CN211602227U - Ultralow temperature pipeline surface temperature measuring device adopting pipe hoop structure - Google Patents

Abstract

The utility model relates to an ultra-low temperature pipeline surface temperature measuring device adopting a pipe hoop structure, which comprises a pipe hoop, a connecting bolt, a limiting bolt, a temperature measuring block and a temperature measuring element; the pipe hoop is fixed on the periphery of the ultralow-temperature pipeline through a connecting bolt, at least one temperature measuring block is arranged between the pipe hoop and the ultralow-temperature pipeline, one surface of the temperature measuring block, which is in contact with the ultralow-temperature pipeline, is an arc surface, and 2 side surfaces, which are in contact with the pipe hoop, are inclined planes which are inclined towards the outer side and the center of the ultralow-temperature pipeline; the cambered surface is provided with a radian matched with the outer surface of the ultralow-temperature pipeline; the temperature measuring block is provided with a cavity for placing a temperature measuring element. Temperature measuring device adopts detachable connected mode with the ultra-low temperature pipeline, need not carry out trompil and welding operation on the ultra-low temperature pipeline to can monitor the difference in temperature of the upper and lower surface of the ultra-low temperature pipeline for the precooling, the appearance of prevention "banana effect".

Description

An ultra-low temperature pipeline surface temperature measuring device using a pipe hoop structure

technical field

The utility model relates to the technical field of low temperature measurement of ultra-low temperature pipelines, in particular to a pipeline surface temperature measurement device used for ultra-low temperature pipelines of -100°C to -273°C

Background technique

At present, the pipelines are classified according to the working temperature in China. Generally, the pipelines with the working temperature of the medium below -40℃ are called low temperature pipelines, and the pipelines with the working temperature of the medium below -100℃ are called ultra-low temperature pipelines. According to this definition, the common working media of ultra-low temperature pipelines mainly include: liquid hydrogen, liquid nitrogen, liquid oxygen and liquefied natural gas (LNG).

Because stainless steel and 9% nickel steel have good low temperature properties, they are widely used in low temperature engineering. In terms of material properties, economic applicability and application maturity, stainless steel is more widely used in low-temperature engineering pipelines.

Due to the danger of ultra-low temperature working medium in the process of transportation and transfer, the surface temperature monitoring of ultra-low temperature pipelines is an important part of the operation monitoring of the pipeline network system of low-temperature industrial facilities. There are three main types of cryogenic temperature measuring elements commonly used at present: thermocouples, diodes and resistance cables. These three temperature measuring elements have different temperature measuring principles and physical characteristics in the ultra-low temperature environment, so they have different advantages and disadvantages and application scopes.

Thermocouple temperature measuring element has general accuracy, relatively small error, and is the most widely used.

The diode temperature measuring element has high precision, slightly larger error, very low temperature measurement limit, and has a lower service life than the other two temperature measuring elements.

For resistance cables, the accuracy and error of temperature measurement are between those of thermocouples and diode elements, and the lower limit of temperature measurement is higher than the former two. The resistance cable is measured by being wound on the outer wall of the pipeline, and the obtained temperature value is the average temperature of the pipeline in the circumferential direction; there is gas-liquid separation inside the ultra-low temperature pipeline and when the ultra-low temperature pipeline is pre-cooled, the resistance cable is not Suitable for temperature measurement.

The traditional ultra-low temperature pipeline surface temperature monitoring adopts the following method: determine the temperature measurement position on the selected pipeline, open a groove on the outer wall of the pipeline at a certain inclination angle, and weld a shell-shaped steel plate at the corresponding inner wall position of the pipeline. The range where the groove is located is wrapped in a closed manner, so that a cavity isolated from the working medium in the pipeline is formed at the inner wall of the opening position of the pipeline. A temperature measuring element is placed in this cavity, a 5-12V DC power supply is supplied through a cable, and the obtained electrical signal is sent out through a signal line.

The above-mentioned ultra-low temperature pipeline temperature measurement methods have the following shortcomings:

1. Due to the high level of fire and explosion protection of liquid hydrogen, liquid oxygen and LNG plants, cutting and welding of pipelines are not allowed on the project site, and only drilling and welding of pipelines can be carried out in the equipment processing plant. Therefore, the selection of temperature measurement points on the pipeline is greatly limited, and once the temperature measurement point is determined, it cannot be adjusted.

