Energy-saving system for recycling gravitational potential energy of hot rolling conveying chain

Abstract

The utility model discloses an energy-saving system for recycling gravitational potential energy of a hot-rolling conveying chain, which relates to the technical field of hot-rolling conveying chains and comprises system elements and a lifting oil cylinder for acting the whole system elements. The system elements comprise a piston type energy accumulator, a nitrogen cylinder set, a hydraulic lock, a first one-way throttle valve, an overflow valve, a pressure sensor, a balance valve, a second one-way throttle valve, a VH1 flow logic valve, a VH2 flow logic valve, a VH3 flow logic valve, a VH4 flow logic valve, a VH5 flow logic valve and a VH6 electromagnetic reversing valve. The piston type energy accumulator serves as a storage element of gravitational potential energy, the gravitational potential energy generated when the walking beam frame and the steel coil descend is recycled and stored in the piston type energy accumulator, the gravitational potential energy is released into the system again in the lifting process, auxiliary power is provided for driving of a hydraulic system, recycling and utilization of the gravitational potential energy are achieved, and the energy saving effect is achieved. And energy consumption is reduced, and resources are saved.

Description

Technical Field

[0001] The utility model relates to the technical field of hot rolling transport chains, in particular to an energy-saving system for recovering the gravitational potential energy of a hot rolling transport chain. Background Art

[0002] As a common device for transporting steel coils in the hot rolling process of the metallurgical industry, the frame of the transport chain drives the steel coil to realize the transportation of the steel coil through lifting, translation, lowering and returning actions. The hot rolling transport chain is usually driven by a hydraulic system. The lifting cylinder in the hydraulic system realizes the up and down movement of the frame, and the translation cylinder realizes the forward and return actions of the frame; the hydraulic pump station provides hydraulic power for the cylinder, and the control valve realizes the action and speed control of the cylinder.

[0003] In the usual design, the hydraulic system of the transport chain does not have a gravitational potential energy recovery device. In the process of the hot rolling transport chain repeatedly transporting steel coils, the gravitational potential energy of the frame and the steel coil is consumed through the heating of hydraulic components and oil, resulting in a large amount of energy waste.

[0004] As described above, for this reason, we have designed an energy-saving system for recovering the gravitational potential energy of a hot rolling transport chain to solve the above problems. Content of the Utility Model

[0005] The purpose of the utility model is to solve the defects existing in the prior art, and to provide an energy-saving system for recovering the gravitational potential energy of a hot rolling transport chain.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] An energy-saving system for recovering the gravitational potential energy of a hot rolling transport chain, including system components and a lifting cylinder for working on the entire system components. The system components include:

[0008] A piston accumulator, a nitrogen cylinder group, a hydraulic lock, a one-way throttle valve I, a relief valve, a pressure sensor, a balance valve, a one-way throttle valve II, a VH1 flow logic valve, a VH2 flow logic valve, a VH3 flow logic valve, a VH4 flow logic valve, a VH5 flow logic valve, a VH6 electromagnetic directional valve;

[0009] The piston accumulator is connected with the nitrogen cylinder group to form an energy storage device. The VH6 electromagnetic directional valve, the hydraulic lock and the one-way throttle valve I form a filling and discharging reversing valve group, and the filling and discharging reversing valve group is connected with the piston accumulator of the energy storage device through a pipeline;

[0010] One end of the VH5 flow logic valve is connected with the piston accumulator, and the other end is connected with the rodless cavity of the lifting cylinder to form a potential energy recovery control unit;

[0011] The connection ports of the relief valve are respectively connected to the rodless cavity of the lifting cylinder and the oil return pipeline to form an anti-overload unit;

[0012] The control port of the balance valve is connected to the oil outlets of the VH2 flow logic valve and the VH4 flow logic valve, and is connected to the rodless cavity of the lifting cylinder through the one-way throttle valve II; the oil inlet port of the balance valve is connected to the outlets of the VH1 flow logic valve and the VH3 flow logic valve, and the oil outlet of the balance valve 7 is connected to the rodless cavity of the lifting cylinder.

[0013] Preferably, the nitrogen bottle group includes twelve nitrogen bottles, and nitrogen is filled inside the twelve nitrogen bottles.

