Automatic detection and alarm device for superheat of thermal power plant based on thermal expansion principle

Abstract

This invention relates to the field of industrial safety monitoring equipment technology, and discloses an automatic overheat detection and alarm device for thermal power plants based on the principle of thermal expansion. The device includes a housing and a bimetallic strip. A vertical rod is slidably connected to the middle of the housing, and a horizontal plate is fixedly connected to the top of the vertical rod. An engaging assembly is disposed inside the housing, and the bimetallic strip is located in the middle of the engaging assembly. The bottom of the vertical rod contacts the top of the bimetallic strip. A visual warning assembly is disposed in the middle of the vertical rod, and an auditory warning assembly is disposed on the rear inner wall of the housing. The bimetallic strip deforms due to heat, pushing the vertical rod upwards, which causes a stop block to release the lock on the spring-loaded gear set, thereby releasing the stored energy of the spring to drive a hammer to continuously strike the warning bell. Simultaneously, a warning sign at the top of the vertical rod extends out of the housing, providing continuous audible and visual signals when overheating occurs, ensuring timely detection of hazards in the noisy environment of a thermal power plant.

Description

Technical Field

[0001] This invention relates to the field of industrial safety monitoring equipment technology, specifically to an automatic detection and alarm device for overheating in thermal power plants based on the principle of thermal expansion. Background Technology

[0002] Boilers, steam pipelines, and auxiliary equipment in thermal power plants operate under high temperature and high pressure for extended periods. Localized overheating caused by insulation damage, valve leakage, or cooling system malfunctions is a major contributing factor to equipment damage and even safety accidents. Therefore, real-time and effective temperature monitoring and alarm systems for critical high-temperature areas are crucial.

[0003] Existing temperature monitoring technologies are mainly divided into two categories: electronic and mechanical. While electronic sensors offer high accuracy, they are highly dependent on external power supplies and signal cables. In the harsh environment of thermal power plants, characterized by high temperatures, strong electromagnetic interference, and vibration, electronic components are prone to aging and failure, and wiring and maintenance costs are high. Existing purely mechanical temperature switches typically use bimetallic strips as trigger elements. Their operation is mostly instantaneous contact closure or a single mechanical release. The audible or visual changes produced by this short, single action are weak and easily overlooked by inspectors in the noisy environment of thermal power plants, failing to provide effective warnings. Furthermore, they lack the continuous driving energy to maintain the alarm status until manual confirmation.

[0004] Furthermore, as the core temperature-sensing element, the bimetallic strip inevitably undergoes aging phenomena such as metal fatigue, decreased elastic modulus, or zero-point drift after long-term exposure to high-temperature and low-temperature cycles. This leads to a change in its trigger threshold (i.e., it cannot generate sufficient displacement to trigger an alarm when the dangerous temperature is reached). However, existing mechanical alarm devices typically employ a closed structure and lack an intuitive self-diagnostic mechanism. Inspectors cannot determine whether the internal bimetallic strip has fatigued and failed during equipment operation, often only discovering the device's malfunction after an accident has occurred. Simultaneously, the internal transmission structure and temperature-sensing element in existing devices are usually integrated or connected by complex screw fasteners. Once bimetallic strip damage is confirmed, it often requires disassembling the entire device casing and linkage mechanism for replacement, making the maintenance process cumbersome and time-consuming, hindering rapid on-site repair and maintenance. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an automatic overheat detection and alarm device for thermal power plants based on the principle of thermal expansion. It solves the problems of weak and short-lived alarm signals due to the lack of a continuous power source in purely mechanical alarm devices, the tendency to miss alarms in noisy environments of thermal power plants, the inability to perform online self-diagnosis after the temperature sensing element ages and becomes fatigued, and the complex connection between the core components and the transmission mechanism, which makes disassembly and maintenance cumbersome.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an automatic overheat detection and alarm device for thermal power plants based on the principle of thermal expansion, comprising a housing and a bimetallic strip, wherein a vertical rod is slidably connected to the middle of the housing, a horizontal plate is fixedly connected to the top of the vertical rod, a locking assembly is provided inside the housing, the bimetallic strip is disposed in the middle of the locking assembly, the bottom of the vertical rod contacts the top of the bimetallic strip, a visual warning assembly is provided in the middle of the vertical rod, an auditory warning assembly is provided on the rear side of the inner wall of the housing, a hanging rod is fixedly connected to the rear side of the inner wall of the housing, an alarm bell is provided at the end of the hanging rod, and a transparent glass is provided on the front side of the housing;

