Plunger pump flow output unit, plunger pump system and plunger pump flow regulation and control method

Abstract

The invention relates to the technical field of hydraulic pressure, in particular to a plunger pump flow output unit, a plunger pump system and a plunger pump flow regulation and control method. The plunger pump flow output unit comprises a first cavity and a second cavity, the first cavity and the second cavity are connected between the low-pressure loop and the high-pressure loop respectively, a connecting channel is communicated between the first cavity and the second cavity, and a digital proportional valve used for adjusting the flow channel sectional area of the connecting channel is arranged on the connecting channel. The reciprocating motion mechanism comprises a driver and a plunger connecting rod, a first plunger and a second plunger are arranged at the two ends of the plunger connecting rod respectively, and the first plunger and the second plunger are arranged in the first cavity and the second cavity respectively in a sliding fit mode. According to the scheme, the defects that in the prior art, a direct-drive digital plunger pump is limited in variable range, and zero-flow output cannot be achieved are overcome, and the requirement for accurate liquid using of a fully-mechanized coal mining face hydraulic support according to needs is met.

Description

Technical Field

[0001] The present invention relates to the field of hydraulic technology, and in particular to a plunger pump flow output unit, a plunger pump system and a plunger pump flow control method. Background Art

[0002] Hydraulic support is an important auxiliary equipment for coal mine fully mechanized mining working face, and its reliability directly affects the safety and efficiency of fully mechanized mining operation. As the power source of hydraulic support, the plunger pump needs to be able to provide high-pressure emulsion and flexibly adjust the flow rate according to the action requirements of the hydraulic support.

[0003] Existing direct-drive digital plunger pumps mainly use a crank slider mechanism or a swash plate mechanism to achieve flow regulation. The crank slider pump uses a variable frequency motor to adjust the speed. Although it can change the reciprocating speed of the plunger to achieve flow regulation, it has a delayed response and a small adjustment range. The swash plate pump changes the plunger stroke by adjusting the inclination angle of the swash plate, but its structure is complex and the flow response is slow. Both cannot meet the requirements of high-precision and fast-response flow regulation in comprehensive mining. Summary of the invention

[0004] The present invention provides a plunger pump flow output unit, a plunger pump system and a plunger pump flow control method, so as to solve the defects of the prior art that the direct-drive digital plunger pump has a limited variable range and cannot achieve zero flow output, so as to meet the demand for accurate and on-demand use of fluid by the hydraulic support of the comprehensive mining working face.

[0005] The present invention provides a plunger pump flow output unit, comprising: a first cavity and a second cavity, both of which are connected between a low-pressure circuit and a high-pressure circuit respectively, a connecting channel is connected between the first cavity and the second cavity, and a digital proportional valve for adjusting the flow channel cross-sectional area of ​​the connecting channel is arranged on the connecting channel; a reciprocating motion mechanism, comprising a driver and a plunger connecting rod, a first plunger and a second plunger are arranged at both ends of the plunger connecting rod respectively, and the first plunger and the second plunger are slidably fitted in the first cavity and the second cavity respectively.

[0006] According to a plunger pump flow output unit of the present invention, the cross-sectional areas of the first cavity and the second cavity, the cross-sectional area of ​​the connecting channel, and the cross-sectional area of ​​the flow channel when the digital proportional valve is fully opened are equal.

[0007] A plunger pump flow output unit according to the present invention has a zero output state, a partial output state and a full output state; in the zero output state, the digital proportional valve is fully opened, all the fluid in the first cavity and the second cavity flows back and forth through the connecting channel, and the plunger pump flow output unit has no flow output to the high-pressure circuit; in the partial output state, the digital proportional valve is partially opened, part of the fluid in the first cavity and the second cavity flows back and forth through the connecting channel, and the plunger pump flow output unit outputs partial flow to the high-pressure circuit; in the full output state, the digital proportional valve is fully closed, no fluid passes through the connecting channel, and the plunger pump flow output unit outputs full flow to the high-pressure circuit.

[0008] According to a plunger pump flow output unit of the present invention, the reciprocating motion mechanism includes a guide block and a slideway; the guide block is arranged on the plunger connecting rod to divide the plunger connecting rod into a first rod body located between the guide block and the first plunger and a second rod body located between the guide block and the second plunger; the slideway is fixedly arranged relative to the first cavity and the second cavity, and the guide block is slidably arranged in the slideway.

