A method for transporting supercritical CO 2 Reciprocating pump for medium

Abstract

The present invention proposes a method for transporting supercritical CO 2 The reciprocating pump of the medium, in which the front chamber section is filled with the front filling assembly, the rear chamber section is filled with the plunger, and the lower chamber section and the upper chamber section are filled with the liquid inlet valve assembly and the liquid discharge valve assembly respectively. This layout makes it possible to provide supercritical CO 2 The volume of the medium entering is small, and when the plunger moves forward, the invalid volume is only the safety gap reserved between the plunger operating chamber, the rear chamber section and the plunger, so that the invalid volume of the present invention is small and the pump efficiency is improved; the upper end of the inlet valve core and the lower end of the discharge valve core of the present invention are located in the plunger operating chamber when the plunger moves backward, and when the plunger moves forward, the upper end of the inlet valve core and the lower end of the discharge valve core are retracted into the inlet valve seat and the discharge valve seat respectively, thereby filling the invalid volume in the inlet valve seat and the discharge valve seat, so that the invalid volume of the present invention is further reduced and the pump efficiency is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of pumps, and in particular to a method for conveying supercritical CO 2 Reciprocating pump for medium. Background Art

[0002] CO 2 The medium has been widely used in various industries, CO 2 The characteristics of the medium are gradually recognized and further promoted by people, and have obtained higher economic benefits.

[0003] Application of liquid CO in tertiary oil recovery technology in oil fields 2 Performing huff and puff and flooding processes, due to CO 2 It is sensitive to pressure and temperature. During the injection process, if the pump inlet pressure and temperature are below the critical point of the saturation data, it is easy to gasify. Once CO 2 Gasification phenomenon will make conventional CO 2 injection equipment is difficult to operate properly; therefore, CO 2 The injection process is kept in a supercritical state (pressure ≥ 20MPa, temperature ≥ 30℃) to achieve the highest injection efficiency.

[0004] In the prior art, supercritical injection is to inject liquid CO 2 After the initial pressurization to the supercritical state, the reciprocating injection pump is used for the second pressurization. 2 Injected into the ground, it instantly replenishes and increases the underground pressure, thereby increasing the recovery rate of crude oil; however, the existing reciprocating injection pump has a large internal invalid volume, such as the volume formed in the body cavity, pump body cavity, various valve cavities, and plunger running cavity, which easily makes the supercritical CO 2 The medium enters these invalid volumes, and during the operation of the plunger, the supercritical CO in these invalid volumes cannot be removed. 2 The medium is discharged, making the reciprocating pump's delivery efficiency low. Summary of the invention

[0005] The problem to be solved by the present invention is to provide a supercritical CO with less dead volume and higher transport efficiency. 2 Reciprocating pump for medium.

[0006] The technical solution adopted by the present invention to solve the above problems is: a method for transporting supercritical CO 2A reciprocating pump for a medium, comprising a vertically arranged pump body, a housing and a plunger arranged on one side of the pump body; the pump body comprises a pump body plunger channel arranged horizontally inside, and a combined valve chamber communicating with the pump body plunger channel and arranged in a cross shape; a housing plunger channel matching the pump body plunger channel is horizontally arranged in the housing; the pump body plunger channel comprises a plunger running chamber, a front chamber section arranged on one side of the plunger running chamber, and a rear chamber section arranged on the other side of the plunger running chamber; the plunger fills the housing plunger channel, and the front end of the plunger can reciprocate in the plunger running chamber and the rear chamber section; the front chamber section is filled with a front filling assembly; the combined valve chamber comprises a lower chamber section and an upper chamber section communicating with the plunger running chamber; the lower chamber section is filled with a liquid inlet valve assembly; the upper chamber section is filled with a liquid discharge valve assembly;

[0007] The inlet valve assembly includes an inlet valve seat and an inlet valve core that moves up and down in a channel of the inlet valve seat, and the drain valve assembly includes a drain valve seat and a drain valve core that moves up and down in a channel of the drain valve seat;

[0008] The inlet valve assembly and the discharge valve assembly are opened and closed by the plunger. When the plunger moves backward, the upper end of the inlet valve core and the lower end of the discharge valve core respectively enter the plunger operating cavity; when the plunger moves forward, the upper end of the inlet valve core and the lower end of the discharge valve core respectively retract and fill the inlet valve seat and the discharge valve seat to control the invalid volume.

