Parallel type gas density relay

Abstract

The invention provides a parallel type gas density relay which is used for monitoring the pressure of gas to be measured, one end of a measuring corrugated pipe is open and communicated with the gas to be measured so that the gas to be measured can flow into a measuring cavity, the measuring corrugated pipe and a compensation corrugated pipe are connected in a staggered mode, pneumatic modules are connected in parallel, and pressure-bearing modules are connected in parallel. The pneumatic module and the pressure-bearing module are connected in parallel, and when the pressure range of monitored to-be-detected gas is large, shells of all compensation corrugated pipes and shells of all second pressure-bearing corrugated pipes share pressure together, so that all the compensation corrugated pipes and all the second pressure-bearing corrugated pipes deform within the effective stroke; when the compensation air pressure is large, the shells of all the measuring corrugated pipes and all the first pressure-bearing corrugated pipes share pressure together, so that all the measuring corrugated pipes and all the first pressure-bearing corrugated pipes deform within the effective stroke, the measuring range of the parallel type gas density relay can be expanded, and the requirement for measuring the gas pressure in a larger range is met.

Description

Technical Field

[0001] The invention relates to the technical field of electrical equipment state monitoring, in particular to a parallel gas density relay. Background Art

[0002] In the power system, the gas density relay is a key device used to monitor and control the density of insulating gas (such as SF6 gas) in power equipment (such as circuit breakers). Since the density of the gas is directly related to the insulation performance and arc extinguishing ability of the equipment, the gas density relay plays a vital role in the power system. It can monitor the changes in gas density in real time and issue an alarm or trigger a protection action when the gas density is abnormal, thereby ensuring the safe operation of the power equipment.

[0003] As a key device in the power transmission and distribution network, once a circuit breaker fails, it may not only cause equipment damage, but also cause large-scale power outages, resulting in huge economic losses and social impacts. Therefore, ensuring the long-term, stable and reliable operation of circuit breakers is an important task in the maintenance and management of power systems.

[0004] To achieve this goal, it is necessary to continuously and closely monitor the various operating indicators of the circuit breaker and ensure that these indicators meet the requirements of relevant standards. Among them, gas density is one of the important parameters of the circuit breaker's operating status. Its changes may indicate leakage, abnormal temperature or other potential problems inside the equipment.

[0005] At present, gas density relays mainly use two methods: Bourdon tube measurement and bellows measurement. Although Bourdon tube measurement has a certain application history, it is relatively limited in accuracy and sensitivity. Bellows measurement has been widely used in the field of low-pressure measurement due to its higher accuracy and sensitivity. As a pressure-sensitive element, bellows can accurately convert pressure changes into mechanical displacement, and then output electrical signals through a transmission mechanism.

[0006] However, the bellows measurement method also has certain limitations. Due to the characteristics of the bellows itself, the range it can measure is relatively small, usually not exceeding 0.3MPa, so it is mainly used in low-pressure measurement occasions, which limits its application in high-pressure measurement fields. Summary of the invention

[0007] In view of the above-mentioned shortcomings of the prior art, the technical problem to be solved by the present invention is to provide a parallel gas density relay for solving the technical problems of the bellows gas density relay in the prior art, such as small measuring range and limited measuring range.

[0008] To achieve the above object, the present invention provides a parallel gas density relay for monitoring the pressure of a gas to be measured, comprising:

[0009] A pneumatic structure, the pneumatic structure comprising at least one pneumatic module and at least one pressure-bearing module; the pneumatic module and the pressure-bearing module are connected in parallel with each other, and each of the pneumatic modules is connected in parallel with each other, and each of the pressure-bearing modules is connected in parallel with each other; the pneumatic module comprises a measuring bellows with an opening at the bottom and a compensating bellows sealed at both ends; a sealed chamber is arranged in the compensating bellows, and the sealed chamber is filled with a compensating gas with the same characteristics as the gas to be measured; a measuring chamber is arranged in the measuring bellows, the bottom end of the measuring bellows is connected with the gas to be measured so that the gas to be measured flows into the measuring chamber, and the measuring bellows is staggeredly connected with the compensating bellows; the pressure-bearing module comprises a first pressure-bearing bellows sealed at both ends and a second pressure-bearing bellows sealed at both ends, the first pressure-bearing bellows is staggeredly connected with the second pressure-bearing bellows, the first pressure-bearing bellows is connected in parallel with the measuring bellows, and the second pressure-bearing bellows is connected in parallel with the compensating bellows;

[0010] A driving structure, the driving structure comprising a connecting assembly and a driving assembly arranged on the connecting assembly, the measuring bellows being staggeredly connected to the compensating bellows through the connecting assembly; the first pressure-bearing bellows being staggeredly connected to the second pressure-bearing bellows through the connecting assembly;

[0011] The indicating structure is connected to the driving assembly. When the pressure of the gas to be measured changes, each of the measuring bellows and each of the first pressure-bearing bellows are deformed, and the driving assembly is driven to move through the connecting assembly to push the indicating structure to rotate and indicate the gas pressure value.

[0012] As a preferred embodiment, the indication structure includes a freely rotatable movement assembly and an indication assembly rotatably connected to the movement assembly, wherein the movement assembly is arranged above the drive assembly and contacts the top of the drive assembly; the indication assembly includes a pointer and a dial arranged between the movement assembly and the pointer, and the pointer is rotatably connected to the movement assembly.

[0013] As a preferred embodiment, it further comprises a pressure signal acquisition module, wherein the pressure signal acquisition module is arranged in one of the measurement chambers to acquire the pressure signal of the gas to be measured.

[0014] As a preferred embodiment, it further includes a circuit board, which is electrically connected to the pressure signal acquisition module to transmit the pressure signal collected by the pressure signal acquisition module to the outside.

[0015] As a preferred embodiment, the connecting assembly includes a first connecting plate and a second connecting plate which are arranged in parallel, and a supporting tube for connecting the first connecting plate and the second connecting plate, the bottom end of the compensating bellows is connected to the first connecting plate, the top end of the measuring bellows is connected to the second connecting plate, the top end of the first pressure-bearing bellows is connected to the second connecting plate, and the bottom end of the second pressure-bearing bellows is connected to the first connecting plate, the first connecting plate is arranged at a position higher than the bottom ends of the measuring bellows and the first pressure-bearing bellows, and the second connecting plate is arranged at a position lower than the top ends of the compensating bellows and the second pressure-bearing bellows, thereby achieving misalignment of the measuring bellows and the compensating bellows in the height direction, and misalignment of the first pressure-bearing bellows and the second pressure-bearing bellows in the height direction.