[0009] According to a plunger pump flow output unit of the present invention, the driver is a linear motor or an electro-hydraulic actuator; the driver is connected to the guide block via a push rod.

[0010] According to the present invention, a plunger pump flow output unit includes: a first suction check valve, arranged between the first cavity and the low-pressure circuit, to limit the one-way flow of fluid from the low-pressure circuit to the first cavity; a second suction check valve, arranged between the second cavity and the low-pressure circuit, to limit the one-way flow of fluid from the low-pressure circuit to the second cavity; a first discharge check valve, arranged between the first cavity and the high-pressure circuit, to limit the one-way flow of fluid from the first cavity to the high-pressure circuit; a second discharge check valve, arranged between the second cavity and the high-pressure circuit, to limit the one-way flow of fluid from the second cavity to the high-pressure circuit.

[0011] The present invention also provides a plunger pump system, comprising: one or more plunger pump flow output units of the above-mentioned embodiments, when the number of the plunger pump flow output units is multiple, the multiple plunger pump flow output units are connected in parallel with each other; a controller controls the flow of a single plunger pump flow output unit, or controls the flow of multiple plunger pump flow output units at the same time.

[0012] The present invention also provides a plunger pump flow control method for controlling a plunger pump system as in the above-mentioned embodiment, the method comprising: obtaining a target flow; determining an operating state of one or more of the plunger pump flow output units according to the target flow, the operating state comprising a zero output state, a partial output state and a full output state.

[0013] According to a plunger pump flow control method of the present invention, before the step of obtaining the target flow, the method comprises: when the plunger pump system is started, all the plunger pump flow output units operate in the zero output state.

[0014] According to a plunger pump flow control method of the present invention, the step of determining the operating status of one or more plunger pump flow output units according to the target flow includes: calculating the number N of the plunger pump flow output units that need to operate in the full output state, wherein the product of the unit flow S and the number N of a single plunger pump flow output unit operating in the full output state is less than or equal to the target flow, and the product of the unit flow S and the number is greater than the target flow; determining that N of the plunger pump flow output units operate in the full output state, and that 1 of the plunger pump flow output units operates in the zero output state or the partial output state.

[0015] The plunger pump flow output unit, plunger pump system and plunger pump flow control method provided by the present invention enable the fluid to flow alternately between the two cavities by adding a connecting channel between the two plunger cavities of the plunger pump flow output unit, thereby realizing the variable output function of the plunger pump. When the digital proportional valve is closed, the first cavity and the second cavity respectively extract fluid from the low-pressure circuit and output it to the high-pressure circuit. If the amount of fluid in the high-pressure circuit needs to be reduced, the digital proportional valve can be opened or partially opened to allow the fluid to circulate between the two plunger cavities through the connecting channel, thereby reducing the actual output to the high-pressure circuit. Compared with the existing variable frequency motor speed regulation and swash plate inclination adjustment technology, the present invention has a faster response speed and a simpler structure, which meets the high-precision and fast response requirements of the comprehensive mining working face for the flow control of the hydraulic support, while improving the flexibility and efficiency of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are 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.

[0017] Figure 1 It is a schematic diagram of the piping principle of the plunger pump flow output unit provided by the present invention.

[0018] Figure 2 It is a schematic diagram of the layout of multiple plunger pump flow output units of the plunger pump system provided by the present invention.

[0019] Figure 3 It is a flow chart of the plunger pump flow control method provided by the present invention.

[0020] Reference numerals: 1. Driver; 2. Push rod; 3. Guide block; 4. Slide; 51. First rod body; 52. Second rod body; 61. First plunger; 62. Second plunger; 71. First cavity; 72. Second cavity; 81. First suction check valve; 82. Second suction check valve; 9. Low-pressure circuit; 101. First discharge check valve; 102. Second discharge check valve; 11. High-pressure circuit; 12. Connecting channel; 13. Digital proportional valve. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] In the description of the embodiments of the present invention, it should be noted that the terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. It should also be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "set", "install", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0023] Combine the following Figure 1-Figure 3 The specific implementation methods of the plunger pump flow output unit, plunger pump system and plunger pump flow control method of the present invention are described.