[0007] The auditory warning component includes a gear set, an anti-reverse component, and a striking component. The gear set is disposed on the rear side of the inner wall of the housing. A sleeve is fixedly connected to the rear side of the inner wall of the housing. A spring is disposed on the inner wall of the sleeve. The end of the spring is disposed on the outer side of one of the shafts of the gear set. A rocker arm is fixedly connected to the outer side of the gear set. The end of the rocker arm away from the gear set passes through the front wall of the housing. The anti-reverse component is disposed on the outer periphery of the rocker arm. The striking component is disposed on the front side of the gear set.

[0008] Preferably, the anti-reverse assembly includes a wheel, which is fixedly connected to the outer periphery of the rocker arm. A second stop is rotatably connected to the middle of the wheel, and a baffle is fixedly connected to the middle of the wheel. The second stop contacts the baffle. A retaining ring is fixedly connected to both the middle of the wheel and the outer side of the second stop. A tension spring is sleeved between the two retaining rings. A fixing rod is fixedly connected to the rear side of the upright, and a support rod is fixedly connected to the rear side of the fixing rod. A first stop is fixedly connected to the outer periphery of the support rod.

[0009] Preferably, the striking assembly includes a connecting rod one, which is fixedly connected to the front side of the gear set, and a connecting rod two is rotatably connected to the end of the connecting rod one away from the gear set, and a hammer is fixedly connected to the end of the connecting rod two away from the connecting rod one.

[0010] Preferably, the visual warning component includes a warning sign, which is disposed on the front side of the pole. A thermometer is fixedly connected to the middle of the pole, and a heat-conducting plate is fixedly connected to the bottom of the pole. The end of the thermometer is in contact with the heat-conducting plate, and a scale is provided on the front side of the pole.

[0011] Preferably, the engaging assembly includes a rotating rod, an elastic component, and an engaging component. The rotating rod is rotatably connected to the middle of the front wall of the housing. A knob is fixedly connected to the front end of the rotating rod. Round rods are fixedly connected to both the left and right sides of the inner wall of the housing. A movable plate is slidably connected to the outer periphery of the round rods. The engaging component is disposed between the movable plate and the rotating rod. An insert block is fixedly connected to the outer side of the movable plate. A connecting block is fixedly connected to the top of the bimetallic strip. An insertion hole is opened in the middle of the connecting block. The insert block is slidably connected to the middle of the insertion hole. The elastic component is disposed on the outer periphery of the round rods.

[0012] Preferably, the meshing assembly includes a spur gear, which is fixedly connected to the outer periphery of the rotating rod, and a rack is fixedly connected to the outer side of the movable plate, the rack meshing with the spur gear.

[0013] Preferably, the elastic component includes a stop block, which is fixedly connected to the outer periphery of the round rod, and a compression spring is sleeved on the outer periphery of the round rod.

[0014] Preferably, a through groove is provided in the middle of the upright, and the rocker arm is located in the middle of the through groove, so that the rocker arm will not cause obstruction when the bimetallic strip pushes the upright.

[0015] Preferably, the top of the outer casing is provided with a sliding groove, the upright is slidably connected to the middle of the sliding groove, the bottom of the horizontal plate is fixedly connected with a limiting rod, the top of the outer casing is provided with a limiting hole, and the limiting rod is slidably connected to the middle of the limiting hole to ensure the stability of the upright sliding.

[0016] Preferably, the outer side of the housing has a through hole, and the alarm bell is vertically centered with the through hole to ensure the propagation of the alarm sound when the alarm bell is struck.

[0017] This invention provides an automatic overheat detection and alarm device for thermal power plants based on the principle of thermal expansion. It has the following beneficial effects:

[0018] 1. This invention uses the deformation of a bimetallic strip due to heat to push the upright pole upward, thereby causing the stop block to release the lock on the spring gear set, and then releasing the stored energy of the spring to drive the hammer to continuously strike the warning bell. At the same time, the warning sign on the top of the upright pole extends out of the shell. The purely mechanical structure does not require an external power source, avoiding the problem of electronic components easily failing at high temperatures. It can also provide a continuous bell sound and visual signal when overheating occurs, ensuring that the danger can be detected in time in the noisy environment of a thermal power plant.

