WO2021218585A1

WO2021218585A1 - Linear motor-driven fracturing pump

Info

Publication number: WO2021218585A1
Application number: PCT/CN2021/085874
Authority: WO
Inventors: 谢梅英; 唐平; 罗权; 程建
Original assignee: 四川宏华石油设备有限公司
Priority date: 2020-04-26
Filing date: 2021-04-08
Publication date: 2021-11-04
Also published as: CN111648933B; CN111648933A

Abstract

A linear motor-driven fracturing pump, comprising at least one hydraulic end (1). Several plungers (4) are provided in parallel on each hydraulic end (1). Each plunger (4) is correspondingly connected to one linear motor (3). The linear motors (3) drive the plungers (4) to move linearly back and forth. The hydraulic end (1) also is provided with several control valves (5). The control valves (5) are used for controlling the intake or discharge of a liquid when the plungers (4) are moving. With the linear motors (3) and the plungers (4) being connected directly, and with the linear motors (3) driving the plungers (4) to move linearly back and forth, parts such as a crankshaft connecting rod mechanism in a conventional fracturing pump are obviated, the structure of the fracturing pump is simplified, the reliability and transmission efficiency of the fracturing pump are effectively increased, the linear motors run steadily and have a constant speed, and pulsations of an output flow and of pressure are theoretically and fundamentally eliminated; meanwhile, because the stroke of the linear motors can be extended, at the same time as requirements for a low number of strokes and a large displacement are satisfied, vibrations of the entire pump and consumption of wearable elements of the hydraulic end are reduced.

Description

A fracturing pump driven by linear motor

Technical field

The invention relates to the technical field of fracturing pumps, in particular to a fracturing pump driven by a linear motor.

Background technique

The role of the fracturing pump is to convert a low-pressure liquid into a high-pressure liquid. The conventional fracturing pump is mainly composed of two parts: the power end and the hydraulic end. The prime mover drives the crankshaft to rotate through the reduction gear, and then drives the plunger to make a reciprocating linear movement through the transmission of the crank connecting rod mechanism, so as to realize the suction and discharge of the liquid. Conventional fracturing pumps have large operating noise and low reliability due to the existence of mechanical structures such as reduction gearboxes and crankshaft connecting rod mechanisms. At the same time, the crankshaft connecting rod mechanism has inherent shortcomings of uneven output flow and large pressure fluctuations. In addition, the crank connecting rod mechanism of the conventional fracturing pump limits the stroke. To achieve a large displacement, it is necessary to increase the stroke number. Excessive stroke number will aggravate the vibration of the entire pump and the consumption of wearing parts.

Summary of the invention

The purpose of the present invention is to solve the problem of complex structure, low reliability, uneven output flow, large pressure fluctuation, and limited stroke due to the crankshaft connecting rod mechanism of the conventional fracturing pump. The problem of demand is to provide a fracturing pump driven by a linear motor. The linear motor is directly connected to the plunger. The linear motor drives the plunger to perform reciprocating linear motion. The stroke of the linear motor can be long to meet the requirements of low strokes and large The demand for displacement solves a series of problems of the above-mentioned conventional fracturing pumps.

In order to achieve the above objectives, the technical solutions adopted by the present invention are as follows:

A fracturing pump driven by a linear motor includes at least one hydraulic end. A plurality of plungers are arranged side by side at one end of each hydraulic end, and each plunger is correspondingly connected with a linear motor. The linear motor The plunger is driven to make a reciprocating linear movement, and the other end of the hydraulic end is also provided with a number of control valves, and the control valves are used to control the suction or discharge of liquid when the plunger moves.

The present invention directly connects the linear motor and the plunger, and drives the plunger to perform reciprocating linear motion through the linear motor, which eliminates the crankshaft connecting rod mechanism and other components in the conventional fracturing pump, simplifies the structure of the fracturing pump, and effectively improves The reliability and transmission efficiency of the fracturing pump, and the linear motor runs smoothly and the speed is constant. Theoretically, the pulsation of the output flow and pressure is basically eliminated. At the same time, the stroke of the linear motor can be extended to meet the requirements of low stroke and large stroke. At the same time as the displacement demand, the vibration of the whole pump and the consumption of the wearing parts of the hydraulic end are reduced.

As a preferred solution of the present invention, the linear motor has a double-ended drive structure, and there are two hydraulic ends corresponding to the two ends of the linear motor. The two ends of each linear motor are connected to the plungers on the two hydraulic ends. Correspondingly connected. By adopting a linear motor with a double-end drive structure, the two ends of each linear motor are connected to the plungers on the two hydraulic ends correspondingly, so that the linear motor can drive the plungers on the two hydraulic ends to work in both strokes. , Which is beneficial to improve the flow rate and efficiency of the fracturing pump.

As a preferred solution of the present invention, the fracturing pump further includes a buffer device for reducing the commutation impact of the linear motor, and the buffer device is arranged between the hydraulic end and the linear motor, and is located between the linear motor. The position of the end commutation.