[0014] Preferably, the VH6 electromagnetic directional valve includes port A, port B, port P and port T. Port P is connected to the high-pressure oil of the hydraulic system, port T is connected to an oil return port, and port A and port B are connected to the hydraulic lock;

[0015] The hydraulic lock (3) includes port A1, port B1, port A2 and port B2. Port B1 of the hydraulic lock (3) is connected to port B of the VH6 electromagnetic directional valve, port A1 of the hydraulic lock (3) is connected to port A of the VH6 electromagnetic directional valve, and port A2 and port B2 of the hydraulic lock 3 are connected to port A1 and port B1 of the one-way throttle valve I (4);

[0016] The one-way throttle valve I (4) includes port A1, port B1, port A2 and port B2. Port A1 and port B1 of the one-way throttle valve I (4) are connected to port A2 and port B2 of the hydraulic lock (3), port A2 of the one-way throttle valve I (4) is connected to the piston accumulator (1), and port B2 of the one-way throttle valve I (4) is blocked.

[0017] Preferably, the VH5 flow logic valve is a logic valve with an adjustable opening. When the VH5 flow logic valve is opened, the high-pressure oil of the piston accumulator is communicated with the rodless cavity of the lifting cylinder.

[0018] Preferably, the lifting cylinder includes a first lifting cylinder and a second lifting cylinder.

[0019] Preferably, the one-way throttle valve II includes throttle valve I, throttle valve II, throttle valve III and throttle valve IV;

[0020] Throttle valve I and throttle valve II are connected in series. The oil inlet ports of throttle valve I and throttle valve II are connected to the oil outlets of the VH2 flow logic valve and the VH4 flow logic valve, and the oil outlet ports of throttle valve I and throttle valve II are connected to the rodless cavity of the first lifting cylinder;

[0021] The throttle valve three and the throttle valve four are connected in series. The oil inlets of the throttle valve three and the throttle valve four are connected to the oil outlets of the VH2 flow logic valve and the VH4 flow logic valve. The oil outlets of the throttle valve three and the throttle valve four are connected to the rodless cavity of the second lifting cylinder.

[0022] Preferably, the balance valve includes a first balance valve, a second balance valve and a third balance valve, and the first balance valve, the second balance valve and the third balance valve are connected in parallel.

[0023] Compared with the prior art, the beneficial effects of the present utility model are as follows: By using a piston accumulator as a storage element for gravitational potential energy, the gravitational potential energy generated when the walking beam frame and the steel coil descend is recovered and stored in the piston accumulator, and then released back into the system during the lifting process to provide auxiliary power for the drive of the hydraulic system, thus realizing the recovery and utilization of gravitational potential energy, reducing energy consumption and saving resources. Description of the Drawings

[0024] Figure 1 It is a system flow chart of an energy-saving system for recovering gravitational potential energy of a hot rolling transportation chain proposed by the present utility model.

[0025] In the figure: 1 piston accumulator, 2 nitrogen cylinder group, 3 hydraulic lock, 4 one-way throttle valve one, 5 overflow valve, 6 pressure sensor, 7 balance valve, 701 balance valve one, 702 balance valve two, 703 balance valve three, 8 one-way throttle valve two, 801 throttle valve one, 802 throttle valve two, 803 throttle valve three, 804 throttle valve four, 9 lifting cylinder, 901 lifting cylinder one, 902 lifting cylinder two. Detailed Embodiments

[0026] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments.

[0027] The following embodiments propose a system that uses an accumulator as an energy storage device + a dedicated control valve group to realize the recovery of gravitational potential energy of the steel coil on the transportation chain.

[0028] Embodiment 1

[0029] Refer to Figure 1 , an energy-saving system for recovering gravitational potential energy of a hot rolling transportation chain, includes system components and a lifting cylinder 9 that works on all the system components. The system components include:

[0030] Piston accumulator 1, nitrogen cylinder group 2, hydraulic lock 3, one-way throttle valve 4, overflow valve 5, pressure sensor 6, balance valve 7, two-way throttle valve 8, VH1 flow logic valve, VH2 flow logic valve, VH3 flow logic valve, VH4 flow logic valve, VH5 flow logic valve, VH6 electromagnetic directional valve. The nitrogen cylinder group 2 includes twelve nitrogen cylinders, and the interiors of the twelve nitrogen cylinders are filled with nitrogen;

[0031] In this embodiment, the piston accumulator 1 and the nitrogen cylinder group 2 are connected to form an energy storage device; among them, the piston accumulator 1 is used to store pressure oil and is connected to the nitrogen cylinder group 2 through a pipeline; when the high-pressure oil in the system enters the piston accumulator 1, the piston in the piston accumulator 1 compresses the nitrogen in the connected nitrogen cylinder group 2, and stores the energy of the high-pressure oil in the energy storage device;

[0032] The nitrogen cylinder group 2 is connected to the piston accumulator 1 through a pipeline. When the nitrogen in the nitrogen cylinder group 2 is compressed, the internal pressure rises, thus playing an energy storage role; it is necessary to pre-fill the nitrogen cylinder group 2 with nitrogen at a certain pressure.

