A potential energy recovery device for a walking beam furnace hydraulic system

Abstract

This invention discloses a potential energy recovery device for a walking beam heating furnace hydraulic system, comprising a lifting cylinder, a speed control circuit, and a potential energy recovery device. The oil ports of the two end chambers of the lifting cylinder are respectively connected to the speed control circuit. The potential energy recovery device is connected in parallel to the rodless chamber circuit of the lifting cylinder. A switching regulating valve group and a flow sensor are installed on the main pipeline connecting the potential energy recovery device and the speed control circuit. This device features a simple structure and low maintenance and modification costs. It can ensure that the lifting motion characteristic curve of the walking beam remains unchanged after reducing the number of online working pumps, with the potential energy recovery device responsible for filling the flow gap, thereby reducing energy consumption.

Description

Technical Field

[0001] This invention relates to the field of metallurgical technology, specifically to a potential energy recovery device for a hydraulic system of a walking beam furnace. Background Technology

[0002] The heating furnace is an indispensable part of the entire steel rolling production line, and the walking beam furnace, due to its unique advantages, has gradually replaced the original pusher furnace and roller hearth furnace. Walking beam furnaces generally have high loads and frequent operations. Therefore, hydraulic transmission, due to its small size, high load capacity, and ease of electromechanical integration control, is widely used in walking beam furnaces. It achieves the uniform forward movement of the steel billet by cyclically moving according to a predetermined program of rising, advancing, falling, and retreating.

[0003] Currently, walking beam furnaces in China are trending towards larger sizes and faster operation. Conventional walking beam furnaces primarily employ a constant-pressure variable pump and proportional control valve design for their hydraulic systems. Bar and wire rod furnaces, due to their smaller maximum flow rate, typically use proportional directional valve speed control loops. Slab furnaces, with their larger system load and higher maximum flow rate, typically use proportional throttle valve speed control loops. These two designs fail to effectively utilize the gravitational potential energy generated during the mechanical descent of the heavy furnace bottom. Furthermore, this potential energy is converted into heat, increasing the temperature of the hydraulic oil and raising the energy consumption of the circulating cooling system.

[0004] Therefore, how to recover and reuse the enormous gravitational potential energy generated when the mechanical steel support at the bottom of the furnace descends determines the energy-saving index of the entire system and is also the key to the energy saving of the entire system.

[0005] Research indicates that a commonly used energy-saving system on wire rod heating furnace production lines utilizes a specially designed two-stage hydraulic cylinder to recover the potential energy of the walking beam. The first-stage hydraulic cylinder is connected to high and low pressure accumulator groups, respectively responsible for recovering the gravitational potential energy during the loaded and unloaded descent of the walking beam, releasing it in stages during the next beam ascent. This type of potential energy recovery device can effectively recover some of the gravitational potential energy during the walking beam's descent and reduce the number of working pumps in the system. However, the recovery relies on a specially designed double-stage hydraulic cylinder, making the device structure complex and increasing maintenance costs. Another type of potential energy recovery device uses an active cylinder, a driven cylinder, a pump source proportional pressure regulating valve, and an accumulator group. This device, due to the addition of two cylinders, has a very complex equipment structure and control logic, and cannot effectively reduce the number of working pumps, resulting in limited energy-saving effects. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a potential energy recovery device for a hydraulic system of a walking beam furnace, which addresses the above-mentioned defects in the existing technology. The device has a simple structure, low maintenance and modification costs, and can ensure that the lifting motion characteristic curve of the walking beam remains unchanged after reducing the number of online working pumps. The potential energy recovery device is responsible for filling the flow gap, thereby reducing energy consumption.

[0007] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0008] A potential energy recovery device for a hydraulic system of a walking beam furnace includes a lifting cylinder, a speed control circuit, and a potential energy recovery device. The oil ports of the two end chambers of the lifting cylinder are respectively connected to the speed control circuit. The potential energy recovery device is connected in parallel to the rodless chamber circuit of the lifting cylinder. A switch regulating valve group and a flow sensor are provided on the main pipeline connecting the potential energy recovery device and the speed control circuit. The switch regulating valve group consists of several two-way cartridge valves.

[0009] According to the above technical solution, the potential energy recovery device includes two independent accumulator groups, namely a primary booster accumulator group and a secondary booster accumulator group. The switching control valve group includes two directional control valve groups. One directional control valve group is located between the rodless chamber of the oil cylinder and the accumulator group and the speed control circuit. It is used to control the hydraulic energy converted from the gravitational potential energy when the stepping beam descends, and is also responsible for controlling the switching between the energy-saving circuit and the speed control circuit. The other directional control valve group is located between the accumulator group and the oil inlet pipe of the speed control circuit. It is responsible for participating in controlling the energy release process.

