1. The axial flow fan blade control system is characterized by comprising an adjusting oil cylinder (1) and a control cabinet (2), wherein a control oil way (21) and an electric control part (22) are arranged in the control cabinet (2), and a P port, a T port, an A port and a B port are arranged on the control cabinet (2);

the adjusting oil cylinder (1) comprises a cylinder body (11), a piston (12) capable of moving axially relative to the cylinder body (11) is arranged in the cylinder body (11), and the cylinder body (11) is divided into a first cavity (111) and a second cavity (112) by the piston (12);

the control oil way (21) is communicated with an external oil source through the port P and the port T, is communicated with a first cavity (111) of the adjusting oil cylinder (1) through the port A, and is communicated with a second cavity (112) of the adjusting oil cylinder (1) through the port B;

the electric control part (22) is electrically connected with the control oil way (21), and the electric control part (22) realizes the movement of the piston (12) along the axial direction of the cylinder body (11) by controlling the flow direction and the pressure of hydraulic oil in the control oil way (21);

the control oil path (21) comprises a first control oil path (211) and a second control oil path (212) which are arranged in a redundant mode.

2. The axial flow fan blade control system according to claim 1, wherein the first control oil path (211) comprises a first proportional valve (1.1), a first reversing valve (2.1) and a second reversing valve (2.2), the first proportional valve (1.1) is a three-position four-way proportional valve, and the first reversing valve (2.1) and the second reversing valve (2.2) are both three-position two-way reversing valves; the port P and the port T of the first proportional valve (1.1) are communicated with an external oil source; the port A of the first proportional valve (1.1) is communicated with the port P of the first reversing valve (2.1), and the port T of the first reversing valve (2.1) is communicated with a first cavity (111) of the adjusting oil cylinder (1); a port P of the second reversing valve (2.2) is communicated with a port B of the first proportional valve (1.1), and a port T of the second reversing valve (2.2) is communicated with a second cavity (112) of the adjusting oil cylinder (1);

the second control oil way (212) comprises a second proportional valve (1.2), a third reversing valve (2.3) and a fourth reversing valve (2.4), the second proportional valve (1.2) is a three-position four-way proportional valve, the third reversing valve (2.3) and the fourth reversing valve (2.4) are both three-position two-way reversing valves, and a P port and a T port of the second proportional valve (1.2) are communicated with an external oil source; the port A of the second proportional valve (1.2) is communicated with the port P of the third reversing valve (2.3), and the port T of the third reversing valve (2.3) is communicated with the first cavity (111) of the adjusting oil cylinder (1); and a port P of the fourth reversing valve (2.4) is communicated with a port B of the second proportional valve (1.2), and a port T of the fourth reversing valve (2.4) is communicated with a second cavity (112) of the adjusting oil cylinder (1).

3. The axial fan blade control system according to claim 2, wherein a first ball valve (3.1) is arranged at a P port of the first proportional valve (1.1), and a second ball valve (3.2) is arranged at a T port; a third ball valve (3.3) is arranged at a position P of the second proportional valve (1.2), and a fourth ball valve (3.4) is arranged at a position T; the T-port of the first reversing valve (2.1) is provided with a fifth ball valve (4.1), the T-port of the second reversing valve (2.2) is provided with a sixth ball valve (4.2), the T-port of the third reversing valve (2.3) is provided with a seventh ball valve (4.3), and the T-port of the fourth reversing valve (2.4) is provided with an eighth ball valve (4.4).

4. The axial flow fan blade control system according to claim 3, wherein the control cabinet (2) further comprises an oil filter device (23), hydraulic oil in an external oil source passes through the oil filter device (23) and then enters the first ball valve (3.1) or the second ball valve (3.1), and the oil filter device (23) is a double-cylinder filter.

5. The axial fan blade control system of claim 2, further comprising a position sensor (3), wherein the position sensor (3) is threadedly connected to the adjustment cylinder (1).

6. The axial fan blade control system of claim 1, wherein the piston (12) comprises a first concave disk (121), a second concave disk (122), a piston body (123), the first concave disk (121) and the second concave disk (122) being arranged in opposition, the piston body (123) being located between the first concave disk (121) and the second concave disk (122), the first concave disk (121) and the second concave disk (122) being provided with a plurality of through holes (124).

7. The axial fan blade control system according to claim 6, characterized in that the edge of the piston body (123) is provided with an integral peripheral edge (1231) parallel to the axis of the piston (12), said integral peripheral edge (1231) being in contact with the convex surfaces of the first concave disk (121) and the second concave disk (122).

8. The axial fan blade control system according to claim 2, further comprising a self-locking structure (4), wherein the self-locking structure (4) comprises a locking housing (41), a first locking body (42), and a second locking body (43), the first locking body (42) and the second locking body (43) are rotatably disposed in the locking housing (41), and a piston rod of the piston (12) is eccentrically inserted between the first locking body (42) and the second locking body (43).

9. The axial fan blade control system of claim 8, wherein the first locking body (42) and the second locking body (43) are each a semi-cylinder.

