A carbon dioxide pump and its application method

Abstract

The present invention relates to the technical field of booster pumps, and proposes a carbon dioxide pump and an application method thereof, including a pump head, a piston cylinder, a piston head, a piston rod and a control valve, wherein the pump head is provided with a liquid inlet hole and a liquid discharge hole; the piston cylinder is sealed and fixed in the pump head, and its outer wall and the pump head are enclosed to form a low-temperature cavity; the piston head is sealed and slides in the piston cylinder; the piston rod is fixedly arranged at one end of the piston head away from the liquid inlet hole; the control valve includes a temperature control valve, a pressure valve and a one-way valve, and the low-temperature cavity is connected to the liquid inlet hole through the temperature control valve, and is connected to the liquid discharge hole through the pressure valve. The present invention can make the carbon dioxide pump adapt to the pressurized delivery of carbon dioxide in different forms by setting a low-temperature cavity, setting a temperature control valve between the low-temperature cavity and the liquid inlet hole, and setting a pressure valve between the low-temperature cavity and the liquid discharge hole, thereby improving the convenience of carbon dioxide delivery.

Description

Technical Field

[0001] The present invention relates to the technical field of booster pumps, and in particular to a carbon dioxide pump and an application method thereof. Background Art

[0002] A carbon dioxide pump is a carbon dioxide booster pump. In the oil field, a carbon dioxide pump is used to inject carbon dioxide into the oil layer of an oil well to displace crude oil. This can not only significantly increase the oil recovery rate of the oil field, but also store carbon dioxide underground, which is beneficial to environmental protection.

[0003] The invention patent with the publication number CN108757367A discloses a reciprocating booster pump, including a pump head, a plunger or piston assembly, a stuffing box assembly or a cylinder sleeve assembly, the pump head is provided with a suction port and a discharge port, a working chamber is provided in the pump head, the plunger or the piston assembly includes an intermediate section, a driving section and a working section, the working section is arranged corresponding to the working chamber, a balance chamber is provided between the stuffing box assembly or the cylinder sleeve assembly, the driving section and the intermediate section, and a connecting channel is provided between the suction port and the balance chamber; the difference between the area of ​​the radial cross section of the intermediate section and the area of ​​the radial cross section of the driving section is equal to the area of ​​the radial cross section of the working section. In this way, no matter how the suction port pressure, the discharge port pressure and the flow rate change, the liquid pressure on the plunger or piston assembly is in a balanced state, effectively avoiding equipment damage and power loss caused by the unbalanced liquid pressure of the working medium, and having good versatility.

[0004] In the above technical solution, a plunger or piston assembly is provided for pressurized transportation of carbon dioxide. However, depending on the working conditions, low-temperature liquid carbon dioxide or room-temperature supercritical carbon dioxide needs to be injected into the oil well. When injecting low-temperature liquid carbon dioxide, although the injection pressure of carbon dioxide is relatively small, it is easily vaporized by heat. When injecting room-temperature supercritical carbon dioxide, although there is no need to consider the problem of vaporization of carbon dioxide by heat, the injection pressure of carbon dioxide is relatively large, which will cause a greater burden on the plunger or piston assembly. Therefore, when pressurized transportation of carbon dioxide, different types of carbon dioxide pumps need to be selected according to the transportation form of carbon dioxide, which makes the transportation operation more inconvenient. Summary of the invention

[0005] In view of this, the present invention proposes a carbon dioxide pump and an application method thereof, which can be adapted to the pressurized delivery of low-temperature liquid carbon dioxide and room-temperature supercritical carbon dioxide, thereby improving the convenience of carbon dioxide delivery.

[0006] The technical solution of the present invention is implemented as follows: On the one hand, the present invention provides a carbon dioxide pump, including a pump head, a piston cylinder, a piston head, a piston rod and a control valve, wherein:

[0007] The pump head is provided with a liquid inlet hole and a liquid discharge hole;

[0008] The piston cylinder is sealed and fixed in the pump head, and its outer wall and the pump head enclose a low-temperature cavity, one end of the piston cylinder is connected to the liquid inlet hole and the liquid discharge hole, and the other end is connected to the low-temperature cavity;

[0009] The piston head seals and slides in the piston cylinder;

[0010] The piston rod is fixedly arranged at one end of the piston head away from the liquid inlet hole and is sealed and slidable with the pump head, and the piston rod is spaced apart from the inner wall of the piston cylinder;

[0011] The control valve includes a temperature control valve, a pressure valve and a one-way valve. The low-temperature chamber is connected to the liquid inlet hole through the temperature control valve and is connected to the liquid discharge hole through the pressure valve. The one-way valve is fixedly arranged in the liquid inlet hole and the liquid discharge hole respectively.