[0010] According to the above technical solution, the booster accumulator group includes a accumulator hydraulic pipeline and multiple accumulators connected to the hydraulic pipeline. One end of the accumulator hydraulic pipeline is connected to the rodless chamber of the lifting cylinder through a one-way valve and a directional control valve group. The one-way valve is used to ensure that the hydraulic energy flows in one direction. The other end of the accumulator hydraulic pipeline is connected to the oil inlet pipe of the speed control circuit through the directional control valve group.

[0011] According to the above technical solution, the hydraulic pipeline is connected to an electromagnetic relief valve and an oil replenishment and discharge circuit; the electromagnetic relief valve prevents the potential energy recovery device from overload, and unloads the system when the accumulator group pressure is too high.

[0012] According to the above technical solution, the oil replenishment and drainage circuit includes a pressure sensor, a speed control valve, a hydraulic lock, and a solenoid directional valve connected in sequence. The accumulator is connected to one end of the speed control valve via a hydraulic pipeline, and the other end of the speed control valve is connected to the hydraulic lock and the solenoid directional valve in sequence. The solenoid directional valve is controlled by the signal fed back from the pressure sensor to replenish or release pressure on the accumulator group, maintaining a constant pressure in the accumulator group.

[0013] According to the above technical solution, the switching control valve group includes four two-way directional control valves: a first two-way directional control valve, a second two-way directional control valve, a third two-way directional control valve, and a fourth two-way directional control valve, forming two sets of directional control valve groups (i.e., the first two-way directional control valve and the second two-way directional control valve form one set, and the third two-way directional control valve and the fourth two-way directional control valve form another set). Each two-way directional control valve is equipped with a directional control cover plate. One end of the first two-way directional control valve is connected to the primary booster accumulator group and the secondary booster accumulator group. One end of the accumulator group is connected to the other end, and the other end is connected to the rodless chamber circuit of the hydraulic cylinder; one end of the second two-way directional control valve is connected to the speed control circuit, and the other end is connected to the rodless chamber circuit of the hydraulic cylinder; when the first two-way directional control valve is open, the second two-way directional control valve must be closed, and vice versa; one end of the third two-way directional control valve is connected to the primary booster accumulator group, and the other end is connected to the oil inlet pipe of the speed control circuit; one end of the fourth two-way directional control valve is connected to the secondary booster accumulator group, and the other end is connected to the oil inlet pipe of the speed control circuit; when the third two-way directional control valve is open, the fourth two-way directional control valve must be closed, and vice versa.

[0014] According to the above technical solution, overflow valves are provided at both ends of the second two-way directional control valve to regulate the pressure fluctuations generated when switching between the energy-saving circuit and the speed control circuit.

[0015] According to the above technical solution, a one-way valve is installed on the oil inlet pipe of the speed control circuit to prevent hydraulic oil backflow.

[0016] According to the above technical solution, a displacement sensor is installed on the lifting cylinder.

[0017] According to the above technical solution, the speed control circuit includes a balance valve, a proportional directional valve 1, and a pressure compensator connected in sequence.

[0018] The present invention has the following beneficial effects:

[0019] This invention effectively utilizes the enormous gravitational potential energy generated during the descent of the walking beam by connecting a potential energy recovery device in parallel to the lifting speed control circuit of the walking beam. This energy is converted into hydraulic energy and then used to fill the flow gap caused by reducing the number of online pumps during the next lifting of the walking beam, by cross-controlling the opening and closing of the valve group through flow and displacement sensors. This hydraulic energy is maintained constant during the next lifting of the walking beam, thus keeping the lifting speed characteristic curve of the walking beam unchanged. Furthermore, the potential energy recovery device and the speed control device are independent in this invention, allowing users to directly add the potential energy recovery device to a general design without dismantling and rebuilding the entire system to achieve energy-saving effects. This invention features low maintenance and modification costs and high applicability. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the potential energy recovery device of the hydraulic system of the walking beam furnace in an embodiment of the present invention;

[0021] In the diagram, 1-proportional directional valve, 2-balance valve, 3-accumulator group, 4-lifting cylinder, 5-displacement sensor, 7-check valve, 10-solenoid relief valve, 11-relief valve, 13-solenoid directional valve, 14-hydraulic lock, 15-speed control valve, 16-pressure compensator, 17-flow sensor.