[0019] 2. This invention uses a heat-conducting sheet to transfer heat to a thermometer installed on the pole in real time, and works in conjunction with a scale fixed on the outer casing. During inspection, by comparing the actual temperature displayed by the thermometer with the scale position of the pole, it is possible to intuitively determine whether the bimetallic strip has suffered metal fatigue or plastic deformation due to long-term high-temperature operation, thereby achieving self-checking of the health status of the core components without disassembling the equipment.

[0020] 3. This invention features a gear and rack transmission-based engagement assembly. Rotating an external knob moves the sprocket and rack, controlling the insertion block to disengage from the bimetallic strip's connecting block. Releasing the knob automatically resets and locks the assembly under the action of a compression spring. This allows operators to quickly replace the sensing element simply by operating the knob when a bimetallic strip failure is detected, without disassembling the complex internal transmission mechanism, thus reducing maintenance difficulty and time costs. Attached Figure Description

[0021] Figure 1 This is a perspective view of the present invention;

[0022] Figure 2 This is a front view of the outer casing of the present invention;

[0023] Figure 3 This is a schematic cross-sectional view of the outer casing of the present invention;

[0024] Figure 4 This is a schematic diagram of the variable speed gear set structure of the present invention;

[0025] Figure 5 This is a front view of the pole of the present invention;

[0026] Figure 6 This is a schematic diagram of the back of the pole of the present invention;

[0027] Figure 7 This is a schematic diagram of the snap-fit ​​assembly structure of the present invention;

[0028] Figure 8 This is an exploded view of the locking assembly of the present invention;

[0029] Figure 9 This is a schematic diagram of the striking component structure of the present invention;

[0030] Figure 10 This is a schematic diagram of the anti-reverse component structure of the present invention;

[0031] Figure 11 This is a schematic diagram of the spring of the present invention.

[0032] The components include: 1. Outer shell; 2. Through hole; 3. Horizontal plate; 4. Rocker arm; 5. Transparent glass; 6. Knob; 7. Bimetallic strip; 8. Vertical pole; 9. Through groove; 10. Warning sign; 11. Connecting block; 12. Round rod; 13. Movable plate; 14. Compression spring; 15. Rack; 16. Hanging rod; 17. Warning bell; 18. Connecting rod one; 19. Connecting rod two; 20. Hammer; 21. Speed-changing gear set. 22. Slide groove; 23. Limiting hole; 24. Gear; 25. Sleeve; 26. Spring; 27. Baffle; 28. Limiting rod; 29. ​​Thermometer; 30. Heat-conducting plate; 31. Scale; 32. Fixing rod; 33. Support rod; 34. Stop block one; 35. Resistance block; 36. Circular gear; 37. Rotating rod; 38. Insertion hole; 39. Insertion block; 40. Snap ring; 41. Stop block two; 42. Tension spring. Detailed Implementation

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Please see the appendix Figure 1 -Appendix Figure 4 This invention provides an automatic overheat detection and alarm device for thermal power plants based on the principle of thermal expansion. The device includes a housing 1 and a bimetallic strip 7. A vertical rod 8 is slidably connected to the middle of the housing 1, and a horizontal plate 3 is fixedly connected to the top of the vertical rod 8. A locking assembly is provided inside the housing 1, with the bimetallic strip 7 located in the middle of the locking assembly. A visual warning assembly is located in the middle of the vertical rod 8. An audible warning assembly is located on the rear inner wall of the housing 1. A hanging rod 16 is fixedly connected to the rear inner wall of the housing 1, and an alarm bell 17 is located at the end of the hanging rod 16. A transparent glass 5 is provided on the front of the housing 1 for quick observation of the interior during maintenance.