2. Because the material of the ultra-low temperature pipeline is different from ordinary carbon steel, the welding performance is relatively poor; for the same DN diameter pipeline, the wall thickness of the ultra-low temperature pipeline is several times that of the ordinary carbon steel pipeline. Therefore, when drilling and welding ultra-low temperature pipelines, it is necessary to use special special electrodes and special welders. After welding the inner wall of the pipe, a leak test operation is required. The above-mentioned processes bring about a significant increase in labor costs.

In addition, for equipment and pipelines that store and transport ultra-low temperature working medium, pre-cooling operation is required when resuming production after commissioning and maintenance. During the pre-cooling operation of the ultra-low temperature pipeline, the temperature difference between the upper part and the lower part of the pipeline will be generated during the transmission and phase change of the pre-cooling working medium. When this temperature difference reaches a certain value, the “banana effect” will occur in the pipeline, and then Lead to irreversible and uncontrollable bending deformation, resulting in serious economic losses and safety accidents. By monitoring the upper and lower surface temperatures of the ultra-low temperature pipeline at different positions during the pre-cooling process, real-time intervention in the pre-cooling process can be performed to avoid the occurrence of the "banana effect". By comparing the temperature difference between the upper and lower surfaces of the ultra-low temperature pipeline at the same position, it is helpful for the precise control of the pre-cooling process and minimizes the probability of accidents and economic losses.

SUMMARY OF THE INVENTION

The utility model provides an ultra-low temperature pipeline surface temperature measuring device adopting a pipe hoop structure. The temperature measuring device and the ultra-low temperature pipeline adopt a detachable connection mode, which does not require drilling and welding operations on the ultra-low temperature pipeline, and can The precooling is monitored by the temperature difference between the upper and lower surfaces of the ultra-low temperature pipeline to prevent the occurrence of the "banana effect".

In order to achieve the above object, the utility model adopts the following technical solutions to realize:

An ultra-low temperature pipeline surface temperature measuring device using a pipe hoop structure, comprising a pipe hoop, a connecting bolt, a limit bolt, a temperature measuring block and a temperature measuring element; the pipe hoop is fixed on the periphery of the ultra-low temperature pipeline through the connecting bolt, and the pipe hoop is connected to the outer periphery of the ultra-low temperature pipeline. There is at least one temperature measuring block between the ultra-low temperature pipelines, the side of the temperature measuring block in contact with the ultra-low temperature pipeline is an arc surface, and the two sides in contact with the pipe hoop are inclined surfaces inclined to the outside and center of the ultra-low temperature pipeline; The curvature of the outer surface of the pipe is matched; the temperature measuring block is provided with a cavity for placing the temperature measuring element.

The pipe hoop is an annular pipe hoop, and the two ends of the annular pipe hoop are respectively provided with connecting sections, and the connecting sections are composed of inclined sections matched with the upper slope of the temperature measuring block and straight sections used for matching connection; limit bolts Set at the straight section close to the inclined section, and the connecting bolt is set at the straight section away from the inclined section.

The middle part of the annular pipe hoop is provided with a hinge.

The pipe hoop is composed of two symmetrical semi-annular pipe hoop; the two ends of the semi-annular pipe hoop are respectively provided with connecting sections, and the connecting sections are composed of inclined sections matched with the upper inclined surface of the temperature measuring block, and a connecting section for matching and connecting. It consists of straight sections; the limit bolts are set at the straight sections close to the inclined sections, and the connecting bolts are set at the straight sections away from the inclined sections.

The temperature measuring element is connected to the DC power supply through a power line, and is connected to a temperature display instrument or a control system through a signal line.

The pipe hoop, connecting bolts, limit bolts and temperature measuring blocks are all made of low temperature resistant alloy steel.

The top surface and the bottom surface of the ultra-low temperature pipeline are respectively provided with a temperature measuring block, the signal lines of the temperature measuring elements in the two temperature measuring blocks are respectively connected to the signal input end of the logic operator, and the signal output end of the logic operator is connected to the alarm. or control system.

The cavity in the temperature measuring block is provided with an opening at one end corresponding to the axial direction of the ultra-low temperature pipeline.

The temperature measuring element is a thermocouple or a diode.