[0016] As a preferred embodiment, it also includes a shell structure, which includes an outer shell, an upper cover arranged on the top of the outer shell and a lower cover arranged on the bottom of the outer shell, and the pneumatic structure and the connecting assembly are arranged in an accommodating inner cavity formed by the outer shell, the upper cover and the lower cover; the bottom of the lower cover is provided with a gas nozzle for connecting with the gas to be measured; the bottom end of the measuring bellows with an opening in each of the pneumatic modules is respectively connected to the gas nozzle, and the bottom end of the first pressure-bearing bellows in each of the pressure-bearing modules is respectively connected to the lower cover; the top end of the compensating bellows in each of the pneumatic modules is respectively fixedly connected to the upper cover, and the top end of the second pressure-bearing bellows in each of the pressure-bearing modules is respectively fixedly connected to the upper cover, so as to connect the pneumatic modules in parallel with each other, the pressure-bearing modules with the pneumatic modules in parallel with each other, and the pressure-bearing modules in parallel with each other.

[0017] As a preferred embodiment, the driving assembly includes a linear driving rod and a sliding block, one end of the linear driving rod is connected to the connecting assembly, and the other end is connected to the sliding block; the movement assembly is arranged above the sliding block and contacts with the top of the sliding block.

[0018] As a preferred embodiment, a first through hole is provided on the upper cover, one end of the linear drive rod passes through the first through hole to be connected to the connecting assembly and can move up and down in the first through hole, and the other end is connected to the sliding block.

[0019] As a preferred embodiment, it also includes an alarm structure, which is arranged below the sliding block and located on the moving path of the sliding block; when the pressure of the gas to be measured changes, the measuring bellows and the first pressure-bearing bellows are deformed, and the sliding block is driven to move away from or close to the alarm structure through the connecting component.

[0020] As a preferred manner, the driving structure further comprises a triggering component for triggering the alarm structure, wherein the triggering component is arranged on the driving component, and the driving component can drive the triggering component to move, thereby triggering the alarm structure to operate.

[0021] As described above, the parallel gas density relay involved in the present invention is used to monitor the pressure of the gas to be measured, and has the following beneficial effects: the bottom end of the measuring bellows is open and connected to the gas to be measured so that the gas to be measured flows into the measuring chamber. When the pressure of the gas to be measured changes, each measuring bellows and the first pressure-bearing bellows are deformed, driving the connecting component to move up and down, and driving the indicating structure to rotate through the driving component to indicate the gas pressure value. When the pressure range of the monitored gas is large, the shells of each compensating bellows and each second pressure-bearing bellows share the pressure together, so that each compensating bellows and each second pressure-bearing bellows are deformed within the effective stroke, and when the compensating gas pressure is large, the shells of each measuring bellows and each first pressure-bearing bellows share the pressure together, so that each measuring bellows and each first pressure-bearing bellows are deformed within the effective stroke, thereby expanding the measurement range of the parallel gas density relay and meeting the needs of a wider range of gas pressure measurements. In addition, each pneumatic module and pressure-bearing module still adopts a high-precision bellows structure, ensuring that high-precision measurements can be maintained over a large range. In addition, when the external ambient temperature changes and causes the pressure of the gas to be measured to change, since the closed chamber is filled with a compensating gas with the same properties as the gas to be measured, the closed chamber and the measuring chamber are subjected to the same gas pressure, and the deformation of the compensating bellows and the measuring bellows are offset, avoiding indication errors caused by changes in ambient temperature, ensuring that the measurement results are not affected by temperature, and allowing the parallel gas density relay to maintain stable measurement performance in an environment with large temperature fluctuations. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram showing the overall structure of the parallel gas density relay of the present invention.

[0023] Figure 2 Shown is a schematic diagram of the pneumatic structure in the parallel gas density relay of the present invention.

[0024] Figure 3 Shown is a three-dimensional structural schematic diagram of the parallel gas density relay of the present invention.

[0025] Figure 4 It shows a schematic diagram of the structure of the parallel gas density relay of the present invention in the remote transmission mode.

[0026] Figure 5It shows a schematic diagram of the staggered connection of the bellows of the parallel gas density relay of the present invention.

[0027] Figure 6 Shown is a cross-sectional view of a parallel gas density relay of the present invention.

[0028] Figure 7 Shown is a partial structural schematic diagram of the parallel gas density relay of the present invention.

[0029] Figure 8 Shown is another partial structural schematic diagram of the parallel gas density relay of the present invention.

[0030] Component number description 1 Pneumatic structure 11 Pneumatic module 111 Measuring bellows 112 Compensation bellows 12 Pressure module 121 First pressure bellows 122 Second pressure bellows 2. Drive structure 21 Connecting components 211 First connecting plate 212 Second connecting plate 213 Support tube 22 Drive components 221 Linear drive rod 222 Slider 2221 Adjustment hole 3 Indicative structure 31 Movement components 311 Movement support plate 312 Movement shaft 3121 Movement Pins 3122 Movement Pusher 313 Gear Structure 32 Indicator Components 321 Pointer 322 Dial 4. Pressure signal acquisition module 5 Circuit Board 6 Shell structure 61 Shell 62 Upper cover 63 Lower cover 631 Air Nozzle 7 Alarm structure 8 Backstage Computer 9 Signal transmission line DETAILED DESCRIPTION

[0031] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0032] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification, so that people familiar with this technology can understand and read them, and are not used to limit the limiting conditions that the present invention can implement, so they have no technical substantive significance. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope of the technical content disclosed by the present invention. The following detailed description should not be considered restrictive, and the scope of the embodiments of the present application is limited only by the claims of the published patents. The terms used here are only for describing specific embodiments and are not intended to limit the present application. Spatially related terms, such as "upper", "lower", "left", "right", "below", "below", "lower", "above", "upper", etc., can be used in the text to facilitate the description of the relationship between an element or feature shown in the figure and another element or feature.

[0033] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix", "hold" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] Furthermore, as used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless there is an indication to the contrary in the context. It should be further understood that the terms "comprise", "include" indicate the presence of the described features, operations, elements, components, items, kinds, and / or groups, but do not exclude the presence, occurrence or addition of one or more other features, operations, elements, components, items, kinds, and / or groups. The terms "or" and "and / or" used herein are interpreted as inclusive, or mean any one or any combination. Therefore, "A, B or C" or "A, B and / or C" means "any of the following: A; B; C; A and B; A and C; B and C; A, B and C". Exceptions to this definition will only occur when the combination of elements, functions or operations is inherently mutually exclusive in some way.

[0035] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the technical solution in the embodiments of the present invention is further described in detail through the following embodiments and in combination with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the invention.