[0035] In one specific embodiment, the outer casing 1 serves as the main support structure of the device, with its bottom designed to fit the shape of the surface of the equipment under test, and is fixed to the surface of high-temperature equipment or pipelines in a thermal power plant by bolts. The bimetallic strip 7 is made of two metals with different coefficients of thermal expansion, and its bottom surface is directly attached to or close to the heated surface of the equipment. The upright 8 serves as a displacement transmission component, vertically penetrating the internal space of the outer casing 1. When the equipment temperature rises, the bimetallic strip 7 bends and deforms due to the difference in thermal expansion, generating an upward thrust on the bottom of the upright 8, pushing the upright 8 to move upward in the vertical direction. The horizontal plate 3 moves synchronously with the upright 8. The locking assembly is used to fix the bimetallic strip 7. The audible warning assembly is located in the rear space inside the outer casing 1, and the warning bell 17 is fixed by the hanging rod 16 and is in a ready-to-fire state.

[0036] The heat energy is converted into mechanical displacement through a purely mechanical connection, which can respond to temperature changes without the need for an external power source. The visual warning component is located on the pole 8 and is used to provide a visual warning when the pole 8 is raised at high temperatures. The pole 8 also triggers the audible warning component to sound an alarm when it is raised. The transparent glass 5 is embedded in the front surface of the outer shell 1. Before maintenance, the inspection personnel can observe the condition of the internal structure through the transparent glass 5 without disassembling the outer shell 1, which is convenient for daily inspection and fault diagnosis.

[0037] See appendix Figure 3 Appendix Figure 4 Appendix Figure 9 and attached Figure 11 The auditory warning component includes a gear set 21, an anti-reverse component, and a striking component. The gear set 21 is located on the rear side of the inner wall of the housing 1. A sleeve 25 is fixedly connected to the rear side of the inner wall of the housing 1. A spring 26 is provided on the inner wall of the sleeve 25. The end of the spring 26 is located on the outside of one of the shafts of the gear set 21. A rocker arm 4 is fixedly connected to the outside of the gear set 21. The end of the rocker arm 4 away from the gear set 21 passes through the front wall of the housing 1. The anti-reverse component is located on the outer periphery of the rocker arm 4. The striking component is located on the front side of the gear set 21.

[0038] In one specific embodiment, the power source of the device is a spring 26, which is installed inside the sleeve 25. The operator inputs mechanical energy by rotating a rocker arm 4 that extends to the outside of the housing 1. The rotation of the rocker arm 4 drives the input shaft of the gear set 21 to rotate, thereby winding the spring 26 connected to the gear shaft and storing elastic potential energy. The gear set 21 serves to increase speed and torque, transmitting the rotational motion of the spring 26 when it is released to the striking component. An anti-reverse component is located on the shaft of the rocker arm 4 and is used to lock the gear set after the spring 26 has stored energy, preventing it from releasing energy in a non-alarm state. The striking component is connected to the output end of the gear set 21. When the anti-reverse component is unlocked, the gear set 21 drives the striking component to operate.

[0039] See appendix Figure 6 Appendix Figure 9 and attached Figure 10 The anti-reverse assembly includes a wheel 24, which is fixedly connected to the outer periphery of the rocker arm 4. A second stop block 41 is rotatably connected to the middle of the wheel 24. A baffle 27 is fixedly connected to the middle of the wheel 24. The second stop block 41 contacts the baffle 27. A retaining ring 40 is fixedly connected to the middle of the wheel 24 and the outer side of the second stop block 41. A tension spring 42 is sleeved between the two retaining rings 40. A fixing rod 32 is fixedly connected to the rear side of the upright arm 8. A support rod 33 is fixedly connected to the rear side of the fixing rod 32. A first stop block 34 is fixedly connected to the outer periphery of the support rod 33.

[0040] In one specific embodiment, the wheel 24 rotates synchronously with the rocker arm 4. The second stop 41 is hinged to the surface of the wheel 24 and, under the tension of the spring 42, has a reset capability. During the winding of the mainspring 26, the second stop 41 contacts the first stop 34, overcomes the tension of the spring 42, deflects, and passes the first stop 34. When the rocker arm 4 stops rotating, the rebound force of the mainspring 26 attempts to drive the rocker arm 4 in the opposite direction. At this time, the second stop 41 resets under the action of the spring 42, its side abutting against the baffle 27, and its end abutting against the first stop 34. The first stop 34 is rigidly connected to the upright 8 via the support rod 33 and the fixing rod 32. At room temperature, the upright 8 is in a low position, and the first stop 34 is lower, blocking the rotation path of the second stop 41, thereby locking the mainspring 26. When the bimetallic strip 7 is heated and pushes the upright 8 to move up to the preset threshold height, the first stop 34 moves upward and breaks away from the rotation trajectory of the second stop 41, releasing the lock on the wheel 24, and the spring 26 releases energy to drive the mechanism to operate.