[0024] like Figure 1As shown, the present invention provides a plunger pump flow output unit, including a first cavity 71, a second cavity 72 and a reciprocating mechanism. The first cavity 71 and the second cavity 72 are respectively connected between the low-pressure circuit 9 and the high-pressure circuit 11, and a connecting channel 12 is connected between the first cavity 71 and the second cavity 72. The connecting channel 12 is provided with a digital proportional valve 13 for adjusting the flow channel cross-sectional area of ​​the connecting channel 12. The reciprocating mechanism includes a driver 1 and a plunger connecting rod, and the first plunger 61 and the second plunger 62 are respectively provided at both ends of the plunger connecting rod, and the first plunger 61 and the second plunger 62 are respectively slidably matched in the first cavity 71 and the second cavity 72. The plunger pump flow output unit can achieve precise flow control under different working conditions. Specifically, when the digital proportional valve 13 is closed, the first cavity 71 and the second cavity 72 operate independently. When the plunger connecting rod drives the first plunger 61 and the second plunger 62 to reciprocate, fluid is respectively extracted from the low-pressure circuit 9 and pressed into the high-pressure circuit 11, so as to ensure the normal flow output of the plunger pump system.

[0025] By adding a plunger cavity connecting channel 12 between the two plunger cavities, the fluid can flow alternately between the first cavity 71 and the second cavity 72, so that the plunger pump obtains the function of variable output. When it is necessary to reduce the amount of fluid flowing to the high-pressure circuit 11, the digital proportional valve 13 can be opened or partially opened. At this time, the fluid can not only be delivered to the high-pressure circuit 11 through the plunger cavity, but also circulate between the two chambers through the connecting channel 12, reducing the amount of fluid actually delivered to the high-pressure circuit 11.

[0026] Compared with the existing technology of changing the output flow rate by adjusting the speed of the variable frequency motor and adjusting the inclination angle of the swash plate, the present invention has a faster response speed and a simpler structure. Although the traditional variable frequency motor speed regulation method can change the reciprocating speed of the plunger to adjust the flow rate, there are problems of response lag and limited adjustment range; the swash plate pump changes the stroke of the plunger by adjusting the angle of the swash plate, but its structure is relatively complex and the flow rate response is slow. In contrast, the present invention provides a more efficient and simple solution, thereby better meeting the high precision and fast response requirements of the hydraulic support for the comprehensive mining working face. In addition, the plunger pump flow output unit also improves the flexibility and efficiency of the system, providing more reliable support for the comprehensive mining working face of coal mines.

[0027] Preferably, according to a plunger pump flow output unit of the present invention, the cross-sectional area of ​​the first cavity 71 and the second cavity 72, the cross-sectional area of ​​the connecting channel 12, and the cross-sectional area of ​​the flow channel when the digital proportional valve 13 is fully opened are equal. By constructing the connecting channel 12 of the plunger cavity between the first cavity 71 and the second cavity 72, and using the digital proportional valve 13 to control the full opening, partial opening and disconnection of the connecting channel 12, a full range of variable flow output of 0~100% can be achieved. Specifically, when the digital proportional valve 13 is closed, the first cavity 71 and the second cavity 72 respectively extract fluid from the low-pressure circuit 9 and output it to the high-pressure circuit 11, ensuring normal flow supply. When it is necessary to reduce the amount of fluid in the high-pressure circuit 11, the digital proportional valve 13 can be opened or partially opened to allow the fluid to circulate between the two plunger cavities through the connecting channel 12, thereby reducing the amount of fluid actually delivered to the high-pressure circuit 11. When the digital proportional valve 13 is fully opened, the fluid circulates completely between the two plunger cavities without flowing into the high-pressure circuit 11, thereby achieving zero flow output. It not only solves the problem that the existing direct-drive digital plunger pump cannot achieve zero flow output due to the limited speed regulation range of driver 1, but also has a faster response speed and a simpler mechanical structure compared with the traditional method of variable frequency motor speed regulation and adjusting the inclination angle of the swash plate, and can better meet the high-precision and rapid response requirements of the coal mine fully mechanized mining working face for the flow control of the hydraulic support.