[0036] like Figure 1-8 As shown, the present invention provides a parallel gas density relay for monitoring the pressure of a gas to be measured, comprising:

[0037] A pneumatic structure 1, wherein the pneumatic structure 1 comprises at least one pneumatic module 11 and at least one pressure-bearing module 12; the pneumatic module 11 and the pressure-bearing module 12 are connected in parallel with each other, and each of the pneumatic modules 11 is connected in parallel with each other, and each of the pressure-bearing modules 12 is connected in parallel with each other; the pneumatic module 11 comprises a measuring bellows 111 with an opening at the bottom and a compensating bellows 112 with sealed ends; a sealed chamber is arranged in the compensating bellows 112, and the sealed chamber is filled with a compensating gas with the same characteristics as the gas to be measured; a measuring chamber is arranged in the measuring bellows 111 , the bottom end of the measuring bellows 111 is connected to the gas to be measured so that the gas to be measured flows into the measuring chamber, and the measuring bellows 111 is staggeredly connected to the compensating bellows 112; the pressure-bearing module 12 includes a first pressure-bearing bellows 121 sealed at both ends, and a second pressure-bearing bellows 122 sealed at both ends, the first pressure-bearing bellows 121 is staggeredly connected to the second pressure-bearing bellows 122, the first pressure-bearing bellows 121 is connected in parallel with the measuring bellows 111, and the second pressure-bearing bellows 122 is connected in parallel with the compensating bellows 112;

[0038] The driving structure 2 comprises a connecting assembly 21 and a driving assembly 22 arranged on the connecting assembly 21, wherein the measuring bellows 111 is staggeredly connected to the compensating bellows 112 through the connecting assembly 21; and the first pressure-bearing bellows 121 is staggeredly connected to the second pressure-bearing bellows 122 through the connecting assembly 21;

[0039] The indicating structure 3 is connected to the driving component 22. When the pressure of the gas to be measured changes, each of the measuring bellows 111 and each of the first pressure-bearing bellows 121 is deformed, and the driving component 22 is driven to move through the connecting component 21, so as to push the indicating structure 3 to rotate and indicate the gas pressure value.

[0040] The parallel gas density relay of the present invention is used to monitor the pressure of the gas to be measured. The bottom end of the measuring bellows 111 is opened and connected to the gas to be measured so that the gas to be measured flows into the measuring chamber. When the pressure of the gas to be measured changes, each measuring bellows 111 and the first pressure-bearing bellows 121 are deformed, driving the connecting component 21 to move up and down, and driving the indicating structure 3 to rotate through the driving component 22 to indicate the gas pressure value. When the pressure range of the monitored gas is large, the shells of each compensating bellows 112 and each second pressure-bearing bellows 122 share the pressure together, so that each compensating bellows 112 and each second pressure-bearing bellows 122 are deformed within the effective stroke, and when the compensating gas pressure is large, the shells of each measuring bellows 111 and each first pressure-bearing bellows 121 share the pressure together, so that each measuring bellows 111 and each first pressure-bearing bellows 121 are deformed within the effective stroke, thereby expanding the measurement range of the parallel gas density relay and meeting the gas pressure measurement needs in a wider range, and each pneumatic module 11 and pressure-bearing module 12 still adopts a high-precision bellows structure to ensure high-precision measurement within a large range. In addition, when the external ambient temperature changes and causes the pressure of the gas to be measured to change, since the closed chamber is filled with a compensating gas with the same properties as the gas to be measured, the closed chamber and the measuring chamber are subjected to the same gas pressure, and the deformation of the compensating bellows 112 and the measuring bellows 111 are offset, thereby avoiding indication errors caused by changes in ambient temperature, ensuring that the measurement results are not affected by temperature, and allowing the parallel gas density relay to maintain stable measurement performance in an environment with large temperature fluctuations.

[0041] It is worth noting that due to the physical properties of the bellows, the air pressure that a single pair of bellows in the prior art can withstand is basically around 0.3Mpa. When the measuring bellows is filled with 0.3Mpa air pressure, the effective stroke of the compensating bellows basically reaches the maximum value; similarly, when the compensating bellows is filled with 0.3Mpa of compensating gas, the effective stroke of the measuring bellows also basically reaches the maximum value. Therefore, the gas density relay in the prior art can measure a small gas pressure range, usually not exceeding 0.3MPa, and is mainly used in low-pressure measurement occasions, which limits its application in the field of high-pressure measurement.

[0042] The parallel gas density relay of the present invention adopts a bellows parallel connection method. When the pressure range of the monitored gas is large, by sharing the pressure, each measuring bellows 111, each first pressure-bearing bellows 121, each compensation bellows 112, and each second pressure-bearing bellows 122 are deformed within the effective stroke, thereby expanding the measurement range of the parallel gas density relay and meeting the gas pressure measurement needs in a wider range.

[0043] In this embodiment, illustratively, Figure 2 As shown, the pneumatic structure 1 includes two pneumatic modules 11 connected in parallel to each other, and two pressure-bearing modules 12 connected in parallel to each other. The pneumatic modules 11 and the pressure-bearing modules 12 are connected in parallel to each other, that is, two measuring bellows 111 connected in parallel to each other, two compensating bellows 112 connected in parallel to each other, two first pressure-bearing bellows 121 connected in parallel to each other, and two second pressure-bearing bellows 122 connected in parallel to each other. The measuring bellows 111 is connected in parallel to the first pressure-bearing bellows 121, and the compensating bellows 112 is connected in parallel to the second pressure-bearing bellows 122. The measuring bellows 111 is staggeredly connected to the compensating bellows 112 through a connecting assembly 21, and the first pressure-bearing bellows 121 is staggeredly connected to the second pressure-bearing bellows 122 through a connecting assembly 21. In order to better illustrate the working principle of the pneumatic structure 1, it is now explained in conjunction with the following specific applications:

[0044] Assuming that the compensation gas pressure is 0.4Mpa, the closed chambers of the two compensation bellows 112 are each filled with 0.4Mpa of compensation gas. Before the two measuring bellows 111 are connected to the gas to be measured, the compensation gas pressure × 2 = the pressure borne by the shell of the measuring bellows + the pressure borne by the shell of the first pressure-bearing bellows. Then, the shell of each measuring bellows 111 and the shell of each first pressure-bearing bellows 121 each bear a pressure of 0.2Mpa.

[0045] (1) When the measuring chambers of the two measuring bellows 111 are introduced with a gas to be measured at a pressure of 0.2 MPa, the compensation gas pressure × 2 = the pressure of the gas to be measured × 2 + the pressure borne by the shell of the measuring bellows + the pressure borne by the shell of the first pressure-bearing bellows. Then, the shell of each measuring bellows 111 and the shell of each first pressure-bearing bellows 121 bear a pressure of 0.1 MPa respectively. Each measuring bellows 111 and each first pressure-bearing bellows 121 deforms upward, driving the connecting assembly 21 to move upward, thereby driving the indicating structure 3 to rotate through the driving assembly 22 and indicating the gas pressure value.

[0046] (2) When the pressure of the gas to be measured decreases, for example, when the gas pressure of the gas to be measured in the measuring chambers of the two measuring bellows 111 decreases from 0.2 MPa to 0.1 MPa, the shell of each measuring bellows 111 and the shell of each first pressure-bearing bellows 121 each bear a pressure of 0.15 MPa, and each measuring bellows 111 and each first pressure-bearing bellows 121 deforms downward, driving the connecting assembly 21 to move downward, thereby driving the indicating structure 3 to rotate through the driving assembly 22 and indicating the gas pressure value.

