Waste heat recovery device for regenerative forging heating furnace

Abstract

The present application relates to a kind of waste heat recovery device of regenerative forging heating furnace, including the inside of waste heat recovery cabinet is provided with heat exchange pipeline, heat exchange pipeline includes water pipe, the middle section of water pipe is provided with throttle pipe, the inside of throttle pipe is sequentially provided with flexible damping member, inductor, throttling piece from water inlet direction to water outlet direction, and the elbow of water pipe is provided with low-resistance vortex line type flow guide elbow, the end of all pipeline in waste heat recovery cabinet is provided with flange ring, inductor includes sliding ring one and sliding ring two slidingly connected in the inner wall of throttle pipe, the inside of sliding ring one is provided with multiple ball hinge piles, and the rotating end of ball hinge pile is provided with elastic pull rope, the other end of elastic pull rope is fixedly connected with connector, the other end of multiple connectors is fixedly provided with outer frame.The present application can adaptively match forging furnace waste heat load fluctuation, stabilize the flow and pressure of water circuit circulation, effectively improve heat exchange stability, reduce pipeline vibration and hydraulic energy consumption.

Description

Technical Field

[0001] This invention relates to the field of waste heat recovery technology, specifically to a waste heat recovery device for a regenerative forging heating furnace. Background Technology

[0002] Regenerative forging furnaces are core thermal equipment used for high-temperature heating of metal billets in the industrial forging field. The equipment adopts an intermittent operation mode, and during billet heating, furnace temperature regulation, and start-up and shutdown switching, high-temperature flue gas with large fluctuations in temperature and flow rate is continuously emitted. Its supporting waste heat recovery device needs to be adapted to such large fluctuations in waste heat load conditions for a long time. At the same time, it needs to complete pipeline water flow vibration reduction, flow stabilization, hydraulic drag reduction, and flow direction optimization. It is the core supporting equipment to ensure efficient recovery of waste heat from the forging furnace and reduce production energy consumption.

[0003] Existing waste heat recovery devices for regenerative forging furnaces often employ a passive structure for water circulation control and flow optimization using fixed orifice plates and ordinary bends. Some improved devices add flow sensors, electrical control units, and electric regulating valves. The flow signal is collected by the electrical control system, which then drives the electric valves to regulate the water flow. Water flow damping relies solely on the passive buffering of flexible pipe joints. There is no dedicated structure for water flow stabilization and diversion drag reduction. Each functional component operates independently without forming a collaborative working mechanism.

[0004] However, in the case of large fluctuations in waste heat load, flue gas temperature and water circulation flow caused by the intermittent operation of the forging furnace, the existing technology is difficult to adaptively match the fluctuations in waste heat load of the forging furnace. This results in large fluctuations in the waste heat recovery efficiency of the device and high system circulation energy consumption. At the same time, it is accompanied by problems such as increased water flow pulsation and vibration in the pipeline. It cannot meet the requirements for stable, efficient and long-term operation of the waste heat recovery device under all working conditions of forging production. Summary of the Invention

[0005] The purpose of this invention is to provide a waste heat recovery device for a regenerative forging furnace, which aims to improve the problem that existing regenerative forging furnace waste heat recovery devices are difficult to adaptively match the fluctuations in waste heat load of the forging furnace.

[0006] The objective of this invention is achieved through the following technical solution: a waste heat recovery device for a regenerative forging heating furnace, comprising a waste heat recovery cabinet, wherein a heat exchange pipeline is provided inside the waste heat recovery cabinet, the heat exchange pipeline includes a water pipe, a throttling pipe is provided in the middle section of the water pipe, and a flexible damping element, a sensing element, and a throttling element are arranged sequentially inside the throttling pipe from the water inlet direction to the water outlet direction, and a low-resistance vortex-type flow guide bend is provided at the bend of the water pipe, and flange rings are provided at the ends of all pipelines inside the waste heat recovery cabinet;

[0007] The sensing element includes a sliding ring one and a sliding ring two that are slidably connected to the inner wall of the throttling tube. Multiple ball joints are provided on the inner side of the sliding ring one, and an elastic pull rope is provided on the rotating end of the ball joint. The other end of the elastic pull rope is fixedly connected to a connector. The other end of the multiple connectors is fixedly provided with an outer frame, and a current collection net is provided on the inner side of the outer frame.

[0008] Multiple connecting rods are provided between the first sliding ring and the second sliding ring, and a return spring is sleeved on the outside of the connecting rod;

[0009] The waste heat recovery cabinet is equipped with a first heat medium fixed channel and a second heat medium fixed channel that are independent of each other and do not cross each other. The direction and diameter of the two heat medium fixed channels are fixed and cannot be adjusted throughout the entire process. They correspond to the independent transportation of high temperature and low temperature waste heat, respectively, and there is no risk of cross-flow.

[0010] As a further description of the above technical solution:

[0011] The throttling device includes a valve seat fixedly connected to the inside of the throttling tube, a sector-shaped block slidably connected to the outside of the valve seat, a hinge plate between the rear end of the sector-shaped block and the second sliding ring, and the front end of the hinge plate is arranged facing the inside of the valve seat. A partition is fixedly connected inside the sector-shaped block, and elastic connecting rings are fixedly connected to both ends of the partition. The two sides of the elastic connecting rings are respectively fixedly connected to the adjacent side of the partition inside the adjacent sector-shaped block.

[0012] As a further description of the above technical solution:

[0013] The valve seat is disposed between sliding ring one and sliding ring two, and the outer side of the connecting rod is slidably connected to the inside of the valve seat. The two ends of the return spring are respectively fixedly connected to the opposite side of sliding ring two and valve seat.

[0014] As a further description of the above technical solution:

[0015] The inner wall of the outlet end of the throttling pipe is provided with six spiral guide grooves, and the six spiral guide grooves are evenly distributed along the circumference of the inner wall of the throttling pipe. The front and rear ends of each spiral guide groove make an angle of 90° with the central axis of the throttling pipe.

