CN116216179A

CN116216179A - Belt conveyor with energy recovery function and operation control method thereof

Info

Publication number: CN116216179A
Application number: CN202211725915.XA
Authority: CN
Inventors: 杨春雨; 藏其亮; 曹博仕; 王勇; 吴天庆; 李德亮; 张荣真
Original assignee: China University of Mining and Technology CUMT
Current assignee: China University of Mining and Technology CUMT
Priority date: 2022-12-29
Filing date: 2022-12-29
Publication date: 2023-06-06

Abstract

The invention discloses a belt conveyor with an energy recovery function and an operation control method thereof, wherein a motor, a motor and an energy accumulator are used as a driving system, a roller is connected with a variable frequency motor through a gear mechanism, and the roller is connected with a hydraulic motor through the gear mechanism and a clutch; the clutch contactor is used for controlling clutch to realize on-off of the motor and the roller; the energy accumulator is used for releasing oil pressure and providing energy in the period from starting to normal operation, low rotation speed to high rotation speed operation or material increasing, and driving the hydraulic motor; the oil is absorbed and energy is stored in the operation phase, the material reduction phase and the braking phase which are adjusted from high rotation speed to low rotation speed. The invention utilizes the energy of the energy accumulator to assist the full load and heavy load starting of the conveyor, meets the application under the limit working condition, can effectively reduce the installed power of the main motor, well avoids the motor from working in a low-efficiency area for a long time, and improves the energy utilization rate.

Description

Belt conveyor with energy recovery function and operation control method thereof

Technical Field

The invention relates to the technical field of belt conveyor, in particular to a belt conveyor with an energy recovery function and an operation control method thereof.

Background

The belt conveyor is used as main conveying equipment for producing and conveying bulk materials, has the characteristics of large conveying capacity, long-distance conveying, high automatic control degree, continuous conveying and the like, and is widely applied to the fields of ports, wharfs, coal mines, metallurgy, grains and the like, and particularly plays an extremely important role in the coal mine production process. With the gradual penetration of coal mining and the update of mining technology, high-speed, long-distance, intelligent and large-traffic belt conveyors are increasingly applied, and particularly, the application of lower belt conveyors is more and more widely applied. The lower belt conveyor is a conveying device for conveying materials from high position to low position, and has relatively lagging development compared with the upper belt conveyor and the flat belt conveyor, and because the lower belt conveyor has fewer application occasions and complex operation working conditions, the driving motor can be in an electric working condition or a power generation working condition according to different conveying volumes, the control of braking is relatively difficult, and unsafe accidents such as slipping, material scattering or galloping are easier to occur when the braking is improper. The downward transportation mode has great advantages, and the downward transportation mode can not only greatly reduce the workload of roadway exploitation, but also greatly reduce the infrastructure cost and shorten the construction period.

The reason that the problem of the downward belt conveyor mechanism is difficult to solve is that the downward sliding component of the gravity of the material is the same as the movement direction of the material and exists as an accelerating force, when the conveyor meets certain inclination angle and load conditions, the downward sliding component of the material is larger than the driving force of the motor to enable the motor to be turned into a power generation braking operation state, and if the load moment exceeds the maximum braking moment generated by the motor, and a reliable speed regulation braking system is not provided, the motor is caused to lose control to enable the conveyor to accelerate until the conveyor flies. Comprehensive analysis, how to handle braking energy is a core problem to be solved by researching the braking system of the lower belt conveyor.

Currently, most downward conveyors realize braking or speed regulation of the system by converting kinetic energy and potential energy of materials in downward movement into heat loss of the braking system, which is also called energy consumption braking, and common methods are to use external brakes such as hydraulic braking, mechanical braking, external braking resistors and the like. For the downward belt conveyor with large inclination angle and large transportation capacity, if the energy consumption type braking is adopted, the braking energy is very large, which means that the energy consumption of the energy consumption type braking is quite large, so that not only is the very high requirement on the braking capacity of a braking system made, but also resources are wasted, larger environmental pollution is easy to cause, and the energy consumption type braking also needs to limit the environmental temperature under a mine due to the limitation of the explosion-proof requirement.

There are also less applied variable frequency regenerative braking than dynamic braking. The variable-frequency feedback braking system is established on the basis of driving of the frequency converter, electric energy generated by the power generation operation of the motor is transmitted to the power grid to realize recycling after being modulated through a feedback unit of the frequency converter, but the feedback braking system needs normal power supply of the power system, the braking capacity of the feedback braking system is completely lost when the power is suddenly cut off, braking accidents are easy to occur, and the power grid is impacted by improper feedback control.

Based on the defects and shortcomings of the prior art, the invention provides a belt conveyor with an energy recovery function and an operation control method thereof, the thought of the belt conveyor is different from two technical routes of the prior art, a variable frequency motor, a hydraulic motor and an energy accumulator are adopted as a driving system, a roller is connected with the variable frequency motor through a gear mechanism, and the roller is connected with the hydraulic motor through the gear mechanism and a clutch; the clutch contactor controls clutch to realize on-off of the motor and the roller; the energy accumulator is used for releasing oil pressure and providing energy in the period from starting to normal operation, low rotation speed to high rotation speed operation or material increasing, and driving the hydraulic motor; the oil is absorbed and energy is stored in the operation phase, the material reduction phase and the braking phase which are adjusted from high rotation speed to low rotation speed.