[0028] Specifically, a plunger pump flow output unit according to the present invention has a zero output state, a partial output state and a full output state. In the zero output state, the digital proportional valve 13 is fully opened, all the fluids in the first cavity 71 and the second cavity 72 flow back and forth through the connecting channel 12, and the plunger pump flow output unit has no flow output to the high pressure circuit 11. When it is not necessary to provide fluid to the hydraulic system, the fluid will circulate between the two plunger cavities, thereby achieving true zero flow output. In the partial output state, the digital proportional valve 13 is partially opened, part of the fluid in the first cavity 71 and the second cavity 72 flows back and forth through the connecting channel 12, and the plunger pump flow output unit outputs part of the flow to the high pressure circuit 11. Part of the fluid in the first cavity 71 and the second cavity 72 flows back and forth through the connecting channel 12, while the other part of the fluid is directed to the high pressure circuit 11, so that the plunger pump flow output unit can output part of the flow to the high pressure circuit 11 according to actual needs, allowing the user to accurately adjust the output flow as needed, and improve the efficiency and flexibility of the hydraulic system. In the full output state, the digital proportional valve 13 is completely closed, no fluid passes through the connecting channel 12, and the plunger pump flow output unit outputs full flow to the high-pressure circuit 11. The flow channel cross-sectional area of ​​the connecting channel 12 is controlled by different opening degrees of the digital proportional valve 13. The present invention can achieve a continuously adjustable flow output from 0% to 100%, overcoming the defects of the direct-drive digital plunger pump in the prior art that the variable range is limited and zero flow output cannot be achieved, and provides a more reliable hydraulic support power source for the fully-mechanized mining working face of the coal mine.

[0029] Close the digital proportional valve 13, disconnect the connecting channel 12, and realize full flow output at this time, specifically as follows: when the plunger pump flow output unit is set to the full output state, the digital proportional valve 13 is completely closed, and the first cavity 71 and the second cavity 72 are isolated from each other. Figure 1 As shown, the driver 1 drives the piston connecting rod to move at a fixed speed and stroke, driving the first piston 61 and the second piston 62 to move synchronously. When the driver 1 drives the piston connecting rod to move to the left, the first piston 61 moves to the left, causing the volume of the first cavity 71 to decrease, thereby outputting high-pressure fluid to the high-pressure circuit 11. At the same time, the second piston 62 also moves to the left, sucking fluid from the low-pressure circuit 9. When the driver 1 drives the piston connecting rod to the left end point, the driver 1 starts to drive in the reverse direction, and the piston connecting rod moves to the right accordingly. At this time, the suction and discharge states of the first cavity 71 and the second cavity 72 are interchanged-the first cavity 71 starts to absorb liquid due to the increase in volume, and the second cavity 72 starts to discharge liquid due to the decrease in volume. By continuously repeating this reciprocating motion process, high-pressure fluid can be continuously provided to the high-pressure circuit 11 in each movement cycle of the piston connecting rod, thereby achieving 100% full flow output.

[0030] The digital proportional valve 13 is fully opened, and the connecting channel 12 is fully opened, and zero flow output is achieved at this time, as follows: When the flow output unit of the plunger pump is set to the zero output state, the digital proportional valve 13 is fully opened, which makes the connecting channel 12 between the first cavity 71 and the second cavity 72 fully open. At this time, no matter how the driver 1 drives the plunger connecting rod to reciprocate, the fluid in the first cavity 71 and the second cavity 72 only circulates between the two cavities, and does not flow into the high-pressure circuit 11. Therefore, the high-pressure circuit 11 has no fluid output during the entire cycle of the reciprocating motion of the plunger connecting rod, and the state of zero flow output of the plunger pump is achieved.

[0031] The digital proportional valve 13 is partially opened, and the connecting channel 12 is opened, and partial flow output is realized at this time, specifically as follows: when partial flow output is required, for example, 50% flow output, the valve port of the digital proportional valve 13 is opened by 50%, so that a part of the fluid can circulate between the first cavity 71 and the second cavity 72 through the connecting channel 12. Therefore, only 50% of the fluid discharged from the first cavity 71 is transported to the second cavity 72 through the connecting channel 12, and the remaining 50% of the fluid is transported to the high-pressure circuit 11. Similarly, when the volume of the second cavity 72 decreases, 50% of the fluid is also discharged into the high-pressure circuit 11, and the other 50% of the fluid returns to the first cavity 71 through the connecting channel 12. Therefore, the high-pressure circuit 11 has only 50% of the fluid output during the entire cycle of the reciprocating motion of the plunger connecting rod. By adjusting the valve port opening ratio of the digital proportional valve 13, such as 20%, 50%, 70%, etc., the partial flow output state of the plunger pump in different proportions can be realized accordingly. In this way, the flow output can be flexibly adjusted according to actual needs to meet the fluid requirements of the hydraulic support under different working conditions.

