compressor can be effectively reduced, that is, by maintaining a reasonable and relatively constant contact force between the outer ring and the cylinder wall, the purpose of prolonging the service life of the piston ring 15 is achieved.

[0053] Embodiment 5:

[0054] This embodiment is further refined on the basis of embodiment 4: The laminated structure is configured such that the end faces of adjacent outer rings are in contact with each other in the axial direction of the piston rod 3, the end faces of adjacent inner rings are in contact with each other, and the inner end faces of the guide rings 17 at both ends of the laminated structure are in contact with the outer rings and the inner rings.

[0055] The above provides a more specific piston assembly 2 structure form, in this scheme, through the mutual adhesion of the outer ring and the outer ring, the mutual adhesion of the inner ring and the inner ring, the mutual adhesion of the guide ring 17 at the end of the laminated structure and the outer ring and the inner ring, the first piston assembly 21 and the second piston assembly 22 are both multi-layer structures with stable structure and relative position between layers. Such multi-layer structure can effectively guarantee the performance reliability of the piston assembly 2 from the aspects of overall vibration and interlayer slip.

[0056] Embodiment 6:

[0057] This embodiment is further refined on the basis of embodiment 4: The inner ring includes a sleeve 24 and a plurality of plate rings 20 in the form of sheets, the central hole is a channel on the sleeve 24, and the plate rings 20 are arranged at intervals in the axial direction of the sleeve 24. The plate rings 20 are all sleeved on the sleeve 24 and welded to the sleeve 24 through ring welds; The inner wall of the outer ring is provided with a number of ring grooves 12 consistent with the number of plate rings 20, the ring grooves 12 are arranged at intervals in the axial direction of the outer ring, the outer edges of the plate rings 20 are embedded in the ring grooves 12, and each ring groove 12 cooperates with a plate ring 20.

[0058] The above provides a specific implementation of the inner ring. The sleeve 24 serves as a connecting framework on the inner side of the plate ring 20 and provides a central hole for sleeving the inner ring on the piston rod 3. The plate ring 20 serves as a support ring between the outer ring and the sleeve 24. The ring weld is preferably formed by laser welding to ensure axial sealing of the welding position and reduce the impact of welding heat on material reliability. In this scheme, compared with the length of the sleeve 24, the plate ring 20 is a thin-walled ring on the inner ring. This thin-walled ring provides support for the inner side of the outer ring. When the temperature of the cylinder body 1 structure rises, the temperature of the plate ring 20 also rises. The thinner plate ring 20 is more likely to deform conically under the extrusion of the outer ring expansion and its own expansion. Compared with a single plate ring 20 with the same thickness as the sleeve 24, the inner ring has less rigid constraint on the outer ring, thereby achieving the purpose of facilitating the control of the contact force between the outer ring and the cylinder wall. In this scheme, the plate ring 20 is connected with the outer ring by embedding the outer side of the plate ring 20 in the ring groove 12 on the inner wall of the outer ring. The purpose is to not only achieve the position constraint of the outer ring in the axial direction of the inner ring through a simple structure, but also to effectively increase the length of the gas leakage gap between the inner ring and the outer ring by embedding the outer edge of the plate ring 20 in the ring groove 12, thereby reducing the possibility of axial leakage of gas through the gap between the inner ring and the outer ring.

[0059] Embodiment 7:

[0060] This embodiment is further refined on the basis of embodiment 6: The gap between the plate ring 20 and the plate ring 20 is filled with a flexible filler layer 18, and the gap between the plate ring 20 and the guide ring 17 is also filled with a flexible filler layer 18.