[0022] 8.1 - First pressure sensor, 8.2 - Second pressure sensor, 8.3 - Third pressure sensor;

[0023] 9.1 - First two-way directional control valve, 9.2 - Second two-way directional control valve, 9.3 - Third two-way directional control valve, 9.4 - Fourth two-way directional control valve;

[0024] 12.1 - First high-pressure ball valve, 12.2 - Second high-pressure ball valve, 12.3 - Third high-pressure ball valve. Detailed Implementation

[0025] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0026] Reference Figure 1 As shown, an embodiment of the present invention provides a potential energy recovery device for a hydraulic system of a walking beam furnace, comprising a lifting cylinder 4, a speed control circuit, and a potential energy recovery device. The oil ports of both ends of the lifting cylinder 4 are connected to the speed control circuit. The potential energy recovery device is connected in parallel to the rodless chamber circuit of the lifting cylinder 4. A switch-regulating valve group and a flow sensor 17 are installed on the connecting pipe between the potential energy recovery device and the speed control circuit. The system flow sensor 17 and the displacement sensor 5 of the lifting cylinder 4 jointly control the opening and closing of the switch-regulating valve group. One end of the potential energy recovery device is connected to the rodless chamber of the cylinder, responsible for recovering the gravitational potential energy generated when the walking beam descends; the other end is connected to the oil inlet pipe of the speed control circuit, responsible for filling the flow gap.

[0027] Furthermore, the potential energy recovery device includes two parallel accumulator groups 3, namely a primary booster accumulator group and a secondary booster accumulator group. The switching control valve group includes two directional control valve groups. One directional control valve group is located between the rodless chamber of the cylinder and the accumulator group and the speed control circuit. It is used to control the hydraulic energy converted from the gravitational potential energy when the stepping beam descends, and is also responsible for controlling the switching between the energy-saving circuit and the speed control circuit. The other directional control valve group is located between the accumulator group and the oil inlet pipe of the speed control circuit. It is responsible for participating in controlling the energy release process.

[0028] Furthermore, the main P pipe is the pressure oil inlet pipe. Generally, the inlet pipe is P and the return pipe is T, which is the industry standard.

[0029] The flow sensor 17 and the displacement sensor 5 of the lifting cylinder jointly participate in the regulation of the directional control valve group. When the flow sensor 17 detects that the system flow is close to the maximum value, the flow sensor 17 will send a signal to the accumulator group to release energy and accelerate the upward movement of the stepping beam. When the displacement sensor 5 of the lifting cylinder detects that the stepping beam is close to the steel support position or the end position, the displacement sensor 5 will send a signal to the accumulator group to stop releasing energy. The proportional valve is responsible for controlling the stepping beam to finally decelerate until it stops. The flow sensor 17 and the displacement sensor 5 are respectively connected to the controller of each accumulator group. The controller of each accumulator group is connected to the switch control valve group and the proportional valve.

[0030] Furthermore, two two-way check valves 7 are installed between the primary booster accumulator group and the secondary booster accumulator group to ensure unidirectional flow of hydraulic energy, and the two accumulator groups work independently.

[0031] The booster accumulator group includes a accumulator hydraulic pipeline and multiple accumulators connected to the hydraulic pipeline. One end of the accumulator hydraulic pipeline is connected to the rodless chamber of the lifting cylinder 4 via a one-way valve 7 and a directional control valve group. The one-way valve 7 is used to ensure unidirectional flow of hydraulic energy. The other end of the accumulator hydraulic pipeline is connected to the oil inlet pipe of the speed control circuit via the directional control valve group.

[0032] The hydraulic pipeline is connected to an electromagnetic relief valve 10 and an oil replenishment and discharge circuit; the electromagnetic relief valve 10 prevents the potential energy recovery device from overloading and unloads the system when the accumulator group pressure is too high.

[0033] Furthermore, the oil replenishment and discharge circuit includes a pressure sensor, a speed control valve 15, a hydraulic lock 14, and a solenoid directional valve 13 connected in sequence. The accumulator is connected to one end of the speed control valve 15 via a hydraulic pipeline, and the other end of the speed control valve 15 is connected to the hydraulic lock 14 and the solenoid directional valve 13 in sequence. The solenoid directional valve 13 is controlled by the signal fed back from the pressure sensor to replenish or release pressure on the accumulator group, maintaining a constant pressure in the accumulator group.