[0009] Compared with the prior art, the body plunger channel in the body of the present invention is filled with the plunger, the pump body plunger channel in the pump body is communicated with the combined valve cavity and is arranged in a cross shape, the pump body plunger channel includes a plunger running cavity, a front cavity section and a rear cavity section, the combined valve cavity includes a lower cavity section and an upper cavity section communicated with the plunger running cavity, wherein the front cavity section is filled with the front filling assembly, the rear cavity section is filled with the plunger, and the interiors of the lower cavity section and the upper cavity section are respectively filled with the liquid inlet valve assembly and the liquid discharge valve assembly. With this layout, supercritical CO can be supplied. 2 The volume that the medium enters only includes the plunger operating chamber and the rear chamber section, and the front end of the plunger reciprocates in the plunger operating chamber and the rear chamber section. When the plunger moves forward, the invalid volume in the present invention only includes the plunger operating chamber, the safety gap reserved between the rear chamber section and the plunger, thereby reducing the invalid volume of the present invention and improving the pump efficiency. In addition, the upper end of the inlet valve core and the lower end of the discharge valve core of the present invention are located in the plunger operating chamber when the plunger moves backward. When the plunger moves forward, the upper end of the inlet valve core and the lower end of the discharge valve core retract into the inlet valve seat and the discharge valve seat, respectively, thereby filling the invalid volume in the inlet valve seat and the discharge valve seat, thereby further reducing the invalid volume of the present invention and further improving the pump efficiency.

[0010] A method for transporting supercritical CO 2 A reciprocating pump for a medium, wherein the discharge valve core includes a lower filling portion arranged at the lower end portion, and the discharge valve seat includes a lower filling chamber arranged below the channel; the lower filling portion gradually enters downward into the plunger running chamber during the backward movement of the plunger; the lower filling portion gradually fills into the lower filling chamber during the forward movement of the plunger; the discharge valve assembly further includes a spring valve cover arranged at the upper section of the upper chamber section; through the above design, the lower filling chamber, which would originally generate an invalid volume during the upward movement of the discharge valve core, is filled by the reserved lower filling portion, thereby reducing the invalid volume of the lower filling chamber.

[0011] A method for transporting supercritical CO 2 A reciprocating pump for a medium, wherein the liquid inlet valve core includes an upper filling section arranged at the upper end, and the liquid inlet valve seat includes an upper filling cavity arranged above the channel; the upper filling section gradually enters the plunger running cavity upward during the backward movement of the plunger; the upper filling section gradually fills the upper filling cavity during the forward movement of the plunger; the liquid inlet valve assembly further includes a spring seat arranged at the lower section of the lower cavity section; through the above design, the upper filling cavity, which would originally generate an invalid volume during the downward movement of the liquid inlet valve core, is filled by the reserved upper filling section, thereby reducing the invalid volume of the upper filling cavity.

[0012] A method for transporting supercritical CO 2 The invention discloses a reciprocating pump for medium, wherein the front filling assembly comprises a front plug and a front flange fixedly connected to the front side of the pump body; the front plug is inserted into and filled in the front cavity section, and is used to fix the liquid inlet valve assembly and the liquid discharge valve assembly; through the above design, the arrangement of the front filling assembly enables the volume in the front cavity section to be filled, which is beneficial to reduce the invalid volume in the pump body, and enables the front cavity section to obtain a reliable seal, thereby avoiding leakage that causes the transmission of supercritical CO 2 Medium pressure changes.