As a preferred solution of the present invention, the hydraulic end corresponds to one buffer device.

As a preferred solution of the present invention, each plunger corresponds to one buffer device.

As a preferred solution of the present invention, the number of the plungers on the hydraulic end is an odd number, and at least three, and the number of the linear motors is the same as the number of the plungers. By setting an odd number of plungers on each hydraulic end, it is beneficial to make the fracturing pump run smoothly.

As a preferred solution of the present invention, the number of the plungers on the hydraulic end is five, and the number of the linear motors is correspondingly five.

As a preferred solution of the present invention, the movement directions of all linear motors are set to the same phase angle difference as the crankshaft. With this setting, all linear motors do not move to the left or right synchronously, which can balance the forces on the two hydraulic ends and make the movement of the entire fracturing pump more stable.

As a preferred solution of the present invention, two control valves are provided at the other end of the hydraulic end, and the control valves are check valves. Each plunger on the hydraulic end is provided with two one-way valves correspondingly. When the linear motor drives the plunger to make a reciprocating linear motion, the low-pressure suction and high-pressure discharge functions of the liquid are realized through the opening and closing of the one-way valve.

As a preferred solution of the present invention, the stroke of the linear motor is greater than or equal to 12". In this way, the requirements of low stroke and large displacement can be met, and the vibration of the entire pump and the consumption of hydraulic end vulnerable parts can be reduced.

In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are:

1. The present invention directly connects the linear motor and the plunger, and drives the plunger to perform reciprocating linear motion through the linear motor, eliminating the need for components such as the crankshaft connecting rod mechanism in the conventional fracturing pump, simplifying the structure of the fracturing pump, and effectively The reliability and transmission efficiency of the fracturing pump are improved, and the linear motor runs smoothly and the speed is constant. Theoretically, the pulsation of the output flow and pressure is basically eliminated. At the same time, the stroke of the linear motor can be extended to meet the low number of strokes. , While requiring large displacement, it reduces the vibration of the entire pump and the consumption of vulnerable parts at the hydraulic end;

2. The present invention adopts a linear motor with a double-end drive structure, and the two ends of each linear motor are connected to the plungers on the two hydraulic ends correspondingly, so that the linear motor can drive the two hydraulic ends with work on both back and forth strokes. The plunger work is beneficial to improve the flow rate and efficiency of the fracturing pump.

Description of the drawings

Figure 1 is a schematic diagram of a fracturing pump driven by a linear motor in the present invention.

Fig. 2 is a cross-sectional view of A-A in Fig. 1.

Marks in the picture: 1-hydraulic end, 2-buffer device, 3-linear motor, 4-plunger, 5-control valve.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings.

In order to make the objectives, technical solutions, and advantages of the present invention clearer, the following further describes the present invention in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, but not used to limit the present invention.

Example 1

This embodiment provides a fracturing pump driven by a linear motor;

As shown in Figures 1 and 2, the fracturing pump driven by a linear motor in this embodiment includes at least one hydraulic end 1. One end of each hydraulic end 1 is provided with a plurality of plungers 4 side by side, each Each of the plungers 4 is connected to a linear motor 3, and all the linear motors 3 are arranged side by side corresponding to the plungers 4. The linear motor 3 drives the plunger 4 to make a reciprocating linear motion, and the other end of the hydraulic end 1 is also Several control valves 5 are provided, and the control valves 5 are used to control the suction or discharge of liquid when the plunger 4 moves.

The present invention directly connects the linear motor and the plunger, and drives the plunger to perform reciprocating linear motion through the linear motor, which eliminates the crankshaft connecting rod mechanism and other components in the conventional fracturing pump, simplifies the structure of the fracturing pump, and effectively improves The reliability and transmission efficiency of the fracturing pump, and the linear motor runs smoothly and the speed is constant. Theoretically, the pulsation of the output flow and pressure is basically eliminated. At the same time, the stroke of the linear motor can be extended to meet the requirements of low stroke and large stroke. At the same time as the displacement demand, the vibration of the entire pump and the consumption of the vulnerable parts of the hydraulic end are reduced; because the electric power is used to drive the plunger to make a reciprocating linear movement through the linear motor, compared with the conventional diesel-driven fracturing pump, the noise is small, There is no exhaust emission pollution, and the cost is lower than that of diesel.

It should be noted that the hydraulic end 1 is provided with a cavity adapted to the plunger 4, and the linear motor 3 drives the plunger 4 to make a reciprocating linear movement in the cavity. When the linear motor 3 pulls the plunger 4 out, low-pressure liquid is sucked into the cavity. When the linear motor 3 drives the plunger 4 to retract, the plunger 4 compresses the liquid in the cavity to form a high-pressure liquid discharge cavity .