10. An axial flow fan blade control method based on the axial flow fan blade control system according to any one of claims 5 to 9, characterized by comprising the steps of:

step S001: selecting a target control oil path, wherein the target control oil path is a first control oil path (211) or a second control oil path (212);

step S002: the electric control part (22) sends out an expected position instruction signal and a proportional valve starting signal of the adjusting oil cylinder (1) and starts a proportional valve and a reversing valve in a target control oil path;

step S003: an external oil source provides hydraulic oil pressure for the adjusting oil cylinder (1) through a target control oil path so as to adjust a piston (12) in the adjusting oil cylinder (1) to a desired position;

step S004: a position sensor connected with the adjusting oil cylinder feeds back the detected position signal to an electric control part (22);

step S005: the electric control part (22) outputs an instruction according to the received position signal of the adjusting oil cylinder (1) so as to control the flow and the direction of a proportional valve in a target control oil way, and further realize the position adjustment of a piston (12) in the adjusting oil cylinder (1).

Background

The axial flow fan with the adjustable moving blades is widely applied to a coal power generation system of a thermal power plant, and is often used as a blower, a primary fan and an induced draft fan of a boiler system and a booster fan used in flue gas desulfurization.

As patent CN106762849B discloses a control system of adjustable improvement axial-flow type frequency conversion energy-saving fan of movable vane, this system includes the control cabinet, be equipped with the standing groove on the control cabinet, the standing groove internal rotation is connected with the fixed plate, one side of fixed plate is equipped with the display slot, be equipped with display module in the display slot. It controls the rotational speed of fan through the control cabinet to make the fan accomplish energy-concerving and environment-protective effect, and the peculiar structure of fan makes the fan dismantle fast, and also can adjust the angle and the quantity of the flabellum of fan, thereby satisfy user's demand.

And the coal power generation system of the power plant requires that the movable blade adjustable axial flow fan has high reliability, and if the fan breaks down in operation, the whole boiler system can stop operation, so that the power plant is not damaged. A blade control system of an axial flow fan with an adjustable moving blade is an important component of the fan and is responsible for adjusting the opening of the fan blade to adapt to different loads. At present, the blade adjustment of the movable blade adjustable axial flow fan mostly adopts a mechanical adjusting mechanism which comprises an actuator, a transmission mechanism, a servo valve, a hydraulic cylinder, an oil station and the like, the precision is relatively poor, the reaction is delayed, the automatic tracking and adjustment are difficult to realize, the phenomena of jamming, oil leakage, connecting rod damage and the like are easy to occur in the operation, and the fault occurrence frequency is high.

Disclosure of Invention

In order to solve at least some of the above problems, a first aspect of the present invention provides an axial flow fan blade control system, which includes an adjusting cylinder and a control cabinet, wherein the control cabinet is provided with a control oil path and an electric control part, and the control cabinet is provided with a port P, a port T, a port a and a port B;

the adjusting oil cylinder comprises a cylinder body, a piston which can axially move relative to the cylinder body is arranged in the cylinder body, and the piston divides the cylinder body into a first cavity and a second cavity;

the control oil way is communicated with an external oil source through the port P and the port T, is communicated with the first cavity of the adjusting oil cylinder through the port A, and is communicated with the second cavity of the adjusting oil cylinder through the port B;

the electric control part is electrically connected with the control oil way, and the electric control part realizes the axial movement of the piston along the cylinder body by controlling the flow direction and the pressure of hydraulic oil in the control oil way;

the control oil path comprises a first control oil path and a second control oil path which are arranged in a redundant mode, and the first control oil path and the second control oil path are identical.

Further, the first control oil path comprises a first proportional valve, a first reversing valve and a second reversing valve, the first proportional valve is a three-position four-way proportional valve, and the first reversing valve and the second reversing valve are both three-position two-way reversing valves; the port P and the port T of the first proportional valve are communicated with an external oil source; the port A of the first proportional valve is communicated with the port P of the first reversing valve, and the port T of the first reversing valve is communicated with the first cavity of the adjusting oil cylinder; a port P of the second reversing valve is communicated with a port B of the first proportional valve, and a port T of the second reversing valve is communicated with a second cavity of the adjusting oil cylinder;

the second control oil way comprises a second proportional valve, a third reversing valve and a fourth reversing valve, the second proportional valve is a three-position four-way proportional valve, and the third reversing valve and the fourth reversing valve are both three-position two-way reversing valves; the port P and the port T of the second proportional valve are communicated with an external oil source; the port A of the second proportional valve is communicated with the port P of the third reversing valve, and the port T of the third reversing valve is communicated with the first cavity of the adjusting oil cylinder; and a port P of the fourth reversing valve is communicated with a port B of the second proportional valve, and a port T of the fourth reversing valve is communicated with the second cavity of the adjusting oil cylinder.

Furthermore, a first ball valve is arranged at a position P of the first proportional valve, and a second ball valve is arranged at a position T of the first proportional valve; a third ball valve is arranged at the position of a P port of the second proportional valve, and a fourth ball valve is arranged at the position of a T port of the second proportional valve; the T-shaped port of the first reversing valve is provided with a fifth ball valve, the T-shaped port of the second reversing valve is provided with a sixth ball valve, the T-shaped port of the third reversing valve is provided with a seventh ball valve, and the T-shaped port of the fourth reversing valve is provided with an eighth ball valve.

Furthermore, the control cabinet further comprises an oil filtering device, hydraulic oil in an external oil source enters the first ball valve or the second ball valve after passing through the oil filtering device, and the oil filtering device is a double-cylinder filter.

Further, axial fan blade control system still includes position sensor, position sensor with adjust the hydro-cylinder through threaded connection.