[0016] As a further description of the above technical solution:

[0017] The flexible damping component includes a corrugated flexible bushing, the front and rear ends of which are fixedly connected to the inside of the throttling tube, and a rubber damping pad is filled between the corrugated flexible bushing and the inside of the throttling tube.

[0018] As a further description of the above technical solution:

[0019] The low-resistance vortex-type flow guide bend includes a 90° bend, and six vortex-type flow guide ribs are provided on the inner side of the bend. The thickness of the vortex-type flow guide ribs gradually decreases from the inlet to the outlet along the water flow direction. The rotation direction of the vortex-type flow guide ribs is the same as the rotation direction of the spiral guide groove inside the throttling pipe.

[0020] As a further description of the above technical solution:

[0021] The waste heat recovery cabinet is divided into a top fan compartment, a middle heat exchange compartment, and a bottom equipment compartment from top to bottom. The middle heat exchange compartment is equipped with a high-temperature flue gas heat exchanger, an air-cooled finned main heat exchanger, and a low-temperature condensing heat exchanger. The top fan compartment is equipped with an axial flow fan connected to the air duct of the air-cooled finned main heat exchanger. The bottom equipment compartment is equipped with a circulating water pump set, an induced draft fan, and an electrical control unit.

[0022] The heat exchange pipeline includes a first fixed heat medium channel (high temperature flue gas medium channel), a second fixed heat medium channel (circulating water medium channel), a refrigerant circulation loop, and a protective pipeline for the electrical control link, which are independently and non-intersectingly arranged inside the waste heat recovery cabinet. The input end of the first fixed heat medium channel is connected to the exhaust port of the regenerative forging furnace, and the output end is connected to the exhaust port of the cabinet, providing a source of waste heat for the device. The second fixed heat medium channel corresponds to two-stage waste heat recovery water circulation loops, which are respectively connected to the corresponding heat exchange sides of the high temperature stage flue gas heat exchanger and the low temperature stage condensing heat exchanger, forming two sets of independent stepped heat exchange closed loops. The two ends of the refrigerant circulation loop are respectively connected to the exhaust port and intake port of the external heat pump system, forming a closed-loop heat pump circulation. The protective pipeline for the electrical control link is physically isolated from the water and flue gas pipelines, and the electrical control unit is electrically connected to the power execution components in the device.

[0023] As a further description of the above technical solution:

[0024] The first heat medium fixed channel (flue gas circuit) of the heat exchange pipeline is arranged along the inner wall of the left and back sides of the cabinet. The flue gas interface on the right side of the cabinet is connected to the exhaust port pipeline of the regenerative forging furnace through a cyclone dust collector, flame arrester, flue gas filter and pressure regulating valve connected in series. The exhaust port of the regenerative forging furnace is connected to the tube inlet of the high-temperature flue gas heat exchanger through a pipeline. The tube outlet of the high-temperature flue gas heat exchanger is connected to the tube inlet of the low-temperature condensing heat exchanger through a pipeline. The tube outlet of the low-temperature condensing heat exchanger is connected to the induced draft fan and the exhaust port on the back of the cabinet in sequence through a pipeline.

[0025] As a further description of the above technical solution:

[0026] The circulating water pump set includes a high-temperature circulating water pump and a low-temperature circulating water pump. The second heat medium fixed channel (two-stage waste heat recovery water circuit) of the heat exchange pipeline includes an independent high-temperature waste heat recovery water circuit and a low-temperature waste heat recovery water circuit.

[0027] The return end of the high-temperature waste heat recovery water circuit is connected to the inlet of the high-temperature circulating water pump through a pipeline. The outlet of the high-temperature circulating water pump is equipped with a throttling pipe of the heat exchange pipeline in situ. The outlet of the throttling pipe is connected to the shell-side inlet of the high-temperature flue gas heat exchanger through the 90° bend of the low-resistance vortex-type guide bend of the heat exchange pipeline. The shell-side outlet of the high-temperature flue gas heat exchanger is connected to the supply end of the high-temperature waste heat recovery water circuit through a pipeline.

[0028] The return end of the low-temperature stage waste heat recovery water circuit is connected to the inlet of the low-temperature circulating water pump through a pipeline. The outlet of the low-temperature circulating water pump is equipped with a throttling pipe of the heat exchange pipeline in situ. The outlet of the throttling pipe is connected to the shell-side inlet of the low-temperature stage condensing heat exchanger through the 90° bend of the low-resistance vortex-type guide bend of the heat exchange pipeline. The shell-side outlet of the low-temperature stage condensing heat exchanger is connected to the supply end of the low-temperature stage waste heat recovery water circuit through a pipeline.

[0029] As a further description of the above technical solution:

[0030] The return end of the intermediate-temperature waste heat recovery water circuit is connected to the inlet of the intermediate-temperature circulating water pump through a pipeline. A throttling pipe is installed in place at the outlet of the intermediate-temperature circulating water pump. The outlet of the throttling pipe is connected to the water-side inlet of the compressor exhaust heat exchanger through a low-resistance vortex-type guide elbow. The water-side outlet of the compressor exhaust heat exchanger is connected to the water-side inlet of the intermediate-temperature plate heat exchanger through a pipeline. The water-side outlet of the intermediate-temperature plate heat exchanger is connected to the supply end of the intermediate-temperature waste heat recovery water circuit through a pipeline. The cylinder liner outlet and cylinder liner inlet of the gas engine are respectively connected to the cylinder liner water-side inlet and outlet of the intermediate-temperature plate heat exchanger, forming an independent cylinder liner water cooling closed loop.