[0061] In the above scheme, on the one hand, the flexible filler layer 18 is used to fill the gap at the corresponding position, so that the side surface of the plate ring 20 has support from the flexible filler, so that the flexible filler layer 18 can effectively constrain the vibration occurring on the plate ring 20 during the reciprocating motion and variable motion of the piston assembly 2, thereby achieving the purpose of optimizing the stability of the piston ring 15; on the other hand, the flexible filler layer 18 is used to fill part of the space in the gap to reduce the air gap in the gap, so as to reduce the influence of the expansion and contraction of the gas in the air gap on the structural stability and sealing reliability of the piston assembly 2. Preferably, due to the working temperature of the cylinder 1 structure, the flexible filler layer 18 itself will also expand to a certain extent, in order to avoid the influence of thermal expansion on the overall form of the piston assembly 2 and the contact force with the cylinder wall, the flexible filler layer 18 is arranged to fill part of the space in the gap and / or the flexible filler layer 18 is made of a material with internal voids. With this scheme, the gap not filled by the flexible filler layer 18 forms an air gap and serves as an expansion space for the flexible filler layer 18, and the voids allow the flexible filler layer 18 to be compressed. Preferably, the flexible filler layer 18 is preferably made of a flexible graphite material or an expanded PTFE material that has good resilience and long-term reliability at the working temperature range of the cylinder 1 structure. The flexible filler layer 18 is not suitable for rubber materials that are prone to failure under high temperature and hydrogen influence.

[0062] Embodiment 8:

[0063] This embodiment is further refined based on Embodiment 1: The cylinder 1 has a double-layer structure with a bushing 13 on the inside and an outer cylinder on the outside, and the outer wall of the bushing 13 and the inner wall of the outer cylinder form a cold water groove 14 for introducing cooling water into the cylinder 1.

[0064] The above scheme provides a specific form of the cylinder 1, and in the specific scheme, the bushing 13 is made of a hydrogen embrittlement resistant material and provides a smooth cylinder wall, and the cold water groove 14 is specifically used to control the temperature of the cylinder 1 structure by introducing circulating cooling water into it. The double-layer structure of the cylinder 1 facilitates the formation of a cold water groove 14 in the form of a spiral structure.

[0065] Embodiment 9:

[0066] The embodiment is based on embodiment 1, and provides a positive displacement hydrogen compressor system, which comprises a driving motor, a middle body 5 and a cylinder body 1 structure, the driving motor is connected with the piston rod 3 of the cylinder body 1 structure through the middle body 5, the middle body 5 is used for converting the rotary motion of the driving motor into the linear reciprocating motion of the piston rod 3, and the cylinder body 1 structure is the cylinder body 1 structure in embodiment 1.

[0067] The above compressor system is a specific application of the cylinder body 1 structure, that is, the compressor system comprises the cylinder body 1 structure. As a person skilled in the art, the driving motor serves as a power source of the system, the power output by the driving motor is transmitted to the piston rod 3 through the middle body 5 and drives the piston rod 3 to perform linear reciprocating motion, and the gas is compressed in the cylinder body 1 structure.

[0068] Embodiment 10: The embodiment is based on embodiment 9 and is further refined. Further comprising a connecting disc 23, the connecting disc 23 comprises a connecting plate and a plurality of ribbings connected with the connecting plate, the ribbings are arranged in the circumferential direction of the connecting plate, the pressure collecting cylinder 4 has a bottom plate at one end and is in a cylindrical structure with the other end being open, the open end of the pressure collecting cylinder 4 is bolted with the connecting plate through the flange disc outside the open end, and the ribbings are bolted on the shell of the middle body 5; Further comprising a processing module, the signal output end of the pressure sensor 8 is signal connected with the signal input end of the processing module, and the processing module is configured to: collect the pressure measurement result of the pressure sensor 8, and compare the pressure measurement result with a preset pressure threshold value and a preset pressure rising rate threshold value; when it is determined that the pressure measurement result is greater than or equal to the pressure threshold value, or the pressure rising rate is greater than or equal to the pressure rising rate threshold value, an abnormal wear judgment result of the piston assembly 2 is output.