[0013] A method for transporting supercritical CO 2 A reciprocating pump for medium, wherein an upper plug is provided above the spring valve cover; an upper flange is provided above the upper plug; through the above design, the gap between the parts at the upper end of the discharge valve assembly is reliably sealed to avoid leakage that may cause the delivery of supercritical CO 2 The medium pressure changes. In addition, the upper plug and the upper flange can compress the spring valve cover to prevent axial movement of the drain valve assembly.

[0014] A method for transporting supercritical CO 2A reciprocating pump for a medium, wherein the housing comprises a main housing fixedly connected to one side of the pump body and having a hollow interior; the inner wall of the main housing is provided with a main filler in contact with the plunger; the main housing is provided with a liquid inlet lubrication manifold and a liquid outlet lubrication manifold which are in communication with the main filler and have circulating lubricating oil, so as to reduce the friction temperature of the plunger; through the above design, the lubricating oil enters the main filler, thereby reducing the friction coefficient, avoiding excessively high temperature of the plunger due to friction during reciprocating motion, so as to reduce the supercritical CO 2 Gasification of the medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is an overall cross-sectional view of the plunger of the present invention when it moves forward to the maximum stroke;

[0016] Figure 2 It is an overall cross-sectional view of the plunger of the present invention running backward to the maximum stroke;

[0017] Figure 3 It is a schematic diagram of the structure of the liquid inlet valve assembly and the liquid discharge valve assembly;

[0018] Figure 4 It is a structural schematic diagram of the liquid inlet valve seat and the liquid discharge valve seat;

[0019] Figure 5 It is a partial cross-sectional view when the plunger moves backward to the maximum stroke;

[0020] Figure 6 A partial cross-sectional view of the plunger when it moves forward to a maximum stroke in some embodiments;

[0021] Figure 7 is a partial cross-sectional view of some other embodiments when the plunger moves forward to the maximum stroke;

[0022] Figure 8 It is a schematic diagram of the structure of the body;

[0023] Fig. 9 This is an enlarged view of the local structure of the container;

[0024] Fig.10 It is a structural schematic diagram of a liquid inlet valve assembly and a liquid discharge valve assembly in the prior art. DETAILED DESCRIPTION

[0025] Before describing in detail any embodiment of the present invention, it should be understood that the present invention is not limited in its application to the construction and arrangement details of the components described below or illustrated in the following figures. The present invention can have other embodiments and can be practiced or carried out in various ways. In addition, it should be understood that the words and terms used here are for descriptive purposes and should not be considered restrictive. The use of "including" or "having" and its variations herein is intended to cover the items and their equivalents and additional items displayed below. Unless otherwise specified or limited, the terms "install", "connect", "support" and "couple" and their variations are widely used and cover direct installation and indirect installation, connection, support and connection. In addition, "connect" and "couple" are not limited to physical or mechanical connections or connections.

[0026] Furthermore, on the first aspect, in the disclosure of the present invention, the orientation or positional relationship indicated by terms such as "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or positional relationship shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore the above terms cannot be understood as limitations on the present invention; on the second aspect, the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" cannot be understood as a limitation on the quantity.

[0027] It should be understood by those skilled in the art that the embodiments of the present invention described above and shown in the accompanying drawings are only examples and do not limit the present invention. The purpose of the present invention has been fully and effectively achieved. The functional and structural principles of the present invention have been demonstrated and explained in the embodiments, and the embodiments of the present invention may be deformed or modified in any way without departing from the principles.

[0028] The embodiments of the present invention are further described below in conjunction with the accompanying drawings.

