CN115218978A - Low-temperature liquid mass flowmeter - Google Patents

Abstract

The invention discloses a low-temperature liquid mass flowmeter, which belongs to the field of Coriolis mass flowmeters and comprises: the device comprises a measuring device, a heat insulation structure arranged outside the measuring device and a stress compensation device connected with the measuring device. The invention can solve the problem that the existing mass measuring meter is not suitable for measuring low-temperature liquid.

Description

Low-temperature liquid mass flowmeter

Technical Field

The invention belongs to the field of Coriolis mass flowmeters, and particularly relates to a low-temperature liquid mass flowmeter.

Background

The Coriolis mass flowmeter is a device for directly measuring mass flow by utilizing the Coriolis force principle that when fluid flows in a vibrating mother sleeve, the fluid generates a force proportional to the mass flow, and the device consists of a flow detection element and a converter. The Coriolis mass flowmeter realizes the direct measurement of mass flow, has the characteristics of high precision and capability of measuring multiple media and multiple process parameters, and is widely applied to the industries of petrifaction, pharmacy, food and the like.

The inventor finds that the prior arts have at least the following technical problems in the practical use process:

the existing Coriolis mass flowmeter is not suitable for measuring low-temperature liquid, a heat insulation structure is not arranged, the low-temperature liquid is easily vaporized, and under the low-temperature condition, the material of the mass flowmeter contracts to generate larger stress and influence the test precision.

Disclosure of Invention

In order to overcome the defects, the inventor of the invention continuously reforms and innovates through long-term exploration and trial and a plurality of experiments and efforts, and provides a low-temperature liquid mass flowmeter which can solve the problem that the existing mass flowmeter is not suitable for measuring low-temperature liquid.

In order to achieve the purpose, the invention adopts the technical scheme that: a cryogenic liquid mass flow meter is provided, comprising: the device comprises a measuring device, a heat insulation structure arranged outside the measuring device and a stress compensation device connected with the measuring device.

According to the invention, a further preferable technical scheme of the low-temperature liquid mass flowmeter is as follows: the measuring device comprises a female sleeve and a shunt body, the female sleeve is connected with an interface of the shunt body,

according to the invention, a further preferable technical scheme of the low-temperature liquid mass flowmeter is as follows: the insulation construction includes: the housing is divided into a first housing covering the pipeline and a second housing covering the shunt body; and one end of the flange is connected with the interface, the other end of the flange seals the first housing, and the pipeline is sleeved in the flange and is connected with the interface through the flange.

According to the invention, a further preferable technical scheme of the low-temperature liquid mass flowmeter is as follows: the flange includes male flange and female flange, female flange includes: the female joint is connected to the interface; the female flange plate is sleeved outside the pipeline and seals the first housing; the two ends of the female sleeve are fixedly connected with the female joint and the flange plate and sleeved between the first housing and the pipeline; the male flange includes: the male connector is inserted on the female connector; the male flange plate is connected to one side of the female flange plate; and the two ends of the male sleeve are fixedly connected with a male connector and a male flange plate and are sleeved between the female sleeve and the pipeline.

According to the invention, a further preferable technical scheme of the low-temperature liquid mass flowmeter is as follows: a first heat insulation layer is formed between the female sleeve and the housing, a second heat insulation layer is formed between the male sleeve and the pipeline, and a vacuum sealing element is arranged on the housing.

According to the invention, a further preferable technical scheme of the low-temperature liquid mass flowmeter is as follows: the stress compensation device is an expansion joint, and the expansion joint comprises: the connecting rings are respectively sleeved between the female sleeve and the female joint; the elastic piece is arranged between the two connecting rings; the protective cover is sleeved on the connecting ring, one end of the protective cover is fixedly connected with the connecting ring on one side, and the other end of the protective cover is in clearance fit with the connecting ring on the other side.