[0031] The return end of the low-temperature stage waste heat recovery water circuit is connected to the inlet of the low-temperature chilled water circulating pump through a pipeline. A throttling pipe is installed in place at the outlet of the low-temperature chilled water circulating pump. The outlet of the throttling pipe is connected to the shell-side inlet of the low-temperature stage condensing heat exchanger through a low-resistance vortex-type guide elbow. The shell-side outlet of the low-temperature stage condensing heat exchanger is connected to the supply end of the low-temperature stage waste heat recovery water circuit through a pipeline.

[0032] All bends in the pipes inside the waste heat recovery cabinet are equipped with low-resistance vortex-type guide elbows.

[0033] As a further description of the above technical solution:

[0034] The refrigerant circulation loop of the heat exchange pipeline is arranged in layers along the inner left side of the cabinet. The exhaust port of the external heat pump system is connected to the tube inlet of the air-cooled finned main heat exchanger through a pipeline. The tube outlet of the air-cooled finned main heat exchanger is connected to the inlet of the electronic expansion valve through a pipeline. The outlet of the electronic expansion valve is connected to the refrigerant side inlet of the low-temperature condensing heat exchanger through a pipeline. The refrigerant side outlet of the low-temperature condensing heat exchanger is connected to the suction port of the external heat pump system through a pipeline, forming a complete closed loop.

[0035] Compared with the prior art, the advantages of the present invention are as follows:

[0036] 1. Through the coordinated operation of flexible damping components, sensing components, throttling components, spiral guide grooves, and low-resistance vortex-type guide bends in the heat exchange pipeline, the water flow first absorbs the impact and pipeline resonance through the corrugated flexible bushing and rubber damping pads. Then, the flow rate is sensed by the flow collection net linkage sliding ring assembly, which drives the fan-shaped baffle to adaptively adjust the flow channel area. Subsequently, the flow is stabilized by the spiral guide grooves and the flow bends reduce resistance and change direction, thereby achieving adaptive matching with the waste heat load fluctuations of the forging furnace, stabilizing the flow rate and pressure of the water circulation, effectively improving heat exchange stability, and reducing pipeline vibration and hydraulic energy consumption.

[0037] 2. Through the independent and fixed channel design of flue gas, water circuit, and refrigerant within the cabinet without cross-flow, and in conjunction with the tiered heat exchange layout of the high-temperature flue gas heat exchanger and the low-temperature condensing heat exchanger, the waste heat is released step by step from high temperature to low temperature through the flue gas circuit. Then, the waste heat at different temperature ranges is recovered in stages through water circulation. Combined with the refrigerant circulation circuit to improve the quality of low-temperature flue gas waste heat, the waste heat of the forging heating furnace exhaust gas is efficiently recovered and utilized across the entire temperature range. This reduces the gas consumption and flue gas thermal pollution in forging production, while eliminating the risk of medium cross-flow and improving the safety and long-term stability of the equipment operation. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the main body of an embodiment of a waste heat recovery device for a regenerative forging heating furnace proposed in this invention.

[0039] Figure 2 This is a schematic diagram of the heat exchange pipeline of a waste heat recovery device for a regenerative forging furnace proposed in this invention.

[0040] Figure 3 This is a schematic diagram of the flexible shock absorber of a waste heat recovery device for a regenerative forging furnace proposed in this invention.

[0041] Figure 4 This is a schematic diagram of the structure of the induction element of a waste heat recovery device for a regenerative forging furnace proposed in this invention;

[0042] Figure 5This is a schematic diagram of the heat collection mesh of a waste heat recovery device for a regenerative forging furnace proposed in this invention.

[0043] Figure 6 This is a schematic diagram of the throttling element of a waste heat recovery device for a regenerative forging furnace proposed in this invention;

[0044] Figure 7 This is a schematic diagram of the spiral guide groove of a waste heat recovery device for a regenerative forging heating furnace proposed in this invention.

[0045] Figure 8 This is a schematic diagram of the low-resistance vortex-type guide bend of the waste heat recovery device for a regenerative forging furnace proposed in this invention.

[0046] Labeling Explanation: 1. Waste heat recovery cabinet; 2. Heat exchange piping; 21. Water pipe; 22. Throttling pipe; 23. Flexible shock absorber; 231. Corrugated flexible bushing; 232. Rubber shock absorber pad; 24. Sensor; 241. Sliding ring one; 242. Ball joint pile; 243. Elastic pull rope; 244. Connector; 245. Outer frame; 246. Collector net; 247. Connecting rod; 248. Return spring; 249. Sliding ring two; 25. Throttling device; 251. Valve seat; 252. Fan-shaped block; 253. Elastic connecting ring; 254. Partition plate; 255. Hinge plate; 26. Spiral guide groove; 27. Low-resistance vortex-type guide bend; 271. Elbow; 272. Vortex-type guide rib; 28. Flange ring. Detailed Implementation

[0047] The present invention will now be described in detail with reference to the accompanying drawings and embodiments:

[0048] like Figures 1 to 8The diagram shown is an embodiment of a waste heat recovery device for a regenerative forging furnace provided by the present invention. The device includes a waste heat recovery cabinet 1, which serves as the main support for the entire device, providing a mounting foundation and physical protection. The cabinet 1 contains heat exchange pipes 2, which act as a dedicated medium transport carrier within the device, ensuring a closed and stable circulation of each functional loop. The heat exchange pipes 2 include water pipes 21, which provide a continuous and closed flow space as a dedicated channel for circulating water. A throttling pipe 22 is installed in the middle section of the water pipe 21, serving as an adaptive flow rate regulator and flow pattern optimization mechanism. The core carrier integrates functional structures. Inside the throttling pipe 22, from the water inlet direction to the water outlet direction, there are flexible shock absorbers 23, sensors 24, and throttling devices 25 arranged sequentially. The flexible shock absorbers 23 absorb water flow impact and pipe resonance, the sensors 24 sense changes in water flow in real time, and the throttling devices 25 adaptively adjust the flow area to stabilize the water circulation flow and pressure. In addition, a low-resistance vortex-type guide bend 27 is set at the bend of the water pipe 21. The low-resistance vortex-type guide bend 27 optimizes the water flow direction and reduces hydraulic resistance and local head loss. All pipe ends in the waste heat recovery cabinet 1 are equipped with flange rings 28. The flange rings 28 realize the pipe sealing connection, improve the convenience of disassembly and assembly, and prevent leakage.

