CN219608637U - Liquid Nitrogen Loading System - Google Patents

Abstract

The utility model discloses a liquid nitrogen loading system, which comprises a support, a liquid nitrogen tank, a piston rod and an electric cylinder. The support includes a base, an electric cylinder mounting seat located above the base, and a column connecting the base and the electric cylinder mounting seat. The liquid nitrogen tank is installed on the base, a nitrogen injection port is provided on the top of the liquid nitrogen tank, a nitrogen discharge port is provided at the bottom, a nitrogen discharge valve is installed on the nitrogen discharge port, and the electric cylinder is installed on the electric cylinder mounting seat , the piston rod is installed on the output end of the electric cylinder, and the end of the piston rod can extend into the liquid nitrogen tank from the nitrogen injection port, and a multi-stage sealing structure is provided at the end of the piston rod, and the sealing structure includes An annular groove on the outer wall of the piston rod and a sealing ring installed in the annular groove. The liquid nitrogen tank adopts a double-layer structure, which improves the heat preservation effect of the liquid nitrogen. The piston rod driven by the electric cylinder can load the liquid nitrogen to a specified pressure, and has a high delivery efficiency to meet the requirements of the ultra-low temperature fracturing simulation test.

Description

Liquid Nitrogen Loading System

technical field

The utility model relates to the technical field of liquid nitrogen loading, in particular to a liquid nitrogen loading system, which is used for loading liquid nitrogen in liquid nitrogen fracturing simulation tests.

Background technique

In the field of petroleum, fracturing refers to a method that uses hydraulic action to form cracks in oil and gas layers during the process of oil or gas recovery, also known as hydraulic fracturing. In recent years, with the increasing demand for fracturing in unconventional reservoirs, liquid nitrogen fracturing technology has become a research hotspot at home and abroad. During the liquid nitrogen fracturing test, the liquid nitrogen is first stored in a certain container, then ballasted to about 70MPa, and finally transported to the rock for the test. At present, the existing liquid nitrogen loading system has poor insulation effect on liquid nitrogen, and liquid nitrogen is easy to vaporize, so it cannot be loaded to the specified pressure. For this, it is necessary to improve the prior art.

Utility model content

In view of the deficiencies of the above-mentioned prior art, the purpose of this utility model is to provide a liquid nitrogen loading system, which ensures that liquid nitrogen has a better heat preservation effect, can load liquid nitrogen to a specified pressure and has a higher delivery efficiency, so as to meet the needs of ultra-low temperature Fracturing simulation test requirements.

For realizing above-mentioned object, the technical solution that the utility model adopts is:

The liquid nitrogen loading system includes a bracket, a liquid nitrogen tank, a piston rod and an electric cylinder. The bracket includes a base, an electric cylinder mount above the base, and a column connecting the base and the electric cylinder mount. The liquid nitrogen tank is installed on On the base, a nitrogen injection port is provided on the top of the liquid nitrogen tank, a nitrogen discharge port is provided at the bottom, a nitrogen discharge valve is installed on the nitrogen discharge port, the electric cylinder is installed on the electric cylinder mounting seat, and the piston rod is installed on the The output end of the electric cylinder, and the end of the piston rod can extend into the liquid nitrogen tank from the nitrogen injection port, and a multi-stage sealing structure is provided at the end of the piston rod. Groove and sealing ring installed in the annular groove.

Preferably, the system also includes a pressure sensor, a pressure measuring port is provided at the bottom of the liquid nitrogen tank, the pressure sensor is installed at the bottom of the liquid nitrogen tank, and the detection end of the pressure sensor extends into the liquid nitrogen tank through the pressure measuring port internal.

Preferably, the liquid nitrogen tank includes an inner tank and an outer shell, a cavity is formed between the inner tank and the outer shell, an air extraction port is provided on the side wall of the outer shell, the air extraction port communicates with the cavity, and an air extraction port is installed on the air extraction port. valve.

Preferably, the system further includes a vacuum pump, which is detachably connected to the air valve.

Preferably, a limit plate is provided between the base and the electric cylinder installation seat, and a guide bearing is installed on the limit plate, and the piston rod passes through the guide bearing and can slide up and down along the guide bearing.