[0041] See appendix Figure 4 and attached Figure 9 The striking assembly includes a connecting rod 18, which is fixedly connected to the front side of the gear set 21. A connecting rod 29 is rotatably connected to the end of the connecting rod 18 away from the gear set 21, and a hammer 20 is fixedly connected to the end of the connecting rod 29 away from the connecting rod 18.

[0042] In one specific embodiment, when the mainspring 26 releases energy to drive the gear set 21 to rotate, the connecting rod 18 acts as a crank, making circular motion. The connecting rod 18 drives the connecting rod 29 and the hammer 20 at its end to swing. Utilizing centrifugal force and the swinging degree of freedom of the connecting rod 29, the hammer 20 periodically strikes the outer or inner wall of the warning bell 17 during rotation. Due to the continuous drive of the gear set, the hammer 20 produces a continuous striking action, emitting a continuous warning sound until the energy of the mainspring 26 is exhausted.

[0043] See appendix Figure 3 and attached Figure 5 The visual warning component includes a warning sign 10, which is located on the front side of the pole 8. The bottom of the pole 8 is in contact with the top of the bimetallic strip 7. A thermometer 29 is fixedly connected to the middle of the pole 8. A heat-conducting plate 30 is fixedly connected to the bottom of the pole 8. The end of the thermometer 29 is in contact with the heat-conducting plate 30. A scale 31 is provided on the front side of the pole 8.

[0044] In one specific embodiment, the warning sign 10 is fixed to the upper end of the pole 8. Under normal temperature, the warning sign 10 is retracted inside the housing 1; when overheating causes the pole 8 to move upward, the pole 8 causes the warning sign 10 to extend from the top of the housing 1, providing a visual alarm. Simultaneously, the heat-conducting plate 30 transfers the heat from the bimetallic strip 7 to the thermometer 29. The thermometer 29 rises and falls synchronously with the pole 8. A fixed scale 31 is provided on the front side of the housing 1 or at a corresponding position on the pole 8. Operators determine the state of the bimetallic strip 7 by observing the correspondence between the reading of the thermometer 29 and the height of the pole 8 extension, i.e., the position of the thermometer 29 relative to the scale 31. If the thermometer 29 indicates that the temperature has reached the alarm threshold, but the displacement of the pole 8 and the thermometer 29 relative to the scale 31 is insufficient, it indicates that the bimetallic strip 7 has experienced fatigue or plastic deformation, resulting in weakened thrust, requiring maintenance or replacement.

[0045] See appendix Figure 3 Appendix Figure 7 and attached Figure 8 The engaging assembly includes a rotating rod 37, an elastic component, and an engaging component. The rotating rod 37 is rotatably connected to the middle of the front wall of the outer casing 1. A knob 6 is fixedly connected to the front end of the rotating rod 37. Round rods 12 are fixedly connected to both the left and right sides of the inner wall of the outer casing 1. A movable plate 13 is slidably connected to the outer periphery of the round rods 12. The engaging component is disposed between the movable plate 13 and the rotating rod 37. An insert block 39 is fixedly connected to the outer side of the movable plate 13. A connecting block 11 is fixedly connected to the top of the bimetallic strip 7. An insertion hole 38 is opened in the middle of the connecting block 11. The insert block 39 is slidably connected to the middle of the insertion hole 38. The elastic component is disposed on the outer periphery of the round rod 12. The engaging component includes a spur gear 36. The spur gear 36 is fixedly connected to the outer periphery of the rotating rod 37. A rack 15 is fixedly connected to the outer side of the movable plate 13. The rack 15 meshes with the spur gear 36.