[0049] The flexible damping component 23 includes a corrugated flexible bushing 231. The corrugated flexible bushing 231 absorbs water flow impact and pipeline vibration through its own deformation. The front and rear ends of the corrugated flexible bushing 231 are fixedly connected to the inside of the throttling pipe 22. A rubber damping pad 232 is filled between the corrugated flexible bushing 231 and the inside of the throttling pipe 22. The rubber damping pad 232 helps absorb vibration energy and provides radial limiting protection for the corrugated flexible bushing 231.

[0050] The sensing element 24 includes a sliding ring 241 and a sliding ring 249 slidably connected to the inner wall of the throttling pipe 22. The sliding ring 241 bears and transmits the mechanical displacement generated by the flow sensing. The sliding ring 249 moves synchronously with the sliding ring 241 and transmits the sensing signal to the throttling element 25. Multiple ball joints 242 are provided on the inner side of the sliding ring 241. The ball joints 242 provide an adaptive rotation base point for the elastic pull rope 243 to ensure smooth force transmission. The rotating end of the ball joint 242 is provided with an elastic pull rope 243. The elastic pull rope 243 transmits the water flow impact force to avoid structural jamming. The other end of the elastic pull rope 243 is fixedly connected to a connector 244. To ensure stable transmission of impact force through rigid connection, an outer frame 245 is fixedly installed at the other end of multiple connectors 244. The outer frame 245 provides support for the flow collection net 246 and synchronously transmits the water flow impact force. The flow collection net 246 is installed on the inner side of the outer frame 245. The flow collection net 246 converts the change in water flow rate into mechanical displacement to trigger flow sensing. Multiple connecting rods 247 are installed between sliding ring one 241 and sliding ring two 249. The connecting rods 247 ensure synchronous displacement of sliding ring one 241 and sliding ring two 249. A return spring 248 is sleeved on the outer side of the connecting rod 247. The return spring 248 provides return elasticity for the sliding ring assembly to ensure the linearity of throttling adjustment.

[0051] The waste heat recovery cabinet 1 has two independent and non-overlapping fixed channels for the first and second heat media. The first heat media channel is used to transport high-temperature flue gas in a directional manner to stably transport high-grade waste heat, while the second heat media channel is used to transport circulating water in a tiered manner to recover waste heat at different temperature ranges. The direction and diameter of the two heat media channels are fixed and cannot be adjusted throughout the entire process, and they correspond to the independent transport of high-temperature and low-temperature waste heat, respectively, without the risk of cross-flow.

[0052] The throttling element 25 includes a valve seat 251 fixedly connected to the inside of the throttling tube 22. The valve seat 251 provides an installation base and sliding limit for the throttling adjustment structure. The valve seat 251 is located between the first sliding ring 241 and the second sliding ring 249, and the outer side of the connecting rod 247 is slidably connected to the inside of the valve seat 251. The two ends of the return spring 248 are fixedly connected to the opposite side of the second sliding ring 249 and the valve seat 251, respectively. A sector-shaped stop 252 is slidably connected to the outer side of the valve seat 251. The sector-shaped stop 252 performs adaptive throttling adjustment by changing the flow channel area through radial sliding. A hinge plate 255 is provided between the rear end of the sector-shaped stop 252 and the sliding ring 249. The hinge plate 255 transmits displacement signals to drive the sector-shaped stop 252 to complete the opening and closing action. The front end of the hinge plate 255 is arranged facing the inside of the valve seat 251. A partition plate 254 is fixedly connected inside the sector-shaped stop 252. The partition plate 254 enhances the structural strength of the sector-shaped stop 252 and ensures the throttling adjustment accuracy. Both ends of the partition plate 254 are fixedly connected to elastic connecting rings 253. The elastic connecting rings 253 ensure that adjacent sector-shaped stops 252 open and close synchronously to achieve reset buffering. The two sides of the elastic connecting rings 253 are respectively fixedly connected to the adjacent side of the partition plate 254 inside the adjacent sector-shaped stops 252.

[0053] The inner wall of the outlet end of the throttling pipe 22 is provided with six spiral guide grooves 26. The spiral guide grooves 26 guide and comb the water flow to form a stable directional vortex. The six spiral guide grooves 26 are evenly distributed along the circumference of the inner wall of the throttling pipe 22. The front and rear ends of each spiral guide groove 26 are at an angle of 90° with the central axis of the throttling pipe 22.

[0054] The low-resistance vortex-type flow guide bend 27 includes a 90° bend 271, which enables the spatial arrangement of the 90° turning adaptation device in the pipeline. Six vortex-type flow guide ribs 272 are provided on the inner side of the bend 271. The vortex-type flow guide ribs 272 separate independent flow channels to guide the water flow to turn smoothly. The thickness of the vortex-type flow guide ribs 272 gradually decreases from the inlet to the outlet along the water flow direction. The rotation direction of the vortex-type flow guide ribs 272 is the same as the rotation direction of the spiral guide groove 26 inside the throttling pipe 22, ensuring the continuous and stable vortex flow state of the water.