Disclosure of Invention

The invention aims at solving the technical problems of the prior art and provides a belt conveyor with an energy recovery function and an operation control method thereof, wherein a variable frequency motor, a hydraulic motor and an energy accumulator are used as a control mode of a driving system, when the conveyor is adjusted from a high rotating speed to a low rotating speed, materials are conveyed to be reduced, braking and other operation stages, the energy released by the conveyor is recovered, and the recovered energy is used for the stages from starting to normal operation, from the low rotating speed to the high rotating speed and the materials are increased, so that the energy consumption is saved.

In order to solve the technical problems, the invention adopts the following technical scheme:

the belt conveyor adopts a motor, a motor and an energy accumulator as a driving system, a roller is connected with a variable frequency motor through a gear mechanism, and the roller is connected with a hydraulic motor through the gear mechanism and a clutch; the clutch contactor is used for controlling clutch to realize on-off of the motor and the roller; the energy accumulator is used for releasing oil pressure and providing energy in the period from starting to normal operation, low rotation speed to high rotation speed operation or material increasing, and driving the hydraulic motor; the oil is absorbed and energy is stored in the operation phase, the material reduction phase and the braking phase which are adjusted from high rotation speed to low rotation speed.

The operation control method specifically comprises the following steps:

step 1, starting to a normal operation stage:

step 1-1, full load or heavy load starting to a normal operation stage:

step 1-1-1, starting a first motor and a second motor, wherein an electromagnetic valve of a variable pump is not powered, the variable pump outputs oil, and the current of an electric proportional overflow valve II is regulated to a preset value; the electromagnetic valve current of the variable pump is gradually increased, the three-position four-way valve and the two-position two-way valve I are powered on, the motor brake is opened, and the motor starts to run;

step 1-1-2, opening a clutch contactor to enable the clutch to be combined with a motor; the oil output by the variable pump enters a motor; the power of the motor and the motor II is transmitted to the roller through the gear mechanism I and the gear mechanism II, and the conveyer belt starts to be fully loaded and started under the common driving of the motor and the motor II;

step 1-1-3, after the set speed is reached, the accumulator control valve assembly starts to release oil until the conveyor belt reaches a stable speed, and full load or heavy load is started successfully;

step 1-2, starting no load or light load to a normal operation stage:

step 1-2-1, starting a motor II to drive the roller to run, wherein the electromagnetic valve of the variable pump is not powered, and the variable pump does not output oil; after the drum speed reaches the set speed, the current of the electric proportional overflow valve II is adjusted to a preset value, the three-position four-way valve and the two-position two-way valve I are powered on, a motor brake is opened, and the motor starts to run;

step 1-2-2, opening a clutch contactor to enable clutch and a motor to be combined, and enabling oil output by an accumulator I to enter the motor through a bidirectional balance valve; the power of the motor and the motor II is transmitted to the roller through the gear mechanism I and the gear mechanism II, and the conveyer belt starts to run under the common drive of the motor and the motor II;

step 1-2-3, along with the increase of the speed of the conveyor belt, the speed of releasing oil by the accumulator control valve assembly is regulated along with the current of the two-position two-way proportional valve until the conveyor belt reaches a stable speed, and no-load or light-load starting is successful;

step 2, adjusting from low rotation speed to high rotation speed or material increasing stage:

step 2-1, a motor II is in an operating state, a variable pump electromagnetic valve is not powered, and an electric proportional overflow valve II is adjusted to a preset value; the three-position four-way valve and the two-position two-way valve I are powered on, a motor brake is opened, and the motor starts to run;

step 2-2, a clutch contactor is opened to enable clutch to be combined with a motor, the variable pump does not output oil, the oil output by the energy accumulator I enters the motor through the two-way balance valve, and power of the motor and the motor II is transmitted to the roller through the gear mechanism I and the gear mechanism II;

step 2-3, under the combined action of the motor drive and the motor II, the speed of the conveyer belt is gradually increased, and along with the increase of the speed, the speed of the oil released by the accumulator control valve assembly is regulated along with the current of the two-position two-way proportional valve until the conveyer belt reaches the stable speed or the conveyer belt is increased to the stable weight of materials;

step 3, adjusting the high rotating speed to the low rotating speed for operation, or reducing materials:

step 3-1, the motor II is in an operating state, the electromagnetic valve of the variable pump is not powered, and the current of the electric proportional overflow valve II is regulated to a preset value; the three-position four-way valve, the two-position two-way valve I and the variable pump are not powered, the two-position two-way valve III is powered, the motor brake is opened, and the motor starts to run;

step 3-2, opening a clutch contactor to enable clutch and a motor to be combined, enabling a variable pump not to output oil, and enabling an accumulator I of an accumulator control valve assembly to receive and store high-pressure oil output by the motor; under the combined action of the motor and the motor II, the speed of the conveyer belt is gradually reduced;

3-3, along with the change of the speed of the conveyor belt, adjusting the speed of the oil received by the energy accumulator control valve assembly along with the current of the two-position two-way proportional valve until the conveyor belt reaches a stable speed or reduces to a stable weight of materials;

step 4, braking:

before braking, the second motor is in an operating state, the variable pump cannot be electrified, and the electric proportional overflow valve II is adjusted to a preset value; the three-position four-way valve, the two-position two-way valve I, the two-position two-way valve II and the variable pump are not powered, the two-position two-way valve III is powered, a motor brake is opened, and the motor starts to run;

step 4-2, opening a clutch contactor to enable clutch and a motor to be combined, enabling a variable pump not to output oil, enabling an accumulator I of an accumulator control valve assembly to receive and store high-pressure oil output by the motor, and enabling the speed of a conveying belt to be gradually reduced under the combined action of the motor and a second motor;

and 4-3, along with the change of the speed of the conveyor belt, adjusting the speed of the oil received by the accumulator control valve assembly along with the current of the two-position two-way proportional valve until the speed of the conveyor belt reaches zero, and completing the braking of the conveyor belt.