[0034] The switching control valve assembly includes four two-way directional control valves: a first two-way directional control valve, a second two-way directional control valve, a third two-way directional control valve, and a fourth two-way directional control valve. These form two sets of directional control valve assemblies (i.e., the first and second two-way directional control valves form one directional control valve assembly, and the third and fourth two-way directional control valves form another directional control valve assembly). Each two-way directional control valve has a directional control cover plate. One end of the first two-way directional control valve is connected to both the primary booster accumulator assembly and the secondary booster accumulator assembly. One end of the first two-way directional control valve is connected to the rodless chamber circuit of the hydraulic cylinder; the other end of the second two-way directional control valve is connected to the speed control circuit; when the first two-way directional control valve is open, the second two-way directional control valve must be closed, and vice versa; one end of the third two-way directional control valve is connected to the primary booster accumulator group, and the other end is connected to the main P pipe of the speed control circuit; one end of the fourth two-way directional control valve is connected to the secondary booster accumulator group, and the other end is connected to the main P pipe of the speed control circuit; when the third two-way directional control valve is open, the fourth two-way directional control valve must be closed, and vice versa.

[0035] Furthermore, the high-pressure ball valve 12 is responsible for manually controlling the switching between the normal mode and the energy-saving mode. There are three high-pressure ball valves 12: the first high-pressure ball valve 12.1, the second high-pressure ball valve 12.2, and the third high-pressure ball valve 12.3. When the potential energy recovery device is working normally, the high-pressure ball valve 12.3 is in the normally closed state.

[0036] Furthermore, an overflow valve 11 is connected in parallel to both ends of the second two-way directional control valve 9.2, which is responsible for regulating the pressure fluctuations that may occur when the stepping beam descends to the steel support position, the directional control valve 9.1 is closed and the directional control valve 9.2 is opened, so as to ensure the smooth operation of the system.

[0037] Furthermore, a displacement sensor 5 is provided on the lifting cylinder 4 to provide feedback signals for the control circuit; the system flow sensor 17 and the displacement sensor of the lifting cylinder 4 jointly participate in controlling the opening and closing of the switch regulating valve group.

[0038] There are two lifting cylinders 4.

[0039] Furthermore, the speed control loop includes a balance valve 2, a proportional directional valve 1, and a pressure compensator 16 connected in sequence.

[0040] The potential energy recovery device's accumulator group is equipped with pressure sensors, which form a closed-loop control with the electromagnetic overflow valve 10 and the electromagnetic directional valve 13 to maintain a constant pressure in the accumulator group. Each two-way directional control valve is a two-way cartridge valve.

[0041] The working process of this invention is as follows: Before activating the energy-saving mode, it is necessary to ensure that the first high-pressure ball valve 12.1 and the second high-pressure ball valve 12.2 are normally open, the third high-pressure ball valve 12.3 is normally closed, and the two solenoid directional valves 13 are opened to the left position. When the accumulator group 3 reaches the set pressure, the two solenoid directional valves 13 return to the middle position, and the system is ready.

[0042] When the walking beam rises under no-load, it first enters a state of gradual acceleration. At this time, the speed of the walking beam's rise and fall is entirely determined by the opening degree of the proportional directional valve 1. Due to the reduction in the number of working pumps operating online, the maximum system flow is limited. When the flow sensor 17 detects that the system flow is close to the maximum value, the third two-way directional control valve 9.3 opens, and the primary booster accumulator group composed of the first accumulator 3.1 and the second accumulator 3.2 releases energy to accelerate the system. When the cylinder displacement sensor detects that the walking beam is close to the billet, the opening degree of the proportional directional valve 1 decreases. When the flow sensor 17 detects that the passing flow is lower than the maximum system flow, the third two-way directional control valve 9.3 closes, and the proportional directional valve 1 controls the walking beam to slowly lift the steel billet.

[0043] When the load on the walking beam increases, the above steps will be repeated. When the system flow rate approaches its maximum value, the two-way directional control valve 9.4 opens, and the secondary booster accumulator group, consisting of the third accumulator 3.3 to the sixth accumulator 3.6, releases energy to provide a secondary acceleration for the system. A speed regulating valve 15 is superimposed on the control circuit of the two-way directional control valve to adjust the opening and closing speed of the valve and ensure a smooth acceleration of the system.