[0012] On the basis of the above technical solution, preferably, a balancing hole is opened on the pump head, the liquid inlet hole, the liquid discharge hole and the balancing hole all pass through the pump head, the balancing hole is connected with the low-temperature chamber, and one end of the balancing hole is connected with one end of the liquid inlet hole through the temperature control valve, and the other end of the balancing hole is connected with one end of the liquid discharge hole through the pressure valve.

[0013] More preferably, it also includes a rubber cone and a retaining spring, wherein:

[0014] The rubber cone is arranged in the low temperature cavity and sleeved on the outside of the piston cylinder. The outer diameter of the end of the rubber cone away from the liquid inlet hole is larger than the outer diameter of the end close to the liquid inlet hole. The end of the balance hole connected to the low temperature cavity is located in the middle of the rubber cone.

[0015] The clamping spring is disposed in the rubber cone at one end away from the liquid inlet hole, and a part of the rubber cone is fixedly pressed against the inner wall of the low-temperature chamber through the clamping spring.

[0016] More preferably, a plurality of annular grooves and a plurality of strip grooves are provided on the circumferential side of the piston cylinder, wherein:

[0017] The annular groove is a dovetail groove in an annular shape, and a plurality of the annular grooves are evenly distributed along the axial direction of the piston cylinder, and one end of the rubber cone cylinder close to the liquid inlet hole is located in one of the annular grooves;

[0018] The strip grooves are long dovetail grooves, and a plurality of the strip grooves are evenly distributed along the circumference of the piston cylinder.

[0019] On the basis of the above technical solution, preferably, the pump head includes a pump body, a blocking plate, a sealing member and a limiting member, wherein:

[0020] The pump body is provided with a mounting hole, the piston cylinder seal slides in the mounting hole, and the liquid inlet hole, the liquid discharge hole and the low temperature chamber are all connected with the mounting hole;

[0021] The blocking plate is fixedly arranged on the pump body by bolts and blocks one end of the mounting hole. The one-way valve in the liquid inlet hole is abutted and arranged between the piston cylinder and the blocking plate.

[0022] The sealing member is fixedly mounted on the pump body by bolts and blocks the other end of the mounting hole, and the piston rod seal slides inside the sealing member;

[0023] The limiting member is disposed between the sealing member and the piston cylinder and is clamped with the two, and the limiting member is slidably connected with the piston rod.

[0024] More preferably, a first through hole and a second through hole are respectively formed at both ends of the circumference of the piston cylinder, wherein:

[0025] The first through hole is connected to the liquid inlet hole and the liquid discharge hole;

[0026] The second through hole is connected to the low temperature chamber and the interior of the piston cylinder, and the piston head is located between the first through hole and the second through hole;

[0027] The limiting member includes a limiting ring, a clamping column and a sliding block, wherein:

[0028] The limiting ring is fixed between the sealing member and the piston cylinder;

[0029] The clamping columns are fixedly arranged on both sides of the limiting ring, and the sealing member and the piston cylinder are both provided with clamping grooves, and the clamping columns are clamped in the clamping grooves and correspond to them one by one;

[0030] The sliding block is fixedly arranged in the limiting ring, a sliding groove is provided on the peripheral side of the piston rod, and the sliding block is slidably arranged in the sliding groove.

[0031] More preferably, two rubber cones and two clamping springs are provided along the axial direction of the piston cylinder, and correspond to each other one by one, and one end of the balancing hole communicating with the low-temperature chamber is located at the middle position of the rubber cone close to the liquid inlet hole;

[0032] The clamping spring close to the liquid inlet hole is located at the bottom side of the rubber cone tube, and the clamping spring away from the liquid inlet hole is located at the top side of the rubber cone tube.

[0033] More preferably, the interior of the piston cylinder is thick at both ends and thin in the middle, and the inner diameters of the positions where the first through hole and the second through hole are arranged on the piston cylinder are larger than the inner diameter at the middle position of the piston cylinder.

[0034] More preferably, the mounting hole, the blocking plate, the sealing member, the limiting member, the piston cylinder, the piston head, the piston rod and the control valve are provided in plurality and correspond to each other one by one.

[0035] In a second aspect, the present invention provides an application method of a carbon dioxide pump, using the above-mentioned carbon dioxide pump to inject carbon dioxide into an oil layer, comprising the following steps:

[0036] S1, connecting the liquid inlet hole to the gas injection port of the carbon dioxide transport tank truck, and connecting the liquid discharge hole to the gas pipeline extending into the oil field, wherein the carbon dioxide transport tank truck is loaded with low-temperature liquid carbon dioxide with a temperature of -25°C to -15°C and a pressure of 2MPa to 5MPa or room-temperature supercritical carbon dioxide with a temperature of 0°C to 35°C and a pressure of 6MPa to 9MPa;

[0037] S2, setting the conduction temperature of the temperature control valve to -10°C. When the temperature of the medium in the temperature control valve is lower than -10°C, the temperature control valve is conducted;

[0038] S3, setting the conduction pressure of the pressure valve to 6MPa, when the pressure of the medium in the pressure valve is higher than 6MPa, the pressure valve is conducted;

[0039] S4, connecting the piston rod to the driving device, and opening the gas injection port of the carbon dioxide transport tanker to inject carbon dioxide into the oil layer to displace the crude oil.