Further preferably, the motor brake is turned on and off in the following manner:

the two-position two-way valve IV, the two-position four-way valve II and the two-position two-way valve are subjected to reversing after being electrified, and oil liquid of the variable pump, the energy accumulator control valve assembly and the energy accumulator II enters the motor brake through the two-position two-way valve IV, the pressure reducing valve and the two-position four-way valve II, so that the motor brake is opened, and the motor can rotate.

After the two-position four-way valve II is powered off, the motor brake is closed after pressure relief, and the motor loses power to stop rotating.

Further preferably, the clutch contactor is opened and closed in the following manner:

the two-position two-way valve IV, the two-position four-way valve I and the two-position two-way valve are subjected to reversing after being electrified, and oil liquid of the variable pump, the energy accumulator control valve assembly and the energy accumulator II passes through the two-position two-way valve IV, the pressure reducing valve and the two-position four-way valve I and enters the clutch contactor, so that the motor provides power for the roller.

After the two-position four-way valve I loses electricity, the clutch contactor releases pressure and then the roller is disconnected with the motor power.

Further preferably, the accumulator control valve assembly is filled with and releases oil in the following control modes:

the variable pump charges the accumulator: the current of the variable pump, the two-position two-way proportional valve and the electric proportional overflow valve I is increased, the three-position four-way valve, the two-position two-way valve II and the two-position three-way valve are subjected to electric reversing, the accumulator I is filled with liquid, and the liquid is filled after the set pressure value is reached according to the detection of the pressure sensor I, the pressure sensor II and the pressure sensor III.

The accumulator releases oil: the two-position two-way valve II and the two-position three-way valve are electrified and commutated, the two-position two-way proportional valve is electrified, and the energy accumulator I releases oil.

Further preferably, in the stage of running from high rotation speed to low rotation speed or material reduction or braking, the two-position two-way valve III is powered, and when the accumulator I absorbs and releases oil, the opening of the two-position two-way proportional valve is proportionally controlled according to the detection of the pressure sensor I, the pressure sensor II and the pressure sensor III, so that the speed of absorbing and releasing the oil by the accumulator I is controlled.

Further preferably, the pressure sensor II and the pressure sensor III are symmetrically distributed at oil inlet and outlet of the motor, and after the pressure is detected, the pressure difference at two ends of the motor is calculated, so that the torque of hydraulic oil acting on the motor is calculated.

Further preferably, during the starting or stopping of the motor, if the motor is in a suction state, the oil is replenished through the one-way valve; if the pressure exceeds a set value in the running process of the motor, overflow is carried out through a one-way valve and an electric proportional overflow valve II; if pressure impact occurs, the oil flows back to the oil tank through the two-position two-way valve I, the throttle valve and the three-position four-way valve.

Further preferably, the set speed in the step 1-1-3 is 2% -5% of the maximum speed of the belt conveyor, and the stable speed is the maximum speed; the set speed in step 1-2-1 is 2% -5% of the maximum speed of the drum.

The invention has the following beneficial effects:

(1) According to the control mode of the conveying system, when the conveyor is adjusted from high rotation speed to low rotation speed, conveyed materials are reduced, braking and other operation stages, energy released by the conveyor is recovered; and the recovered energy is used for the period from starting to normal operation, from low rotation speed to high rotation speed operation and material increasing, thereby saving energy consumption.

(2) The invention utilizes the energy of the energy accumulator to assist the full load and heavy load starting of the conveyor, meets the application under the limit working condition, can effectively reduce the installed power of the main motor, well avoids the motor from working in a low-efficiency area for a long time, and improves the energy utilization rate.

(3) The system has strong expansibility, and the energy accumulator control valve assembly and the motor can be expanded according to the power requirement and the use condition (such as an uplink mode, a downlink mode, abrupt change of the weight of materials and the like) of the conveyor.

(4) According to the invention, the impact is reduced through the cooperation control of the throttle valve and the electric proportional overflow valve according to the working conditions, and the motor is ensured to start and stop stably.

(5) According to the invention, when the accumulator absorbs and releases oil, the opening of the valve is proportionally controlled according to the detection of the pressure sensor, and the speed of the accumulator absorbing and releasing the oil is good in controllability.

Drawings

Fig. 1 is a schematic diagram of the operating principle of the prior art.

Fig. 2 is a graph showing power versus time at full start of the conveyor.

Fig. 3 is a schematic diagram of a belt conveyor operation control method with energy recovery function of the present invention.