[0029] See also Figure 1-10 , a method for delivering supercritical CO 2A reciprocating pump for a medium comprises a vertically arranged pump body 1, a housing 2 and a plunger 3 arranged at one side of the pump body 1; the pump body 1 comprises a pump body plunger passage 11 arranged horizontally inside, and a combined valve chamber 12 communicating with the pump body plunger passage 11 and arranged in a cross shape; a housing plunger passage 21 matching the pump body plunger passage 11 is arranged horizontally in the housing 2; the pump body plunger passage 11 comprises a plunger operating chamber 111, a front chamber section 112 arranged at one side of the plunger operating chamber 111 and a valve chamber 12 arranged in a cross shape; The rear chamber section 113 is arranged on the other side of the plunger running chamber 111; the plunger 3 fills the plunger channel 21 of the housing, and the front end of the plunger 3 can reciprocate in the plunger running chamber 111 and the rear chamber section 113; the front chamber section 112 is filled with a front filling assembly 13; the combined valve chamber 12 includes a lower chamber section 121 and an upper chamber section 122 communicated with the plunger running chamber 111; the lower chamber section 121 is filled with a liquid inlet valve assembly 14; the upper chamber section 122 is filled with a liquid discharge valve assembly 15;

[0030] The inlet valve assembly 14 includes an inlet valve seat 141 and an inlet valve core 143 that moves up and down in the channel of the inlet valve seat 141. The drain valve assembly 15 includes a drain valve seat 151 and a drain valve core 153 that moves up and down in the channel of the drain valve seat 151.

[0031] The inlet valve assembly 14 and the discharge valve assembly 15 are controlled to open and close by the plunger 3. When the plunger 3 moves backward, the upper end of the inlet valve core 143 and the lower end of the discharge valve core 153 enter the plunger operating chamber 111 respectively; when the plunger 3 moves forward, the upper end of the inlet valve core 143 and the lower end of the discharge valve core 153 retract into the inlet valve seat 141 and the discharge valve seat 151 respectively to control the invalid volume.

[0032] Please continue reading Fig.10 , Fig.10 The structure of the liquid inlet valve assembly and the liquid discharge valve assembly in the prior art is shown, wherein when the plunger moves forward to the maximum stroke, the liquid inlet valve core and the liquid discharge valve core are retracted to the liquid inlet valve seat and the liquid discharge valve core respectively. Since the upper end of the liquid inlet valve core and the lower end of the liquid discharge valve core are not reserved, when retracted, the liquid inlet valve seat and the liquid discharge valve core form two dead volumes S2 and S1 respectively. During the reciprocating motion of the plunger body, the supercritical CO in the two volumes S2 and S1 2 The medium cannot be pressed out, which reduces the pump efficiency.

[0033] based on Fig.10In the case shown in the figure, the body plunger channel 21 in the body 2 of the present invention is filled with the plunger 3, the pump body plunger channel 11 in the pump body 1 is communicated with the combined valve chamber 12 and is arranged in a cross shape, the pump body plunger channel 11 includes a plunger running chamber 111, a front chamber section 112 and a rear chamber section 113, and the combined valve chamber 12 includes a lower chamber section 121 and an upper chamber section 122 communicated with the plunger running chamber 111, wherein the front chamber section 112 is filled with the front filling assembly 13, the rear chamber section 113 is filled with the plunger 3, and the lower chamber section 121 and the upper chamber section 122 are filled with the liquid inlet valve assembly 14 and the liquid discharge valve assembly 15 respectively. With this layout, supercritical CO can be supplied. 2 The volume for the medium to enter only includes the plunger operating chamber 111 and the rear chamber section 113, and the front end of the plunger 3 reciprocates between the plunger operating chamber 111 and the rear chamber section 113. When the plunger 3 moves forward, the invalid volume in the present invention only includes the safety gap reserved between the plunger operating chamber 111, the rear chamber section 113 and the plunger 3, thereby reducing the invalid volume of the present invention and improving the pump efficiency. In addition, the upper end of the inlet valve core 143 and the lower end of the discharge valve core 153 of the present invention are located in the plunger operating chamber 111 when the plunger 3 moves backward. When the plunger 3 moves forward, the upper end of the inlet valve core 143 and the lower end of the discharge valve core 153 retract into the inlet valve seat 141 and the discharge valve seat 151, respectively, thereby filling the invalid volume in the inlet valve seat 141 and the discharge valve seat 151, thereby further reducing the invalid volume of the present invention and further improving the pump efficiency.