[0033] In this embodiment, the VH6 electromagnetic directional valve, the hydraulic lock 3 and the one-way throttle valve 4 constitute a filling and discharging directional valve group, and the filling and discharging directional valve group is connected to the piston accumulator 1 of the energy storage device through a pipeline;

[0034] The VH6 electromagnetic directional valve includes port A, port B, port P and port T. Port P is connected to the high-pressure oil of the hydraulic system, port T is connected to an oil return port, and ports A and B are connected to the hydraulic lock 3;

[0035] The hydraulic lock 3 includes port A1, port B1, port A2 and port B2. Port B1 of the hydraulic lock 3 is connected to port B of the VH6 electromagnetic directional valve, port A1 of the hydraulic lock 3 is connected to port A of the VH6 electromagnetic directional valve, and ports A2 and B2 of the hydraulic lock 3 are connected to ports A1 and B1 of the one-way throttle valve 4;

[0036] The one-way throttle valve 4 includes port A1, port B1, port A2 and port B2. Ports A1 and B1 of the one-way throttle valve 4 are connected to ports A2 and B2 of the hydraulic lock 3, port A2 of the one-way throttle valve 4 is connected to the piston accumulator 1, and port B2 of the one-way throttle valve 4 is blocked.

[0037] Among them, the VH6 electromagnetic directional valve is used to fill or discharge the piston accumulator 1 when the pressure of the piston accumulator 1 is too low or too high. Port P of the VH6 electromagnetic directional valve is connected to the high-pressure oil of the hydraulic system, port T of the VH6 electromagnetic directional valve is connected to the oil return port, and ports A and B of the VH6 electromagnetic directional valve are connected to ports A1 and B1 of the hydraulic lock 3.

[0038] Hydraulic lock 3: When there is no need for liquid filling or discharging, the hydraulic lock 3 can lock the hydraulic oil in the piston accumulator 1. The B1 port of the hydraulic lock 3 is connected to the B port of the VH6 electromagnetic directional control valve, and the A1 port of the hydraulic lock 3 is connected to the A port of the VH6 electromagnetic directional control valve; the A2 port and B2 port of the hydraulic lock 3 are connected to the A1 port and B1 port of the one-way throttle valve 4.

[0039] One-way throttle valve 4: During liquid filling, the pressure oil enters the piston accumulator without throttling through the one-way valve of the one-way throttle valve 4; during liquid discharging, the pressure oil in the piston accumulator 1 flows through the throttle orifice of the one-way throttle valve 4 and enters the return oil pipe. By adjusting the throttle orifice of the one-way throttle valve 4, the liquid discharging speed can be controlled. The A1 port and B1 port of the one-way throttle valve 4 are connected to the A2 port and B2 port of the hydraulic lock 3.

[0040] It should be noted that in this embodiment,

[0041] One end of the VH5 flow logic valve is connected to the piston accumulator, and the other end is connected to the rodless cavity of the lifting cylinder 9, forming a potential energy recovery control unit;

[0042] Among them, the VH5 flow logic valve controls whether the potential energy recovery is put into use. The VH5 flow logic valve is a logic valve with an adjustable opening. When the VH5 flow logic valve is opened, the high-pressure oil in the piston accumulator 1 is connected to the rodless cavity of the lifting cylinder 9, and the opening degree of the valve orifice when the valve is opened can be adjusted to control the flow rate in and out of the piston accumulator 1.

[0043] In this embodiment, the connection ports of the overflow valve 5 are respectively connected to the rodless cavity of the lifting cylinder 9 and the return oil pipeline to form an anti-overload unit; the overflow valve 5 is used to prevent the rodless cavity of the lifting cylinder 9 from overpressure; the P port and T port of the overflow valve 5 are respectively connected to the rodless cavity of the lifting cylinder 9 and the return oil pipeline.