Compared with the prior art, the beneficial effects of the present utility model are:

1) The temperature measuring device of the present utility model is easy to disassemble and move, can measure the surface temperature of the ultra-low temperature pipeline at different positions along the circumferential direction, can move and adjust along the radial direction of the ultra-low temperature pipeline, and also measure the surface temperature on different pipeline lengths; Compared with the conventional measuring devices of the same kind, the adaptability to different working conditions and different process requirements is fundamentally improved.

2) The temperature measuring device of the present invention adopts a detachable connection method with the ultra-low temperature pipeline, which does not require opening and welding operations on the ultra-low temperature pipeline, and basically does not require welding operations during the manufacturing process, so fundamentally Reduce the amount of consumables, workload and requirements for welders for special welding;

3) It is easy to replace the temperature measuring element. For the ultra-low temperature pipeline for pre-cooling, a logic operator is used to calculate the temperature difference between the upper and lower surfaces, and an alarm signal is sent on the basis of logical judgment according to the calculation result;

4) The overall structure is simple, the manufacturing cost is low, and the use is safe and reliable; it is especially suitable for use in large LNG plants and stations, and can play a key role in improving the temperature monitoring of ultra-low temperature pipelines.

Description of drawings

1 is a schematic structural diagram of a device for measuring the surface temperature of an ultra-low temperature pipeline in Embodiment 1 of the present invention.

FIG. 2 is a side view of FIG. 1 .

Figure 3a is a front view of the annular pipe hoop in Embodiment 1 of the present invention.

Figure 3b is a side view of Figure 3a.

4 is a schematic structural diagram of a device for measuring the surface temperature of an ultra-low temperature pipeline in Embodiment 2 of the present invention.

FIG. 5 is a side view of FIG. 4 .

Fig. 6a is a front view of the semi-annular pipe hoop in the second embodiment of the present invention.

Figure 6b is a side view of Figure 6a.

Figure 7a is a front view of the temperature measuring block of the present invention.

Figure 7b is a top view of the temperature measuring block of the present invention.

In the figure: 1. Pipe hoop 11. Ring pipe hoop 12. Semi-annular pipe hoop 2. Connecting bolts 3. Limit bolts 4. Temperature measuring block 41. Cavity 42. Arc surface 43. Inclined surface 5. Temperature measuring element 6. Logic operator 7. Ultra-low temperature pipeline 8. Folding

Detailed ways

The specific embodiments of the present utility model will be further described below in conjunction with the accompanying drawings:

As shown in Figure 1, Figure 2, Figure 4, Figure 5, a device for measuring the surface temperature of an ultra-low temperature pipeline using a pipe hoop structure according to the present invention includes a pipe hoop 1, a connecting bolt 2, a limit bolt 3, a temperature measuring device Block 4 and temperature measuring element 5; the pipe hoop 1 is fixed on the periphery of the ultra-low temperature pipeline 7 by connecting bolts 2, at least one temperature measuring block 4 is provided between the pipe hoop 1 and the ultra-low temperature pipeline 7, and the temperature measuring block 4 and the ultra-low temperature pipeline 7 The one side in contact is an arc surface 42, and the 2 sides that are in contact with the pipe hoop 1 are inclined surfaces 43 that are inclined to the outside and the center of the ultra-low temperature pipeline 7; the arc surface 42 has a radian that matches the outer surface of the ultra-low temperature pipeline 7; the temperature measuring block 4 A cavity 41 is opened on it for placing the temperature measuring element 5 .

As shown in Figure 1, Figure 2, Figure 3a, Figure 3b, the pipe hoop 1 is an annular pipe hoop 11, and the two ends of the annular pipe hoop 11 are respectively provided with connecting sections. 43 It is composed of a matching inclined section and a straight section for matching connection; the limit bolt 3 is set at the straight section close to the inclined section, and the connecting bolt 2 is set at the straight section away from the inclined section.

A hinge 8 is provided in the middle of the annular pipe hoop 11 .

As shown in Figure 4, Figure 5, Figure 6a, Figure 6b, the pipe hoop 1 is composed of two symmetrical semi-annular pipe hoop 12; The inclined section matched with the inclined surface of the temperature measuring block 4 and the straight section used for matching connection are composed of; the limit bolt 3 is set at the straight section close to the inclined section, and the connecting bolt 2 is set at the straight section away from the inclined section.