[0047] (3) When the measuring chambers of the two measuring bellows 111 are filled with 1 MPa of the gas to be measured, the compensating gas pressure × 2 + the pressure on the shell of the compensating bellows + the pressure on the shell of the second pressure-bearing bellows = the pressure of the gas to be measured × 2, the pressure on the shell of the compensating bellows + the pressure on the shell of the second pressure-bearing bellows = the pressure of the gas to be measured × 2 - the compensating gas pressure × 2 = 2 MPa - 0.8 MPa = 1.2 MPa, then the shell of each compensating bellows 112 and the shell of each second pressure-bearing bellows 122 each bear a pressure of 0.3 MPa, each measuring bellows 111 and the first pressure-bearing bellows 121 deforms upward, driving the connecting assembly 21 to move upward, thereby driving the indicating structure 3 to rotate through the driving assembly 22 and indicating the gas pressure value.

[0048] (4) The closed chamber of the compensation bellows 112 is filled with a compensation gas with the same characteristics as the gas to be measured. When the gas pressure in the measuring chamber of the measuring bellows 111 is the same as the gas pressure in the closed chamber of the compensation bellows 112, the system is in a balanced state, and the indicating structure 3 indicates the current gas pressure value. When the external ambient temperature changes, due to the same gas characteristics, the gas volume and pressure in the measuring chamber and the closed chamber will change in the same way, and the forces generated by the measuring bellows 111 and the compensation bellows 112 are also the same. The force balance prevents the measuring bellows 111 and the compensation bellows 112 from relative displacement, and the drive assembly 22 does not move, so that the indicating structure 3 remains stationary and the indicated value remains unchanged. In this way, the compensation bellows 112 can automatically offset the influence of the ambient temperature change on the measurement result. Regardless of whether the temperature rises or falls, the compensation bellows 112 can ensure that the measurement result only reflects the actual change in gas pressure without being affected by temperature, so that the parallel gas density relay can still maintain stable measurement performance in an environment with large temperature fluctuations.

[0049] Furthermore, each pneumatic module 11 is connected in parallel with each other, each pressure-bearing module 12 is connected in parallel with each other, the pneumatic module 11 and the pressure-bearing module 12 are connected in parallel with each other, and the measuring bellows 111 is staggeredly connected to the compensating bellows 112 through the connecting component 21, and the first pressure-bearing bellows 121 is staggeredly connected to the second pressure-bearing bellows 122 through the connecting component 21, so that multiple measuring bellows 111, multiple compensating bellows 112, multiple first pressure-bearing bellows 121, and multiple second pressure-bearing bellows 122 can be compactly arranged to make full use of the space. If the measuring range needs to be further expanded, it is only necessary to increase the number of bellows, which has high scalability.

[0050] In this embodiment, the bellows pressure calculation formula is as follows:

[0051] P=kx / S; Formula (1).

[0052] Among them, P represents the maximum pressure that the bellows can measure, S represents the effective area of ​​the bellows, k represents the single-wave axial stiffness of the bellows, and x represents the single-wave maximum axial displacement of the bellows.

[0053] It is worth noting that when the bellows is used for pressure measurement, its measurement range is determined by its own single-wave axial stiffness, single-wave maximum axial displacement and effective area. According to the numerical calculation in the common specifications of sensitive bellows in JB / T 6169, the P value is less than 0.4Mpa. Therefore, the range of the bellows density meter on the market is currently 0.2-0.3Mpa, and the measurement range is narrow. The present invention increases the k value by adopting the bellows parallel connection mode, and the total stiffness k of the pneumatic structure 1 is 总 =n×k, where n is the number of parallel bellows. The total stiffness of the pneumatic structure 1 increases, and the pneumatic structure 1 can withstand a greater gas pressure. In a high-pressure environment, the stiffness and stability of the system are improved, and the vibration under high pressure is reduced.

[0054] In this embodiment, exemplarily, the pneumatic structure 1 includes two pneumatic modules 11 connected in parallel to each other, and two pressure-bearing modules 12 connected in parallel to each other. The pneumatic modules 11 and the pressure-bearing modules 12 are connected in parallel to each other. Each pneumatic module 11 includes a measuring bellows 111 and a compensating bellows 112. Each pressure-bearing module 12 includes a first pressure-bearing bellows 121 sealed at both ends and a second pressure-bearing bellows 122 sealed at both ends. By using the bellows in parallel, the measurement range is superimposed upward. At this time, the overall stiffness of the pneumatic structure 1 is 4k. According to formula (I), the P value can reach 1.6Mpa, thereby achieving the expected measurement range of more than 1Mpa, which not only maintains the high-precision characteristics of the bellows itself, but also increases the measurement range.

[0055] In this embodiment, the present invention can adapt to all working conditions from low pressure to ultra-high pressure by adjusting the number of pneumatic modules 11, and the measurement range can reach 0-5Mpa. At the same time, it also maintains the high precision advantage of the bellows itself, and retains the characteristics of gas compensation being better than bimetallic strips, thereby ensuring the accuracy and reliability of the measurement, thereby obtaining better accuracy and stability than the original meter under a large range.

[0056] It should be noted that JB / T 6169 is a standard number in the Chinese machinery industry standard, and its specific name is "Technical Conditions for Gas Density Relays". This standard stipulates the technical requirements, test methods, inspection rules, as well as marking, packaging, transportation and storage of gas density relays, and is applicable to relay equipment used to monitor gas density in industries such as electricity, chemical industry, petroleum, and natural gas.

[0057] In this embodiment, if Figure 1 , 3As shown in FIGS. 4 and 8, the indicating structure 3 includes a freely rotatable movement assembly 31 and an indicating assembly 32 rotatably connected to the movement assembly 31. The movement assembly 31 is arranged above the driving assembly 22 and contacts the top of the driving assembly 22. The indicating assembly 32 includes a pointer 321 and a dial 322 arranged between the movement assembly 31 and the pointer 321. The pointer 321 is rotatably connected to the movement assembly 31.