[0040] The carbon dioxide pump and its application method of the present invention have the following beneficial effects compared with the prior art:

[0041] (1) By providing a low-temperature chamber, a temperature control valve between the low-temperature chamber and the liquid inlet, and a pressure valve between the low-temperature chamber and the liquid discharge hole, the carbon dioxide pump can be adapted to pressurize and transport carbon dioxide in different forms, thereby improving the convenience of transporting carbon dioxide;

[0042] (2) By setting up a rubber cone and a retaining spring, the circulation capacity of the gas in the low-temperature chamber can be improved, and the cooling effect in the low-temperature chamber can be improved. By setting up annular grooves and strip grooves, not only can the cooling effect of the low-temperature chamber be improved, but the rubber cone can also be assisted in fixing to prevent it from being wrinkled due to the influence of medium flow. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 is a cross-sectional view of a carbon dioxide pump of the present invention;

[0045] Figure 2 A cross-sectional view of a pump body in a carbon dioxide pump of the present invention;

[0046] Figure 3 A three-dimensional diagram of a carbon dioxide pump of the present invention on one side of a piston rod;

[0047] Figure 4 A three-dimensional diagram of a carbon dioxide pump of the present invention on one side of a blocking plate;

[0048] Figure 5 A cross-sectional view of a liquid inlet hole in a carbon dioxide pump of the present invention;

[0049] Figure 6 A cross-sectional view of a discharge hole in a carbon dioxide pump of the present invention;

[0050] Figure 7 A cross-sectional view of a balance hole in a carbon dioxide pump of the present invention;

[0051] Figure 8 A cross-sectional view of a rubber cone in a carbon dioxide pump of the present invention;

[0052] Fig. 9 A three-dimensional diagram of a rubber cone and a retaining spring in a carbon dioxide pump of the present invention;

[0053] Fig.10 A three-dimensional diagram of a piston cylinder in a carbon dioxide pump of the present invention;

[0054] Fig.11 A cross-sectional view of a piston cylinder in a carbon dioxide pump of the present invention;

[0055] Fig.12 An exploded view of a limiter in a carbon dioxide pump of the present invention;

[0056] Fig.13 The present invention is a cross-sectional view of a plurality of mounting holes in a carbon dioxide pump.

[0057] Wherein: 1. Pump head; 11. Pump body; 12. Blocking plate; 13. Seal; 14. Limiting piece; 141. Limiting ring; 142. Clamping column; 143. Slider; 100. Mounting hole; 101. Liquid inlet hole; 102. Liquid discharge hole; 103. Low temperature chamber; 104. Balance hole; 2. Piston cylinder; 201. Ring groove; 202. Strip groove; 203. First through hole; 204. Second through hole; 205. Clamping groove; 3. Piston head; 4. Piston rod; 401. Slide groove; 5. Control valve; 51. Temperature control valve; 52. Pressure valve; 53. One-way valve; 6. Rubber cone; 7. Retaining spring. DETAILED DESCRIPTION

[0058] The following will be combined with the specific implementation of the present invention to clearly and completely describe the technical solution in the present invention. Obviously, the described implementation is only a part of the implementation of the present invention, not all of the implementation. Based on the implementation of the present invention, all other implementations obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0059] like Figure 1-Figure 13 As shown, a carbon dioxide pump of the present invention comprises a pump head 1, a piston cylinder 2, a piston head 3, a piston rod 4, a control valve 5, a rubber cone 6 and a retaining spring 7, and is used for pressurizing and delivering carbon dioxide.

[0060] Among them, the pump head 1 is the main structure of the carbon dioxide pump, which is used to carry other components. The pump head 1 is provided with a liquid inlet hole 101 and a liquid discharge hole 102. The liquid inlet hole 101 is used to be connected to a carbon dioxide supply device (such as a carbon dioxide tanker, etc.), and the liquid discharge hole 102 is used to be connected to a carbon dioxide receiving device (such as a pipeline extending into an oil well, etc.).

[0061] The piston cylinder 2 is used to provide a sealed environment for the piston head 3. The piston cylinder 2 is sealed and fixed in the pump head 1, and its outer wall and the pump head 1 enclose a low-temperature chamber 103; one end of the piston cylinder 2 is connected to the liquid inlet hole 101 and the liquid discharge hole 102, and the other end is connected to the low-temperature chamber 103.

[0062] The piston head 3 is used to pressurize the carbon dioxide. The piston head 3 slides in the piston cylinder 2 in a sealed manner, and the pressure of the carbon dioxide is changed by sliding in the piston cylinder 2.