[0044] When the walking beam descends under load, the first two-way directional control valve 9.1 opens and the second two-way directional control valve 9.2 closes. The primary and secondary booster accumulator groups work together to recover all the gravitational potential energy generated during the walking beam's descent and provide back pressure. At this time, the walking beam's descent speed is controlled by the proportional directional valve 1. When the cylinder displacement sensor 5 detects that the billet is about to contact the walking beam of the heating furnace, the first two-way directional control valve 9.1 closes and the second two-way directional control valve 9.2 opens. At this time, the walking beam's descent switches to normal control, and the proportional directional valve 1 controls the walking beam to descend to the low position. The overflow valve 11 is used to buffer the inertial impact generated by the walking beam's own weight during the opening and closing of the first two-way directional control valve 9.1 and the second two-way directional control valve 9.2.

[0045] After one stepping cycle, the first pressure sensor 8.1 and the second pressure sensor 8.2 calibrate the accumulator group pressure. The oil replenishment / relief circuit, composed of the solenoid directional valve 13, hydraulic lock 14, and speed control valve 15, maintains the accumulator group pressure at the set value. If the accumulator group absorbs excessive energy during the stepping beam's descent, causing the pressure to rise to the upper limit of the set value, the two solenoid relief valves 10 automatically open to relieve system pressure. The two one-way valves 7, together with the first two-way directional control valves 9.1 to the fourth two-way directional control valves 9.4, are used to control the unidirectional flow of recovered energy. The one-way valves 7 are located at the very front of the potential energy recovery circuit, installed on the oil inlet pipe of the speed control circuit, to prevent the system pressure from dropping and the accumulator group's energy from leaking out during the accumulator group's oil replenishment process if other equipment in the system operates. Furthermore, the set pressure of the accumulator groups 3.1 to 3.6 cannot be too high; otherwise, the stepping beam may be obstructed during its entire unloaded descent. Therefore, a third pressure sensor 8.3 is installed in the rod chamber circuit of the hydraulic cylinder. When the rod chamber pressure reaches the system pressure but the hydraulic cylinder does not move, the first two-way directional control valve 9.1 should automatically close, and the second two-way directional control valve 9.2 should open. Speed ​​regulating valves 15 are superimposed on the control cover plates of both the first two-way directional control valve 9.1 and the second two-way directional control valve 9.2 to control the valve opening and closing speed, reduce the impact load generated during valve opening and closing, and ensure smooth system operation.

[0046] The working principle of this invention: The hydraulic control circuit for lifting and lowering a walking beam typically uses a proportional valve in conjunction with a pressure compensator 16 for speed control, hereinafter referred to as the speed control circuit. This invention adds a potential energy recovery device to the speed control circuit. The potential energy recovery device mainly consists of an accumulator group, a two-way directional control valve, a pressure sensor, a flow sensor, a one-way valve, a relief valve, and a replenishment circuit. The accumulators are divided into two groups, namely, accumulator group one (i.e., primary booster accumulator group) and accumulator group two (i.e., secondary booster accumulator group), which are responsible for jointly recovering all the gravitational potential energy generated when the walking beam load decreases, converting the gravitational potential energy into hydraulic energy stored in the high-pressure accumulator group, and releasing it in two stages during the next lifting of the walking beam. The two-way directional control valve with a directional control cover is responsible for controlling the on / off state of the energy-saving circuit and participates in the control of the lifting and lowering of the walking beam together with the speed control circuit.

[0047] When the walking beam rises under no-load, the proportional directional valve in the speed control circuit first gradually increases the speed of the lifting cylinder 4. Due to the reduction in the number of online working pumps, the maximum flow rate of the system is limited. At this time, the directional control valve of the first accumulator group opens to increase the speed of the system once. When the walking beam is about to contact the billet, the displacement sensor built into the cylinder will send a signal to decelerate the walking beam. At this time, the directional control valve of the first accumulator group closes, and the speed is controlled by the proportional directional valve.

[0048] When the load rises after the stepping beam supports the steel, the proportional directional valve in the speed control circuit first gradually increases the speed of the lifting cylinder 4. When the maximum flow rate of the system is reached, the directional control valve of the second accumulator group opens. When the stepping beam is about to reach the highest position, the sensor will still send a signal, the control valve of the second accumulator group will close, and the speed will be gradually reduced to zero by the proportional directional valve.

[0049] Since the volume of the rod chamber in a hydraulic cylinder is typically half that of the rodless chamber, pressurized oil enters the rod chamber when the walking beam descends. To maintain a constant system operating cycle, at least 50% of the system's maximum flow rate needs to be involved in speed control during the walking beam's descent. The remaining 50% needs to be recovered and reused during the walking beam's descent. Undoubtedly, the walking beam has higher gravitational potential energy during its descent under load.