The method comprises the following steps: 1. a one-way valve; 2a, an electric proportional overflow valve I; 2b, an electric proportional overflow valve II; 3. a two-position three-way valve; 4. a shuttle valve; 5. a two-position two-way proportional valve; 6a, an accumulator I; 6b, an accumulator II; 7. an accumulator control valve assembly; 8a, a pressure sensor I; 8b, a pressure sensor II; 8c, a pressure sensor III; 9a, a motor I; 9b, a second motor; 10. a variable displacement pump; 11. a three-position four-way valve; 12. a throttle valve; 13a, a two-position two-way valve I; 13b, a two-position two-way valve II; 13c, a two-position two-way valve III; 13d, a two-position two-way valve IV; 14. a two-way balancing valve; 15. a motor brake; 16. a motor; 17. clutching; 18. a clutch contactor; 19a, a gear mechanism I; 19b, a gear mechanism II; 20. a roller; 21a, a two-position four-way valve I; 21b, a two-position four-way valve II; 22. two-position two-way valve; 23. an overflow valve; 24. a pressure reducing valve.

Detailed Description

In the description of the present invention, it should be understood that the terms "left", "right", "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the apparatus or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and "first", "second", etc. do not indicate the importance of the components, and thus are not to be construed as limiting the present invention. The specific dimensions adopted in the present embodiment are only for illustrating the technical solution, and do not limit the protection scope of the present invention.

The invention will be described in further detail with reference to the accompanying drawings and specific preferred embodiments.

The conventional driving mode of the conveyor belt is usually that one, two or more variable frequency motors drive one roller, and the roller drives the conveyor belt, and the power transmission of the roller is shown in fig. 1 by taking the driving mode of two motors as an example. After the two variable frequency motors are connected through the gear mechanism and the speed reducer, the two power sources jointly drive the roller of the conveyor, so that the conveyor belt is driven to act.

The variable frequency motor can meet the requirement of a user on the motor rotating speed of the downward-running conveyor, can realize controllable control on starting and stopping, and realizes a controllable speed regulating function. The variable frequency speed regulation technology generally adopts a vector control technology, has outstanding advantages in the aspects of speed regulation characteristic and load capacity of the motor, has a wider setting range of acceleration time and deceleration time when starting and stopping, can effectively control soft start and soft stop of flexible load of the conveyor, and realizes power matching among driving devices.

When designing the installed power of the belt conveyor driving device, the prior art generally selects according to the full load condition. However, in order to meet the power requirement under the limit condition of full-load starting, the installed power of the selected motor is far larger. Taking full-load starting of a small-sized conveyor as an example, as shown in fig. 2, the required power is larger before the conveyor runs at a constant speed, but the required power is reduced more after the conveyor reaches a constant-speed running stage, and the motor tends to run in an inefficiency area. In order to meet the power requirement under the limit condition of full-load starting, the power of the motor is far greater than the power required by stable operation, so that the motor works in a low-efficiency area for a long time to cause energy waste, and meanwhile, when the conveyor is adjusted from high rotation speed to low rotation speed, materials are conveyed to be reduced, braking and other operation states, the conveyor can release a lot of energy, and the energy is wasted.

Therefore, the invention provides a belt conveyor with an energy recovery function and an operation control method thereof, wherein a motor, a motor and an energy accumulator are used as a driving system, a roller is connected with a variable frequency motor through a gear mechanism, and the roller is connected with a hydraulic motor through the gear mechanism and a clutch; the clutch contactor is used for controlling clutch and realizing on-off of the motor and the roller. The invention recovers the energy released by the conveyor when the conveyor is adjusted from high rotation speed to low rotation speed, the conveyed materials are reduced, braked and the like; and the recovered energy is used for the period from starting to normal operation, from low rotation speed to high rotation speed operation and material increasing, thereby saving energy consumption. Meanwhile, the energy of the energy accumulator is utilized to assist the full load and heavy load starting of the conveyor, the application under the limit working condition is met, the installed power of the main motor can be effectively reduced, the motor is well prevented from working in a low-efficiency area for a long time, and the energy utilization rate is improved.

The main power device of the belt conveyor is a motor and a motor, the motor provides oil through the variable pump and the energy accumulator and transmits power, so that the roller is driven to drive the belt to run or stop.

The motor brake 15 is used for controlling the rotation and stop of the motor 16, and the motor brake 15 is opened and closed in the following control modes:

the two-position two-way valve IV 13d, the two-position four-way valve II 21b and the two-position two-way valve 22 are commutated after being electrified, and oil liquid of the variable pump 10, the energy accumulator control valve assembly 7 and the energy accumulator II 6b enters the motor brake 15 through the two-position two-way valve IV 13d, the pressure reducing valve 24 and the two-position four-way valve II 21b, the motor brake 15 is opened, and the motor 16 can rotate; after the two-position four-way valve II 21b is powered off, the motor brake 15 is closed after pressure relief, and the motor 16 is powered off to stop rotating.

The clutch contactor 18 is used for controlling the clutch 17 to realize the on-off of the motor 16 and the roller 20, and the opening and closing control modes of the clutch contactor 18 are as follows:

the two-position two-way valve IV 13d, the two-position four-way valve I21 a and the two-position two-way valve 22 are commutated after being electrified, and oil liquid of the variable pump 10, the energy accumulator control valve assembly 7 and the energy accumulator II 6b enters the clutch contactor 18 through the two-position two-way valve IV 13d, the pressure reducing valve 24 and the two-position four-way valve I21 a, so that the motor 16 provides power for the roller 20; after the two-position four-way valve I21 a is powered off, the clutch contactor 18 releases pressure and then the roller 20 and the motor 16 are powered off.