[0063] In order to achieve the communication effect between the piston cylinder 2 and the liquid inlet hole 101, the liquid discharge hole 102 and the low temperature chamber 103, as shown in FIG. Figure 1 and Fig.11As shown, preferably, a first through hole 203 and a second through hole 204 are respectively opened at both ends of the circumference of the piston cylinder 2, and the first through hole 203 is connected to the liquid inlet hole 101 and the liquid discharge hole 102; the second through hole 204 is connected to the low-temperature chamber 103 and the interior of the piston cylinder 2, so that the piston head 3 is located between the first through hole 203 and the second through hole 204.

[0064] like Figure 1 and Fig.11 As shown, the interior of the piston cylinder 2 is thick at both ends and thin in the middle, and the inner diameters of the first through hole 203 and the second through hole 204 provided on the piston cylinder 2 are larger than the inner diameter of the middle position of the piston cylinder 2. In this case, even if the piston head 3 moves to the positions of the first through hole 203 and the second through hole 204, the first through hole 203 and the second through hole 204 will not be blocked, but the piston head 3 cannot leave the middle position in the piston cylinder 2.

[0065] The piston rod 4 is used to drive the piston head 3 and is connected to the driving device. The piston rod 4 is fixedly arranged at one end of the piston head 3 away from the liquid inlet hole 101, and is sealed and slidable with the pump head 1, and the piston rod 4 is spaced apart from the inner wall of the piston cylinder 2.

[0066] The control valve 5 is used to control the communication of each pipeline (liquid inlet hole 101, liquid discharge hole 102 and low temperature chamber 103), so that the carbon dioxide pump can adapt to different forms of carbon dioxide. The control valve 5 includes a temperature control valve 51, a pressure valve 52 and a one-way valve 53. The low temperature chamber 103 is connected to the liquid inlet hole 101 through the temperature control valve 51, and is connected to the liquid discharge hole 102 through the pressure valve 52. The one-way valve 53 is fixedly arranged in the liquid inlet hole 101 and the liquid discharge hole 102 respectively; the liquid inlet hole 101 and the liquid discharge hole 102 are connected to each other. 02 are connected through the piston cylinder 2, and the two one-way valves 53 are set so that the carbon dioxide in the pipeline can only flow from the liquid inlet hole 101 to the piston cylinder 2 and then to the liquid discharge hole 102, and the carbon dioxide cannot flow back. When the driving device (such as a cylinder, etc.) drives the piston rod 4 to move back and forth, it can drive the piston head 3 to move back and forth, thereby continuously pressurizing the carbon dioxide between the liquid inlet hole 101 and the liquid discharge hole 102, so as to achieve the pressurization effect of the carbon dioxide pump on the carbon dioxide.

[0067] Whether the temperature control valve 51 is turned on or not is affected by its turn-on temperature parameter. When the temperature of the carbon dioxide in the temperature control valve 51 is lower than its turn-on temperature, the temperature control valve 51 will be turned on, that is, the low-temperature chamber 103 and the liquid inlet 101 will be turned on; whether the pressure valve 52 is turned on or not is affected by its turn-on pressure parameter. When the pressure of the carbon dioxide in the pressure valve 52 is greater than its turn-on pressure, the pressure valve 52 will be turned on, that is, the low-temperature chamber 103 and the liquid discharge hole 102 will be connected. The structure and principle of the temperature control valve 51 and the pressure valve 52 are the existing technology; Figure 1As shown, when the carbon dioxide pump delivers cryogenic liquid carbon dioxide, its temperature and pressure are relatively low, so that the temperature control valve 51 is turned on, but the pressure valve 52 is not turned on, that is, the low temperature chamber 103 is turned on with the liquid inlet hole 101, but not with the liquid discharge hole 102. When the carbon dioxide enters the liquid inlet hole 101 from the supply device, the first path of carbon dioxide passes through the one-way valve 53 in the liquid inlet hole 101, the inside of the piston cylinder 2 and the one-way valve 53 in the liquid discharge hole 102 in sequence and enters the liquid discharge hole 102, and increases The second carbon dioxide passes through the temperature control valve 51 and enters the low temperature chamber 103 and the gap between the piston rod 4 and the piston cylinder 2, thereby cooling the piston cylinder 2, the piston head 3 and the piston rod 4, so as to avoid the heat generated during operation causing the first carbon dioxide to vaporize; when the carbon dioxide pump delivers room temperature supercritical carbon dioxide, its temperature and pressure are relatively high, so that the temperature control valve 51 is not turned on, but the pressure valve 52 is turned on, that is, the low temperature chamber 103 is not connected to the liquid inlet hole 1 01 is connected, and is connected with the discharge hole 102. When the carbon dioxide enters the liquid inlet hole 101 from the supply device, it passes through the one-way valve 53 in the liquid inlet hole 101, the inside of the piston cylinder 2 and the one-way valve 53 in the discharge hole 102 in turn to enter the discharge hole 102 and complete the pressurization effect. At this time, the first path of carbon dioxide is directly delivered to the receiving device, and the second path of carbon dioxide passes through the pressure valve 52 to enter the low-temperature chamber 103 and the gap between the piston rod 4 and the piston cylinder 2, thereby applying pressure to the end of the piston head 3 close to the piston rod 4 to offset part of the pressure on the end of the piston head 3 close to the liquid inlet hole 101, and avoid damage to the piston head 3 due to excessive pressure. In summary, the carbon dioxide pump can keep the carbon dioxide at a low temperature when transporting low-temperature liquid carbon dioxide, and can reduce the pressure burden on the piston head 3 when transporting supercritical carbon dioxide at room temperature, so that the carbon dioxide pump can be adapted to pressurized transportation of carbon dioxide in different forms, thereby improving the convenience of carbon dioxide transportation.