[0044] The inlet port of the balance valve 7 is connected to the outlets of the VH1 flow logic valve and VH3 flow logic valve, and the outlet port of the balance valve 7 is connected to the rodless cavity of the lifting cylinder 9; the control port of the balance valve 7 is connected to the outlets of the VH2 flow logic valve and VH4 flow logic valve, and is connected to the rodless cavity of the lifting cylinder 9 through the one-way throttle valve 8 to ensure that the oil pressure in the rodless cavity controls the opening degree of the balance valve and prevent the rodless cavity of the lifting cylinder 9 from overspeed.

[0045] More specifically, the lifting cylinder 9 includes a first lifting cylinder 901 and a second lifting cylinder 902;

[0046] Among them, the one-way throttle valve 8 includes a throttle valve 801, a throttle valve 802, a throttle valve 803 and a throttle valve 804;

[0047] The throttle valve 1 801 and the throttle valve 2 802 are connected in series. The oil inlets of the throttle valve 1 801 and the throttle valve 2 802 are connected to the oil outlets of the VH2 flow logic valve and the VH4 flow logic valve. The oil outlets of the throttle valve 1 801 and the throttle valve 2 802 are connected to the rod chamber of the lifting cylinder 1 901; The throttle valve 3 803 and the throttle valve 4 804 are connected in series. The oil inlets of the throttle valve 3 803 and the throttle valve 4 804 are connected to the oil outlets of the VH2 flow logic valve and the VH4 flow logic valve. The oil outlets are connected to the rod chamber of the lifting oil cylinder 2 902.

[0048] By adjusting the throttle orifice sizes of the throttle valve 1 801 and the throttle valve 2 802, the rising and falling speeds of the lifting cylinder 1 901 can be changed; Similarly, by adjusting the throttle orifice sizes of the throttle valve 3 803 and the throttle valve 4 804, the rising and falling speeds of the lifting oil cylinder 2 902 can be changed.

[0049] In this embodiment, the balance valve 7 includes a balance valve 1 701, a balance valve 2 702, and a balance valve 3 703, which are connected in parallel between the balance valve 1 701, the balance valve 2 702, and the balance valve 3 703.

[0050] More specifically, when the lifting oil cylinder 9 descends, the balance valve 1 701, the balance valve 2 702, and the balance valve 3 703 are used to prevent the lifting oil cylinder 9 from stalling due to excessive load weight. The control port of the balance valve 7 is connected to the oil outlets of the VH1 flow logic valve and the VH4 flow logic valve, and is connected to the rodless chamber of the lifting oil cylinder 9 through the one-way throttle valve 2 8; The oil inlet of the balance valve 7 is connected to the outlets of the VH1 flow logic valve and the VH3 flow logic valve. The oil outlet of the balance valve 7 is connected to the rodless chamber of the lifting oil cylinder 9. This connection method determines that when the lifting oil cylinder 9 descends, the balance valve can only be opened when the pressure in the rod chamber of the lifting oil cylinder 9 reaches the opening pressure of the balance valve, and the lifting oil cylinder descends; Thus, it is ensured that there is always a certain pressure in the rod chamber of the lifting oil cylinder 9, avoiding the stalling descent of the lifting oil cylinder 9 caused by excessive load.

[0051] More specifically, the rising and falling of the lifting oil cylinder 9 are controlled by the VH1 flow logic valve, the VH2 flow logic valve, the VH3 flow logic valve, and the VH4 flow logic valve. Among them, the oil outlets of the VH1 flow logic valve and the VH3 flow logic valve are connected to the oil inlet of the balance valve 7 and are connected to the rodless chamber of the lifting oil cylinder 9 through the balance valve 7; The oil inlet of the VH1 flow logic valve is connected to the system high-pressure oil, and the oil inlet of the VH3 flow logic valve is connected to the oil return pipeline.

[0052] The oil outlets of the VH2 flow logic valve and the VH4 flow logic valve are connected to the oil inlet of the one-way throttle valve 2 8 and are connected to the rod chamber of the lifting oil cylinder 9 through the one-way throttle valve 2 8; The oil inlet of the VH2 flow logic valve is connected to the system high-pressure oil, and the oil inlet of the VH4 flow logic valve is connected to the oil return pipeline.

[0053] When the VH1 flow logic valve and the VH4 flow logic valve are opened, the lifting cylinder 9 rises; when the VH2 flow logic valve and the VH3 flow logic valve are opened, the lifting cylinder 9 descends.

[0054] The following further describes the working process of potential energy recovery:

[0055] S1. Oil replenishment for the accumulator bank

[0056] When initially enabling the potential energy recovery hydraulic system, the VH6 electromagnetic directional valve is used to replenish oil for the piston accumulator 1 until the set pressure is reached.