The two-position three-way valve 22 is different from the two-position three-way valves I-IV appearing later in function, the two-position three-way valve 22 is normally open, and the two-position three-way valves I-IV are normally closed.

The accumulator control valve assembly 7 is used for controlling the accumulator I6 a to charge and release oil for the accumulator I6 a, and the control mode is as follows:

the variable pump charges the accumulator: the current of the variable pump 10, the two-position two-way proportional valve 5 and the electric proportional overflow valve I2 a is increased, the three-position four-way valve 11, the two-position two-way valve II 13b and the two-position three-way valve 3 are subjected to electric reversing, the accumulator I6 a is filled, and the filling is finished after the set pressure value is reached according to the detection of the pressure sensor I8 a, the pressure sensor II 8b and the pressure sensor III 8 c; the accumulator releases oil: the two-position two-way valve II 13b and the two-position three-way valve 3 are electrified and commutated, the two-position two-way proportional valve 5 is electrified, and the accumulator I6 a releases oil.

The opening pressure of the electric proportional relief valve I2 a and the opening pressure of the electric proportional relief valve II 2b can be changed through a control program, the relief valve 23 can be distinguished, the relief valve 23 is a constant-value relief valve, and the opening pressure cannot be changed through the control program because the valves are set in advance.

The shuttle valve is used for pressure selection, the pressure of which of the accumulator I6 a and the two-position two-way proportional valve 5 is larger than the pressure of which is selected, and the pressure used for energy storage is released or maintained.

As shown in fig. 3, the belt conveyor operation control method with the energy recovery function specifically includes the following steps:

step 1, starting to a normal operation stage:

step 1-1, full load or heavy load starting to a normal operation stage: the two motors run simultaneously, and the variable pump and the energy accumulator supply oil together to drive the motors to rotate;

step 1-1-1, starting a first motor 9a and a second motor 9b, wherein the electromagnetic valve of the variable pump 10 is not powered, the swing angle of the pump is very small, and the displacement of the pump is basically 0; the current of the electro proportional relief valve ii 2b is adjusted to a preset value, which is determined in connection with the load, typically a little larger than the operating current.

It should be noted that: the electric proportional overflow valves II (2 b) in the steps 1-1-1, 1-2-1, 3-1 and 4-1 are all adjusted to preset values, and the values to be adjusted are different according to different working conditions, and the current is adjusted to a certain value after calculation according to a program according to the working conditions, especially full load or near full load and light load, wherein the vertical current is slightly larger than the working current.

The solenoid valve current of the variable displacement pump 10 is gradually increased, the three-position four-way valve 11 and the two-position two-way valve I13 a are powered, the motor brake 15 is opened, and the motor 16 starts to operate.

Step 1-1-2, clutch contactor 18 is opened such that clutch 17 is engaged with motor 16; the oil output by the variable pump 10 enters a motor 16; the power of the motor 16 and the motor 9b is transmitted to the roller 20 through the gear mechanism I19 a, the gear mechanism II 19b and the speed reducer, and the conveyor belt starts to start up under the common driving of the motor 16 and the motor 9b.

And 1-1-3, after a certain speed is reached, the accumulator control valve assembly 7 starts to release oil until the conveying belt reaches a stable speed, and full load or heavy load is started successfully.

According to the technical parameter, the motor, the energy accumulator I6 a and the energy accumulator control valve assembly 7 can be increased, the number is not limited, and the connection mode of the motor and the roller is not limited, such as coupling transmission, belt transmission or any other forms.

Step 1-2, starting no load or light load to a normal operation stage: the accumulator releases oil to drive the motor at this stage;

step 1-2-1, starting a motor No. 9b to drive the roller 20 to run, wherein the electromagnetic valve of the variable pump 10 is not powered, and the variable pump 10 does not output oil; after the speed of the roller 20 reaches a certain value, the current of the electric proportional overflow valve II 2b is adjusted to a preset value, the three-position four-way valve 11 and the two-position two-way valve I13 a are powered on, the motor brake 15 is opened, and the motor 16 starts to operate.

Step 1-2-2, opening a clutch contactor 18 to enable a clutch 17 to be combined with a motor 16, and enabling oil output by an accumulator I6 a to enter the motor 16 through a two-way balance valve 14; at the moment, the two-position two-way valve II 13b is opened, the two-position three-way valve 3 is powered on, the flow is regulated through the energy accumulator I6 a, and meanwhile, the electric proportional overflow valve I2 a is powered on, so that the overflow pressure is regulated; the power of the motor 16 and the motor 9b is transmitted to the roller 20 through the gear mechanism I19 a and the gear mechanism II 19b, and the conveyor belt starts to run under the common drive of the motor 16 and the motor 9b.

And 1-2-3, along with the increase of the speed of the conveyor belt, the speed of releasing oil by the accumulator control valve assembly 7 is regulated along with the current of the two-position two-way proportional valve 5 until the conveyor belt reaches a stable speed, and no-load or light-load starting is successful.