[0032] According to a plunger pump flow output unit of the present invention, the reciprocating mechanism includes a guide block 3 and a slideway 4; the guide block 3 is arranged on the plunger connecting rod to divide the plunger connecting rod into a first rod body 51 located between the guide block 3 and the first plunger 61 and a second rod body 52 located between the guide block 3 and the second plunger 62; the slideway 4 is fixed relative to the first cavity 71 and the second cavity 72, and the guide block 3 is slidably arranged in the slideway 4. The guide block 3 not only divides the plunger connecting rod into the first rod body 51 and the second rod body 52, but also slides in the slideway 4 as a connecting member to guide the reciprocating motion of the plunger connecting rod. By adding the guide block 3 between the driver 1 and the two oppositely arranged plungers, the guide block 3 becomes the medium between the driver 1 and the plunger, thereby improving the guiding property of the plunger and enhancing the stability of the operation of the plunger pump. The smooth sliding of the guide block 3 in the slideway 4 ensures the precise movement of the plunger connecting rod, thereby ensuring the effective suction and discharge of the fluid in the plunger cavity, and improving the reliability and efficiency of the operation of the plunger pump.

[0033] Further, according to a plunger pump flow output unit of the present invention, the driver 1 is a high-frequency drive mechanism such as a linear motor or an electro-hydraulic actuator; the driver 1 is connected to the guide block 3 through a push rod 2. Specifically, the driver 1 is fixed to the push rod 2, the push rod 2 is fixed to the guide block 3, the guide block 3 is fixed to the first rod body 51 and the second rod body 52 respectively, and the first rod body 51 and the second rod body 52 are fixed to the first plunger 61 and the second plunger 62 respectively. When the driver 1 (whether it is a linear motor or an electro-hydraulic actuator) works, the linear motion generated by it is transmitted to the guide block 3 through the push rod 2, thereby driving the guide block 3 to slide in the slideway 4. The motion of the guide block 3 will be directly converted into the reciprocating motion of the first rod body 51 and the second rod body 52 of the plunger connecting rod, and finally realize the reciprocating motion of the first plunger 61 and the second plunger 62 in their respective plunger cavities. Such a transmission chain ensures the directness and efficiency of the motion, reduces energy loss, and improves the working efficiency and stability of the entire plunger pump flow output unit.

[0034] A plunger pump flow output unit according to the present invention includes a first suction check valve 81, a second suction check valve 82, a first discharge check valve 101 and a second discharge check valve 102. The first suction check valve 81 is arranged between the first cavity 71 and the low-pressure circuit 9 to limit the one-way flow of fluid from the low-pressure circuit 9 to the first cavity 71. The second suction check valve 82 is arranged between the second cavity 72 and the low-pressure circuit 9 to limit the one-way flow of fluid from the low-pressure circuit 9 to the second cavity 72. The first discharge check valve 101 is arranged between the first cavity 71 and the high-pressure circuit 11 to limit the one-way flow of fluid from the first cavity 71 to the high-pressure circuit 11. The second discharge check valve 102 is arranged between the second cavity 72 and the high-pressure circuit 11 to limit the one-way flow of fluid from the second cavity 72 to the high-pressure circuit 11. The design of the check valve ensures that the fluid flows in the correct direction when the plunger pump is working. When the volume of the first cavity 71 decreases, the fluid is compressed and delivered to the high-pressure circuit 11 through the first liquid discharge check valve 101; at the same time, the volume of the second cavity 72 increases, and the fluid enters the second cavity 72 from the low-pressure circuit 9 through the second liquid suction check valve 82. When the direction of the plunger connecting rod is reversed, the direction of the fluid flow is also switched, thereby ensuring that the plunger pump can continuously deliver fluid to the high-pressure circuit 11, and there is only one-way flow at any time, avoiding the backflow of the fluid. Such a design optimizes the fluid transmission efficiency and improves the working performance of the plunger pump.