[0069] The above scheme provides a specific connecting mode of the pressure collecting cylinder 4. Specifically, for the pressure collecting cylinder 4 implementation form separated by the partition plate 19 into the first pressure collecting cavity 9 and the second pressure collecting cavity 10, the open end of the pressure collecting cylinder 4 is used to complete the configuration and maintenance of the first sealing assembly. Regarding the end plate, the bottom plate serves as the end plate at one end of the pressure collecting cylinder 4, the second sealing assembly of the end plate is arranged outside the bottom plate, the connecting plate serves as the end plate at the other end of the pressure collecting cylinder 4, the second sealing assembly of the end plate is arranged outside the connecting plate, and the connecting disc 23 serves as the intermediate connecting structure of the pressure collecting cylinder 4 and the middle body 5 and is provided with a plurality of ribbings arranged in the circumferential direction of the connecting plate, so as to use the space between the ribbings to debug and maintain the second sealing assembly outside the connecting plate. The processing module is used to collect the pressure measurement result of the pressure sensor 8 and determine whether the piston assembly 2 has an abnormal wear based on the pressure threshold value and the pressure rising rate threshold value.

[0070] The above detailed description of the specific embodiments of the present application is provided for the purpose of further explaining the objects, technical solutions and advantages of the present application, and it should be understood that the above description is only a specific embodiment of the present application and is not used to limit the protection scope of the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A positive displacement hydrogen compressor cylinder structure comprising a cylinder (1), a piston assembly (2) mounted in the cylinder (1), a piston rod (3) connected to the piston assembly (2), characterized in that, The piston assembly (2) comprises a first piston assembly (21) and a second piston assembly (22), the first piston assembly (21) and the second piston assembly (22) are spaced apart and installed on the piston rod (3), and the first piston assembly (21) and the second piston assembly (22) each comprise a piston ring (15) and a guide ring (17); The piston rod (3) is provided with a gas guide hole (11), and an annular groove (12) is formed between the first piston assembly (21) and the second piston assembly (22), one end of the gas guide hole (11) is communicated with the annular groove (12); Further comprising a pressure collecting cylinder (4), the pressure collecting cylinder (4) is configured with a closed cavity, the piston rod (3) passes through the pressure collecting cylinder (4) and passes through the cavity, and the other end of the gas guide hole (11) is configured to be communicated with the cavity when the piston assembly (2) is in a gas compression stroke. Further comprising a pressure sensor (8) installed on the pressure collecting cylinder (4) for measuring the pressure in the cavity.

2. A positive displacement hydrogen compressor cylinder structure according to claim 1, wherein, The pressure collecting cylinder (4) is a cylindrical structure with an axis parallel to the axis of the piston rod (3), end plates at both ends, and a partition plate (19) in the center, and the cavity comprises a first pressure collecting cavity (9) and a second pressure collecting cavity (10) separated by the partition plate (19); The piston rod (3) passes through the partition plate (19) and the end plates at both ends of the pressure collecting cylinder (4), the partition plate (19) is provided with a first sealing assembly for achieving gap axial sealing between the hole on the partition plate (19) and the piston rod (3), and the end plates are each provided with a second sealing assembly for achieving gap axial sealing between the hole on the end plate and the piston rod (3); The first pressure collecting cavity (9) and the second pressure collecting cavity (10) are each provided with a pressure sensor (8) for measuring the pressure in the respective cavity; Both ends of the cylinder (1) are provided with an air inlet (7) and an air outlet (6); The first pressure collecting cavity (9) and the second pressure collecting cavity (10) are configured such that, during reciprocating movement of the piston assembly (2) in the cylinder (1), when the piston assembly (2) compresses the gas on one side of the cylinder (1), the gas guide hole (11) is communicated with one of the first pressure collecting cavity (9) and the second pressure collecting cavity (10), and when the piston assembly (2) compresses the gas on the other side of the cylinder (1), the gas guide hole (11) is communicated with the other one of the first pressure collecting cavity (9) and the second pressure collecting cavity (10).