[0058] In this embodiment, if Figure 1 As shown, the movement assembly 31 includes a movement support plate 311, a movement shaft 312 rotatably arranged on one side of the movement support plate 311, a gear structure 313 arranged on the other side of the movement support plate 311, and a pointer shaft connected to the gear structure 313. The movement shaft 312 is provided with a movement pin 3121 and a movement push rod 3122. The gear structure 313 is provided with a hairspring spring. The movement support plate 311 is provided with a second through hole. The movement push rod 3122 passes through the second through hole and contacts the gear structure 313. The movement pin 3121 contacts the top of the driving assembly 22. The pointer 321 is connected to the pointer shaft. The hairspring spring is provided to provide a preload force, so that when the driving assembly 22 moves up and down, the movement pin 3121 is always in contact with the top of the driving assembly 22, and the movement push rod 3122 is always in contact with the gear structure 313. When the pressure of the gas to be measured changes, the measuring bellows 111 and the first pressure-bearing bellows 121 are deformed, and the driving component 22 is driven to move up and down through the connecting component 21. Since the movement pin 3121 and the movement push rod 3122 are acted upon by the elastic force of the hairspring, the movement pin 3121 is always in contact with the top of the driving component 22, and the movement push rod 3122 is always in contact with the gear structure 313. When the driving component 22 moves up and down, the driving component 22 pushes the movement pin 3121 to drive the movement shaft 312 to rotate, and drives the gear structure 313 to rotate through the movement push rod 3122, so as to drive the pointer 321 to rotate around the connection point with the pointer shaft through the pointer shaft. After the pointer 321 rotates, it is aligned with the scale marked on the dial 322, which is the gas pressure value of the gas to be measured.

[0059] In this embodiment, if Figure 4 , 6As shown, it also includes a pressure signal acquisition module 4, which is arranged in one of the measurement chambers to collect the pressure signal of the gas to be measured. Since one end of the opening of each measurement bellows 111 is connected to the gas to be measured, the gas to be measured can flow freely in each measurement chamber, and the pressure in the measurement chamber of each measurement bellows 111 is the same. Therefore, by only setting the pressure signal acquisition module 4 in one measurement chamber, the pressure signal of the gas to be measured can be collected, which reduces the number of pressure signal acquisition modules 4 used and simplifies system design and cost.

[0060] In this embodiment, if Figure 1-7 As shown, each measuring bellows 111 has an open end connected to an external air chamber filled with the gas to be measured. According to the principle of pressure transmission: in a fluid (gas or liquid), pressure is transmitted evenly. If the pressure of the external air chamber is 1MPa, then this pressure will act evenly on each part of the external air chamber, including each measuring bellows 111 connected to the external air chamber. Therefore, the gas pressure inside each measuring chamber will be 1MPa. Each measuring bellows 111 is connected in parallel to the same external air chamber, and they will feel the same gas pressure at the same time. The pressure will not be shared because there are multiple measuring bellows 111 (that is, it will not become 0.5MPa each), but each measuring bellows 111 will independently feel the gas pressure of 1MPa. Gas pressure is an intensity quantity (independent of area), not an extensive quantity (such as force). Therefore, the gas pressure will not be shared because of the connection of multiple measuring bellows, and each measuring bellows will feel the same 1MPa pressure.

[0061] In this embodiment, the pressure signal acquisition module 4 includes a piezoresistor or a pressure sensor. A piezoresistor is a component whose resistance value changes with pressure, and can convert a pressure signal into a change in resistance value. A piezoresistor is installed in the measurement chamber. When the gas to be measured flows into the measurement chamber, the gas pressure acts on the piezoresistor, and the resistance value of the piezoresistor changes with the change in gas pressure. By measuring the change in resistance value, the pressure of the gas to be measured can be indirectly calculated.

[0062] In this embodiment, the pressure sensor is a device that directly converts a pressure signal into an electrical signal, and has the characteristics of high precision and fast response. When the gas to be measured flows into the measurement chamber, the gas pressure acts on the pressure sensor, and the pressure sensor outputs an electrical signal proportional to the pressure, which is convenient for subsequent signal processing and data acquisition.

[0063] In this embodiment, if Figure 1 , 3, 4, and 8, it also includes a circuit board 5, which is electrically connected to the pressure signal acquisition module 4 to transmit the pressure signal collected by the pressure signal acquisition module 4 to the outside. The circuit board 5 is electrically connected to the pressure signal acquisition module 4 through a signal transmission line 9. The circuit board 5 calculates the resistance value measured by the varistor to obtain the pressure of the gas to be measured and transmits it to the outside. The circuit board 5 processes the electrical signal output by the pressure sensor to obtain the pressure of the gas to be measured and transmits it to the outside.

[0064] In this embodiment, if Figure 4 As shown, the circuit board 5 is electrically connected to the background computer 8 through the signal transmission line 9, or the circuit board 5 is communicatively connected to the background computer 8 to transmit the pressure of the gas to be measured to the background computer 8, so as to realize the remote transmission of the pressure signal. The background computer 8 can judge whether there is a fault in the system (such as gas leakage, pressure abnormality, etc.) by analyzing the change of gas pressure, and the operator can remotely monitor the change of gas pressure without going to the site in person. Therefore, the parallel gas density relay of the present invention has a remote transmission function.

[0065] In this embodiment, if Figure 1-7 As shown, the measuring bellows 111 and the compensating bellows 112 of each pneumatic module 11 are provided with an initial compression amount (pre-compression), which means that when not subjected to external force, both are in a partially contracted state, but have not reached the maximum contraction limit. The initial compression amount makes the measuring bellows 111 and the compensating bellows 112 in a pre-tightened state when not subjected to external force. When the pressure of the gas to be measured changes, even if the range of change is small, the measuring bellows 111 and the compensating bellows 112 can respond, which broadens the application scope of the parallel gas density relay and enables it to play a stable measurement role under more diverse working conditions.

[0066] It is worth noting that both the measuring bellows 111 and the compensating bellows 112 are provided with an initial compression amount. When the external pressure (especially the negative pressure) changes, the measuring bellows 111 can respond to small changes, because the negative pressure usually changes slightly and has a narrow range (such as -0.1 MPa to 0 MPa). Both the measuring bellows 111 and the compensating bellows 112 are provided with an initial compression amount, so that the measuring bellows 111 and the compensating bellows 112 maintain a linear response within the working range, reduce nonlinear errors, and improve the stability, seismic and shock resistance of the system.

[0067] In this embodiment, if Figure 1-7As shown, the measuring bellows 111 can sense the pressure change of the gas to be measured, while the compensating bellows 112 can offset the influence of the ambient temperature, and the initial compression between the two can be achieved by mechanical preload. When the system is in a negative pressure state, the external pressure is higher than the internal pressure, and the measuring bellows 111 will shrink axially. Due to the existence of the initial compression, the measuring bellows 111 is already in a pre-shrinkage state, so the measuring bellows 111 can be displaced immediately without overcoming its own elastic resistance, eliminating the measurement lag and ensuring that the system can respond to negative pressure changes. The compensating bellows 112 is axially elongated by the contraction of the measuring bellows 111, and drives the driving assembly 22 to move through the connecting assembly 21, so as to drive the movement assembly 31 to rotate and drive the indicating assembly 32 to indicate the gas pressure value in real time.