[0068] like Figure 3-Figure 7 As shown, in order to facilitate the connection between the low-temperature chamber 103 and the liquid inlet hole 101 and the liquid discharge hole 102, and to facilitate the installation of the temperature control valve 51 and the pressure valve 52, it is preferred to open a balancing hole 104 on the pump head 1, the liquid inlet hole 101, the liquid discharge hole 102 and the balancing hole 104 all pass through the pump head 1, the balancing hole 104 is connected to the low-temperature chamber 103, and one end of the balancing hole 104 is connected to one end of the liquid inlet hole 101 through the temperature control valve 51, and the other end of the balancing hole 104 is connected to one end of the liquid discharge hole 102 through the pressure valve 52, the end of the liquid inlet hole 101 that is not connected to the temperature control valve 51 is connected to the supply device, and the end of the liquid discharge hole 102 that is not connected to the pressure valve 52 is connected to the receiving device.

[0069] The rubber cone cylinder 6 is used to improve the cooling effect of the low-temperature chamber 103. The rubber cone cylinder 6 is arranged in the low-temperature chamber 103 and is sleeved on the outside of the piston cylinder 2. The outer diameter of the rubber cone cylinder 6 away from the liquid inlet hole 101 is larger than the outer diameter of the end close to the liquid inlet hole 101, and the end of the balance hole 104 connected to the low-temperature chamber 103 is located in the middle position of the rubber cone cylinder 6; the rubber cone cylinder 6 is made of rubber material and can undergo elastic deformation when under pressure.

[0070] The retaining spring 7 is used to fix the rubber cone 6. Fig. 9 As shown, the clamp spring 7 is an arc-shaped elastic structure, not a circular structure. The clamp spring 7 is arranged in the rubber cone 6 at one end away from the liquid inlet hole 101, and a part of the rubber cone 6 is fixed against the inner wall of the low-temperature cavity 103 by the clamp spring 7. The clamp spring 7 does not completely seal the rubber cone 6 and the inner wall of the low-temperature cavity 103, but allows a part of the rubber cone 6 to be connected to the low-temperature cavity 103 without sealing; as shown in FIG. Figure 8 As shown, when the cryogenic liquid carbon dioxide in the balance hole 104 flows into the cryogenic chamber 103, it is guided by the rubber cone 6 to flow to the right first, filling the right side of the cryogenic chamber 103, and then flows to the left side of the cryogenic chamber 103 along the position where the rubber cone 6 and the cryogenic chamber 103 are not fixed by the retaining spring 7, and enters the gap between the piston rod 4 and the piston cylinder 2, cooling the piston rod 4, the piston head 3 and the piston cylinder 2. When the piston head 3 moves to the left, part of the carbon dioxide in the gap between the piston rod 4 and the piston cylinder 2 will return to the balance hole 104 along the original path and be transported to the drain hole 102. When the piston head 3 moves to the right, the newly input carbon dioxide enters the cryogenic chamber 103 and the gap between the piston rod 4 and the piston cylinder 2 to realize the circulation of carbon dioxide and enhance its cooling effect. During this period, the setting of the rubber cone 6 allows the carbon dioxide to fully flow through the cryogenic chamber 103, thereby enhancing its cooling effect. Figure 8 As shown, in order to allow the cryogenic liquid carbon dioxide to fill the cryogenic chamber 103, a storage chamber is preferably opened at the top of the cryogenic chamber 103, so that the original gas inside the cryogenic chamber 103 can be compressed into this storage chamber, thereby further improving the cooling effect inside the cryogenic chamber 103; of course, in order to improve the fixing firmness of the retaining spring 7, a corresponding fixing groove can be set on the inner wall of the cryogenic chamber 103.