[0034] It is worth mentioning that one end of the plunger 3 away from the pump body 1 extends out from the box body 2 and is connected to an external power component to realize the reciprocating motion of the plunger 3; the pump body 1 can be arranged into a single-cylinder, double-cylinder, triple-cylinder, five-cylinder or multi-cylinder form according to actual needs, and the pump body 1 can be selected from forgings or cast steel parts, and the material or heat treatment process requirements can be selected according to different pressure and temperature.

[0035] Please continue reading Figure 1-6 , wherein the drain valve core 153 includes a lower filling portion 1531 arranged at the lower end portion, and the drain valve seat 151 includes a lower filling chamber 1511 arranged below the channel; the lower filling portion 1531 gradually enters the plunger running chamber 111 downward during the backward movement of the plunger 3; the lower filling portion 1531 gradually fills into the lower filling chamber 1511 during the forward movement of the plunger 3; the drain valve assembly 15 further includes a spring valve cover 152 arranged at the upper section of the upper chamber section 122.

[0036] When in use, the forward and backward movement of the plunger 3 can drive the drain valve core 153 to move up and down in the channel of the drain valve seat 151; when the plunger 3 moves forward, the drain valve core 153 moves upward, pushing open the spring valve cover 152, so that the supercritical CO in the plunger operation chamber 111 2The medium is discharged from the flow channel in the drain valve core 153. When the plunger 3 moves backward, the drain valve core 153 moves downward. Under the cooperation of the spring valve cover 152, the drain valve core 153 and the drain valve seat 151 cooperate to close, so that the supercritical CO in the plunger operation chamber 111 is 2 and due to the cooperation between the lower filling portion 1531 and the lower filling chamber 1511, the lower filling chamber 1511, which would have generated invalid volume during the upward movement of the discharge valve core 153, is filled with the reserved lower filling portion 1531, thereby reducing the invalid volume of the lower filling chamber 1511.

[0037] A method for transporting supercritical CO 2 A reciprocating pump for a medium, wherein the liquid inlet valve core 143 includes an upper filling section 1431 arranged at the upper end, and the liquid inlet valve seat 141 includes an upper filling chamber 1411 arranged above the channel; the upper filling section 1431 gradually enters the plunger running chamber 111 upward during the backward movement of the plunger 3; the upper filling section 1431 gradually fills the upper filling chamber 1411 during the forward movement of the plunger 3; the liquid inlet valve assembly 14 further includes a spring seat 142 arranged at the lower section of the lower chamber section 121.

[0038] When in use, the forward and backward movement of the plunger 3 can drive the liquid inlet valve core 143 to move up and down in the channel of the liquid inlet valve seat 141; when the plunger 3 moves forward, the liquid inlet valve core 143 moves downward, and with the cooperation of the spring seat 142, the flow channel in the liquid inlet valve seat 141 is closed, and the external supercritical CO 2 The medium cannot enter the plunger operating chamber 111. When the plunger 3 moves backward, the liquid inlet valve core 143 moves upward, pulling the spring seat 142 open, and the flow channel in the liquid inlet valve seat 141 opens, allowing the external supercritical CO 2 The medium enters the plunger running chamber 111; and due to the cooperation between the upper filling section 1431 and the upper filling chamber 1411, the upper filling chamber 1411, which would have generated invalid volume during the downward movement of the liquid inlet valve core 143, is filled with the reserved upper filling section 1431, thereby reducing the invalid volume of the upper filling chamber 1411.

[0039] Please continue reading Figure 6 In some embodiments, the volume of the lower filling portion 1531 is equal to the volume of the lower filling cavity 1511; when the plunger 3 moves forward to the maximum stroke, the lower filling portion 1531 is completely filled into the lower filling cavity 1511, and the upper filling section 1431 is completely filled into the upper filling cavity 1411.

[0040] Under this arrangement, the ineffective volume in the lower filling chamber 1511 is completely filled by the lower filling portion 1531, and the ineffective volume in the upper filling chamber 1411 is also filled to a large extent, so that the overall ineffective volume is small and the pump efficiency is high.