[0068] In this embodiment, if Figure 1-7 As shown, the connecting assembly 21 includes a first connecting plate 211 and a second connecting plate 212 arranged in parallel, and a supporting tube 213 for connecting the first connecting plate 211 and the second connecting plate 212, the bottom end of the compensating bellows 112 is connected to the first connecting plate 211, the top end of the measuring bellows 111 is connected to the second connecting plate 212, the top end of the first pressure-bearing bellows 121 is connected to the second connecting plate 212, and the bottom end of the second pressure-bearing bellows 122 is connected to the first connecting plate 211, the first connecting plate 211 is arranged at a position higher than the bottom ends of the measuring bellows 111 and the first pressure-bearing bellows 121, and the second connecting plate 212 is arranged at a position lower than the top ends of the compensating bellows 112 and the second pressure-bearing bellows 122, thereby achieving the misalignment of the measuring bellows 111 and the compensating bellows 112 in the height direction, and the misalignment of the first pressure-bearing bellows 121 and the second pressure-bearing bellows 122 in the height direction.

[0069] In this embodiment, if Figure 1-7 As shown, when the pressure of the gas to be measured rises, each measuring bellows 111 and each first pressure-bearing bellows 121 deform upward, driving the connecting assembly 21 to move upward as a whole, and then driving the driving assembly 22 to move upward, and the driving assembly 22 pushes the movement pin 3121 to drive the movement shaft 312 to rotate, and pushes the gear structure 313 to rotate through the movement push rod 3122, so as to drive the pointer 321 to rotate through the pointer shaft and indicate the gas pressure value. When the pressure of the gas to be measured decreases, each measuring bellows 111 and each first pressure-bearing bellows 121 deform downward, driving the connecting assembly 21 to move downward as a whole, and then driving the driving assembly 22 to move downward, and the driving assembly 22 pushes the movement pin 3121 to drive the movement shaft 312 to rotate, and pushes the gear structure 313 to rotate through the movement push rod 3122, so as to drive the pointer 321 to rotate through the pointer shaft and indicate the gas pressure value.

[0070] In this embodiment, if Figure 1 , 3 , 4, 6-8, further comprising a shell structure 6, the shell structure 6 comprising a shell 61, an upper cover 62 arranged on the top of the shell 61 and a lower cover 63 arranged at the bottom of the shell 61, the pneumatic structure 1 and the connecting assembly 21 are arranged in an accommodating inner cavity enclosed by the shell 61, the upper cover 62 and the lower cover 63; the bottom of the lower cover 63 is provided with a gas nozzle 631 for communicating with the gas to be measured; the measuring bellows 111 in each of the pneumatic modules 11 has an open bottom end They are respectively connected to the air nozzle 631, and the bottom ends of the first pressure-bearing bellows 121 in each of the pressure-bearing modules 12 are respectively connected to the lower cover 63; the top ends of the compensating bellows 112 in each of the pneumatic modules 11 are respectively fixedly connected to the upper cover 62, and the top ends of the second pressure-bearing bellows 122 in each of the pressure-bearing modules 12 are respectively fixedly connected to the upper cover 62, so as to connect the pneumatic modules 11 in parallel with each other, the pressure-bearing modules 12 and the pneumatic modules 11 in parallel with each other, and the pressure-bearing modules 12 in parallel with each other.

[0071] In this embodiment, an annular gas channel is provided at the bottom of the lower cover 63, and the annular gas channel extends all the way to the gas nozzle 631. The bottom ends of the openings of the measuring bellows 111 in each of the pneumatic modules 11 are respectively connected to the annular gas channel, so that the bottom ends of the openings of each measuring bellows 111 are respectively connected to the gas nozzle 631.

[0072] In this embodiment, if Figure 1-7As shown, the bottom end of the measuring bellows 111 in each pneumatic module 11 is connected to the air nozzle 631, and the top end is connected to the second connecting plate 212; the bottom end of the first pressure-bearing bellows 121 in each pressure-bearing module 12 is connected to the lower cover 63, and the top end is connected to the second connecting plate 212; the bottom end of the compensating bellows 112 in each pneumatic module 11 is connected to the first connecting plate 211, and the top end is fixedly connected to the upper cover 62; the bottom end of the second pressure-bearing bellows 122 in each pressure-bearing module 12 is connected to the first connecting plate 211, and the top end is fixedly connected to the upper cover 62, thereby realizing the mutual parallel connection of each pneumatic module 11 and the mutual parallel connection of the pressure-bearing module 12 and the pneumatic module 11. By connecting the pneumatic modules 11 in parallel, connecting the pressure-bearing modules 12 and the pneumatic modules 11 in parallel, and connecting the pressure-bearing modules 12 in parallel, when the pressure range of the monitored gas is large, the shells of the compensating bellows 112 and the second pressure-bearing bellows 122 share the pressure together, so that the compensating bellows 112 and the second pressure-bearing bellows 122 are deformed within the effective stroke, and when the compensating gas pressure is large, the shells of the measuring bellows 111 and the first pressure-bearing bellows 121 share the pressure together, thereby expanding the measuring range of the parallel gas density relay, so that the relay can adapt to various measurement requirements.

[0073] In this embodiment, a compensating gas filling port is provided on the upper cover 62 to fill the closed chamber of each compensating bellows 112 with compensating gas.

[0074] In this embodiment, if Figure 1 , 3 -4, 6-8, the driving assembly 22 includes a linear driving rod 221 and a sliding block 222, one end of the linear driving rod 221 is connected to the connecting assembly 21, and the other end is connected to the sliding block 222; the movement assembly 31 is arranged above the sliding block 222 and contacts the top of the sliding block 222. The movement pin 3121 is always in contact with the top of the sliding block 222. When the pressure of the gas to be measured changes, the measuring bellows 111 and the first pressure-bearing bellows 121 are deformed, and the linear driving rod 221 is driven to move up and down through the connecting assembly 21, and the sliding block 222 is driven to push the movement pin 3121 to drive the movement shaft 312 to rotate, and the gear structure 313 is driven to rotate through the movement push rod 3122, thereby driving the pointer 321 to rotate through the pointer shaft and indicating the gas pressure value.

[0075] In this embodiment, if Figure 1 , 3-4, 6-8, the upper cover 62 is provided with a first through hole, one end of the linear drive rod 221 passes through the first through hole to connect with the connecting assembly 21, and can move up and down in the first through hole, and the other end is connected with the sliding block 222. The sliding block 222, the circuit board 5, the movement assembly 31, and the indicating assembly 32 are all located above the shell structure 6. When the pressure of the gas to be measured changes, the measuring bellows 111 and the first pressure-bearing bellows 121 are deformed, the second connecting plate 212 drives the first connecting plate 211 to move up and down, and drives the sliding block 222 to move up and down through the linear drive rod 221, so that the sliding block 222 drives the movement pin 3121 to drive the movement shaft 312 to rotate, and drives the gear structure 313 to rotate through the movement push rod 3122, thereby driving the pointer 321 to rotate through the pointer shaft and indicating the gas pressure value.