[0057] S2. Unloaded ascent (before the frame touches the steel coil)

[0058] During unloaded ascent, the VH1 flow logic valve and the VH4 flow logic valve are energized. High-pressure oil enters the rodless cavity of the transport chain lifting cylinder 9, and the rod cavity is connected to the oil tank for oil return. The lifting cylinder 9 drives the frame to rise to the set position, at which time the frame has not yet touched the steel coil.

[0059] S3. Loaded ascent (the frame drives the steel coil to rise)

[0060] The VH4 flow logic valve remains energized, the VH1 flow logic valve is de-energized, and the VH5 flow logic valve is energized. At this time, the rodless cavity of the lifting cylinder 9 is connected to the piston accumulator 1, and the rod cavity is still connected to the oil return pipeline through the VH4 flow logic valve for oil return. The one-way throttle valve II 8 controls the speed of the lifting cylinder 9. Under the action of the high-pressure oil provided by the accumulator, the lifting cylinder 9 pushes the frame and the steel coil to rise to the set position.

[0061] S4. Loaded descent (the frame drives the steel coil to descend)

[0062] This process is the load gravitational potential energy recovery stage. The VH5 flow logic valve and the VH2 flow logic valve are energized, and the VH4 flow logic valve is de-energized. The rodless cavity of the lifting cylinder 9 is connected to the piston accumulator 1, and the rod cavity is connected to the system pressure oil. Under the combined action of the system pressure oil and the load gravity, the hydraulic oil in the rodless cavity of the lifting cylinder 9 is pressed into the piston accumulator 1 through the valve port of the VH5 flow logic valve. The one-way throttle valve II 8 controls the descent speed of the lifting cylinder 9 until the frame and the steel coil descend to the set position.

[0063] S5. Unloaded descent (detaching from the steel billet)

[0064] The VH2 flow logic valve and the VH3 flow logic valve are energized, the VH5 flow logic valve is de-energized, and the piston accumulator 1 is disconnected from the rodless cavity of the lifting cylinder 9. The system pressure oil enters the rod cavity of the lifting cylinder 9, and the rodless cavity is connected to the oil tank for oil return. Under the action of the system pressure, the lifting cylinder 9 descends to the end position.

[0065] As described in S1 above, during the process of the transportation chain frame driving the steel coil to rise, the pressure oil of the piston accumulator 1 cuts into the rodless cavity of the lifting cylinder, and the lifting cylinder 9 pushes the frame and the steel coil to rise, and the lifting speed is regulated by the one-way throttle valve.

[0066] As described in S2 above, during the process of the transportation chain frame driving the steel coil to descend, the rod chamber of the lifting cylinder 9 is connected to the system pressure oil, and the rodless cavity is connected to the piston accumulator 1. Under the combined action of the transportation chain frame, the gravity of the steel coil and the pressure in the rod chamber, the hydraulic oil in the rodless cavity is pressed into the piston accumulator 1 for storage.

[0067] As described in S3 above, the number of cylinders of the actuator is not limited to 1, and may include multiple lifting cylinders 9 working in parallel.

[0068] In the above solution, the potential energy recovery technology of the hot rolling transportation chain still uses a hydraulic pump as the power source, hydraulic valves as the control components for the pressure, direction and speed of the hydraulic system, and the piston accumulator 1 as the storage component for gravitational potential energy. The gravitational potential energy when the walking beam frame and the steel coil descend is recovered and stored in the piston accumulator 1, and is released back into the system during the lifting process to provide auxiliary power for the drive of the hydraulic system, realizing the recovery and utilization of gravitational potential energy, reducing energy consumption and saving resources.

[0069] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0070] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of protection required by the present invention. The scope of protection required by the present invention is defined by the appended claims and their equivalents.