[0035] In addition to the above-mentioned one-way valve design, other settings can also be used to ensure the correct flow direction of the fluid in the output unit, such as an electronically controlled solenoid valve. The solenoid valve can be installed at a key position in the fluid path, and the switch of the solenoid valve can be controlled by an electronic control system, thereby accurately controlling the flow direction of the fluid.

[0036] The plunger pump system provided by the present invention is described below. The plunger pump system described below and the plunger pump flow output unit described above can be referenced to each other.

[0037] like Figure 2 As shown, the present invention also provides a plunger pump system, comprising: one or more plunger pump flow output units of the above-mentioned embodiments, when the number of the plunger pump flow output units is multiple, the multiple plunger pump flow output units are connected in parallel with each other; a controller controls the flow of a single plunger pump flow output unit, or controls the flow of multiple plunger pump flow output units at the same time.

[0038] Specifically, when only one plunger pump flow output unit is working, different output states from zero flow to full flow can be achieved through different opening states of the digital proportional valve 13 (fully closed, partially open, fully open). The controller adjusts the opening of the digital proportional valve 13 according to preset or real-time requirements, thereby accurately controlling the output flow. In the full output state, the digital proportional valve 13 is completely closed, and the fluid can only be delivered to the high-pressure circuit 11 through the first discharge check valve 101 and the second discharge check valve 102. In the partial output state, the digital proportional valve 13 is partially opened, and part of the fluid circulates between the first cavity 71 and the second cavity 72 through the connecting channel 12, while the rest is delivered to the high-pressure circuit 11. In the zero output state, the digital proportional valve 13 is fully opened, and the fluid circulates completely between the first cavity 71 and the second cavity 72, and does not enter the high-pressure circuit 11.

[0039] When there are multiple plunger pump flow output units working in parallel in the system, each unit can independently adjust its output flow to meet different load requirements. The controller can control the opening of the digital proportional valve 13 of each plunger pump flow output unit individually, or coordinate the working status of multiple units to achieve uniform distribution of the overall flow or distribute the flow according to specific needs. Multiple parallel plunger pump flow output units can be flexibly configured according to actual needs. For example, in some cases, only some units may need to work to meet lower flow requirements, while during peak loads, all units can be activated to achieve maximum flow output.

[0040] Among them, the controller is the core component of the plunger pump system, which can receive data from sensors, such as pressure sensors, flow meters, etc., and adjust the working status of each plunger pump flow output unit in real time according to these data. Through the pre-programmed logic algorithm, the controller can accurately control the opening of the digital proportional valve 13 of each plunger pump flow output unit to ensure that the system can provide the required flow and pressure under various working conditions. In a multi-unit system, the controller can also balance the load between each unit, prevent overload, and ensure the long-term stable operation of the system. The plunger pump system of the present invention can achieve precise flow control by integrating digital proportional valve 13 technology and intelligent control system, meeting the high precision and rapid response requirements of the hydraulic support of the coal mine comprehensive mining working face.

[0041] The plunger pump flow control method provided by the present invention is described below. The plunger pump flow control method described below and the plunger pump system and plunger pump flow output unit described above can correspond to each other.

[0042] like Figure 3 As shown, the present invention also provides a plunger pump flow control method for controlling the plunger pump system as in the above embodiment, the method comprising: Step 100: Obtain target traffic.

[0043] First, it is necessary to determine the flow rate required by the hydraulic system, which is usually determined by sensor data in the control system or a pre-set target value. For example, the control system may collect real-time data through pressure sensors, flow meters or other monitoring devices based on the action requirements of the hydraulic support, and then calculate the required target flow rate. The target flow rate can be a static value or a dynamic value that changes with time and working conditions. In either case, obtaining an accurate target flow rate is the basis for achieving precise flow control.

[0044] Step 200: Determine the operating state of one or more plunger pump flow output units according to the target flow, the operating state including a zero output state, a partial output state and a full output state.

[0045] According to the target flow obtained in step 100, the controller needs to determine the operating state of one or more plunger pump flow output units. Among them, if the target flow is zero, the controller will fully open the digital proportional valve 13 so that the fluid circulates between the first cavity 71 and the second cavity 72 without entering the high-pressure circuit 11, thereby achieving zero flow output. If the target flow is between zero and the maximum output, the controller will adjust the opening of the digital proportional valve 13 according to actual needs, and part of the fluid will circulate between the two plunger cavities through the connecting channel 12, while the remaining fluid will be delivered to the high-pressure circuit 11. If the target flow reaches the maximum output, the controller will completely close the digital proportional valve 13 to prevent the fluid from circulating through the connecting channel 12, so that all fluids extracted from the low-pressure circuit 9 are delivered to the high-pressure circuit 11, thereby achieving full flow output.