[0076] In this embodiment, if Figure 1 , 3 -4, 8, further comprising an alarm structure 7, the alarm structure 7 is arranged below the sliding block 222 and located on the moving path of the sliding block 222. When the pressure of the gas to be measured changes, the measuring bellows 111 and the first pressure-bearing bellows 121 are deformed, and the sliding block 222 is driven to move away from or close to the alarm structure 7 through the connecting assembly 21.

[0077] In this embodiment, if Figure 1 , 3 -4, 8, the alarm structure 7 includes a plurality of micro switches, each of which is respectively arranged on the circuit board 5, and the circuit board 5 is arranged below the sliding block 222 and is located on the moving path of the sliding block 222. The circuit board 5 is arranged on the top of the upper cover 62. When the pressure of the gas to be measured rises, each measuring bellows 111 and each first pressure-bearing bellows 121 are deformed upward, and the second connecting plate 212 drives the first connecting plate 211 to move upward as a whole, and drives the sliding block 222 to move upward through the linear driving rod 221, and the sliding block 222 moves away from the micro switch, and the sliding block 222 drives the movement assembly 31 to rotate, so as to drive the indicating assembly 32 to rotate and indicate the gas pressure value. When the gas to be measured leaks, that is, the pressure of the gas to be measured drops, each measuring bellows 111 and each first pressure-bearing bellows 121 deforms downward, and the second connecting plate 212 drives the first connecting plate 211 to move downward as a whole, and drives the sliding block 222 to move downward through the linear driving rod 221. The sliding block 222 approaches the micro switch and triggers the micro switch to operate, and the sliding block 222 drives the movement assembly 31 to rotate, so as to drive the indicating assembly 32 to rotate and indicate the gas pressure value.

[0078] In this embodiment, the driving structure 2 also includes a trigger component for triggering the alarm structure 7. The trigger component is arranged on the driving component 22. The driving component 22 can drive the trigger component to move, thereby triggering the alarm structure 7 to operate.

[0079] In this embodiment, if Figure 3 , 8 As shown, the sliding block 222 is provided with adjustment holes 2221, the number of which is the same as that of the micro switches. The trigger component is a trigger screw arranged in the adjustment hole 2221. The trigger screw passes through the bottom of the adjustment hole 2221 and is used to trigger the micro switch. By adjusting the position of the trigger screw in the adjustment hole 2221 and adjusting the distance of the trigger screw relative to the micro switch, alarm triggering of different pressure thresholds can be achieved, thereby realizing the function of multi-level alarm.

[0080] In this embodiment, exemplarily, the number of micro switches is four, namely, the first micro switch, the second micro switch, the third micro switch, and the fourth micro switch. The sliding block 222 is provided with four adjustment through holes 2221, and each adjustment through hole 2221 is provided with a trigger screw, namely, the first trigger screw, the second trigger screw, the third trigger screw, and the fourth trigger screw, and each trigger screw is at a different distance from the micro switch. When the pressure of the gas to be measured is reduced to the first preset pressure threshold, the first trigger screw moves to a position in contact with the first micro switch, triggers the first micro switch and acts, and the switch signal emitted by the first micro switch is transmitted to the external device through the circuit board 5. When the pressure of the gas to be measured is reduced to the second preset pressure threshold, the second trigger screw moves to a position in contact with the second micro switch, triggers the second micro switch and acts, and the switch signal emitted by the second micro switch is transmitted to the external device through the circuit board 5. When the pressure of the gas to be measured is reduced to the third preset pressure threshold, the third trigger screw moves to a position in contact with the third micro switch, triggers the third micro switch and acts, and the switch signal emitted by the third micro switch is transmitted to the external device through the circuit board 5. When the pressure of the gas to be measured drops to the fourth preset pressure threshold, the fourth trigger screw moves to a position in contact with the fourth micro switch, triggering the fourth micro switch to operate. The switch signal emitted by the fourth micro switch is transmitted to the external device through the circuit board 5, thereby achieving the effect of segmented triggering of the parallel gas density relay. It can be used in a variety of occasions or on a variety of electrical equipment and has strong applicability.

[0081] In this embodiment, a meter cover is also included, which is arranged on the upper cover 62. The circuit board 5, the alarm structure 7, the sliding block 222, the movement assembly 31, and the indication assembly 32 are all arranged in the meter cover to prevent dust, moisture and other pollutants from entering the meter cover, thereby ensuring that the parallel gas density relay can work normally in a clean and dry environment.

[0082] In summary, the parallel gas density relay of the present invention has the following advantages:

[0083] (1) Expanding the measurement range: When the pressure range of the monitored gas is large, the shells of each compensating bellows 112 and each second pressure-bearing bellows 122 share the pressure together, so that each compensating bellows 112 and each second pressure-bearing bellows 122 are deformed within the effective stroke. Moreover, when the compensating gas pressure is large, the shells of each measuring bellows 111 and each first pressure-bearing bellows 121 share the pressure together, so that each measuring bellows 111 and each first pressure-bearing bellows 121 are deformed within the effective stroke. This can expand the measurement range of the parallel gas density relay and meet the needs of a wider range of gas pressure measurements.

[0084] (2) High-precision measurement: Each pneumatic module 11 still adopts a high-precision bellows structure to ensure high-precision measurement within a wide range.

[0085] (3) Temperature compensation: The compensation bellows 112 is filled with a compensation gas having the same characteristics as the gas to be measured, which can automatically offset the influence of ambient temperature changes on the measurement results. When the temperature changes, the deformation of the compensation bellows 112 and the measurement bellows 111 offsets each other, ensuring that the measurement results are not affected by temperature. Thus, in an environment with large temperature fluctuations, the parallel gas density relay can still maintain stable measurement performance.

[0086] (4) Realizing a multi-level alarm function: The trigger screw passes through the bottom of the adjusting through hole 2221 and is used to trigger the micro switch. By adjusting the position of the trigger screw in the adjusting through hole 2221, the distance between the trigger screw and the micro switch can be adjusted to achieve alarm triggering at different pressure thresholds, thereby realizing a multi-level alarm function to meet the needs of different application scenarios.

[0087] (5) Remote transmission of pressure signals: The circuit board 5 is electrically connected to the back-end computer 8 via the signal transmission line 9 to transmit the pressure signal of the gas to be tested to the back-end computer 8. The back-end computer 8 can determine whether there is a fault in the system (such as gas leakage, abnormal pressure, etc.) by analyzing the changes in the pressure signal. The operator can remotely monitor the changes in the gas pressure.

[0088] (6) Simple structure: the pneumatic modules 11 are connected in parallel with each other, the pressure-bearing modules 12 are connected in parallel with each other, the pneumatic modules and the pressure-bearing modules 12 are connected in parallel with each other, and the measuring bellows 111 and the compensating bellows 112 in each pneumatic module 11 are staggered and connected, and the first pressure-bearing bellows 121 and the second pressure-bearing bellows 122 in each pressure-bearing module 12 are staggered and connected, which makes full use of space, compactly arranges, has simple structure and process, and is very suitable for mass production.