According to the invention, a further preferable technical scheme of the low-temperature liquid mass flowmeter is as follows: the pipeline is divided into an inlet pipe and an outlet pipe, and the flow dividing body comprises: a main body; the interface is arranged on the main body and is divided into an inlet connected with the inlet pipe and an outlet connected with the outlet pipe; the double-row measuring tube is provided with a driving coil and a detection coil, and two ends of the double-row measuring tube are connected with the main body and are connected with the inlet tube and the outlet tube through the main body to form a passage.

According to the invention, the further preferable technical scheme is as follows: the flow distribution body further comprises a connecting piece, and the double-row measuring pipe is fixedly connected with the main body through the connecting piece.

According to the invention, a further preferable technical scheme of the low-temperature liquid mass flowmeter is as follows: the connecting piece divide into first connecting piece and second connecting piece, double survey buret is welded with first connecting piece argon arc and is connected, the main part is welded with second connecting piece argon arc and is connected, first connecting piece and second connecting piece argon arc are welded and are connected.

According to the invention, the further preferable technical scheme is as follows: the second connecting piece is provided with a groove, and the bottom of the first connecting piece is inserted into the groove in a matched mode to form an arc-shaped flow dividing cavity.

Compared with the prior art, the technical scheme of the invention has the following advantages/beneficial effects:

the invention improves the mass flowmeter, and the outer side of the measuring device is provided with the heat insulation structure to prevent low-temperature liquid from gasifying and further influencing the testing precision. Meanwhile, a stress compensation device is arranged on the measuring device to compensate the stress, so that the situation that the material shrinks to generate larger stress when meeting cold to influence the measuring precision of the flowmeter is prevented.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a schematic cross-sectional view of a mass flowmeter for cryogenic liquids according to the present invention.

Fig. 2 is a schematic view of a connection structure of an expansion joint and a flange according to the present invention.

Fig. 3 is a side view schematic of the shunt of the present invention.

The labels in the figure are respectively: 1, measuring a device, 2, a heat insulation structure and 3, an expansion joint; an inlet pipe 11, a split fluid 12 and an outlet pipe 13; 121 a main body, 122 interfaces, 123 double-row measuring tubes, 124 driving coils, 125 detection coils, 126 a first connecting piece, 127 a second connecting piece, 128 a shunt cavity and 129 a fixed block; 1221 inlet, 1222 outlet; 21 a first casing, 22 a second casing, 23 a male flange, 24 a female flange, 26 a vacuum seal; 231 male connector, 232 male flange, 233 male sleeve; 241 female joint, 242 female flange and 243 female sleeve; 31 connecting rings, 32 elastic pieces and 33 shields.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are a part of the embodiments of the present invention, not all of the embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without inventive efforts based on the embodiments of the present invention, are within the scope of protection of the present invention. Thus, the detailed description of the embodiments of the present invention provided below is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it may not be further defined and explained in subsequent figures.

Example (b):

as shown in fig. 1, a cryogenic liquid mass flowmeter comprises: measuring device 1, insulation construction 2, stress compensation device (expansion joint 3). The heat insulation structure 2 is arranged outside the measuring device 1 to prevent low-temperature liquid from vaporizing, and the expansion joint 3 is used as a stress compensation device to solve the problem of stress concentration.

The cryogenic liquid may be liquid hydrogen, liquid nitrogen, liquid oxygen, liquefied natural gas, or other cryogenic liquid. This example will be described with reference to liquid hydrogen.

The measuring device 1 includes: a conduit and a diverter 12, the conduit being connected to the diverter 12. The pipeline is divided into: an inlet pipe 11 and an outlet pipe 13, wherein the low-temperature liquid enters the flow splitting body 12 from the inlet pipe 11 and then flows out from the outlet pipe 13. As shown in fig. 3, the flow distribution body 12 includes: main part 121, interface 122 and double row survey buret 123, interface 122 sets up on main part 121, interface 122 divide into import 1221 and export 1222, and import pipe 11 passes through the flange and is connected with import 1221, outlet pipe 13 passes through the flange and is connected with export 1222, double row surveys buret 123 comprises two female sleeves, and its both ends head draws close the setting each other on main part 121, makes double row survey buret 123 form the triangle-shaped structure, and its both ends head communicates with import pipe 11 and outlet pipe 13 respectively, and cryogenic liquids loops through import pipe 11, main part 121's import 1221, the export 1222 of double row survey buret 123 and main part 121 promptly. Two ends of the double-row measuring pipe 123 adopt a fixing block 129 to clamp and position two parallel measuring pipes, a driving coil 124 is installed in the middle of the double-row measuring pipe 123, detecting coils 125 are respectively arranged at two corners of a triangle on the double-row measuring pipe 123, the detecting coils 125 need to be installed with magnetic steel and the detecting coils 125, phase difference is measured to obtain mass flow, and the measurement of mass flow is prior art, so detailed description is omitted.