[0050] When the walking beam is lowered under load, the potential energy recovery device engages, cutting off the passage between the rodless chamber and the proportional directional valve via the directional control valve. The speed control circuit controls the lifting and lowering speed of the walking beam, while the potential energy recovery device recovers all the potential energy during the descent of the walking beam and provides back pressure. Once the billet is gradually decelerated and placed on the fixed beam of the heating furnace, the directional control valve cuts off the passage of the potential energy recovery device, and the speed control circuit controls the unloaded walking beam to land smoothly. This cycle repeats continuously.

[0051] The potential energy recovery device is equipped with an electromagnetic overflow valve 10, a pressure sensor, and a flow sensor. The electromagnetic overflow valve 10 is used to realize the system overload protection and unloading functions. The flow sensor carries an analog signal and controls the opening and closing of the accumulator group when the flow rate of the walking beam rising system approaches the maximum value. The pressure sensor also carries an analog signal and is responsible for maintaining a constant pressure in the accumulator group when other equipment operates after each stepping cycle.

[0052] The above are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any equivalent changes made in accordance with the claims of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A potential energy recovery device for a hydraulic system of a walking beam furnace, characterized in that, It includes a lifting cylinder, a speed control circuit, and a potential energy recovery device. The oil ports of the two end chambers of the lifting cylinder are connected to the speed control circuit respectively. The potential energy recovery device is connected in parallel to the rodless chamber circuit of the lifting cylinder. The connecting pipe between the potential energy recovery device and the speed control circuit is equipped with a switch regulating valve group and a flow sensor. The potential energy recovery device includes two independent accumulator groups: a primary booster accumulator group and a secondary booster accumulator group. The switching control valve group includes two sets of directional control valve groups. One set of directional control valve groups is located between the rodless chamber of the lifting cylinder and the accumulator group and the speed control circuit. It is used to control the hydraulic energy converted from the gravitational potential energy during the descent of the walking beam and is also responsible for controlling the switching between the energy-saving circuit and the speed control circuit. The other set of directional control valve groups is located between the accumulator group and the oil inlet pipe of the speed control circuit and is responsible for participating in controlling the energy release process. The booster accumulator group includes a accumulator hydraulic pipeline and multiple accumulators connected to the accumulator hydraulic pipeline. One end of the accumulator hydraulic pipeline is connected to the rodless chamber of the lifting cylinder through a one-way valve and a directional control valve group. The other end of the accumulator hydraulic pipeline is connected to the oil inlet pipe of the speed control circuit through the directional control valve group. The switching control valve group includes four two-way directional control valves: a first two-way directional control valve, a second two-way directional control valve, a third two-way directional control valve, and a fourth two-way directional control valve, forming two sets of directional control valve groups. One end of the first two-way directional control valve is connected to the primary booster accumulator group and the secondary booster accumulator group, and the other end is connected to the rodless chamber circuit of the hydraulic cylinder. One end of the second two-way directional control valve is connected to the speed control circuit, and the other end is connected to the rodless chamber circuit of the hydraulic cylinder. One end of the third two-way directional control valve is connected to the primary booster accumulator group, and the other end is connected to the oil inlet pipe of the speed control circuit. One end of the fourth two-way directional control valve is connected to the secondary booster accumulator group, and the other end is connected to the oil inlet pipe of the speed control circuit.

2. The potential energy recovery device for the hydraulic system of the walking beam furnace according to claim 1, characterized in that, The energy storage hydraulic pipeline is connected to an electromagnetic relief valve and an oil replenishment and drain circuit.

3. The potential energy recovery device for the hydraulic system of the walking beam furnace according to claim 2, characterized in that, The oil replenishment and drainage circuit includes a pressure sensor, a speed control valve, a hydraulic lock, and a solenoid directional valve connected in sequence.

4. The potential energy recovery device for the hydraulic system of the walking beam furnace according to claim 1, characterized in that, The two ends of the second two-way directional control valve are connected in parallel with relief valves.

5. The potential energy recovery device for the hydraulic system of the walking beam furnace according to claim 1, characterized in that, A check valve is installed on the oil inlet pipe of the speed control circuit to prevent hydraulic oil backflow.

6. The potential energy recovery device for the hydraulic system of the walking beam furnace according to claim 1, characterized in that, The lifting cylinder is equipped with a displacement sensor.

7. The potential energy recovery device for the hydraulic system of the walking beam furnace according to claim 1, characterized in that, The speed control circuit includes a balance valve, a proportional directional valve, and a pressure compensator connected in sequence.

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