[0089] In summary, the present invention effectively overcomes various shortcomings of the prior art and has high industrial utilization value.

[0090] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A parallel gas density relay for monitoring the pressure of a gas to be measured, characterized in that: include: A pneumatic structure (1), the pneumatic structure (1) comprising at least one pneumatic module (11) and at least one pressure-bearing module (12); the pneumatic module (11) and the pressure-bearing module (12) are connected in parallel with each other, the pneumatic modules (11) are connected in parallel with each other, and the pressure-bearing modules (12) are connected in parallel with each other; the pneumatic module (11) comprises a measuring bellows (111) with an opening at the bottom end and a compensating bellows (112) with sealed ends; a sealed chamber is provided in the compensating bellows (112), and the sealed chamber is filled with a compensating gas having the same characteristics as the gas to be measured; a measuring chamber is provided in the measuring bellows (111). chamber, the bottom end of the measuring bellows (111) is in communication with the gas to be measured so that the gas to be measured flows into the measuring chamber, and the measuring bellows (111) and the compensating bellows (112) are connected in a staggered manner; the pressure-bearing module (12) comprises a first pressure-bearing bellows (121) sealed at both ends, and a second pressure-bearing bellows (122) sealed at both ends, the first pressure-bearing bellows (121) and the second pressure-bearing bellows (122) are connected in a staggered manner, the first pressure-bearing bellows (121) and the measuring bellows (111) are connected in parallel, and the second pressure-bearing bellows (122) and the compensating bellows (112) are connected in parallel; A drive structure (2), the drive structure (2) comprising a connection component (21) and a drive component (22) arranged on the connection component (21), the measuring bellows (111) being staggeredly connected to the compensating bellows (112) via the connection component (21); and the first pressure-bearing bellows (121) being staggeredly connected to the second pressure-bearing bellows (122) via the connection component (21); An indicating structure (3), the indicating structure (3) being connected to the driving assembly (22), and when the pressure of the gas to be measured changes, each of the measuring bellows (111) and each of the first pressure-bearing bellows (121) deforms, and drives the driving assembly (22) to move through the connecting assembly (21), so as to push the indicating structure (3) to rotate and indicate the gas pressure value.

2. The parallel gas density relay according to claim 1, characterized in that: The indicating structure (3) comprises a freely rotatable movement assembly (31) and an indicating assembly (32) rotatably connected to the movement assembly (31); the movement assembly (31) is arranged above the drive assembly (22) and contacts the top of the drive assembly (22); the indicating assembly (32) comprises a pointer (321) and a dial (322) arranged between the movement assembly (31) and the pointer (321); the pointer (321) is rotatably connected to the movement assembly (31).

3. The parallel gas density relay according to claim 1, characterized in that: It also comprises a pressure signal acquisition module (4), wherein the pressure signal acquisition module (4) is arranged in one of the measurement chambers to acquire the pressure signal of the gas to be measured.

4. The parallel gas density relay according to claim 3, characterized in that: It also comprises a circuit board (5), wherein the circuit board (5) is electrically connected to the pressure signal acquisition module (4) so ​​as to transmit the pressure signal acquired by the pressure signal acquisition module (4) to the outside.

5. The parallel gas density relay according to claim 1, characterized in that: The connection assembly (21) comprises a first connection plate (211), a second connection plate (212) and a support tube (213) for connecting the first connection plate (211) and the second connection plate (212), the bottom end of the compensating bellows (112) being connected to the first connection plate (211), the top end of the measuring bellows (111) being connected to the second connection plate (212), the top end of the first pressure-bearing bellows (121) being connected to the second connection plate (212), and the bottom end of the second pressure-bearing bellows (122) being connected to the The first connecting plate (211) is connected, the first connecting plate (211) is arranged at a position higher than the bottom ends of the measuring bellows (111) and the first pressure-bearing bellows (121), and the second connecting plate (212) is arranged at a position lower than the top ends of the compensating bellows (112) and the second pressure-bearing bellows (122), thereby achieving the misalignment of the measuring bellows (111) and the compensating bellows (112) in the height direction, and the misalignment of the first pressure-bearing bellows (121) and the second pressure-bearing bellows (122) in the height direction.

6. The parallel gas density relay according to claim 2, characterized in that: The invention also comprises a shell structure (6), wherein the shell structure (6) comprises a shell (61), an upper cover (62) arranged on the top of the shell (61), and a lower cover (63) arranged on the bottom of the shell (61); the pneumatic structure (1) and the connecting assembly (21) are arranged in a receiving cavity formed by the shell (61), the upper cover (62), and the lower cover (63); a gas nozzle (631) for communicating with the gas to be measured is arranged at the bottom of the lower cover (63); the measuring bellows (111) in each of the pneumatic modules (11) has an open bottom end, respectively. The air nozzle (631) is connected to the air nozzle, and the bottom end of the first pressure-bearing bellows (121) in each of the pressure-bearing modules (12) is connected to the lower cover (63) respectively; the top end of the compensating bellows (112) in each of the pneumatic modules (11) is fixedly connected to the upper cover (62) respectively, and the top end of the second pressure-bearing bellows (122) in each of the pressure-bearing modules (12) is fixedly connected to the upper cover (62) respectively, so as to connect the pneumatic modules (11) in parallel with each other, the pressure-bearing modules (12) and the pneumatic modules (11) in parallel with each other, and the pressure-bearing modules (12) in parallel with each other.

7. The parallel gas density relay according to claim 6, characterized in that: The driving assembly (22) comprises a linear driving rod (221) and a sliding block (222); one end of the linear driving rod (221) is connected to the connecting assembly (21), and the other end is connected to the sliding block (222); the movement assembly (31) is arranged above the sliding block (222) and contacts the top of the sliding block (222).

8. The parallel gas density relay according to claim 7, characterized in that: The upper cover (62) is provided with a first through hole, one end of the linear drive rod (221) passes through the first through hole to be connected to the connecting component (21) and is capable of moving up and down in the first through hole, and the other end is connected to the sliding block (222).

9. The parallel gas density relay according to claim 7, characterized in that: It also includes an alarm structure (7), which is arranged below the sliding block (222) and on the moving path of the sliding block (222); when the pressure of the gas to be measured changes, the measuring bellows (111) and the first pressure-bearing bellows (121) are deformed, and the sliding block (222) is driven to move in a direction away from or close to the alarm structure (7) through the connecting component (21).

10. The parallel gas density relay according to claim 9, characterized in that: The driving structure (2) further comprises a trigger component for triggering the alarm structure (7); the trigger component is arranged on the driving component (22); the driving component (22) can drive the trigger component to move, thereby triggering the alarm structure (7) to operate.

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