Step 2, adjusting from low rotation speed to high rotation speed or material increasing stage: the accumulator releases oil to drive the motor at this stage;

step 2-1, a motor 9b is in an operating state, an electromagnetic valve of the variable pump 10 is not powered, and an electric proportional overflow valve II 2b is adjusted to a preset value; the three-position four-way valve 11 and the two-position two-way valve I13 a are powered, the motor brake 15 is opened, and the motor 16 starts to operate.

In step 2-2, the clutch contactor 18 is opened to enable the clutch 17 to be combined with the motor 16, the variable pump 10 does not output oil, the oil output by the accumulator I6 a enters the motor 16 through the two-way balance valve 14, and the power of the motor 16 and the motor II 9b is transmitted to the roller 20 through the gear mechanism I19 a and the gear mechanism II 19b.

Step 2-3, under the combined action of the motor 16 and the motor No. 9b, the speed of the conveyer belt is gradually increased, and along with the increase of the speed, the speed of the oil released by the accumulator control valve assembly 7 is adjusted along with the current of the two-position two-way proportional valve 5 until the conveyer belt reaches the stable speed or the conveyer belt is increased to the stable weight of materials.

Step 3, adjusting the high rotating speed to the low rotating speed for operation, or reducing materials: the accumulator absorbs oil and stores kinetic energy.

Step 3-1, a second motor 9b is in an operating state, the electromagnetic valve of the variable pump 10 is not powered, and the current of the electric proportional overflow valve II 2b is adjusted to a preset value; the three-position four-way valve 11, the two-position two-way valve I13 a and the variable pump 10 are not powered, the two-position two-way valve III 13c is powered, the motor brake 15 is opened, and the motor 16 starts to run.

Step 3-2, opening a clutch contactor 18 to enable a clutch 17 to be combined with a motor 16, enabling the variable pump 10 not to output oil, and enabling an accumulator I6 a of the accumulator control valve assembly 7 to receive and store high-pressure oil output by the motor 16; the motor is operated in a pumping state, oil is pumped to the accumulator by the roller drive, and the motor plays a braking role.

Step 3-3, under the combined action of the motor 16 and the motor 9b, the speed of the conveyer belt is gradually reduced; as the speed of the conveyor belt changes, the speed of the accumulator control valve assembly 7 receiving oil is adjusted with the current of the two-position two-way proportional valve 5 until the conveyor belt reaches a stable speed or is reduced to a stable weight of material.

Step 4, braking:

before the step 4-1 and braking, the motor 9b is in an operating state, the variable pump 10 is not powered, and the electric proportional overflow valve II 2b is adjusted to a preset value; the three-position four-way valve 11, the two-position two-way valve I13 a, the two-position two-way valve II 13b and the variable pump 10 are not powered, the two-position two-way valve III 13c is powered, the motor brake 15 is opened, and the motor 16 starts to operate.

Step 4-2, the clutch contactor 18 is opened to enable the clutch 17 to be combined with the motor 16, the variable pump 10 does not output oil, the accumulator I6 a of the accumulator control valve assembly 7 receives and stores high-pressure oil output by the motor 16, and the speed of the conveyor belt is gradually reduced under the combined action of the motor 16 and the second motor 9b.

And 4-3, along with the change of the speed of the conveyor belt, the speed of the accumulator control valve assembly 7 for receiving the oil is regulated along with the current of the two-position two-way proportional valve 5 until the speed of the conveyor belt reaches zero, and the braking of the conveyor belt is completed.

The valve mechanisms of the invention are all self-matched with the electromagnetic valves, and the power on and off of the electromagnetic valves are controlled by the controller.

In the stage of running from high rotation speed to low rotation speed or material reduction and braking, the two-position two-way valve III 13c is powered, and the speed of absorbing and releasing oil by the energy accumulator I6 a is controlled by proportionally controlling the opening of the two-position two-way proportional valve 5 according to detection of the pressure sensor I8 a, the pressure sensor II 8b and the pressure sensor III 8c when the energy accumulator I6 a absorbs and releases oil.

During the starting or stopping process of the motor, if the motor 16 is in a suction phenomenon, the oil is replenished through the one-way valve; if the pressure exceeds a set value in the running process of the motor 16, overflow is carried out through a one-way valve and an electric proportional overflow valve II 2 b; if pressure impact occurs, the oil flows back to the oil tank through the two-position two-way valve I13 a, the throttle valve 12 and the three-position four-way valve 11.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific details of the above embodiments, and various equivalent changes can be made to the technical solution of the present invention within the scope of the technical concept of the present invention, and all the equivalent changes belong to the protection scope of the present invention.