Further, the piston comprises a first concave disc, a second concave disc and a piston main body, wherein the first concave disc and the second concave disc are oppositely arranged, the piston main body is located between the first concave disc and the second concave disc, and a plurality of through holes are formed in the first concave disc and the second concave disc.

Further, the edge of the piston main body is provided with an integrated periphery parallel to the axis of the piston, and the integrated periphery is in contact with the first concave disc and the second concave disc.

Further, the axial flow fan blade control system further comprises a self-locking structure, wherein the self-locking structure comprises a locking shell, a first locking body and a second locking body, the first locking body and the second locking body are rotatably arranged in the locking shell, and a piston rod of the piston is eccentrically inserted between the first locking body and the second locking body.

Further, the first locking body and the second locking body are both semi-cylinders.

In a second aspect of the present invention, there is provided an axial flow fan blade control method, which is based on the axial flow fan blade control system, and includes the following steps:

step S001: selecting a target control oil way, wherein the target control oil way is a first control oil way or a second control oil way;

step S002: the electric control part sends out an expected position command signal of the adjusting oil cylinder and a proportional valve starting signal, and starts a proportional valve and a reversing valve in a target control oil way;

step S003: an external oil source provides hydraulic oil pressure for the adjusting oil cylinder through a target control oil path so as to adjust a piston in the adjusting oil cylinder to a desired position;

step S004: a position sensor connected with the adjusting oil cylinder feeds back the detected position signal to the electric control part;

step S005: the electric control part outputs an instruction according to the received position signal of the adjusting oil cylinder so as to control the flow and the direction of the proportional valve in the target control oil way, and further realize the position adjustment of the piston in the adjusting oil cylinder.

Compared with the prior art, the invention has the beneficial effects that:

1) according to the invention, the control oil circuit of the blade control system of the axial flow fan and the control oil circuit of the electric control part are integrated together, namely the control oil circuit and the electric control part are integrated in the integrated control cabinet, so that the control structure is simple, the occupied space is small, the original control mode is simplified, the equipment installation material and labor cost are reduced, and the debugging time of the whole set of equipment is shortened.

2) The control oil way comprises a first control oil way and a second control oil way which are arranged in a redundant mode, and the structural composition of the first control oil way is completely the same as that of the second control oil way. The electric control part in the invention can realize the relative motion between the piston and the cylinder body in the adjusting oil cylinder by controlling the related components in the first control oil path, and can also realize the relative motion between the piston and the cylinder body in the adjusting oil cylinder by controlling the related components in the second control oil path. When equipment in a certain control oil way needs to be replaced or maintained, the electric control part can selectively control another control oil way to realize the motion control of the adjusting oil cylinder. Therefore, the axial flow fan system can be maintained and components and parts can be replaced without stopping.

3) The blade control system of the axial flow fan can perform closed-loop control on the speed and the direction of the piston of the adjusting oil cylinder, and realize high-precision and high-reliability control on the adjusting oil cylinder.

4) The oil filtering device in the control cabinet provided by the invention uses the double-cylinder filter, and the filter can be manually switched to carry out filter element replacement work under a non-stop state.

5) According to the piston structure, the first concave disc and the second concave disc are oppositely arranged, so that under the condition that the normal movement of the piston is ensured, the inner wall of the adjusting oil cylinder can be tightly grabbed by the edges of the first concave disc and the second concave disc of the piston under the condition that the adjusting oil cylinder suddenly loses pressure, the piston is locked on the inner wall of the cylinder body, and the piston is prevented from moving.

6) According to the self-locking structure, the piston rod is eccentrically inserted into the first locking body and the second locking body, the rotating centers of the first locking body and the second locking body are eccentric with the piston rod, so that when the piston rod needs to be locked, the first locking body rotates in the anticlockwise direction, the second locking body rotates in the clockwise direction, the piston rod is clamped between the locking bodies and the second locking body to be locked, and the position of the piston is locked.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments of the present invention or in the description of the prior art will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic structural diagram of an axial flow fan blade control system according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of the control cabinet shown in FIG. 1;

FIG. 3 is a control schematic of a control cabinet according to one embodiment of the present invention;

FIG. 4 is a schematic structural diagram of an adjusting cylinder with a self-locking structure according to an embodiment of the present invention;

FIG. 5 is a schematic view of the piston of FIG. 4;

FIG. 6 is a cross-sectional view of the self-locking mechanism of FIG. 4;

FIG. 7 is a flow chart illustrating a method for controlling an axial flow fan blade according to an embodiment of the present invention;

in the figure, 1-adjusting oil cylinder, 11-cylinder body, 111-first cavity, 112-second cavity, 12-piston, 121-first concave disc, 1211-first spacing body, 122-second concave disc, 1221-second spacing body, 123-piston main body, 1231-integrated periphery, 124-through hole, 2-control cabinet, 21-control oil path, 211-first control oil path, 212-second control oil path, 22-electric control part, 23-oil filter device, 3-position sensor, 4-self-locking structure, 41-locking shell, 42-first locking body, 43-second locking body;

1.1-a first proportional valve, 1.2-a second proportional valve, 2.1-a first reversing valve, 2.2-a second reversing valve, 2.3-a third reversing valve, 2.4-a fourth reversing valve, 3.1-a first ball valve, 3.2-a second ball valve, 3.3-a third ball valve, 3.4-a fourth ball valve, 4.1-a fifth ball valve, 4.2-a sixth ball valve, 4.3-a seventh ball valve, 4.4-an eighth ball valve.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings of the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or the orientations or positional relationships that the products of the present invention are conventionally placed in use, and are only used for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