[0046] Through the above steps, the plunger pump flow control method of the present invention can dynamically adjust the working state of the plunger pump flow output unit according to actual needs, thereby ensuring that the hydraulic system can always obtain the required fluid supply and meet the precise flow requirements of the hydraulic support of the coal mine comprehensive mining working face.

[0047] According to a plunger pump flow control method of the present invention, before the step of obtaining the target flow, it includes: when the plunger pump system is started, all the plunger pump flow output units operate in a zero output state. Specifically, when the plunger pump system is started, all the plunger pump flow output units will be initialized to a zero output state. At this time, the digital proportional valve 13 is fully opened, so that the fluid circulates between the first cavity 71 and the second cavity 72 without entering the high-pressure circuit 11. This initial setting ensures that the system will not have unnecessary fluid output during the startup phase, thereby avoiding instability or unexpected situations that may occur when the system starts.

[0048] In addition, at the beginning of the system startup, before the plunger pump flow output unit starts to operate, it is preferred to determine the maximum number of plunger pump flow output units that may be involved in the work according to the maximum hydraulic demand of the hydraulic device (such as a hydraulic support). In this way, when the plunger pump system is started, only the corresponding number of plunger pump flow output units are started and set to zero output state, and the remaining plunger pump flow output units remain in standby state and do not participate in the work, thereby saving energy consumption.

[0049] In this way, the system can pre-plan the number of plunger pump flow output units involved in the work according to the actual maximum demand when it starts, which can not only avoid starting too many plunger pump flow output units without actual demand, reducing unnecessary energy consumption, but also reduce equipment wear and extend the service life of the system. When the actual demand changes, the controller can dynamically adjust the number of working plunger pump flow output units and their operating status according to the new target flow, ensuring that the system can both meet the flow demand of the hydraulic support and achieve energy saving.

[0050] Further, according to a plunger pump flow control method of the present invention, the step of determining the operating state of one or more plunger pump flow output units according to the target flow includes: Step 201: Calculate the number N of plunger pump flow output units that need to run in full output state, wherein the product of the unit flow S and the number N of a single plunger pump flow output unit running in full output state is less than or equal to the target flow, and the product of the unit flow S and the number is greater than the target flow.

[0051] Here, N refers to the number of units that will run at full output, ensuring that the product of the unit flow rate S of a single plunger pump flow output unit running at full output and the number N is less than or equal to the target flow rate, but as close to the target flow rate as possible. That is, N×S≤target flow rate<(N+1)×S, where S is the unit flow rate of a single plunger pump flow output unit at full output.

[0052] Step 202: Determine whether N plunger pump flow output units are operating in a full output state, and whether 1 plunger pump flow output unit is operating in a zero output state or a partial output state.

[0053] According to the result calculated in step 201, it is determined that N plunger pump flow output units are running in full output state. If the target flow exceeds N×S, then another plunger pump flow output unit is required to supplement the remaining flow demand. This unit can be set to a partial output state to make up the difference, or if the target flow is exactly equal to N×S, it can be set to a zero output state to avoid excessive output.

[0054] Through the above steps, the plunger pump flow control method of the present invention can dynamically adjust the working state of the plunger pump flow output unit according to actual needs, ensuring that the hydraulic system can always obtain the required fluid supply and meet the precise flow requirements of the hydraulic support of the coal mine comprehensive mining working face, which not only improves the flexibility and efficiency of the system, but also ensures the effective use of resources.

[0055] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "mode", "specific mode", or "some modes" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or mode are included in at least one embodiment or mode of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or mode. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or modes in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or modes described in this specification and the features of the different embodiments or modes, without contradiction.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A plunger pump flow output unit, characterized in that: include: A first cavity (71) and a second cavity (72), the two being connected between a low-pressure circuit (9) and a high-pressure circuit (11) respectively; a connecting passage (12) is connected between the first cavity (71) and the second cavity (72); a digital proportional valve (13) for adjusting a flow passage cross-sectional area of ​​the connecting passage (12) is provided on the connecting passage (12); A reciprocating mechanism comprises a driver (1) and a plunger connecting rod, wherein two ends of the plunger connecting rod are respectively provided with a first plunger (61) and a second plunger (62), and the first plunger (61) and the second plunger (62) are respectively slidably fitted in the first cavity (71) and the second cavity (72).