In the present invention, the coil bobbin constituting the detection coil 125 and the drive coil 124, and materials such as an adhesive and an adhesive tape to be used are made of materials suitable for low temperatures. For example, DW-3 is adopted as the adhesive, and polyimide is adopted as the low-temperature material related to the measurement pipe accessory.

The conventional mass flowmeter only carries out heat preservation on the shunting body 12, and does not carry out heat preservation design on the inlet pipe 11 and the outlet pipe 13, but the temperature of liquid hydrogen is extremely low, and when the liquid hydrogen is extremely easy to gasify in a flow-through mass flowmeter, the testing precision of the flowmeter can be seriously influenced. Therefore, the insulation structure 2 of the present invention includes: the measuring device comprises a housing and a flange, wherein the housing is sleeved on the outer side of the measuring device 1, one end of the flange is arranged at the interface 122, and the other end of the flange is used for sealing the housing.

Specifically, the housing is divided into a first housing 21 and a second housing 22, two ends of the first housing 21 are open, and the second housing 22 is arranged on the outer wall of the first housing 21 and the interior of the second housing is communicated with the first housing 21. The first cover 21 covers the outer sides of the inlet pipe 11 and the outlet pipe 13 and is used for insulating the inlet pipe 11 and the outlet pipe 13, and the second cover 22 covers the split fluid 12 and is used for insulating the split fluid 12.

Preferably, the flange includes a male flange 23 and a female flange 24, the male flange 23 is inserted into the female flange 24, and the female flange 24 includes: the female joint 241 is installed at the interface, one end far away from the female joint 241 is provided with a female sleeve 243, the female sleeve 243 is sleeved between the housing and the pipeline, the other end of the female sleeve 243 is fixedly connected with a female flange 242, and the female flange 242 seals an opening at the end of the first housing 21. The male flange 23 includes: the male flange plate 232 is arranged on one side, away from the housing, of the female flange plate 242, the male sleeve 233 is arranged on the male flange plate 232, and the other end of the male sleeve 233 is fixedly connected with the male connector 231. The male connector 231 and the male sleeve 233 form an extending structure and extend into the female sleeve 243, and the male connector 231 is inserted into a groove matched with the female connector 241 and is communicated with the interface. The pipe end is connected to the male connector 231, which in turn communicates with the interface.

Specifically, the pipeline is divided into an inlet pipe 11 and an outlet pipe 13, flanges are arranged at an inlet and an outlet of the flow dividing body, the inlet pipe 11 is connected with the inlet through the flanges, and the outlet pipe 13 is connected with the outlet through the flanges. Taking the inlet of the flow splitting body as an example, one end of the inlet pipe 11 is connected to the male connector 231, and then is communicated with the interface. The male sleeve 233, the female sleeve 243 and the first cover 21 are sequentially sleeved outside the inlet pipe 11.

In the invention, a first heat-insulating layer is formed between the female sleeve 243 and the housing, a second heat-insulating layer is formed between the male sleeve 233 and the inlet pipe 11 in a sealing manner, the first heat-insulating layer and the second heat-insulating layer are of vacuum structures, and a pipeline and a measuring device are heat-insulated by arranging double vacuum layers, so that the heat-insulating effect is good. The vacuum sealing element is further arranged on the housing, the distance between the heat preservation layers is related to the caliber of the pipe, in order to meet the heat insulation requirement, the distance between the heat preservation layers needs to be adjusted according to the actual requirement, and in the embodiment, the distance between the first heat preservation layers is 40mm to 50mm.