3. A positive displacement hydrogen compressor cylinder structure according to claim 2, wherein The first sealing assembly is a sealing ring installed in the annular groove of the hole on the partition plate (19), the number of the sealing rings is greater than or equal to 3, and each sealing ring is provided with an independent annular groove; the second sealing assembly is a packing sealing assembly installed on the end plate, the packing sealing assembly comprises packing and a pressing ring for pressing the packing, the packing is arranged in a packing box of the end plate, and the pressing ring is connected to the end plate through a pressing bolt, and the end of the pressing ring acts on the packing.

4. A positive displacement hydrogen compressor cylinder structure according to claim 1, wherein The first piston assembly (21) and the second piston assembly (22) are both configured to include a plurality of piston rings (15) stacked in the axial direction of the piston rod (3), the guide ring (17) is fixed on the piston rod (3), and both ends of the stacked structure are provided with guide rings (17), and the stacked structure is clamped between the guide rings (17). The piston ring (15) is a plate structure including an outer ring and an inner ring, the outer ring is a polymer ring, and the inner ring is a metal plate (16) with a central hole, the inner ring is sleeved on the piston rod (3) through the central hole, and the outer ring is fixed on the outer edge of the inner ring. The outer ring is in contact with the cylinder wall of the cylinder (1).

5. A positive displacement hydrogen compressor cylinder structure according to claim 4, wherein The stacked structure is configured such that the end faces of adjacent outer rings are in contact with each other in the axial direction of the piston rod (3), the end faces of adjacent inner rings are in contact with each other, and the inner end faces of the guide rings (17) at both ends of the stacked structure are in contact with the outer rings and the inner rings.

6. A positive displacement hydrogen compressor cylinder structure according to claim 4, wherein The inner ring includes a sleeve (24) and a plurality of sheet-shaped plate rings (20), the central hole is a channel on the sleeve (24), and the plate rings (20) are arranged in the axial direction of the sleeve (24) and are sleeved on the sleeve (24) and welded to the sleeve (24) by ring welds. The inner wall of the outer ring is provided with a number of ring grooves corresponding to the number of plate rings (20), the ring grooves are arranged in the axial direction of the outer ring, and the outer edges of the plate rings (20) are embedded in the ring grooves.

7. A positive displacement hydrogen compressor cylinder structure according to claim 6, wherein The gaps between the plate rings (20) and the gaps between the plate rings (20) and the guide rings (17) are filled with flexible filler layers (18).

8. A positive displacement hydrogen compressor cylinder structure according to any one of claims 1 to 7, wherein The cylinder (1) has a double-layer structure with a liner (13) on the inside and an outer cylinder on the outside, and a cold water groove (14) is formed between the outer wall of the liner (13) and the inner wall of the outer cylinder for introducing cooling water into the cylinder (1).

9. A positive-displacement hydrogen compressor system comprising a drive motor, a middle body (5) and a cylinder structure, the drive motor being connected via the middle body (5) to a piston rod (3) of the cylinder structure, the middle body (5) being designed to convert the rotary motion of the drive motor into a linear reciprocating motion of the piston rod (3), characterized in that The cylinder structure is any one of the cylinder structures in claims 1-7.

10. A positive-displacement hydrogen compressor system according to claim 9, wherein, It also includes a connecting disc (23) including a connecting plate and a plurality of rib strips connected to the connecting plate, the rib strips are arranged in the circumferential direction of the connecting plate, the pressure collecting cylinder (4) has a bottom plate at one end and an open end, the open end of the pressure collecting cylinder (4) is bolted to the connecting plate through the flange on the outside, and the rib strips are bolted to the shell of the middle body (5). It also includes a processing module, the signal output end of the pressure sensor (8) is signal connected to the signal input end of the processing module, the processing module is configured to collect the pressure measurement results of the pressure sensor (8) and compare them with the preset pressure threshold and the preset pressure rise rate threshold, and output the piston assembly (2) wear abnormality determination result when the pressure measurement result is greater than or equal to the pressure threshold or the pressure rise rate is greater than or equal to the pressure rise rate threshold.

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