[0055] Waste heat recovery cabinet 1 is divided from top to bottom into a top fan nacelle, a middle heat exchange compartment, and a bottom equipment compartment. The top fan nacelle provides enclosed installation space for axial fans and organizes the exhaust duct. The middle heat exchange compartment provides installation space for heat exchangers at various stages, forming an efficient heat exchange duct. The bottom equipment compartment houses power and control equipment, achieving physical isolation to ensure operational safety. The middle heat exchange compartment contains a high-temperature flue gas heat exchanger, an air-cooled finned main heat exchanger, and a low-temperature condensing heat exchanger. The high-temperature flue gas heat exchanger recovers high-grade waste heat from high-temperature flue gas, and the air-cooled finned main heat exchanger... The system achieves heat exchange and condensation between refrigerant and air. The low-temperature stage condensing heat exchanger deeply recovers the waste heat from the low-temperature flue gas. The top fan compartment is equipped with an axial flow fan connected to the air duct of the air-cooled finned main heat exchanger. The axial flow fan drives forced air convection to enhance the air-cooled heat exchange efficiency. The bottom equipment compartment is equipped with a circulating water pump group, an induced draft fan, and an electrical control unit. The circulating water pump group provides circulation power for the two-stage waste heat recovery water circuit. The induced draft fan pulls the flue gas to ensure stable flow and smooth operation of the flue gas circuit. The electrical control unit centrally controls the power execution components to ensure the safe and stable operation of the device.

[0056] The heat exchange pipeline 2 includes a first fixed heat medium channel, a second fixed heat medium channel, a refrigerant circulation loop, and a protective pipeline for the electrical control link, which are independently and non-intersectingly arranged inside the waste heat recovery cabinet 1. The refrigerant circulation loop completes the closed-loop circulation of refrigerant to improve the waste heat quality of the low-temperature flue gas. The protective pipeline for the electrical control link isolates electrical cables from fluid pipelines to ensure the safety of the electrical system. The input end of the first fixed heat medium channel is connected to the exhaust port of the regenerative forging furnace, and the output end is connected to the exhaust port of the cabinet, providing a source of waste heat for the device. The second fixed heat medium channel corresponds to the two-stage waste heat recovery water circulation loop, which is connected to the corresponding heat exchange side of the high-temperature stage flue gas heat exchanger and the low-temperature stage condensing heat exchanger, respectively, forming two sets of independent stepped heat exchange closed loops. The two ends of the refrigerant circulation loop are connected to the exhaust port and intake port of the external heat pump system, respectively, forming a closed-loop heat pump circulation. The protective pipeline for the electrical control link is physically isolated from the water and flue gas pipelines. The electrical control unit is electrically connected to the power execution components in the device.

[0057] The first heat medium fixed channel of heat exchange pipeline 2 is laid along the inner wall of the left side and back of the cabinet. The flue gas interface on the right side of the cabinet is connected to the exhaust port pipeline of the regenerative forging heating furnace through a cyclone dust collector, flame arrester, flue gas filter, and pressure regulating valve connected in series. The cyclone dust collector removes large particulate impurities such as oxide scale and dust in the flue gas. The flame arrester prevents backfire in the flue gas circuit and improves operational safety. The flue gas filter filters out small impurities in the flue gas to avoid clogging of the heat exchanger. The pressure regulating valve stabilizes the flue gas pressure and flow rate to ensure stable heat exchange conditions. The exhaust port of the regenerative forging heating furnace is connected to the tube inlet of the high-temperature flue gas heat exchanger through a pipeline. The tube outlet of the high-temperature flue gas heat exchanger is connected to the tube inlet of the low-temperature condensing heat exchanger through a pipeline. The tube outlet of the low-temperature condensing heat exchanger is connected to the induced draft fan and the exhaust port on the back of the cabinet in sequence through a pipeline.

[0058] The circulating water pump set includes a high-temperature circulating water pump and a low-temperature circulating water pump. The high-temperature circulating water pump provides dedicated circulation power for the high-temperature waste heat recovery water circuit, and the low-temperature circulating water pump provides dedicated circulation power for the low-temperature waste heat recovery water circuit. The second heat medium fixed channel of heat exchange pipeline 2 includes independent high-temperature waste heat recovery water circuit and low-temperature waste heat recovery water circuit. The high-temperature waste heat recovery water circuit recovers waste heat from high-temperature flue gas and delivers it to the high-temperature load of the process, and the low-temperature waste heat recovery water circuit recovers waste heat from low-temperature flue gas and delivers it to the low-temperature load.

[0059] The return end of the high-temperature waste heat recovery water circuit is connected to the inlet of the high-temperature circulating water pump through a pipeline. The outlet of the high-temperature circulating water pump is equipped with a throttling pipe 22 of the heat exchange pipeline 2 in situ. The outlet of the throttling pipe 22 is connected to the shell-side inlet of the high-temperature flue gas heat exchanger through the 90° elbow 271 of the low-resistance vortex-type guide bend 27 of the heat exchange pipeline 2. The shell-side outlet of the high-temperature flue gas heat exchanger is connected to the supply end of the high-temperature waste heat recovery water circuit through a pipeline.

[0060] The return end of the low-temperature stage waste heat recovery water circuit is connected to the inlet of the low-temperature circulating water pump through a pipeline. The outlet of the low-temperature circulating water pump is equipped with a throttling pipe 22 of the heat exchange pipeline 2 in situ. The outlet of the throttling pipe 22 is connected to the shell-side inlet of the low-temperature stage condensing heat exchanger through the 90° elbow 271 of the low-resistance vortex-type guide bend 27 of the heat exchange pipeline 2. The shell-side outlet of the low-temperature stage condensing heat exchanger is connected to the supply end of the low-temperature stage waste heat recovery water circuit through a pipeline.

[0061] The refrigerant circulation loop of heat exchange pipeline 2 is arranged in layers along the inner wall of the left side of the cabinet. The exhaust port of the external heat pump system is connected to the tube inlet of the air-cooled finned main heat exchanger through a pipeline. The tube outlet of the air-cooled finned main heat exchanger is connected to the inlet of the electronic expansion valve through a pipeline. The electronic expansion valve throttles and reduces the pressure of the refrigerant to ensure the evaporation heat exchange efficiency. The outlet of the electronic expansion valve is connected to the refrigerant side inlet of the low-temperature stage condensing heat exchanger through a pipeline. The refrigerant side outlet of the low-temperature stage condensing heat exchanger is connected to the suction port of the external heat pump system through a pipeline, forming a complete closed loop.