As shown in FIG. 2 , the temperature measuring element 5 is connected to a DC power supply through a power line, and is connected to a temperature display instrument or a control system through a signal line.

The pipe hoop 1 , the connecting bolts 2 , the limit bolts 3 and the temperature measuring block 4 are all made of low temperature resistant alloy steel.

As shown in FIG. 5 , the top surface and the bottom surface of the ultra-low temperature pipeline 7 are respectively provided with a temperature measuring block 4 , and the signal lines of the temperature measuring elements 5 in the two temperature measuring blocks 4 are respectively connected to the signal input ends of the logic operator 6 , the signal output end of the logic operator 6 is connected to an alarm or a control system.

As shown in FIGS. 7 a and 7 b , the cavity 41 in the temperature measuring block 4 is provided with an opening at one end corresponding to the axial direction of the ultra-low temperature pipeline 7 .

The temperature measuring element 5 is a thermocouple or a diode.

The following examples are implemented on the premise of the technical solutions of the present utility model, and provide detailed implementation manners and specific operation processes, but the protection scope of the present utility model is not limited to the following examples. The methods used in the following examples are conventional methods unless otherwise specified.

[Example 1]

In the present embodiment, the ultra-low temperature pipeline surface temperature measurement device using the pipe hoop structure includes an annular locking structure formed by an annular pipe hoop 11, a connecting bolt 2 and a limit bolt 3, which is used to constrain the movement of the temperature measuring block 4, One temperature measuring block 4 is provided, and the limit bolt 3 forces the temperature measuring block 4 to be fitted and fixed on the top of the outer surface of the ultra-low temperature pipeline 7. The connecting bolt 2 and the limit bolt 3 work together to connect and provide more safety constraints. Prevent the temperature measuring block 4 from falling off due to the failure of the annular pipe hoop 11 in the ultra-low temperature environment.

A hinge 8 is provided in the middle of the annular pipe hoop 11 to facilitate the opening, disassembly and movement of the annular pipe hoop 11 . The connecting ends on both sides of the annular pipe hoop 11 are respectively provided with four bolt holes for the limit bolts 3 and the connecting bolts 2 to pass through.

The temperature measuring block 4 is provided with a cavity 41 inside, and the temperature measuring element 5 is installed and fixed in the cavity 41 during application. The temperature measuring element 5 is connected with a power supply line and a signal line, and is used for sending out the obtained temperature signal for processing. Further, the external transmission of the temperature signal can be performed in a wired or wireless manner, that is, a temperature signal transmission manner in a wireless manner is also within the protection scope of the present invention.

The annular pipe hoop 11 , the connecting bolt 2 , the limit bolt 3 and the temperature measuring block 4 are all made of alloy steel with better low temperature performance. After the installation of the ultra-low temperature pipeline surface temperature measurement device is completed, relevant operations need to be carried out according to the thermal insulation requirements of the ultra-low temperature pipeline.

[Example 2]

In this embodiment, the ultra-low temperature pipeline surface temperature measuring device is used to measure the temperature of the upper and lower surfaces of the ultra-low temperature pipeline for pre-cooling. The shape locking structure is used to restrain the movement of the two temperature measuring blocks 4 arranged on the upper and lower surfaces of the ultra-low temperature pipeline 7. The limit bolts 3 force the temperature measuring blocks 4 to fit and fix on the outer surface side of the ultra-low temperature pipeline 7, and the connecting bolts 2 and the limit bolt 3 work together to connect, and provide more safety constraints to prevent the temperature measuring block 4 from falling off due to the failure of the annular pipe hoop 11 in the ultra-low temperature environment.

Each half-annular pipe hoop 12 is a group of two, and the opposite handles are combined together, which is convenient for opening, dismantling and moving, and also convenient for replacing the temperature measuring block 4 . The half-annular pipe hoop 12 is provided with four bolt holes at the connecting sections at both ends, for the connecting bolts 2 and the limit bolts 3 to pass through.

The temperature measuring block 4 is provided with a cavity 41 inside, and the temperature measuring element 5 is installed and fixed in the cavity 41 during temperature measurement. The temperature measuring element 5 is connected with a power supply line and a signal line, and during the temperature measuring process, the obtained temperature signal is sent to the logic operator 6 for processing. After receiving the temperature signals from the two temperature measuring elements 5, the logic operator 6 calculates the temperature difference between the upper and lower surfaces of the ultra-low temperature pipeline. When the difference is greater than the limit judgment value (5-10°C), an alarm signal is issued. The specific limit judgment value is related to the diameter of the ultra-low temperature pipeline 7. As the diameter of the ultra-low temperature pipeline 7 increases, this limit value also increases accordingly. Cold-operated cryogenic pipes will bend and fail due to the "banana effect".