Claims

1. An energy-saving system for recovering gravitational potential energy of a hot rolling conveyor chain, comprising system components and a lifting cylinder (9) for performing work on the entire system components, characterized in that: The system components include: Piston accumulator (1), nitrogen cylinder group (2), hydraulic lock (3), one-way throttle valve (4), overflow valve (5), pressure sensor (6), balance valve (7), one-way throttle valve (8), VH1 flow logic valve, VH2 flow logic valve, VH3 flow logic valve, VH4 flow logic valve, VH5 flow logic valve, VH6 electromagnetic reversing valve; The piston accumulator (1) is connected to the nitrogen cylinder group (2) to form an energy storage device, and the VH6 electromagnetic reversing valve, the hydraulic lock (3) and the one-way throttle valve (4) form a liquid filling and discharging reversing valve group, and the liquid filling and discharging reversing valve group is connected to the piston accumulator (1) of the energy storage device through a pipeline; One end of the VH5 flow logic valve is connected to the piston accumulator, and the other end is connected to the rodless chamber of the lifting cylinder (9), forming a potential energy recovery control unit; The connection port of the relief valve (5) is respectively connected to the rodless chamber of the lifting cylinder (9) and the oil return pipeline to form an overload protection unit; The control port of the balancing valve (7) is connected to the oil outlets of the VH2 flow logic valve and the VH4 flow logic valve, and is connected to the rodless chamber of the lifting cylinder (9) via the second one-way throttle valve (8); the oil inlet of the balancing valve (7) is connected to the oil outlets of the VH1 flow logic valve and the VH3 flow logic valve, and the oil outlet of the balancing valve (7) is connected to the rodless chamber of the lifting cylinder (9).

2. The energy-saving system for recovering gravitational potential energy of a hot rolling conveyor chain according to claim 1 is characterized in that: The nitrogen cylinder group (2) comprises twelve nitrogen cylinders, and the interiors of the twelve nitrogen cylinders are filled with nitrogen.

3. The energy-saving system for recovering gravitational potential energy of a hot rolling conveyor chain according to claim 1 is characterized in that: The VH6 electromagnetic reversing valve comprises an A port, a B port, a P port and a T port, the P port is connected to the high-pressure oil of the hydraulic system, the T port is connected to the oil return port, and the A port and the B port are connected to the hydraulic lock (3); The hydraulic lock (3) comprises an A1 port, a B1 port, an A2 port and a B2 port, the B1 port of the hydraulic lock (3) is connected to the B port of the VH6 electromagnetic reversing valve, the A1 port of the hydraulic lock (3) is connected to the A port of the VH6 electromagnetic reversing valve, and the A2 port and the B2 port of the hydraulic lock (3) are connected to the A1 port and the B1 port of the one-way throttle valve (4); The one-way throttle valve (4) comprises an A1 port, a B1 port, an A2 port and a B2 port. The A1 port and the B1 port of the one-way throttle valve (4) are connected to the A2 port and the B2 port of the hydraulic lock (3). The A2 port of the one-way throttle valve (4) is connected to the piston accumulator (1). The B2 port of the one-way throttle valve (4) is blocked.

4. The energy-saving system for recovering gravitational potential energy of a hot rolling conveyor chain according to claim 1, characterized in that: The VH5 flow logic valve is a logic valve with an adjustable opening. When the VH5 flow logic valve is opened, the high-pressure oil in the piston accumulator (1) is connected to the rodless chamber of the lifting cylinder (9).

5. The energy-saving system for recovering gravitational potential energy of a hot rolling conveyor chain according to claim 1, characterized in that: The lifting cylinder (9) comprises a lifting cylinder 1 (901) and a lifting cylinder 2 (902).

6. The energy-saving system for recovering gravitational potential energy of a hot rolling conveyor chain according to claim 5, characterized in that: The one-way throttle valve 2 (8) includes throttle valve 1 (801), throttle valve 2 (802), throttle valve 3 (803) and throttle valve 4 (804); The throttle valve 1 (801) and the throttle valve 2 (802) are connected in series, the oil inlets of the throttle valve 1 (801) and the throttle valve 2 (802) are connected to the oil outlets of the VH2 flow logic valve and the VH4 flow logic valve, and the oil outlets of the throttle valve 1 (801) and the throttle valve 2 (802) are connected to the rod chamber of the lifting cylinder 1 (901); The throttle valve three (803) and the throttle valve four (804) are connected in series, the oil inlets of the throttle valve three (803) and the throttle valve four (804) are connected to the oil outlets of the VH2 flow logic valve and the VH4 flow logic valve, and the oil outlets of the throttle valve three (803) and the throttle valve four (804) are connected to the rod chamber of the lifting cylinder two (902).

7. The energy-saving system for recovering gravitational potential energy of a hot rolling conveyor chain according to claim 1, characterized in that: The balancing valve (7) comprises a balancing valve 1 (701), a balancing valve 2 (702) and a balancing valve 3 (703), and the balancing valve 1 (701), the balancing valve 2 (702) and the balancing valve 3 (703) are connected in parallel.

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