[0062] Working principle: After the device is started, the entire process of waste heat recovery of the regenerative forging heating furnace is started synchronously. The flue gas circuit, the two-stage waste heat recovery water circuit, and the refrigerant circulation circuit run synchronously along the fixed channels that are preset in the waste heat recovery cabinet 1, which are independent and do not cross-flow. Through the step-by-step heat exchange, the waste heat of the exhaust gas from the forging heating furnace is efficiently recovered and its grade is improved. All pipe bends in the device are diverted by low-resistance vortex-type guide bends 27, and all pipe ends are sealed by flange rings 28. The entire process is stable and controllable.

[0063] The high-temperature flue gas generated from the combustion of gas and heating of forgings in the regenerative forging furnace is discharged from the furnace's exhaust port and enters the flue gas interface on the right side of the waste heat recovery cabinet 1 along the pipeline. It then passes sequentially through a cyclone dust collector, flame arrester, flue gas filter, and pressure regulating valve to remove oxide scale, dust, and solid impurities from the flue gas, while simultaneously stabilizing the flue gas pressure and flow rate. Subsequently, under the traction of the induced draft fan, it enters the tube side of the high-temperature flue gas heat exchanger along the first fixed heat medium channel arranged against the inner wall of the cabinet, where it interacts with the circulating water in the shell side. After completing the first stage of high-temperature waste heat transfer and releasing most of the heat, the flue gas flows out from the tube-side outlet of the high-temperature flue gas heat exchanger, and then enters the tube-side of the low-temperature condensing heat exchanger along the pipeline. There, it completes the second stage of deep low-temperature waste heat recovery with the circulating water and refrigerant medium in the shell side. Finally, the cooled and clean flue gas flows out from the tube-side outlet of the low-temperature condensing heat exchanger, and is discharged from the exhaust port at the back of the cabinet by the induced draft fan, completing the entire process of flue gas waste heat release and providing a stable waste heat source for the device.

[0064] While the waste heat from the flue gas is released, the two-stage waste heat recovery water circuit simultaneously completes the cascade heat exchange process. This circuit is divided into an independent high-temperature waste heat recovery water circuit and a low-temperature waste heat recovery water circuit. In the high-temperature waste heat recovery water circuit, the low-temperature return water from high-temperature loads such as forging billet preheating and combustion air preheating enters the high-temperature circulating water pump inlet in the equipment compartment at the bottom of the cabinet along the pipeline. After being pressurized by the pump, it flows out from the outlet and enters the throttling pipe 22 installed in place to complete the whole process adaptive adjustment and flow optimization. In the low-temperature waste heat recovery water circuit, the low-temperature return water from low-temperature loads such as workshop heating and domestic hot water supply enters the low-temperature circulating water pump inlet in the equipment compartment at the bottom of the cabinet along the pipeline. After being pressurized by the pump, it flows out from the outlet and also enters the throttling pipe 22 installed in place to complete the treatment. After the water enters the throttling pipe 22, it first flows through the flexible damping component 23 and then through the internal channel of the corrugated flexible bushing 231. The corrugated flexible bushing 231 and the rubber damping pad 232 filled on its outside synchronously absorb the water flow impact and pipeline vibration, eliminate pipeline resonance caused by the operation of equipment in the forging workshop, and avoid water flow pulsation affecting heat exchange stability.

[0065] After the shock absorption treatment, the water continues to flow along the throttling pipe 22 towards the outlet, entering the effective range of the sensing element 24. The water flows through the collecting net 246 inside the sliding ring 241. Under the impact of the water flow, the collecting net 246 drives the outer frame 245 to move towards the outlet. The outer frame 245, through the cooperation of the connector 244, the elastic rope 243, and the ball joint 242, drives the sliding ring 241 to slide along the inner wall of the throttling pipe 22 towards the outlet. The sliding ring 241 drives the sliding ring 249 to slide synchronously through the connecting rod 247. During the sliding process, the return spring 248 is stretched synchronously. The greater the water flow rate, the greater the impact force on the collecting net 246, and the greater the sliding stroke of the sliding ring 241 and the sliding ring 249, thereby achieving accurate sensing of the water flow rate; completing the flow sensing. The water continues to flow towards the outlet end and enters the effective range of the throttling element 25. When the sliding ring 249 slides towards the outlet end, it drives the fan-shaped block 252 on the outside of the valve seat 251 to slide radially outward through the hinge plate 255. The elastic connecting ring 253 between adjacent fan-shaped blocks 252 is stretched synchronously. The flow passage area formed between multiple sets of fan-shaped blocks 252 increases synchronously with the sliding stroke. When the water flow rate decreases, the return spring 248 pushes the sliding ring 249 and the sliding ring 241 to return to the inlet end. The hinge plate 255 drives the fan-shaped block 252 to slide radially inward. The elastic connecting ring 253 contracts synchronously, and the flow passage area decreases synchronously. This achieves adaptive throttling adjustment according to the changes in waste heat load of the forging furnace and fluctuations in water flow rate, and stabilizes the flow rate and pressure of the water circulation.

[0066] After completing the adaptive throttling adjustment, the water continues to flow towards the outlet end, passing through the six spiral guide grooves 26 on the inner wall of the outlet end of the throttling pipe 22. The water forms a stable directional vortex along the spiral guide grooves 26, eliminating turbulence and eddies inside the water flow, and then flows out from the outlet end of the throttling pipe 22 and enters the interior of the low-resistance vortex-type guide bend 27. The water completes a 90° turn along the independent flow channels separated by the six vortex-type guide ribs 272 on the inner side of the bend. The thickness of the guide ribs gradually decreases along the direction of water flow, and the vortex direction is the same as that of the spiral guide grooves 26 inside the throttling pipe 22. The water maintains a stable vortex flow state throughout the turn, significantly reducing the water flow resistance and local head loss at the bend 271, and avoiding eddies and cavitation.