[0071] like Figure 8As shown, two rubber cones 6 and retaining springs 7 are arranged along the axial direction of the piston cylinder 2, and correspond one to one, and the end of the balancing hole 104 connected to the low-temperature cavity 103 is located in the middle position of the rubber cone 6 close to the liquid inlet hole 101; the retaining spring 7 close to the liquid inlet hole 101 is located at the bottom side of the rubber cone 6, and the retaining spring 7 away from the liquid inlet hole 101 is located at the top side of the rubber cone 6, so that carbon dioxide can flow through the low-temperature cavity 103 in an S-shaped path, increasing the path length of carbon dioxide in the low-temperature cavity 103, and increasing the contact area between carbon dioxide and various components in the low-temperature cavity 103. At the same time, multiple rubber cones 6 also form a fin-like structure, which helps to accelerate the heat dissipation of the piston cylinder 2, thereby further improving the cooling effect in the low-temperature cavity 103.

[0072] In order to increase the contact area between the carbon dioxide and the piston cylinder 2 and improve the cooling effect in the low temperature chamber 103, a plurality of annular grooves 201 and a plurality of strip grooves 202 may be provided on the circumference of the piston cylinder 2; Figure 8 , Fig.10 and Fig.11 As shown, the annular groove 201 is a circular dovetail groove, and multiple annular grooves 201 are evenly distributed along the axial direction of the piston cylinder 2, and one end of the rubber cone 6 close to the liquid inlet hole 101 is located in one of the annular grooves 201, but the two are not sealed and connected; the strip groove 202 is a long strip dovetail groove, and multiple strip grooves 202 are evenly distributed along the circumference of the piston cylinder 2; the arrangement of the annular grooves 201 and the strip grooves 202 allows the surface of the piston cylinder 2 to form multiple inverted quadrangular pyramid-shaped structures, which have a larger surface area and are more suitable for heat dissipation. At the same time, the corners of the inverted quadrangular pyramid-shaped structures are all pointed, which can produce a certain degree of fixing effect with the inner wall of the rubber cone cylinder 6, thereby preventing the flow of carbon dioxide in the low-temperature chamber 103 from causing wrinkles in the rubber cone cylinder 6.

[0073] The pump head 1 includes a pump body 11, a blocking plate 12, a sealing member 13 and a limiting member 14. Figure 2 As shown, a mounting hole 100 is penetrated through the pump body 11, the piston cylinder 2 is sealed and slid in the mounting hole 100, and the liquid inlet hole 101, the liquid discharge hole 102 and the low-temperature chamber 103 are all connected with the mounting hole 100; the blocking plate 12 is fixedly arranged on the pump body 11 by bolts, and blocks one end of the mounting hole 100, and the one-way valve 53 in the liquid inlet hole 101 is abutted and set between the piston cylinder 2 and the blocking plate 12; the sealing member 13 is fixedly arranged on the pump body 11 by bolts, and blocks the other end of the mounting hole 100, the piston rod 4 is sealed and slid in the sealing member 13, and the piston rod 4 passes through the sealing member 13; the limiting member 14 is abutted and set between the sealing member 13 and the piston cylinder 2, and is clamped with the two, and the limiting member 14 is slidably connected with the piston rod 4, and the setting of the mounting hole 100 facilitates the assembly of various components in the device.

[0074] like Figure 8 , Fig.10 and Fig.12 As shown, the limiting member 14 includes a limiting ring 141, a clamping column 142 and a slider 143. The limiting ring 141 is fixed between the sealing member 13 and the piston cylinder 2; the clamping column 142 is fixedly arranged on both sides of the limiting ring 141, and a clamping groove 205 is provided on the sealing member 13 and the piston cylinder 2. The clamping column 142 is clamped in the clamping groove 205 and corresponds to it one by one; the slider 143 is fixedly arranged in the limiting ring 141, and a sliding groove 401 is provided on the peripheral side of the piston rod 4, and the slider 143 is slidably arranged in the sliding groove 401 ; The setting of the slide groove 401 can increase the contact area between the piston rod 4 and the carbon dioxide, thereby improving its heat dissipation effect. The setting of the clamping column 142 and the slider 143 can prevent the piston rod 4 and the piston cylinder 2 from rotating during operation, thereby ensuring the normal operation of the device; at the same time, when assembling the device, the rotation of the limit member 14 can drive the piston cylinder 2 to rotate, thereby facilitating the alignment of various hole positions; in order to reduce the air pressure resistance, it is preferred to set the slider 143 to a wedge-shaped structure.

[0075] like Fig.13 As shown, there are multiple mounting holes 100, plugging plates 12, sealing members 13, limit members 14, piston cylinders 2, piston heads 3, piston rods 4 and control valves 5, and they correspond one to one, that is, the device is provided with multiple boosting stations, and multiple carbon dioxide receiving devices can be connected at the same time; and when the carbon dioxide pump is connected to a carbon dioxide receiving device, the boosting range and boosting effect of the carbon dioxide pump can be increased by controlling the three piston rods 4. Of course, only one of the boosting stations can be used, and the other two boosting stations can be blocked.