Furthermore, the terms "horizontal", "vertical", "overhang" and the like do not imply that the components are required to be absolutely horizontal or overhang, but may be slightly inclined. For example, "horizontal" merely means that the direction is more horizontal than "vertical" and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

In the present invention, unless otherwise expressly stated or limited, the first feature may be present on or under the second feature in direct contact with the first and second feature, or may be present in the first and second feature not in direct contact but in contact with another feature between them. Also, the first feature being above, on or above the second feature includes the first feature being directly above and obliquely above the second feature, or merely means that the first feature is at a higher level than the second feature. A first feature that underlies, and underlies a second feature includes a first feature that is directly under and obliquely under a second feature, or simply means that the first feature is at a lesser level than the second feature.

The axial flow fan with the adjustable moving blades is widely applied to a coal power generation system of a thermal power plant, and is often used as a blower, a primary fan and an induced draft fan of a boiler system and a booster fan used in flue gas desulfurization. The movable blade axial flow fan applied to the existing thermal power plant has the following problems:

1) the equipment maintenance and replacement cost is high. In the prior art, when a certain part of an axial flow fan breaks down, the whole boiler system can be overhauled only after being stopped, and the shutdown of the whole boiler system can bring about no small loss to a power plant.

2) The bucket control system is complex. A blade control system of an axial flow fan with an adjustable moving blade is an important component of the axial flow fan and is responsible for adjusting the opening of the fan blade to adapt to different loads. At present, the blade adjustment of the movable blade adjustable axial flow fan mostly adopts a mechanical adjusting mechanism which comprises an actuator, a transmission mechanism, a servo valve, a hydraulic oil cylinder, an oil station and the like, the precision is relatively poor, the reaction is delayed, the automatic tracking adjustment is difficult to realize, the phenomena of jamming, oil leakage, connecting rod damage and the like are easy to occur in the operation, and the fault occurrence frequency is high.

At present, an electro-hydraulic control system based on a proportional valve is also provided, namely, electromagnets at two ends of the proportional valve drive a valve core of the proportional valve to move (namely, a slide valve type rotary joint mechanism) so as to complete station switching of the three-position four-way proportional valve and finally realize the forward and backward movement of a piston of a hydraulic cylinder. However, the existing proportional valve control system is generally separated from a hydraulic part and an electric control part and generally comprises a PLC (programmable logic controller) or an upper computer, a proportional valve driver, a proportional valve and a sensor. Such a control system is complicated in structure, and the amount of debugging work required for the system at the time of installation is also large because the control section and the hydraulic section are separated.

3) When hydraulic oil in a hydraulic system is cut off once, the installation angle of the blade is randomly changed under the action of working condition load moment and internal leakage, and the movable blade has no function of keeping the position.

In view of this, as shown in fig. 1 and fig. 2, in an embodiment of the present invention, an axial flow fan blade control system is provided, the system includes an adjusting cylinder 1 and a control cabinet 2, a control oil path 21 and an electric control part 22 are arranged in the control cabinet 2, and a port P, a port T, a port a and a port B are arranged on the control cabinet 2;

the adjusting oil cylinder 1 comprises a cylinder body 11, a piston 12 which can move axially relative to the cylinder body 11 is arranged in the cylinder body 11, and the cylinder body 11 is divided into a first cavity 111 and a second cavity 112 by the piston 12;

the control oil path 21 is communicated with an external oil source through the port P and the port T, is communicated with a first cavity 111 of the adjusting oil cylinder 1 through the port A, and is communicated with a second cavity 112 of the adjusting oil cylinder 1 through the port B;

the electric control part 22 is electrically connected with the control oil path 21, and the electric control part 22 controls the flow direction and pressure of hydraulic oil in the control oil path 21 to realize the movement of the piston 12 along the axial direction of the cylinder 11;

the control oil path 21 includes a first control oil path 211 and a second control oil path 212 which are provided redundantly, and the first control oil path 211 and the second control oil path 212 are identical.

In the prior art, the structure of the blade adjusting mechanism of the axial flow fan is mostly similar, and the working principle is as follows: the servo mechanism is controlled by the control system, so that the oil cylinder regulating valve and the notch channel are changed, the oil quantity and the oil pressure of two side surfaces of the piston are changed, the piston is pushed to move axially relative to the cylinder body, the regulating element in the rotor blade connected with the piston is driven, and the angle of the blade is changed. When the external regulating arm and the regulating valve are in a given position, the piston will be in equilibrium without oscillation when the hydraulic forces on the two sides of the piston are equal, and the angle of the moving vanes will not change.

However, the blade control system of the axial flow fan in the prior art (more commonly, a proportional valve control system) generally comprises a PLC or an upper computer, a proportional valve driver, a proportional valve and a sensor, the control system has a complex structure, a hydraulic part (namely a control oil way) and an electric control part are separated, and the debugging workload required by the system during installation is very large.