[0067] The high-temperature water flow, after being processed by the throttling pipe 22 and the guide bend, enters the shell side of the high-temperature flue gas heat exchanger, where it exchanges heat with the high-temperature flue gas from the forging furnace in the tube side. The heated hot water then flows out from the shell side outlet of the high-temperature flue gas heat exchanger and is transported along the pipeline to the high-temperature load end of the forging process for use in processes such as billet preheating and combustion air heating, completing the closed-loop circulation of the high-temperature water circuit and realizing the direct and efficient recovery of high-temperature waste heat from the forging furnace. The low-temperature water flow, after being processed by the throttling pipe 22 and the guide bend, enters the shell side of the low-temperature condensing heat exchanger, where it exchanges heat with the cooling flue gas in the tube side. The heated hot water then flows out from the shell side outlet of the low-temperature condensing heat exchanger and is transported along the pipeline to the low-temperature load end such as workshop heating and domestic hot water tanks, completing the closed-loop circulation of the low-temperature water circuit and realizing the deep recovery of waste heat from the forging furnace flue gas.

[0068] During operation, the refrigerant circulation loop starts synchronously. The refrigerant compressor of the external heat pump system compresses the internal refrigerant, and the high-temperature, high-pressure refrigerant is discharged from the exhaust port at the top of the compressor. It then enters the tube side of the air-cooled finned main heat exchanger through the refrigerant circulation loop pipes arranged in layers along the inner wall of the left side of the cabinet. There, it exchanges heat and condenses with the forced convection air driven by the axial flow fan in the top fan nacelle. The condensed refrigerant flows out from the tube side outlet of the air-cooled finned main heat exchanger and enters the electronic expansion valve for throttling and pressure reduction. The depressurized, low-temperature, low-pressure refrigerant flows out from the outlet of the electronic expansion valve and enters the refrigerant side of the low-temperature stage condensing heat exchanger through the pipes. There, it absorbs heat and evaporates with the low-temperature flue gas in the tube side and the circulating water in the shell side. Finally, it flows out from the refrigerant side outlet of the low-temperature stage condensing heat exchanger and returns to the suction port of the compressor of the external heat pump system, completing a complete closed-loop refrigerant circulation and achieving the grade improvement and efficient utilization of the waste heat of the low-temperature flue gas in the forging furnace.

Claims

1. A waste heat recovery device for a regenerative forging furnace, comprising a waste heat recovery cabinet (1), characterized in that: The waste heat recovery cabinet (1) is equipped with a heat exchange pipeline (2), which includes a water pipe (21). A throttling pipe (22) is installed in the middle section of the water pipe (21). The throttling pipe (22) is equipped with a flexible shock absorber (23), a sensor (24), and a throttling device (25) in sequence from the water inlet direction to the water outlet direction. A low-resistance vortex-type flow guide bend (27) is installed at the bend of the water pipe (21). All pipe ends in the waste heat recovery cabinet (1) are equipped with flange rings (28). The sensing element (24) includes a sliding ring one (241) and a sliding ring two (249) slidably connected to the inner wall of the throttling tube (22). Multiple ball joints (242) are provided on the inner side of the sliding ring one (241), and an elastic pull rope (243) is provided on the rotating end of the ball joint (242). A connector (244) is fixedly connected to the other end of the elastic pull rope (243). An outer frame (245) is fixedly provided on the other end of the multiple connectors (244), and a current collecting net (246) is provided on the inner side of the outer frame (245). Multiple connecting rods (247) are provided between the first sliding ring (241) and the second sliding ring (249), and a return spring (248) is sleeved on the outside of the connecting rod (247). The waste heat recovery cabinet (1) is equipped with a first heat medium fixed channel and a second heat medium fixed channel that are independent of each other and do not cross each other. The direction and diameter of the two heat medium fixed channels are fixed and cannot be adjusted throughout the entire process. They correspond to the independent transportation of waste heat at high temperature and low temperature, respectively, without the risk of cross-flow.

2. The waste heat recovery device for a regenerative forging furnace according to claim 1, characterized in that: The throttling device (25) includes a valve seat (251) fixedly connected to the inside of the throttling tube (22). A fan-shaped block (252) is slidably connected to the outside of the valve seat (251). A hinge plate (255) is provided between the rear end of the fan-shaped block (252) and the sliding ring (249). The front end of the hinge plate (255) is arranged facing the inside of the valve seat (251). A partition plate (254) is fixedly connected inside the fan-shaped block (252). Both ends of the partition plate (254) are fixedly connected to elastic connecting rings (253). The two sides of the elastic connecting rings (253) are respectively fixedly connected to the adjacent side of the partition plate (254) inside the adjacent fan-shaped block (252).

3. The waste heat recovery device for a regenerative forging furnace according to claim 2, characterized in that: The valve seat (251) is disposed between the sliding ring one (241) and the sliding ring two (249), and the outer side of the connecting rod (247) is slidably connected to the inside of the valve seat (251). The two ends of the return spring (248) are respectively fixedly connected to the opposite side of the sliding ring two (249) and the valve seat (251).

4. The waste heat recovery device for a regenerative forging furnace according to claim 1, characterized in that: The inner wall of the outlet end of the throttling pipe (22) is provided with six spiral guide grooves (26), and the six spiral guide grooves (26) are evenly distributed along the circumference of the inner wall of the throttling pipe (22). The front and rear ends of each spiral guide groove (26) are at an angle of 90° with the central axis of the throttling pipe (22).