Compared with the prior art, the utility model has the beneficial effects:

The utility model relates to a liquid nitrogen loading system. The liquid nitrogen tank adopts a double-layer structure, which improves the heat preservation effect of the liquid nitrogen. The piston rod driven by the electric cylinder can load the liquid nitrogen to a specified pressure, and at the same time, it has a high delivery efficiency. To meet the requirements of ultra-low temperature fracturing simulation test. In addition, the system has simple structure, convenient use and high practicability.

Description of drawings

In order to illustrate the technical solution of the utility model more clearly, the accompanying drawings used in the implementation will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some implementations of the utility model. Ordinary technicians can also obtain other drawings based on these drawings on the premise of not paying creative work.

Fig. 1 is a schematic diagram of the overall structure of the utility model.

Fig. 2 is a schematic diagram of the sealing structure of the piston rod of the present invention.

In the figure: 1. Liquid nitrogen tank; 2. Piston rod; 3. Electric cylinder; 4. Pressure sensor; 5. Base; 6. Column; 7. Limiting plate; 8. Electric cylinder mounting seat; 9. Nitrogen injection port ; 10, air extraction port; 11, annular groove.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention.

In addition, in the description of the present utility model, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installation", "connection", "connection" and "fixation" should be understood in a broad sense, for example, it can be a fixed The connection can also be a detachable connection or an integral connection; it can be a mechanical connection; it can be a direct connection or an indirect connection through an intermediary, and it can be an internal communication between two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present utility model in specific situations.

As shown in Figure 1, a preferred embodiment of the present utility model provides a liquid nitrogen loading system, including: a bracket, a liquid nitrogen tank 1, a piston rod 2, an electric cylinder 3, a pressure sensor 4 and a vacuum pump (not shown in the figure out).

Among them, the bracket is made of metal material, including base 5, column 6, limit plate 7 and electric cylinder mounting seat 8, electric cylinder mounting seat 8 is located above the base 5, and the base 5 and electric cylinder mounting seat 8 are fixed by column 6 Connection, specifically, there are four columns 6 arranged in a square shape. The limiting plate 7 is fixedly installed on the four columns 6, and the limiting plate 7 is located in the middle of the base 5 and the electric cylinder mounting base 8, and a guide bearing is fixedly installed in the center of the limiting plate 7.

The liquid nitrogen tank 1 is used to store liquid nitrogen, and the liquid nitrogen tank 1 is fixedly installed on the base 5 . The top of the liquid nitrogen tank 1 is provided with a nitrogen injection port 9 , and liquid nitrogen is injected into the liquid nitrogen tank 1 through the nitrogen injection port 9 . A nitrogen unloading port is provided at the bottom of the liquid nitrogen tank 1, and a nitrogen unloading valve is installed on the nitrogen unloading port. The nitrogen unloading valve is connected with a nitrogen pipeline, and the liquid nitrogen is transported to the test rock through the nitrogen pipeline. There is also a side pressure port at the bottom of the liquid nitrogen tank 1, the pressure sensor 4 is installed at the bottom of the liquid nitrogen tank 1, and the detection end of the pressure sensor 4 extends into the inside of the liquid nitrogen tank 1 through the pressure measuring port for real-time detection The pressure value in the liquid nitrogen tank 1.

In order to improve the heat preservation effect of the liquid nitrogen tank 1 on liquid nitrogen, the liquid nitrogen tank 1 adopts a double-layer structure, specifically, it includes an inner tank and an outer shell, a cavity is formed between the inner tank and the outer shell, and a pump is provided on the side wall of the outer shell. Air port 10, the air extraction port 10 is communicated with the cavity, and an air extraction valve is installed on the air extraction port 10. The pumping end of the vacuum pump is detachably connected to the pumping valve, and the cavity in the liquid nitrogen tank 1 can be vacuumed through the vacuum pump, thereby improving the heat preservation effect of the liquid nitrogen tank 1 .

The electric cylinder 3 is fixedly installed on the electric cylinder mounting seat 8, and the output end of the electric cylinder 3 is set downward through the electric cylinder mounting seat 8. It should be noted that the electric cylinder 3 is a prior art, and its working principle refers to the prior art , which will not be repeated here.