[0076] The application method of a carbon dioxide pump of the present invention is used to inject carbon dioxide into an oil layer, comprising the following steps:

[0077] S1, connect the liquid inlet 101 to the gas injection port of the carbon dioxide transport tanker, and connect the liquid discharge hole 102 to the gas pipeline extending into the oil field;

[0078] S2, setting the conduction temperature of the temperature control valve 51 to -10°C. When the temperature of the medium in the temperature control valve 51 is lower than -10°C, the temperature control valve 51 is conducted;

[0079] S3, setting the conduction pressure of the pressure valve 52 to 6 MPa. When the pressure of the medium in the pressure valve 52 is higher than 6 MPa, the pressure valve 52 is conducted;

[0080] S4, connecting the piston rod 4 to the driving device, and opening the gas injection port of the carbon dioxide transport tank truck to inject carbon dioxide into the oil layer to displace the crude oil.

[0081] When the carbon dioxide transport tank truck is loaded with cryogenic liquid carbon dioxide (temperature of -25°C to -15°C, pressure of 2MPa to 5MPa), the temperature control valve 51 is turned on and the pressure valve 52 is turned off, so that part of the input low-temperature carbon dioxide can enter the low-temperature chamber 103 to cool the piston cylinder 2, the piston head 3 and the piston rod 4 to avoid the vaporization of the pressurized carbon dioxide; when the carbon dioxide transport tank truck is loaded with room temperature supercritical carbon dioxide (temperature of 0°C to 35°C, pressure of 6MPa to 9MPa), the temperature control valve 51 is turned off and the pressure valve 52 is turned on, so that part of the output high-pressure carbon dioxide can enter the gap between the piston rod 4 and the piston cylinder 2 to offset part of the pressure on the piston head 3, so as to reduce the burden on the piston head 3, thereby achieving a certain energy-saving effect.

[0082] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A carbon dioxide pump, characterized in that: It comprises a pump head (1), a piston cylinder (2), a piston head (3), a piston rod (4) and a control valve (5), wherein: The pump head (1) is provided with a liquid inlet hole (101) and a liquid discharge hole (102); The piston cylinder (2) is sealed and fixed in the pump head (1), and its outer wall and the pump head (1) enclose a low-temperature chamber (103); one end of the piston cylinder (2) is connected to the liquid inlet hole (101) and the liquid discharge hole (102), and the other end is connected to the low-temperature chamber (103); The piston head (3) slides in a sealing manner in the piston cylinder (2); The piston rod (4) is fixedly arranged at one end of the piston head (3) away from the liquid inlet hole (101), and is sealed and slidable with the pump head (1), and the piston rod (4) is spaced apart from the inner wall of the piston cylinder (2); The control valve (5) comprises a temperature control valve (51), a pressure valve (52) and a one-way valve (53); the low-temperature chamber (103) is connected to the liquid inlet hole (101) through the temperature control valve (51), and is connected to the liquid discharge hole (102) through the pressure valve (52); and the one-way valve (53) is fixedly arranged in the liquid inlet hole (101) and the liquid discharge hole (102), respectively; The pump head (1) is provided with a balancing hole (104); the liquid inlet hole (101), the liquid discharge hole (102) and the balancing hole (104) all penetrate the pump head (1); the balancing hole (104) is connected to the low-temperature chamber (103); one end of the balancing hole (104) is connected to one end of the liquid inlet hole (101) via the temperature control valve (51); and the other end of the balancing hole (104) is connected to one end of the liquid discharge hole (102) via the pressure valve (52); It also includes a rubber cone (6) and a retaining spring (7), wherein: The rubber cone cylinder (6) is arranged in the low-temperature chamber (103) and is sleeved on the outside of the piston cylinder (2); the outer diameter of the end of the rubber cone cylinder (6) away from the liquid inlet hole (101) is larger than the outer diameter of the end close to the liquid inlet hole (101); and the end of the balancing hole (104) connected to the low-temperature chamber (103) is located in the middle of the rubber cone cylinder (6); The clamping spring (7) is disposed in abutment against an end of the rubber cone cylinder (6) away from the liquid inlet hole (101), and a part of the rubber cone cylinder (6) is fixedly abutted against the inner wall of the low-temperature chamber (103) via the clamping spring (7).

2. A carbon dioxide pump according to claim 1, characterized in that: A plurality of annular grooves (201) and a plurality of strip grooves (202) are provided on the circumferential side of the piston cylinder (2), wherein: The annular groove (201) is a dovetail groove in the shape of a circular ring, and a plurality of the annular grooves (201) are evenly distributed along the axial direction of the piston cylinder (2), and one end of the rubber cone cylinder (6) close to the liquid inlet hole (101) is located in one of the annular grooves (201); The strip groove (202) is a long strip dovetail groove, and a plurality of the strip grooves (202) are evenly distributed along the circumference of the piston cylinder (2).