The difference between the present embodiment and the prior art is:

firstly, in this embodiment, the control oil path of the blade control system of the axial flow fan and the control oil path 21 of the electric control part 22 are integrated together, that is, the control oil path 21 and the electric control part 22 are integrated in the integrated control cabinet 2, so that the control structure is simple, the occupied space is small, the original control mode is simplified, the equipment installation material and labor cost are reduced, and the debugging time of the whole set of equipment is shortened.

Secondly, the control oil path in this embodiment includes a first control oil path 211 and a second control oil path 212 which are provided redundantly, and the structural composition of the first control oil path 211 is identical to that of the second control oil path 212. That is, the electronic control portion 22 in the above-described aspect may implement the relative movement between the piston 12 and the cylinder 11 in the adjustment cylinder 1 by controlling the related components in the first control oil path 211, or implement the relative movement between the piston 12 and the cylinder 11 in the adjustment cylinder 1 by controlling the related components in the second control oil path 212. When equipment in a certain control oil path needs to be replaced or maintained, the electric control part 22 can selectively control another control oil path to realize the motion control of the adjusting oil cylinder 1. Therefore, the axial flow fan system can be maintained and components and parts can be replaced without stopping.

Further, as shown in fig. 3, the first control oil path 211 includes a first proportional valve 1.1, a first direction valve 2.1, and a second direction valve 2.2, where the first proportional valve 1.1 is a three-position four-way proportional valve, and the first direction valve 2.1 and the second direction valve 2.2 are both three-position two-way direction valves; the port P and the port T of the first proportional valve 1.1 are communicated with an external oil source; the port A of the first proportional valve 1.1 is communicated with the port P of the first reversing valve 2.1, and the port T of the first reversing valve 2.1 is communicated with the first cavity 111 of the adjusting oil cylinder 1; a port P of the second reversing valve 2.2 is communicated with a port B of the first proportional valve 1.1, and a port T of the second reversing valve 2.2 is communicated with a second cavity 112 of the adjusting oil cylinder 1;

the second control oil path 212 comprises a second proportional valve 1.2, a third reversing valve 2.3 and a fourth reversing valve 2.4, the second proportional valve 1.2 is a three-position four-way proportional valve, and the third reversing valve 2.3 and the fourth reversing valve 2.4 are both three-position two-way reversing valves; the port P and the port T of the second proportional valve 1.2 are communicated with an external oil source; the port A of the second proportional valve 1.2 is communicated with the port P of the third reversing valve 2.3, and the port T of the third reversing valve 2.3 is communicated with the first cavity 111 of the adjusting oil cylinder 1; the port P of the fourth direction valve 2.4 is communicated with the port B of the second proportional valve 1.2, and the port T of the fourth direction valve 2.4 is communicated with the second chamber 112 of the adjusting cylinder 1.

In the foregoing solution, a specific composition of the first control oil path 211/the second control oil path 212 is given, where:

the first proportional valve 1.1 and the second proportional valve 1.2 are three-position four-way proportional valves. Namely, the first proportional valve 1.1/the second proportional valve 1.2 have three working positions and four oil ports (two inlets and two outlets, which are respectively represented by P, T, A, B, P is an oil inlet, T is an oil return port, and A \ B is respectively connected with an upper cavity and a lower cavity of an actuating element), and the valve is in a neutral position when in a natural position.

The first reversing valve 2.1, the second reversing valve 2.2, the third reversing valve 2.3 and the fourth reversing valve 2.4 are all three-position two-way reversing valves. Namely, the first change valve 2.1/the second change valve 2.2/the third change valve 2.3/the fourth change valve 2.4 all have three working positions, and two oil ports (one is inlet and one is outlet, P, T is used respectively, P is an oil inlet, and T is an oil return port) are arranged, and the valve is in a middle position when in a natural position. The purpose of the reversing valve is to provide a shut-off for the first 1.1/second 1.2 proportional valve. In particular, the amount of the solvent to be used,

the port P and the port T of the first proportional valve 1.1 are communicated with an external oil source; the port A of the first proportional valve 1.1 is communicated with the port P of the first reversing valve 2.1, and the port T of the first reversing valve 2.1 is communicated with the first cavity 111 of the adjusting oil cylinder 1; a port P of the second reversing valve 2.2 is communicated with a port B of the first proportional valve 1.1, and a port T of the second reversing valve 2.2 is communicated with a second cavity 112 of the adjusting oil cylinder 1;

the port P and the port T of the second proportional valve 1.2 are communicated with an external oil source; the port A of the second proportional valve 1.2 is communicated with the port P of the third reversing valve 2.3, and the port T of the third reversing valve 2.3 is communicated with the first cavity 111 of the adjusting oil cylinder 1; a port P of the fourth reversing valve 2.4 is communicated with a port B of the second proportional valve 1.2, and a port T of the fourth reversing valve 2.4 is communicated with a second cavity 112 of the adjusting oil cylinder 1;

all the proportional valves, the reversing valve and the adjusting oil cylinder 1 are communicated through oil pipes.

Further, the electric control part 22 in the above scheme includes a dual power supply module, an upper control side, a first proportional valve controller, a second proportional valve controller, a first signal isolator and a second signal isolator which are electrically connected with each other.

The upper control party is used for instruction signals, and the instruction signals comprise a position instruction signal (signal a) and a proportional valve starting signal (signal b) which are expected by the adjusting oil cylinder 1.