The piston rod 2 is fixedly installed on the output end of the electric cylinder 3, and the piston rod 2 passes through the guide bearing. Driven by the electric cylinder 3, the piston rod 2 can slide up and down along the guide bearing, and the end of the piston rod 2 can slide from the injection The nitrogen port 9 extends into the liquid nitrogen tank 1 inside.

As shown in FIG. 2 , a multi-stage sealing structure is provided at the end of the piston rod 2 to ensure that the liquid nitrogen will not overflow from the nitrogen injection port 9 when the piston rod 2 is ballasting liquid nitrogen downward. The utility model is provided with a two-stage sealing structure. Specifically, the sealing structure includes an annular groove 11 arranged on the outer wall of the piston rod 2 and a sealing ring (not shown) installed in the annular groove 11. The piston rod 2 During the up and down movement of the inside of the liquid nitrogen tank 1, the sealing ring is in close contact with the inner wall of the liquid nitrogen tank 1, thereby realizing the effect of sealing.

The use process of the present utility model is described:

First connect the vacuum pump to the exhaust valve, open the exhaust valve, start the vacuum pump for vacuuming, close the exhaust valve after the vacuum is completed, and then turn off the vacuum pump.

Pour liquid nitrogen into the liquid nitrogen tank 1 from the nitrogen injection port 9, then quickly start the electric cylinder 3, and drive the piston rod 2 to move downward to load the liquid nitrogen. The pressure value of the liquid nitrogen in the liquid nitrogen tank 1 is observed through the pressure sensor 4, and when it is loaded to a specified pressure, such as 70MPa, the nitrogen unloading valve is opened to transport the liquid nitrogen to the test rock.

In summary, in the liquid nitrogen loading system described in the embodiment of the utility model, the liquid nitrogen tank adopts a double-layer structure, which improves the heat preservation effect of the liquid nitrogen, and the piston rod driven by the electric cylinder can load the liquid nitrogen to a specified pressure. At the same time, it has high delivery efficiency to meet the requirements of ultra-low temperature fracturing simulation tests. In addition, the system has simple structure, convenient use and high practicability.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present utility model, and are not intended to limit it; although the utility model has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: It is still possible to modify the technical solutions recorded in the foregoing embodiments, or to perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit of the technical solutions of the various embodiments of the present utility model. and range.

Claims (5)

1. The liquid nitrogen loading system is characterized by comprising a support, a liquid nitrogen tank, a piston rod and an electric cylinder, wherein the support comprises a base, an electric cylinder mounting seat arranged above the base and an upright post connected with the base and the electric cylinder mounting seat, the liquid nitrogen tank is mounted on the base, a nitrogen injection port is arranged at the top of the liquid nitrogen tank, a nitrogen discharge port is arranged at the bottom of the liquid nitrogen tank, a nitrogen discharge valve is mounted on the nitrogen discharge port, the electric cylinder is mounted on the electric cylinder mounting seat, the piston rod is mounted at the output end of the electric cylinder, the end part of the piston rod can extend into the liquid nitrogen tank from the nitrogen injection port, a multistage sealing structure is arranged at the end part of the piston rod, and the sealing structure comprises an annular groove formed in the outer wall of the piston rod and a sealing ring mounted in the annular groove.

2. The liquid nitrogen loading system according to claim 1, further comprising a pressure sensor, wherein a pressure measuring port is provided at the bottom of the liquid nitrogen tank, the pressure sensor is installed at the bottom of the liquid nitrogen tank, and a detection end of the pressure sensor extends into the liquid nitrogen tank through the pressure measuring port.

3. The liquid nitrogen loading system of claim 1, wherein the liquid nitrogen tank comprises a liner and a shell, a cavity is formed between the liner and the shell, an extraction opening is formed in the side wall of the shell, the extraction opening is communicated with the cavity, and an extraction valve is installed on the extraction opening.

4. A liquid nitrogen loading system according to claim 3 further comprising a vacuum pump detachably connected to the suction valve.

5. The liquid nitrogen loading system according to claim 1, wherein a limiting plate is arranged between the base and the electric cylinder mounting seat, a guide bearing is mounted on the limiting plate, and the piston rod penetrates through the guide bearing and can slide up and down along the guide bearing.