Claims

1. The utility model provides a belt conveyor with energy recuperation function which characterized in that: the belt conveyor adopts a motor, a motor and an energy accumulator as a driving system, a roller (20) is connected with a second motor (9 b) through a gear mechanism II (19 b), and the roller (20) is connected with a motor (16) through a gear mechanism I (19 a) and a clutch (17); the clutch contactor (18) is used for controlling the clutch (17) to realize the on-off of the motor (16) and the roller (20);

the energy accumulator control valve assembly (7) is connected with the variable pump (10) and the first motor (9 a), and the energy accumulator control valve assembly (7) is used for releasing oil pressure and providing energy to drive the hydraulic motor in the period from starting to normal operation, the period from low rotation speed to high rotation speed operation or the period from material increasing; absorbing oil and storing energy in a running stage, a material reduction stage and a braking stage from a high rotation speed to a low rotation speed;

the energy accumulator control valve assembly (7) comprises a one-way valve (1), an electric proportional overflow valve II (2 a), a two-position three-way valve (3), a two-position two-way proportional valve (5) and an energy accumulator I (6 a) which are connected in sequence; the energy accumulator I (6 a) is connected with the motor (16) through a two-position two-way valve III (13 c);

one path of outlet of the first motor (9 a) is connected with the clutch contactor (18) through a two-position two-way valve IV (13 d), a pressure reducing valve (24), an overflow valve (23), a two-position two-way valve (22), a two-position four-way valve I (21 a); the other outlet of the first motor (9 a) is connected with a motor brake through a two-position two-way valve IV (13 d), a pressure reducing valve (24) and a two-position four-way valve II (21 b).

2. The belt conveyor operation control method with the energy recovery function according to claim 1, which is characterized by comprising the following steps:

step 1, starting to a normal operation stage:

step 1-1, full load or heavy load starting to a normal operation stage:

step 1-1-1, starting a first motor (9 a) and a second motor (9 b), wherein an electromagnetic valve of a variable pump (10) is not powered, the variable pump (10) outputs oil, and the current of an electric proportional overflow valve II (2 b) is regulated to a preset value; the electromagnetic valve current of the variable pump (10) is gradually increased, the three-position four-way valve (11) and the two-position two-way valve I (13 a) are powered on, the motor brake (15) is opened, and the motor (16) starts to operate;

step 1-1-2, opening the clutch contactor (18) to enable the clutch (17) to be combined with the motor (16); the oil output by the variable pump (10) enters a motor (16); the power of the motor (16) and the motor II (9 b) is transmitted to the roller (20) through the gear mechanism I (19 a) and the gear mechanism II (19 b), and the conveyor belt starts to start in full load under the common driving of the motor (16) and the motor II (9 b);

step 1-1-3, after the set speed is reached, the accumulator control valve assembly (7) starts to release oil until the conveyor belt reaches a stable speed, and full load or heavy load is started successfully;

step 1-2, starting no load or light load to a normal operation stage:

step 1-2-1, starting a motor II (9 b) to drive a roller (20) to run, wherein an electromagnetic valve of a variable pump (10) is not powered, and the variable pump (10) does not output oil; after the speed of the roller (20) reaches a set speed, the current of the electric proportional overflow valve II (2 b) is adjusted to a preset value, the three-position four-way valve (11) and the two-position two-way valve I (13 a) are powered on, the motor brake (15) is opened, and the motor (16) starts to operate;

step 1-2-2, opening a clutch contactor (18) to enable a clutch (17) to be combined with a motor (16), and enabling oil output by an accumulator I (6 a) to enter the motor (16) through a two-way balance valve (14); the power of the motor (16) and the motor II (9 b) is transmitted to the roller (20) through the gear mechanism I (19 a) and the gear mechanism II (19 b), and the conveyer belt starts to run under the common drive of the motor (16) and the motor II (9 b);

step 1-2-3, along with the increase of the speed of the conveyor belt, the speed of releasing oil by the energy accumulator control valve assembly (7) is regulated along with the current of the two-position two-way proportional valve (5) until the conveyor belt reaches a stable speed, and no-load or light-load starting is successful;

step 2-1, a motor II (9 b) is in an operating state, an electromagnetic valve of a variable pump (10) is not powered, and an electric proportional overflow valve II (2 b) is adjusted to a preset value; the three-position four-way valve (11) and the two-position two-way valve I (13 a) are powered on, the motor brake (15) is opened, and the motor (16) starts to operate;

step 2-2, a clutch contactor (18) is opened to enable a clutch (17) to be combined with a motor (16), the variable pump (10) does not output oil, the oil output by the energy accumulator I (6 a) enters the motor (16) through the bidirectional balance valve (14), and the power of the motor (16) and a motor II (9 b) is transmitted to the roller (20) through the gear mechanism I (19 a) and the gear mechanism II (19 b);

step 2-3, under the combined action of the motor (16) and the motor II (9 b), the speed of the conveyer belt is gradually increased, and along with the increase of the speed, the speed of the oil released by the energy accumulator control valve assembly (7) is regulated along with the current of the two-position two-way proportional valve (5) until the conveyer belt reaches the stable speed or the conveyer belt is increased to the stable weight of materials;

step 3-1, a motor II (9 b) is in an operating state, an electromagnetic valve of a variable pump (10) is not powered, and the current of an electric proportional overflow valve II (2 b) is regulated to a preset value; the three-position four-way valve (11), the two-position two-way valve I (13 a) and the variable pump (10) are not powered, the two-position two-way valve III (13 c) is powered, the motor brake (15) is opened, and the motor (16) starts to operate;

step 3-2, opening a clutch contactor (18) to enable a clutch (17) to be combined with a motor (16), enabling a variable pump (10) not to output oil, and enabling an accumulator I (6 a) of an accumulator control valve assembly (7) to receive and store high-pressure oil output by the motor (16); under the combined action of the motor (16) and the motor II (9 b), the speed of the conveyer belt is gradually reduced;