The first proportional valve controller is used for controlling the flow and the direction of the first proportional valve 1.1, and the second proportional valve controller is used for controlling the flow and the direction of the second proportional valve 1.2. The first/second proportional valve controller is developed according to the characteristics of the proportional valve, the parameter setting is simple, the PID operation is used for controlling the slow start, the midway fast operation and the deceleration of the adjusting oil cylinder 1 to accurately reach the position of the command signal, and the overshoot and the oscillation of the piston 12 at the target position can be avoided.

The signal isolator is used for ensuring the signal stability of the signal in the transmission process.

Further, as shown in fig. 3, a first ball valve 3.1 is arranged at a P port of the first proportional valve 1.1, and a second ball valve 3.2 is arranged at a T port; a third ball valve 3.3 is arranged at a position P of the second proportional valve 1.2, and a fourth ball valve 3.4 is arranged at a position T; a fifth ball valve 4.1 is arranged at the T-port of the first reversing valve 2.1, a sixth ball valve 4.2 is arranged at the T-port of the second reversing valve 2.2, a seventh ball valve 4.3 is arranged at the T-port of the third reversing valve 2.3, and an eighth ball valve 4.4 is arranged at the T-port of the fourth reversing valve 2.4.

In the above scheme, the ball valve is arranged to enable the corresponding control oil path to be in a completely cut-off state. For example, when the first proportional valve 1.1 is operated, the third ball valve 3.3, the fourth ball valve 3.4, the seventh ball valve 4.3 and the eighth ball valve 4.4 can be closed, and the second proportional valve 1.2, the third reversing valve 2.3 and the fourth reversing valve 2.4 can be replaced; when the second proportional valve 1.2 works, the first ball valve 3.1, the second ball valve 3.2, the fifth ball valve 4.1 and the sixth ball valve 4.2 can be shut off, and the first proportional valve 1.1, the first reversing valve 2.1 and the second reversing valve 2.2 are replaced.

In an embodiment of the present invention, as shown in fig. 2 and 3, the control cabinet 2 further includes an oil filtering device 23, hydraulic oil in an external oil source passes through the oil filtering device 23 and then enters the first ball valve 3.1 or the second ball valve 3.1, and the oil filtering device 23 is a double-cylinder filter.

In the above-described aspect, the oil filter device 23 is provided to filter the hydraulic oil that enters the first control oil passage 211 and/or the second control oil passage 212.

Preferably, the oil filter device 23 is a double-cylinder filter, which includes two single-cylinder filter two-position six-way reversing valves. The relative position of the sealing assembly in the valve body is changed to enable each channel of the valve body to be communicated or disconnected, so that the reversing and starting and stopping of the fluid are controlled. The oil inlets of the first ball valve 3.1 and the second ball valve 3.2 are respectively communicated with one single-cylinder filter of the oil filtering device 23. The control device uses a double-cylinder filter, and the filter can be manually switched to carry out filter element replacement work under the state of no stop.

Further, the axial flow fan blade control system further comprises a position sensor 3, and the position sensor 3 is connected with the adjusting oil cylinder 1 through threads.

In the above solution, the position sensor 3 is provided for detecting the position of the piston 12 of the adjusting cylinder 1, and the position sensor 3 is electrically connected to the electronic control part 22.

The working principle of the axial flow fan blade control system for realizing the adjustment of the axial flow fan blade through the first control oil path 211 is as follows:

an upper control party provides an expected position instruction signal (signal a) of an adjusting oil cylinder 1 and a signal (signal b) for starting a first proportional valve 1.1, a first proportional valve 1.1 control device outputs current after receiving the instruction signal, drives the first proportional valve 1.1 and starts a corresponding first reversing valve 2.1 and a corresponding second reversing valve 2.2, an external oil source provides hydraulic oil pressure not exceeding 35MPa for a first control oil path 211 through a power oil path (P) and an oil return path (T), and the movement of a piston 12 of the adjusting oil cylinder 1 relative to a cylinder body 11 is controlled, so that the position and the angle of a blade of an axial flow fan are adjusted; meanwhile, a position sensor 3 connected with the adjusting oil cylinder 1 feeds back a detected position analog quantity signal to a first signal isolator, the first signal isolator transmits one path of the feedback signal to an upper control party (monitoring the position condition of the piston 12), the other path of the feedback signal is output to a first proportional valve controller, the first proportional valve controller outputs an instruction signal to control the output flow and the direction of a first proportional valve 1.1, and the speed and the direction of the piston 12 of the adjusting oil cylinder 1 are subjected to closed-loop control.

The working principle of the axial flow fan blade control system for realizing the adjustment of the axial flow fan blade through the second control oil way 212 is as follows:

an upper control party provides an expected position instruction signal (signal a) of the adjusting oil cylinder 1 and a signal (signal b) for starting a second proportional valve 1.2, a second proportional valve 1.2 control device outputs current after receiving the instruction signal, drives the second proportional valve 1.2 and starts a corresponding third reversing valve 2.3 and a corresponding fourth reversing valve 2.4, an external oil source provides hydraulic oil pressure not exceeding 35MPa for a second control oil path 212 through a power oil path (P) and an oil return path (T), and the movement of a piston 12 of the adjusting oil cylinder 1 relative to a cylinder body 11 is controlled, so that the position and the angle of a blade of the axial flow fan are adjusted; meanwhile, a position sensor 3 connected with the adjusting oil cylinder 1 feeds back a detected position analog quantity signal to a second signal isolator, the second signal isolator transmits one path of the feedback signal to an upper control party (monitoring the position condition of the piston 12), the other path of the feedback signal is output to a second proportional valve controller, the second proportional valve controller outputs an instruction signal to control the output flow and the direction of a second proportional valve 1.2, and the speed and the direction of the piston 12 of the adjusting oil cylinder 1 are subjected to closed-loop control.