5. The waste heat recovery device for a regenerative forging furnace according to claim 1, characterized in that: The flexible damping component (23) includes a corrugated flexible bushing (231), the front and rear ends of which are fixedly connected to the inside of the throttling tube (22), and a rubber damping pad (232) is filled between the corrugated flexible bushing (231) and the inside of the throttling tube (22).

6. The waste heat recovery device for a regenerative forging furnace according to claim 1, characterized in that: The low-resistance vortex-type guide bend (27) includes a 90° bend (271). The inner side of the bend (271) is provided with six vortex-type guide ribs (272). The thickness of the vortex-type guide ribs (272) gradually decreases from the inlet to the outlet along the water flow direction. The rotation direction of the vortex-type guide ribs (272) is the same as the rotation direction of the spiral guide groove (26) inside the throttling pipe (22).

7. The waste heat recovery device for a regenerative forging furnace according to claim 1, characterized in that: The waste heat recovery cabinet (1) is divided into a top fan compartment, a middle heat exchange compartment and a bottom equipment compartment from top to bottom. The middle heat exchange compartment is equipped with a high-temperature flue gas heat exchanger, an air-cooled finned main heat exchanger and a low-temperature condensing heat exchanger. The top fan compartment is equipped with an axial flow fan connected to the air duct of the air-cooled finned main heat exchanger. The bottom equipment compartment is equipped with a circulating water pump set, an induced draft fan and an electrical control unit. The heat exchange pipeline (2) includes a first heat medium fixed channel (high temperature flue gas medium channel), a second heat medium fixed channel (circulating water medium channel), a refrigerant circulation loop, and a protective pipeline for the electrical control link, which are arranged independently and without intersection within the waste heat recovery cabinet (1). The input end of the first heat medium fixed channel is connected to the exhaust port of the regenerative forging furnace, and the output end is connected to the exhaust port of the cabinet, providing a source of waste heat for the device. The second heat medium fixed channel corresponds to two-stage waste heat recovery water circulation loops, which are connected to the corresponding heat exchange sides of the high temperature stage flue gas heat exchanger and the low temperature stage condensing heat exchanger, respectively, forming two sets of independent stepped heat exchange closed loops. The two ends of the refrigerant circulation loop are connected to the exhaust port and intake port of the external heat pump system, respectively, forming a closed-loop heat pump circulation. The protective pipeline for the electrical control link is physically isolated from the water and flue gas pipelines. The electrical control unit is electrically connected to the power execution components in the device.

8. The waste heat recovery device for a regenerative forging furnace according to claim 7, characterized in that: The first heat medium fixed channel (flue gas circuit) of the heat exchange pipeline (2) is arranged along the inner wall of the left side and back of the cabinet. The flue gas interface on the right side of the cabinet is connected to the exhaust port pipeline of the regenerative forging furnace through a cyclone dust collector, flame arrester, flue gas filter and pressure regulating valve connected in series. The exhaust port of the regenerative forging furnace is connected to the tube inlet of the high-temperature flue gas heat exchanger through a pipeline. The tube outlet of the high-temperature flue gas heat exchanger is connected to the tube inlet of the low-temperature condensing heat exchanger through a pipeline. The tube outlet of the low-temperature condensing heat exchanger is connected to the exhaust port of the induced draft fan and the back of the cabinet through a pipeline.

9. The waste heat recovery device for a regenerative forging furnace according to claim 8, characterized in that: The circulating water pump group includes a high-temperature circulating water pump and a low-temperature circulating water pump. The second heat medium fixed channel (two-stage waste heat recovery water circuit loop) of the heat exchange pipeline (2) includes an independent high-temperature waste heat recovery water circuit and a low-temperature waste heat recovery water circuit. The return end of the high-temperature waste heat recovery water circuit is connected to the inlet of the high-temperature circulating water pump through a pipeline. The outlet of the high-temperature circulating water pump is equipped with a throttling pipe (22) of the heat exchange pipeline (2) in situ. The outlet of the throttling pipe (22) is connected to the shell-side inlet of the high-temperature flue gas heat exchanger through the 90° elbow (271) of the low-resistance vortex-type guide bend (27) of the heat exchange pipeline (2). The shell-side outlet of the high-temperature flue gas heat exchanger is connected to the supply end of the high-temperature waste heat recovery water circuit through a pipeline. The return end of the low-temperature stage waste heat recovery water circuit is connected to the inlet of the low-temperature circulating water pump through a pipeline. The outlet of the low-temperature circulating water pump is equipped with a throttling pipe (22) of the heat exchange pipeline (2) in situ. The outlet of the throttling pipe (22) is connected to the shell-side inlet of the low-temperature stage condensing heat exchanger through the 90° elbow (271) of the low-resistance vortex-type guide bend (27) of the heat exchange pipeline (2). The shell-side outlet of the low-temperature stage condensing heat exchanger is connected to the supply end of the low-temperature stage waste heat recovery water circuit through a pipeline. All bends in the internal pipes of the waste heat recovery cabinet (1) are provided with low-resistance vortex-type guide bends (27) of the heat exchange pipes (2).

10. The waste heat recovery device for a regenerative forging furnace according to claim 7, characterized in that: The refrigerant circulation loop of the heat exchange pipeline (2) is arranged in layers along the inner wall of the left side of the cabinet. The exhaust port of the external heat pump system is connected to the tube inlet of the air-cooled finned main heat exchanger through the pipeline. The tube outlet of the air-cooled finned main heat exchanger is connected to the inlet of the electronic expansion valve through the pipeline. The outlet of the electronic expansion valve is connected to the refrigerant side inlet of the low-temperature condensing heat exchanger through the pipeline. The refrigerant side outlet of the low-temperature condensing heat exchanger is connected to the suction port of the external heat pump system through the pipeline, forming a complete closed loop.

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