[0041] Please continue reading Figure 7 In other embodiments, the volume of the lower filling portion 1531 is greater than the volume of the lower filling chamber 1511; when the plunger 3 moves forward to the maximum stroke, the lower end of the lower filling portion 1531 is located in the plunger running chamber 111, and the upper end of the upper filling section 1431 is located in the plunger running chamber 111.

[0042] Under this arrangement, the lower filling portion 1531 can not only fill the invalid volume in the lower filling chamber 1511, but its lower end can also fill the invalid volume in the plunger running chamber 111. At the same time, the upper filling section 1431 can not only fill the invalid volume in the upper filling chamber 1411, but its upper end can also fill the invalid volume in the plunger running chamber 111, thereby reducing the overall invalid volume. It is worth mentioning that when the plunger 3 runs forward to the maximum stroke, the lower end of the lower filling portion 1531 filled into the plunger running chamber 111 and the upper end of the upper filling section 1431 should not interfere with the plunger 3.

[0043] Please continue reading Figure 1 , Figure 2 , wherein the front filling assembly 13 includes a front plug 131 and a front flange 132 fixedly connected to the front side of the pump body 1; the front plug 131 is inserted into and filled in the front cavity section 112 to fix the liquid inlet valve assembly 14 and the liquid discharge valve assembly 15.

[0044] When in use, the front filling assembly 13 is arranged so that the volume in the front cavity section 112 is filled, which is beneficial to reducing the invalid volume in the pump body 1 and making the front cavity section 112 obtain a reliable seal to avoid leakage and thus causing the supercritical CO to be transported. 2 Medium pressure changes.

[0045] Please continue reading Figure 1 , Figure 2 , wherein an upper plug 154 is provided above the spring valve cover 152 ; an upper flange 155 is provided above the upper plug 154 .

[0046] When in use, the upper plug 154 and the upper flange 155 are arranged so that the gap between the parts at the upper end of the drain valve assembly 15 is reliably sealed to avoid leakage that may cause the transport of supercritical CO 2 The medium pressure changes. In addition, the upper plug 154 and the upper flange 155 can compress the spring valve cover 152 to prevent the axial movement of the drain valve assembly 15.

[0047] Please continue reading Figure 1 , Figure 2 , Figure 8 , Fig. 9The housing 2 includes a main housing 22 which is fixedly connected to one side of the pump body 1 and is hollow inside; the inner wall of the main housing 22 is provided with a main filler 23 in contact with the plunger 3; the main housing 22 is provided with a liquid inlet lubrication manifold 24 and a liquid outlet lubrication manifold 25 which are in communication with the main filler 23 and have circulating lubricating oil, so as to reduce the friction temperature of the plunger 3.

[0048] Due to supercritical CO 2 The medium is sensitive to temperature. Therefore, the present invention provides a liquid inlet lubrication manifold 24 and a liquid discharge lubrication manifold 25 on the main body 22, and introduces lubricating oil through an external circulation device so that the lubricating oil enters the main filler 23, thereby reducing the friction coefficient and preventing the plunger 3 from generating excessively high temperature due to friction during reciprocating motion. The circulating lubricating oil itself also has the function of cooling the plunger 3, so that the temperature of the plunger 3 is maintained at a temperature that is conducive to maintaining supercritical CO 2 The medium is stable in order to reduce the supercritical CO 2 The medium is gasified, and at the same time, the lubricating oil cooperates with the main filler 23 to reduce the wear of the plunger 3 and increase its service life.

[0049] Please continue reading Figure 1 , Figure 2 , Figure 8 , Fig. 9 A main filling gap 211 is provided between the main box body 22 and the plunger 3, and a main filler 23 is arranged in the main filling gap 211; a front guide sleeve 212 is provided at the front end of the main filling gap 211; and a main flow blocking ring 213 is provided at the rear end.