Preferably, the position sensor 3 belongs to a magnetostrictive displacement sensor. The magnetostrictive displacement sensor accurately measures the position by utilizing the magnetostrictive principle and generating a strain pulse signal through the intersection of two different magnetic fields; the measuring element is a waveguide tube, and a sensitive element in the waveguide tube is made of special magnetostrictive materials; the measuring process is that current pulse is generated in an electronic chamber of the sensor, the current pulse is transmitted in the waveguide tube, so that a circumferential magnetic field is generated outside the waveguide tube, when the magnetic field is intersected with a magnetic field generated by a movable magnetic ring sleeved on the waveguide tube and used as position change, a strain mechanical wave pulse signal is generated in the waveguide tube under the action of magnetostriction, and the strain mechanical wave pulse signal is transmitted at a fixed sound speed and is detected by the electronic chamber quickly.

By adopting the blade control system of the axial flow fan in the scheme, closed-loop control can be performed on the speed and the direction of the piston 12 of the adjusting oil cylinder 1, high-precision and high-reliability control over the adjusting oil cylinder 1 is realized, non-stop maintenance and component replacement can be realized simultaneously, and the blade control system is suitable for the conditions that equipment needs to run for a long time, and components and parts need to be repaired and replaced without stopping.

Further, as shown in fig. 4 and 5, the piston 12 includes a first concave disk 121, a second concave disk 122, and a piston main body 123, the first concave disk 121 and the second concave disk 122 are arranged with their convex surfaces facing each other, the piston main body 123 is located between the first concave disk 121 and the second concave disk 122, and a plurality of through holes 124 are provided on the first concave disk 121 and the second concave disk 122.

When the adjusting oil cylinder 1 suddenly loses pressure, the piston 12 is driven to move towards a certain direction under the action of the inertia of the movable blades, the installation angle of the blades changes randomly, and the movable blade position-keeping function is not achieved. In the scheme, the structure of the piston 12 in the fuel saving cylinder 1 is improved, and the piston 12 has certain self-locking capacity while the sealing performance of the piston 12 and the cylinder body 11 is ensured.

Specifically, the piston 12 includes a first annular concave disk 121, a second annular concave disk 122, and a piston main body 123, where the first annular concave disk 121 and the second annular concave disk 122 are disposed oppositely, and the piston main body 123 is located between the first annular concave disk 121 and the second annular concave disk 122, and the three are disposed coaxially.

Further, spacers, i.e., the first spacer 1211 and the second spacer 1221, are uniformly disposed on the first concave disk 121 and the second concave disk 122. When the first concave disk 121 and the second concave disk 122 are disposed oppositely, the first spacer 1211 and the second spacer 1221 are in contact. The piston body 123 is axially movable relative to the first and second spacer bodies 1211, 1221. The piston rod of the piston 12 passes through the center of the piston 12 (i.e., the center of the first concave disk 121, the second concave disk 122, and the piston body 123), the piston rod of the piston 12 is fixedly connected to the piston 12, and the position of the piston 12 is changed by the movement of the piston rod of the piston 12. A plurality of through holes 124 are provided on the first and second concave disks 121 and 122, and fluid can flow from one surface of the concave disk (the first concave disk 121 or the second concave disk 122) to the other surface through the through holes 124, thereby directly pressing the piston main body 123.

The self-locking principle will be described below by taking the piston 12 moving in the rightward direction in fig. 4 as an example:

normally, when it is desired to move the piston 12, there is fluid pressure on both sides of the piston 12. When it is required to move the piston 12 to the right, additional fluid pressure is applied to the left side surface of the piston 12 (i.e., the left side surface of the first concave disk 121), fluid enters between the first concave disk 121 and the piston main body 123 through the through hole 124, and fluid pressure is applied to the left side surface of the piston main body 123, thereby pushing the piston main body 123, so that the piston main body 123 moves rightward along the spacer bodies (the first spacer body 1211 and the second spacer body 1221), and the piston main body 123 moving rightward presses the second concave disk 122, so that the edge of the second concave disk contracts inward and separates from the inner wall of the cylinder 11, so that the piston 12 can move rightward smoothly.

If the adjusting oil cylinder 1 loses pressure suddenly, fluid pressure can be lost on two sides of the piston 12, and the blade exerts a force to move the piston 12 to the right through a piston rod of the piston 12 under the action of inertia; at this time, only the portion of the second concave disk 122 of the piston 12 that contacts the piston rod of the piston 12 (i.e., the center of the second concave disk 122) receives a rightward force applied by the piston rod of the piston 12, so that the outer peripheral edge of the second concave disk 122 is splayed away from the cylinder 11, so that the edge of the second concave disk 122 tightly grips the inner wall of the cylinder 11, thereby locking the piston 12 on the inner wall of the cylinder 11 to prevent the piston 12 from moving.

The piston 12 is moved to the left, and the principle is similar to moving the piston 12 to the right, which will not be described in detail herein.