3-3, along with the change of the speed of the conveyor belt, the speed of the oil received by the energy accumulator control valve assembly (7) is regulated along with the current of the two-position two-way proportional valve (5) until the conveyor belt reaches a stable speed or is reduced to a stable weight of materials;

step 4, braking:

before the step 4-1 and braking, the motor II (9 b) is in an operating state, the variable pump (10) cannot be powered, and the electric proportional overflow valve II (2 b) is adjusted to a preset value; the three-position four-way valve (11), the two-position two-way valve I (13 a), the two-position two-way valve II (13 b) and the variable pump (10) are not powered, the two-position two-way valve III (13 c) is powered, the motor brake (15) is opened, and the motor (16) starts to run;

step 4-2, a clutch contactor (18) is opened to enable a clutch (17) to be combined with a motor (16), the variable pump (10) does not output oil, an accumulator I (6 a) of an accumulator control valve assembly (7) receives and stores high-pressure oil output by the motor (16), and the speed of a conveying belt is gradually reduced under the combined action of the motor (16) and a second motor (9 b);

and 4-3, along with the change of the speed of the conveyor belt, the speed of the oil received by the energy accumulator control valve assembly (7) is regulated along with the current of the two-position two-way proportional valve (5) until the speed of the conveyor belt reaches zero, and the braking of the conveyor belt is completed.

3. The belt conveyor operation control method with an energy recovery function according to claim 2, characterized in that: the motor brake (15) is controlled to be opened and closed in the following manner:

the two-position two-way valve IV (13 d), the two-position four-way valve II (21 b) and the two-position two-way valve (22) are commutated after being electrified, oil liquid passing through the two-position two-way valve IV (13 d), the pressure reducing valve (24) and the two-position four-way valve II (21 b) enters the motor brake (15), the motor brake (15) is opened, and the motor (16) can rotate;

after the two-position four-way valve II (21 b) is powered off, the motor brake (15) is closed after pressure relief, and the motor (16) loses power to stop rotating.

4. The belt conveyor operation control method with an energy recovery function according to claim 2, characterized in that: the clutch contactor (18) is opened and closed in a control mode that:

the two-position two-way valve IV (13 d), the two-position four-way valve I (21 a) and the two-position two-way valve (22) are subjected to reversing after being electrified, and oil liquid of the variable pump (10), the energy accumulator control valve assembly (7) and the energy accumulator II (6 b) passes through the two-position two-way valve IV (13 d), the pressure reducing valve (24) and the two-position four-way valve I (21 a) and enters the clutch contactor (18), so that the motor (16) provides power for the roller (20);

after the two-position four-way valve I (21 a) is powered off, the clutch contactor (18) releases pressure, and the roller (20) and the motor (16) are powered off.

5. The belt conveyor operation control method with an energy recovery function according to claim 2, characterized in that: the control mode of charging and releasing oil of the accumulator control valve assembly (7) is as follows:

the variable pump charges the accumulator: the variable pump (10), the two-position two-way proportional valve (5), the electric proportional overflow valve I (2 a) are increased in current, the three-position four-way valve (11), the two-position two-way valve II (13 b) and the two-position three-way valve (3) are subjected to electric reversing, the accumulator I (6 a) is filled with liquid, and the liquid is filled after the set pressure value is reached according to the detection of the pressure sensor I (8 a), the pressure sensor II (8 b) and the pressure sensor III (8 c);

the accumulator releases oil: the two-position two-way valve II (13 b) and the two-position three-way valve (3) are electrified and commutated, the two-position two-way proportional valve (5) is electrified, and the accumulator I (6 a) releases oil.

6. The belt conveyor operation control method with an energy recovery function according to claim 2, characterized in that: in the stage of running from high rotation speed to low rotation speed or material reduction and braking, the two-position two-way valve III (13 c) is powered, and the speed of absorbing and releasing oil by the energy accumulator I (6 a) is controlled by controlling the opening of the two-position two-way proportional valve (5) in proportion according to detection of the pressure sensor I (8 a), the pressure sensor II (8 b) and the pressure sensor III (8 c) when the energy accumulator I (6 a) absorbs and releases oil.

7. The belt conveyor operation control method with an energy recovery function according to claim 6, characterized in that: the pressure sensor II (8 b) and the pressure sensor III (8 c) are symmetrically distributed at oil inlet and oil outlet of the motor 16, and after the pressure is detected, the pressure difference at two ends of the motor 16 is calculated, so that the torque of hydraulic oil acting on the motor is calculated.

8. The belt conveyor operation control method with an energy recovery function according to claim 2, characterized in that: in the starting or stopping process of the motor, if the motor (16) is in a suction phenomenon, the oil is replenished through the one-way valve; if the pressure exceeds a set value in the running process of the motor (16), overflow is carried out through a one-way valve and an electric proportional overflow valve II (2 b); if pressure impact occurs, the oil flows back to the oil tank through the two-position two-way valve I (13 a), the throttle valve (12) and the three-position four-way valve (11).

9. The belt conveyor operation control method with an energy recovery function according to claim 2, characterized in that: the set speed in the step 1-1-3 is 2% -5% of the maximum speed of the belt conveyor, and the stable speed is the maximum speed; the set speed in step 1-2-1 is 2% -5% of the maximum speed of the drum.