In the invention, the heat insulation structure is not limited to be internally vacuum, and the heat insulation structure can be filled with a foaming agent for heat insulation, wherein the foaming agent is a polyurethane foaming heat insulation material.

When the temperature changes, materials can expand or contract, if the expansion and contraction degrees of all parts of the structure are different, or the expansion and contraction of the structure are limited, thermal stress can be generated, the thermal stress is too large and exceeds the allowable stress of the materials, the internal stress can influence the testing precision of the flowmeter, and in order to solve the problem, a stress compensation device is arranged in the invention and used for compensating the stress, so that the thermal stress is eliminated.

The stress compensation device is an expansion joint 3, as shown in fig. 2, expansion joints are arranged on the female flanges at two ends of the split fluid, the expansion joint 3 is arranged between the female joint and the female sleeve, and the stress compensation device comprises: an attachment ring 31, a resilient member 32 and a shield 33. Connect the ring to have two, one sets up the tip at female joint, one sets up the tip at female sleeve, elastic component 32 is the spring, and it sets up between two connect rings 31, both ends respectively with connect ring 31 fixed connection, connect the cross-section of ring 31 to be the L type, be provided with the guard shield 33 that plays supporting role at the top that connects ring 31, guard shield 33 one end and female sleeve on connect ring 31 fixed connection, the other end and female joint on connect ring 31 clearance fit.

After the cryogenic liquids got into, arouse each parts shrink, elastic component 32 along female sleeve axial flexible deformation, carry out axial length compensation on female sleeve, eliminate thermal stress, expansion joint 3 sets up in the junction of female sleeve and female joint simultaneously, prevents stress concentration.

In the present invention, the stress compensating device may be a bent pipe type expansion joint or a sleeve type expansion joint in addition to the expansion joint 3 described in the present embodiment.

The existing measuring tube is directly connected with the main body 121 through brazing, the measuring tube is easily deformed due to overlarge stress generated by directly welding the measuring tube with the main body 121, and meanwhile, the brazing filler metal is not hydrogen-brittle and is not suitable for measuring low-temperature liquid hydrogen. In order to solve the problems, the connecting part is arranged at the joint of the main body 121 and the double-row measuring tube 123, so that the measuring tube is prevented from being deformed due to the direct welding of the main body 121 and the measuring tube, meanwhile, the main body 121 is connected with the connecting part through argon arc welding, and the measuring tube is connected with the connecting part through argon arc welding, so that the phenomenon of hydrogen embrittlement and cracking of a shunt body are prevented.

Preferably, the connecting member is divided into a first connecting member 126 and a second connecting member 127, the first connecting member 126 and the second connecting member 127 are both cylinders, a groove is formed in the second connecting member 127, the groove is matched with the bottom of the first connecting member 126, the bottom of the first connecting member 126 is in an inward concave arc shape, and the bottom of the first connecting member 126 is inserted into the groove to form an arc-shaped flow dividing cavity 128. Double-row survey buret 123 is connected with first connecting piece 126 argon arc welding, main part 121 is connected with second connecting piece 127 argon arc welding, first connecting piece 126 and second connecting piece 127 argon arc welding are connected.

When the device is used, low-temperature liquid enters the main body 121 through the inlet pipe 11, the male connector 231 and the female connector 241 in sequence, then enters the double-row measuring pipe 123 through the smoothly-transitional flow dividing cavity 128 in a divided mode, the low-temperature liquid is divided into two paths and then enters the double-row measuring pipe 123 to generate Coriolis force through vibration, and the flow dividing cavity 128 is arranged into an arc-shaped structure, so that the low-temperature liquid can be divided more uniformly. The detected cryogenic liquid flows from the double-row measurement pipe 123 again through the diversion chamber 128, joins the outlet pipe 13, completes diversion and joining, and finally flows out of the outlet pipe 13.