Further, in order to ensure the sealing property between the first concave disk 121, the second concave disk 122 and the cylinder 11, the outer edge diameter of the second concave disk 122 of the first concave disk 121 is set to be slightly larger than the inner diameter of the cylinder 11.

Further, in order to ensure the sealing performance among the piston 12, the piston rod of the piston 12, and the cylinder 11, an annular groove may be provided at an edge of the piston main body 123 contacting the cylinder 11, and annular grooves may be provided on the first and second spacers 121 and 1221, and sealing rings may be provided in the annular grooves.

Further, an integral peripheral edge 1231 parallel to the axis of the piston 12 is provided at the edge of the piston body 123, and the integral peripheral edge 1231 is in contact with the first concave disk 121 and the second concave disk 122.

In the above-described embodiment, an integrated peripheral edge 1231 is provided at a portion where the edge of the piston main body 123 contacts the inner wall of the cylinder 11, and the integrated peripheral edge 1231 contacts the convex surfaces of the first concave disk 121 and the second concave disk 122. When it is desired to move the piston 12 to the right, additional fluid pressure is applied to the left side of the piston 12, fluid acts on the left side of the piston main body 123 through the through-holes 124 of the first concave disk 121, the piston main body 123 moves to the right, and contacts and bends the convex surface of the second concave disk 122 through the integrated peripheral edge 1231 of the piston main body 123, thereby reducing the outer diameter of the second concave disk 122, and thus moving the edge of the second concave disk 122 away from the inner wall of the cylinder 11, thereby achieving the movement of the piston 12.

When it is desired to move the piston 12 to the left, additional fluid pressure is applied to the right side of the piston 12, the fluid acts on the right side of the piston body 123 through the through-hole 124 of the second concave disk 122, the piston body 123 moves to the left, and contacts and bends the convex surface of the first concave disk 121 through the integral peripheral edge 1231 of the piston body 123, thereby reducing the outer diameter of the first concave surface, and thus moving the edge of the first concave disk 121 away from the inner wall of the cylinder 11, thereby achieving the movement of the piston 12.

Further, as shown in fig. 4 and 6, the axial flow fan blade control system further includes a self-locking structure 4, the self-locking structure 4 includes a locking housing 41, a first locking body 42, and a second locking body 43, the first locking body 42 and the second locking body 43 are rotatably disposed in the locking housing 41, and a piston rod of the piston 12 is eccentrically inserted between the first locking body 42 and the second locking body 43.

Further, the first locking body 42 and the second locking body 43 are both semi-cylinders.

In order to further realize the movable blade position keeping function of the axial flow fan, a self-locking mechanism 4 is further arranged, and the self-locking mechanism 4 is used for realizing the locking of a piston rod of the piston 12. At the time of assembly, the first locking body 42 and the second locking body 43 are first assembled into the locking housing 41, and then the piston rod of the piston 12 is eccentrically inserted into the inside of the first locking body 42 and the second locking body 43, and an assembling space is left at the fitting portions of the two locking bodies so that they can be rotated to some extent with each other. The piston rod of piston 12 is axially slidable with respect to self-locking structure 4 after being inserted inside first and second locking bodies 42, 43.

When the piston rod of piston 12 is not required to be locked, first locking body 42 and second locking body 43 are in the position shown in fig. 6, and the piston rod of piston 12 is axially slidable with respect to self-locking mechanism 4.

When the piston rod of the piston 12 needs to be locked, the first locking body 42 is rotated in the counterclockwise direction and the second locking body 43 is rotated in the clockwise direction. Since the rotation centers of the first and second locking bodies 42 and 43 and the piston rod of the piston 12 are eccentric, the first locking body 42 pushes the piston rod of the piston 12 downward, and the second locking body 43 pushes the piston rod of the piston 12 upward, so that the piston rod of the piston 12 is locked by being sandwiched by the locking bodies 42 and 43, thereby achieving locking of the position of the piston 12.

As for the driving manner for realizing the rotation of the first locking body 42 and the second locking body 43, the driving manner may be an electromagnetic driving manner, a mechanical driving manner, or some other common driving manner, and is not limited herein.

Preferably, the first locking body 42 and the second locking body 43 are both semi-cylinders.

In another embodiment of the present invention, as shown in fig. 7, there is provided an axial flow fan blade control method, based on the axial flow fan blade control system, including the following steps:

step S001: selecting a target control oil path, wherein the target control oil path is a first control oil path 211 or a second control oil path 212;

step S002: the electric control part 22 sends out an expected position instruction signal (signal a) and a proportional valve starting signal (signal b) of the adjusting oil cylinder 1, and starts a proportional valve and a reversing valve in a target control oil path;

step S003: an external oil source provides hydraulic oil pressure for the adjusting oil cylinder 1 through a target control oil path so as to adjust the piston 12 in the adjusting oil cylinder 1 to a desired position;

step S004: the position sensor 3 connected with the adjusting oil cylinder 1 feeds back the detected position signal to the electric control part 22;

step S005: the electronic control part 22 outputs an instruction according to the received position signal of the adjusting oil cylinder 1 to control the flow and the direction of the proportional valve in the target control oil path, so as to realize the position adjustment of the piston 12 in the adjusting oil cylinder 1.

The blade control method for the axial flow fan can realize high-precision and high-reliability control of a fan hydraulic actuating mechanism (an oil cylinder and the like), simplifies the original control mode and realizes on-site closed-loop control of the proportional valve.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.