After the logic operator 6 sends the alarm signal, the alarm mode can adopt different methods such as sound and photoelectricity, and the logic operator 6 can also select wired or wireless mode to send the alarm signal to the remote control room.

The semi-annular pipe hoop 12, the connecting bolts 2, the limit bolts 3 and the temperature measuring block 4 are all made of alloy steel with better low temperature performance. perform related operations.

The above description is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited to this. Equivalent replacement or modification of the new technical solution and its utility model concept shall be included within the protection scope of the present utility model.

Claims (9)

1. A measuring device for the surface temperature of an ultralow temperature pipeline adopting a pipe hoop structure is characterized by comprising a pipe hoop, a connecting bolt, a limiting bolt, a temperature measuring block and a temperature measuring element; the pipe hoop is fixed on the periphery of the ultralow-temperature pipeline through a connecting bolt, at least one temperature measuring block is arranged between the pipe hoop and the ultralow-temperature pipeline, one surface of the temperature measuring block, which is in contact with the ultralow-temperature pipeline, is an arc surface, and 2 side surfaces, which are in contact with the pipe hoop, are inclined planes which are inclined towards the outer side and the center of the ultralow-temperature pipeline; the cambered surface is provided with a radian matched with the outer surface of the ultralow-temperature pipeline; the temperature measuring block is provided with a cavity for placing a temperature measuring element.

2. The ultra-low temperature pipeline surface temperature measuring device adopting the pipe hoop structure as claimed in claim 1, wherein the pipe hoop is an annular pipe hoop, two ends of the annular pipe hoop are respectively provided with a connecting section, and the connecting section consists of an inclined section matched with the upper inclined surface of the temperature measuring block and a straight section for matching connection; the limiting bolt is arranged at the straight section close to the inclined section, and the connecting bolt is arranged at the straight section far away from the inclined section.

3. The ultra-low temperature pipeline surface temperature measuring device adopting the pipe clamp structure as claimed in claim 2, wherein the middle of the ring-shaped pipe clamp is provided with a hinge.

4. The ultra-low temperature pipeline surface temperature measuring device adopting the pipe clamp structure as claimed in claim 1, wherein the pipe clamp is composed of 2 symmetrical semi-annular pipe clamps; two ends of the semi-annular pipe hoop are respectively provided with a connecting section, and the connecting section consists of an inclined section matched with the inclined plane on the temperature measuring block and a straight section used for matching connection; the limiting bolt is arranged at the straight section close to the inclined section, and the connecting bolt is arranged at the straight section far away from the inclined section.

5. The ultra-low temperature pipeline surface temperature measuring device adopting the pipe hoop structure as claimed in claim 1, wherein the temperature measuring element is connected with a direct current power supply through a power line, and is connected with a temperature display instrument or a control system through a signal line.

6. The ultra-low temperature pipeline surface temperature measuring device adopting the pipe hoop structure as claimed in claim 1, wherein the pipe hoop, the connecting bolt, the limiting bolt and the temperature measuring block are all made of low temperature resistant alloy steel.

7. The ultra-low temperature pipeline surface temperature measuring device adopting the pipe hoop structure as claimed in claim 1, wherein 1 temperature measuring block is respectively arranged on the top surface and the bottom surface of the ultra-low temperature pipeline, the signal lines of the temperature measuring elements in 2 temperature measuring blocks are respectively connected with the signal input end of the logic arithmetic unit, and the signal output end of the logic arithmetic unit is connected with an alarm or a control system.

8. The ultra-low-temperature pipeline surface temperature measuring device adopting the pipe hoop structure as claimed in claim 1, wherein the cavity in the temperature measuring block is provided with an opening at one end corresponding to the axial direction of the ultra-low-temperature pipeline.

9. The ultra-low temperature pipeline surface temperature measuring device adopting the pipe clamp structure as claimed in claim 1, 5 or 7, wherein the temperature measuring element is a thermocouple or a diode.

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