[0050] When in use, the front guide sleeve 212 has the function of guiding the movement of the plunger 3 and making it reciprocate more smoothly, and the front guide sleeve 212 cooperates with the main flow blocking ring 213 to increase the sealing effect between the container body 2 and the plunger 3, thereby preventing supercritical CO 2 medium leakage; in addition, through the cooperation of the front guide sleeve 212 and the main baffle ring 213, the lubricating oil is confined in the main filling gap 211 and is not easy to leak to other areas, so as to facilitate the recycling of the lubricating oil.

[0051] Please continue reading Figure 1 , Figure 2 , Figure 8 , Fig. 9 , wherein the box body 2 further includes an auxiliary box body 26 with a hollow interior, and a main adjusting nut 27; the auxiliary box body 26 is fixedly connected to one side of the main box body 22 through the main adjusting nut 27; the auxiliary box body 26 includes a limiting plate 261; the limiting plate 261 extends into the main filling gap 211 and abuts against the main flow blocking ring 213.

[0052] When in use, the auxiliary housing 26 and the stopper 261 are arranged so that the section of the plunger 3 extending out of the main housing 22 has a load, thereby making the operation of the plunger 3 more stable, and at the same time, the main flow blocking ring 213 has a carrier for installation, thereby increasing the sealing effect of the main filling gap 211 and preventing supercritical CO 2 Medium leakage.

[0053] Please continue reading Figure 1 , Figure 2 , Figure 8 , Fig. 9 , wherein a secondary filling gap 262 is provided between the secondary box body 26 and the plunger 3; a secondary filler 28 is provided in the secondary filling gap 262; a secondary flow blocking ring 263 is provided on one side of the secondary filling gap 262; the secondary filler 28 is restricted between the limiting piece 261 and the secondary flow blocking ring 263; a secondary adjusting nut 29 is also provided on one side of the secondary box body 26; the secondary adjusting nut 29 abuts against the secondary flow blocking ring 263 to allow the secondary flow blocking ring 263 to enter the secondary filling gap 262.

[0054] When in use, the auxiliary filling gap 262 and the auxiliary filler 28 in the auxiliary filling gap 262 cooperate with the main filler 23 to further reduce the friction of the plunger 3 during reciprocating motion, thereby reducing the heat generated by friction and the wear of the plunger 3, which is beneficial to the temperature control of the plunger 3 and prolonging the service life of the plunger 3, and further increases the sealing effect between the container body 2 and the plunger 3 to prevent supercritical CO 2 Medium leakage.

[0055] It is worth mentioning that the depth of oil wells is usually required to reach 1000 meters to 3000 meters, so the working pressure of the injection equipment is required to be greater than 30MPa to achieve CO 2 The CO injected into the oil well penetrates into the formation. 2 All of them are in supercritical state, which has the greatest effect on extracting crude oil from the oil layer and the highest recovery rate. 2 The density in the supercritical state is close to that of liquid, the viscosity is close to that of gas, and the diffusion coefficient is 100 times that of liquid. It has a large solubility. 2 The fluidity, rheology and reservoir properties of crude oil are fully improved, solving the problems of difficult water injection, difficult oil production and reservoir. 2 When the medium is injected into the oil well, it is easy to maintain CO due to the small dead volume and temperature control function. 2 The supercritical state of the medium makes the injection efficiency of the reciprocating pump higher, ensuring the CO 2 The characteristics of the medium can better serve the oil production industry.

[0056] The above description is only for the best embodiment of the present invention, but it should not be understood as limiting the claims. The present invention is not limited to the above embodiments, and its specific structure is allowed to be changed. All changes made within the scope of protection of the independent claims of the present invention are within the scope of protection of the present invention.