2. The plunger pump flow output unit according to claim 1, characterized in that: The cross-sectional areas of the first cavity (71) and the second cavity (72), the cross-sectional area of ​​the connecting channel (12), and the cross-sectional area of ​​the flow channel when the digital proportional valve (13) is fully opened are equal.

3. The plunger pump flow output unit according to claim 2, characterized in that: It has a zero output state, a partial output state and a full output state; In the zero output state, the digital proportional valve (13) is fully opened, all fluids in the first cavity (71) and the second cavity (72) flow back and forth through the connecting channel (12), and the plunger pump flow output unit outputs no flow to the high-pressure circuit (11); In the partial output state, the digital proportional valve (13) is partially opened, part of the fluid in the first cavity (71) and the second cavity (72) flows back and forth through the connecting channel (12), and the plunger pump flow output unit outputs part of the flow to the high-pressure circuit (11); In the full output state, the digital proportional valve (13) is completely closed, no fluid passes through the connecting channel (12), and the plunger pump flow output unit outputs full flow to the high-pressure circuit (11).

4. The plunger pump flow output unit according to claim 1, characterized in that: The reciprocating motion mechanism comprises a guide block (3) and a slideway (4); The guide block (3) is arranged on the plunger connecting rod to divide the plunger connecting rod into a first rod body (51) located between the guide block (3) and the first plunger (61) and a second rod body (52) located between the guide block (3) and the second plunger (62); The slideway (4) is fixedly arranged relative to the first cavity (71) and the second cavity (72), and the guide block (3) is slidably arranged in the slideway (4).

5. The plunger pump flow output unit according to claim 4, characterized in that: The driver (1) is a linear motor or an electro-hydraulic actuator; The driver (1) and the guide block (3) are connected via a push rod (2).

6. The plunger pump flow output unit according to any one of claims 1 to 5, characterized in that: include: a first liquid suction one-way valve (81) disposed between the first cavity (71) and the low-pressure circuit (9) to limit one-way flow of fluid from the low-pressure circuit (9) to the first cavity (71); a second liquid suction one-way valve (82) disposed between the second chamber (72) and the low-pressure circuit (9) to limit one-way flow of fluid from the low-pressure circuit (9) to the second chamber (72); a first liquid discharge one-way valve (101), arranged between the first cavity (71) and the high-pressure circuit (11), to limit one-way flow of fluid from the first cavity (71) to the high-pressure circuit (11); The second liquid discharge one-way valve (102) is arranged between the second chamber (72) and the high-pressure circuit (11) to limit the one-way flow of fluid from the second chamber (72) to the high-pressure circuit (11).

7. A plunger pump system, characterized in that: include: One or more plunger pump flow output units according to any one of claims 1 to 6, wherein when there are multiple plunger pump flow output units, the multiple plunger pump flow output units are connected in parallel; The controller controls the flow rate of a single plunger pump flow output unit, or controls the flow rates of a plurality of plunger pump flow output units simultaneously.

8. A plunger pump flow control method, characterized in that: For controlling the plunger pump system as claimed in claim 7, the method comprises: Get targeted traffic; The operating state of one or more of the plunger pump flow output units is determined according to the target flow, and the operating state includes a zero output state, a partial output state and a full output state.

9. The plunger pump flow control method according to claim 8, characterized in that: Before the step of obtaining the target traffic, the method includes: When the plunger pump system is started, all of the plunger pump flow output units operate in the zero output state.

10. The plunger pump flow control method according to claim 8 or 9, characterized in that: The step of determining the operating state of one or more of the plunger pump flow output units according to the target flow rate comprises: Calculating the number N of the plunger pump flow output units that need to be operated in the full output state, wherein the product of the unit flow S and the number N of a single plunger pump flow output unit operating in the full output state is less than or equal to the target flow, and the product of the unit flow S and the number (N+1) is greater than the target flow; Determine that N of the plunger pump flow output units operate in a full output state, and that 1 of the plunger pump flow output units operates in a zero output state or a partial output state.

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