When the low-temperature liquid is in the inlet pipe 11 or the outlet pipe 13, the low-temperature liquid is in the heat preservation range of the first heat preservation layer and the second heat preservation layer, and the low-temperature liquid can be effectively prevented from being gasified. And, public sleeve and female sleeve are the heat bridge route, and when low-temperature liquid flowed to public joint and female joint department, the heat passed through the heat bridge route, flows along the direction of public ring flange and female ring flange, because the heat bridge is the only heat propagation route, so greatly reduced external and inside heat exchange, reinforcing heat preservation effect.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the equipment or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood according to specific situations by those of ordinary skill in the art.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. The first feature being "under," "below," and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or merely indicates that the first feature is at a lower level than the second feature.

The above is only a preferred embodiment of the present invention, and it should be noted that the above preferred embodiment should not be considered as limiting the present invention, and the protection scope of the present invention should be subject to the scope defined by the claims. It will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the spirit and scope of the invention, and should be considered to be within the scope of the invention.

Claims (10)

1. A cryogenic liquid mass flowmeter, comprising: the device comprises a measuring device, a heat insulation structure arranged outside the measuring device and a stress compensation device connected with the measuring device.

2. The cryogenic liquid mass flowmeter of claim 1, wherein the measurement device comprises a conduit and a shunt body, the conduit being interfaced with the shunt body.

3. The cryogenic liquid mass flowmeter of claim 2, wherein the thermal insulation structure comprises: the housing is divided into a first housing covering the pipeline and a second housing covering the shunt body; and one end of the flange is connected with the interface, the other end of the flange seals the first housing, and the pipeline is sleeved in the flange and is connected with the interface through the flange.

4. The cryogenic liquid mass flow meter of claim 3, wherein the flanges comprise a male flange and a female flange, the female flange comprising: the female joint is connected to the interface; the female flange plate is sleeved outside the pipeline and seals the first housing; the two ends of the female sleeve are fixedly connected with the female joint and the female flange plate and are sleeved between the first housing and the pipeline; the male flange includes: the male connector is inserted on the female connector; the male flange plate is connected to one side of the female flange plate; and the two ends of the male sleeve are fixedly connected with a male connector and a male flange plate and are sleeved between the female sleeve and the pipeline.

5. The cryogenic liquid mass flowmeter of claim 4, wherein a first thermal insulation layer is formed between the female sleeve and the housing, a second thermal insulation layer is formed between the male sleeve and the pipeline, the first thermal insulation layer and the second thermal insulation layer are vacuum structures, and a vacuum seal is arranged on the housing.

6. The cryogenic liquid mass flowmeter of claim 5, wherein the stress compensating device is an expansion joint comprising: the connecting ring is sleeved on the female sleeve and the female joint respectively; the elastic piece is arranged between the two connecting rings; the protective cover is sleeved on the connecting ring, one end of the protective cover is fixedly connected with the connecting ring on one side, and the other end of the protective cover is in clearance fit with the connecting ring on the other side.

7. The cryogenic liquid mass flowmeter of claim 6, wherein the conduit is divided into an inlet pipe and an outlet pipe, the dividing fluid comprising: a main body; the interface is arranged on the main body and is divided into an inlet connected with the inlet pipe and an outlet connected with the outlet pipe; the double-row measuring tube is provided with a driving coil and a detection coil, and two ends of the double-row measuring tube are connected with the main body and are connected with the inlet tube and the outlet tube through the main body to form a passage.

8. The cryogenic liquid mass flow meter of claim 7, wherein the flow divider further comprises a connector, and the dual-row measurement pipe is fixedly connected to the main body by the connector.

9. The cryogenic liquid mass flow meter of claim 8, wherein the connecting piece is divided into a first connecting piece and a second connecting piece, the double-row measuring tube is connected with the first connecting piece by argon arc welding, the main body is connected with the second connecting piece by argon arc welding, and the first connecting piece is connected with the second connecting piece by argon arc welding.

10. The low-temperature liquid mass flowmeter as claimed in claim 9, wherein a groove is formed in the second connecting piece, and the bottom of the first connecting piece is inserted into the groove in a matching manner to form an arc-shaped flow dividing cavity.

Images