Claims

1. A reciprocating pump for conveying supercritical CO2 medium, characterized in that: The invention comprises a vertically arranged pump body (1), a housing (2) and a plunger (3) arranged on one side of the pump body (1); the pump body (1) comprises a pump body plunger channel (11) arranged horizontally inside, and a combined valve cavity (12) communicating with the pump body plunger channel (11) and arranged in a cross shape; a housing plunger channel (21) matching the pump body plunger channel (11) is horizontally arranged in the housing (2); the pump body plunger channel (11) comprises a plunger operating cavity (111), a front cavity section (112) arranged on one side of the plunger operating cavity (111), and a valve cavity (12) arranged on the side of the plunger operating cavity (111). The rear chamber section (113) is on the other side of the cavity (111); the plunger (3) fills the plunger channel (21) of the housing, and the front end of the plunger (3) can reciprocate in the plunger operation cavity (111) and the rear chamber section (113); the front chamber section (112) is filled with a front filling assembly (13); the combined valve cavity (12) comprises a lower chamber section (121) and an upper chamber section (122) which are in communication with the plunger operation cavity (111); the lower chamber section (121) is filled with a liquid inlet valve assembly (14); and the upper chamber section (122) is filled with a liquid discharge valve assembly (15); The liquid inlet valve assembly (14) comprises a liquid inlet valve seat (141) having an upper filling cavity (1411) arranged above the channel, and a liquid inlet valve core (143) moving up and down in the channel of the liquid inlet valve seat (141); the liquid discharge valve assembly (15) comprises a liquid discharge valve seat (151) having a lower filling cavity (1511) arranged below the channel, and a liquid discharge valve core (153) moving up and down in the channel of the liquid discharge valve seat (151); The inlet valve assembly (14) and the discharge valve assembly (15) are controlled to open and close by the plunger (3); when the plunger (3) moves backward, the upper end of the inlet valve core (143) and the lower end of the discharge valve core (153) respectively enter the plunger operation chamber (111); when the plunger (3) moves forward, the upper end of the inlet valve core (143) and the lower end of the discharge valve core (153) respectively retract and fill the inlet valve seat (141) and the discharge valve seat (151) to control the dead volume; The liquid discharge valve core (153) comprises a lower filling portion (1531) arranged at the lower end portion and a spring valve cover (152) arranged at the upper portion of the upper chamber section (122); the liquid inlet valve core (143) comprises an upper filling section (1431) arranged at the upper end portion and a spring seat (142) arranged at the lower portion of the lower chamber section (121); the front filling assembly (13) comprises a front plug (131) and a front flange (132) fixedly connected to the front side of the pump body (1).

2. The reciprocating pump for conveying supercritical CO2 medium according to claim 1, characterized in that: The lower filling portion (1531) gradually moves downward into the plunger operation chamber (111) during the backward movement of the plunger (3); and the lower filling portion (1531) gradually fills into the lower filling chamber (1511) during the forward movement of the plunger (3).

3. The reciprocating pump for conveying supercritical CO2 medium according to claim 2, characterized in that: The upper filling section (1431) gradually moves upward into the plunger running chamber (111) during the backward movement of the plunger (3); and the upper filling section (1431) gradually fills into the upper filling chamber (1411) during the forward movement of the plunger (3).

4. The reciprocating pump for conveying supercritical CO2 medium according to claim 1, characterized in that: The front plug (131) is inserted into and filled in the front cavity section (112) and is used to fix the liquid inlet valve assembly (14) and the liquid discharge valve assembly (15).

5. The reciprocating pump for conveying supercritical CO2 medium according to claim 2, characterized in that: An upper plug (154) is provided above the spring valve cover (152); and an upper flange (155) is provided above the upper plug (154).

6. The reciprocating pump for conveying supercritical CO2 medium according to claim 1, characterized in that: The housing (2) comprises a main housing (22) which is fixedly connected to one side of the pump body (1) and has a hollow interior; the inner wall of the main housing (22) is provided with a main filler (23) in contact with the plunger (3); the main housing (22) is provided with a liquid inlet lubrication manifold (24) and a liquid outlet lubrication manifold (25) which are in communication with the main filler (23) and through which circulating lubricating oil flows, so as to reduce the friction temperature of the plunger (3).

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