In this embodiment, the linear motor 3 is a double-ended drive structure. There are two hydraulic ends 1 and correspondingly located at the two ends of the linear motor 3. The two ends of each linear motor 3 are connected to the two hydraulic ends 1. The plunger 4 is connected correspondingly. By adopting a linear motor with a double-end drive structure, the two ends of each linear motor are connected to the plungers on the two hydraulic ends correspondingly, so that the linear motor can drive the plungers on the two hydraulic ends to work in both strokes. , Which is beneficial to improve the flow rate and efficiency of the fracturing pump.

In this embodiment, the fracturing pump further includes a buffer device 2 for reducing the commutation impact of the linear motor 3, and the buffer device 2 is arranged between the hydraulic end 1 and the linear motor 3, and is located in the The position where both ends of the linear motor commutate. Specifically, the buffer device is fixedly installed on the sleeve outside the plunger, and the plunger slides through the buffer device. Preferably, the hydraulic end corresponds to one buffer device, and all linear motors 3 share one buffer device 2 at each end, that is, the buffer device is a whole, and there are two buffer devices 2 in this example. This arrangement can reduce the installation work of the buffer device. The specific structure of the buffer device is in the prior art, and will not be repeated here.

In this embodiment, the number of the plungers 4 on the hydraulic end 1 is an odd number, and at least three, and the number of the linear motors 3 is the same as the number of the plungers 4. By setting an odd number of plungers on each hydraulic end, it is conducive to the smooth operation of the fracturing pump. Preferably, the number of the plungers 4 on the hydraulic end 1 is five, and the number of the linear motors 3 is correspondingly five. Further, the movement direction of the five linear motors 3 is set to the same phase angle difference as the crankshaft, that is, the five linear motors do not move synchronously to the left or right. In this way, the forces on the two hydraulic ends can be balanced, and the entire The fracturing pump moves more smoothly. Specifically, the movement directions of the five linear motors 3 can be controlled by a program to achieve the same phase angle difference as the crankshaft, so that the discharge pressure of the pump is stable.

In this embodiment, the other end of the hydraulic end 1 is provided with two control valves 5, the control valve 5 is a one-way valve, each plunger 4 is provided with two one-way valves, when the plunger moves to two In the limit position, the two control valves are opened or closed correspondingly, so as to realize the function of liquid suction or discharge. Each plunger on the hydraulic end is provided with two one-way valves correspondingly. When the linear motor drives the plunger to make a reciprocating linear motion, the low-pressure suction and high-pressure discharge functions of the liquid are realized through the opening and closing of the one-way valve.

In this embodiment, the stroke of the linear motor 3 is greater than or equal to 12". In this way, the requirements of low stroke and large displacement can be met, and the vibration of the entire pump and the consumption of vulnerable parts of the hydraulic end can be reduced.

Example 2

The difference between this embodiment and the first embodiment is that each plunger corresponds to one buffer device, that is, the buffer device is processed into an independent small individual.

Example 3

The difference between this embodiment and the embodiment 1 or the embodiment 2 is that the number of the plungers 4 on the hydraulic end 1 is three or seven, and the number of the linear motors 3 corresponds to three or Seven.

The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modification, equivalent replacement and improvement made within the principle of the present invention shall be included in the protection scope of the present invention. Inside.

Claims

A fracturing pump driven by a linear motor is characterized by comprising at least one hydraulic end, one end of each hydraulic end is provided with a plurality of plungers side by side, and each plunger is correspondingly connected with a linear motor, The linear motor drives the plunger to make a reciprocating linear movement, and the other end of the hydraulic end is also provided with several control valves, and the control valves are used to control the suction or discharge of liquid when the plunger moves.
The fracturing pump driven by a linear motor according to claim 1, wherein the linear motor is a double-ended drive structure, and there are two hydraulic ends corresponding to the two ends of the linear motor. The two ends are correspondingly connected with the plungers on the two hydraulic ends.
The fracturing pump driven by a linear motor according to claim 1 or 2, further comprising a buffer device for reducing the commutation impact of the linear motor, and the buffer device is arranged on the hydraulic end and the linear motor. Between the two ends of the linear motor commutation position.
The fracturing pump driven by a linear motor according to claim 3, wherein the hydraulic end corresponds to one buffer device.
The fracturing pump driven by a linear motor according to claim 3, wherein each plunger corresponds to one buffer device.
The fracturing pump driven by a linear motor according to any one of claims 1-5, wherein the number of the plungers on the hydraulic end is an odd number and at least three, and the linear motor has an odd number of plungers. The number is the same as the number of the plungers.
The fracturing pump driven by a linear motor according to claim 6, wherein the number of the plungers on the hydraulic end is five, and the number of the linear motors is correspondingly five.
The fracturing pump driven by a linear motor according to claim 7, wherein the movement direction of all linear motors is set to the same phase angle difference as the crankshaft.
The fracturing pump driven by a linear motor according to any one of claims 1 to 5, wherein the other end of the hydraulic end is provided with two control valves, and the control valves are one-way valves.
The fracturing pump driven by a linear motor according to any one of claims 1 to 5, wherein the stroke of the linear motor is greater than or equal to 12".