3. A carbon dioxide pump according to claim 1, characterized in that: The pump head (1) comprises a pump body (11), a blocking plate (12), a sealing member (13) and a limiting member (14), wherein: The pump body (11) is provided with a mounting hole (100) extending therethrough, the piston cylinder (2) sealingly slides in the mounting hole (100), and the liquid inlet hole (101), the liquid discharge hole (102) and the low-temperature chamber (103) are all in communication with the mounting hole (100); The blocking plate (12) is fixedly mounted on the pump body (11) by means of bolts and blocks one end of the mounting hole (100); the one-way valve (53) in the liquid inlet hole (101) is disposed between the piston cylinder (2) and the blocking plate (12); The sealing member (13) is fixedly mounted on the pump body (11) by means of bolts and blocks the other end of the mounting hole (100); the piston rod (4) slides in a sealing manner within the sealing member (13); The limiting member (14) is disposed between the sealing member (13) and the piston cylinder (2) and is engaged with the two, and the limiting member (14) is slidably connected to the piston rod (4).

4. A carbon dioxide pump as claimed in claim 3, characterized in that: A first through hole (203) and a second through hole (204) are respectively provided at two ends of the circumferential side of the piston cylinder (2), wherein: The first through hole (203) is in communication with the liquid inlet hole (101) and the liquid discharge hole (102); The second through hole (204) is in communication with the low-temperature chamber (103) and the interior of the piston cylinder (2), and the piston head (3) is located between the first through hole (203) and the second through hole (204); The limiting member (14) comprises a limiting ring (141), a clamping column (142) and a sliding block (143), wherein: The limiting ring (141) is abutted and fixed between the sealing component (13) and the piston cylinder (2); The clamping columns (142) are respectively fixedly arranged on both sides of the limiting ring (141); the sealing member (13) and the piston cylinder (2) are both provided with clamping grooves (205); the clamping columns (142) are clamped in the clamping grooves (205) and correspond one to one therewith; The sliding block (143) is fixedly arranged in the limiting ring (141); a sliding groove (401) is provided on the peripheral side of the piston rod (4), and the sliding block (143) is slidably arranged in the sliding groove (401).

5. A carbon dioxide pump according to claim 1, characterized in that: Two of the rubber cone cylinders (6) and the retaining springs (7) are provided along the axial direction of the piston cylinder (2) and correspond to each other one by one, and one end of the balancing hole (104) connected to the low-temperature chamber (103) is located at a middle position of the rubber cone cylinder (6) close to the liquid inlet hole (101); The retaining spring (7) close to the liquid inlet hole (101) is located at the bottom side of the rubber cone cylinder (6), and the retaining spring (7) away from the liquid inlet hole (101) is located at the top side of the rubber cone cylinder (6).

6. A carbon dioxide pump as claimed in claim 4, characterized in that: The interior of the piston cylinder (2) is thick at both ends and thin in the middle, and the inner diameter of the position where the first through hole (203) and the second through hole (204) are arranged on the piston cylinder (2) is larger than the inner diameter of the middle position of the piston cylinder (2).

7. A carbon dioxide pump as claimed in claim 3, characterized in that: The mounting hole (100), the blocking plate (12), the sealing member (13), the limiting member (14), the piston cylinder (2), the piston head (3), the piston rod (4) and the control valve (5) are all provided in plurality and correspond to each other one by one.

8. An application method of a carbon dioxide pump, using the carbon dioxide pump as claimed in any one of claims 1 to 7 to inject carbon dioxide into an oil layer, characterized in that: The following steps are involved: S1, connecting the liquid inlet (101) to the gas injection port of the carbon dioxide transport tank truck, and connecting the liquid discharge hole (102) to the gas pipeline extending into the oil field, wherein the carbon dioxide transport tank truck is loaded with low-temperature liquid carbon dioxide with a temperature of -25°C to -15°C and a pressure of 2MPa to 5MPa or room-temperature supercritical carbon dioxide with a temperature of 0°C to 35°C and a pressure of 6MPa to 9MPa; S2, setting the conduction temperature of the temperature control valve (51) to -10°C, and when the temperature of the medium in the temperature control valve (51) is lower than -10°C, the temperature control valve (51) is conducted; S3, setting the conduction pressure of the pressure valve (52) to 6 MPa, and when the pressure of the medium in the pressure valve (52) is higher than 6 MPa, the pressure valve (52) is conducted; S4, connecting the piston rod (4) to the driving device, and opening the gas injection port of the carbon dioxide transport tanker to inject carbon dioxide into the oil layer to displace the crude oil.

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