[0046] In one specific embodiment, during normal operation, the insert 39 is inserted into the socket 38 of the connecting block 11, fixing the upper end of the bimetallic strip 7. When it is necessary to replace the aging bimetallic strip 7, the operator removes the alarm device, rotates the external knob 6, and drives the rotating rod 37 and the sprocket 36 to rotate. The sprocket 36 drives the rack 15 to move laterally, thereby causing the movable plate 13 to slide along the round rod 12. The movement of the movable plate 13 causes the insert 39 to exit the socket 38, releasing the lock on the connecting block 11, at which point the bimetallic strip 7 can be removed downwards.

[0047] See appendix Figure 7 and attached Figure 8 The elastic component includes a stop block 35, which is fixedly connected to the outer periphery of the round rod 12, and a compression spring 14 is sleeved on the outer periphery of the round rod 12.

[0048] In one specific embodiment, the compression spring 14 is located between the movable plate 13 and the stop block 35 at the end of the round rod 12. When the knob 6 is rotated, causing the movable plate 13 to move to pull out the insert 39, the movable plate 13 compresses the compression spring 14. When the knob 6 is released, the compression spring 14 releases its elastic potential energy, pushing the movable plate 13 back to its original position, allowing the insert 39 to be reinserted into the insertion hole 38 of the newly installed bimetallic strip 7, thus achieving automatic locking.

[0049] See appendix Figure 3 Appendix Figure 5 and attached Figure 6 A through groove 9 is provided in the middle of the upright pole 8, and the rocker arm 4 is located in the middle of the through groove 9. The rocker arm 4 is used to prevent obstruction when the bimetallic strip 7 pushes the upright pole 8.

[0050] In one specific embodiment, the through groove 9 is an elongated hole opened on the body of the upright 8. The shaft of the rocker arm 4 passes through the through groove 9. The vertical length of the through groove 9 is greater than the maximum working stroke of the upright 8, ensuring that the inner wall of the upright 8 will not mechanically interfere with the shaft of the rocker arm 4 during the up and down movement of the upright 8, thus ensuring smooth movement.

[0051] See appendix Figure 3 The top of the outer casing 1 is provided with a sliding groove 22, and the upright 8 is slidably connected to the middle of the sliding groove 22. The bottom of the horizontal plate 3 is fixedly connected with a limiting rod 28, and the top of the outer casing 1 is provided with a limiting hole 23. The limiting rod 28 is slidably connected to the middle of the limiting hole 23 to ensure the stability of the sliding of the upright 8.

[0052] In one specific embodiment, the slide groove 22 and the limiting hole 23 cooperate to form a dual guide structure. The slide groove 22 restricts the displacement path of the top of the upright 8, and the limiting hole 23 constrains the lateral swing of the upright 8 by limiting the limiting rod 28. Especially at the moment when the mainspring 26 releases torque, the second stop 41 applies a lateral force to the first stop 34. The dual guide structure can effectively counteract the lateral force, prevent the upright 8 from tilting and jamming, and ensure the sensitivity of the triggering action.

[0053] See appendix Figure 1 Appendix Figure 2 and attached Figure 4 The outer side of the outer casing 1 has a through hole 2, and the warning bell 17 is vertically centered with the through hole 2 to ensure the transmission of the warning sound when the warning bell 17 is struck.

[0054] In one specific embodiment, the through hole 2 is located on the outer casing 1 at the position corresponding to the alarm bell 17, serving as a sound wave conduction channel. The through hole 2 reduces the obstruction of sound by the outer casing 1, allowing the mechanical waves generated by the hammer 20 to propagate more effectively to the external environment, thereby increasing the decibel level and propagation distance of the alarm sound.

[0055] Working principle: First, align the bottom of the outer casing 1 with the surface of the equipment and fix it so that the bimetallic strip 7 is in contact with the equipment. Then, rotate the rocker arm 4 to drive the gear set 21. At the same time, under the action of the sleeve 25, one of the shafts of the gear set 21 will drive the spring 26 to wind up. When rotating the rocker arm 4, the rocker arm 4 will drive the wheel 24 to rotate together. When the spring 26 is winding up, the side of the second stop 41 near the baffle 27 will contact the first stop 34, so that the second stop 41 can rotate and pull the tension spring 42, thus not obstructing the winding of the spring 26. After releasing the rocker arm 4, the side of the second stop 41 away from the baffle 27 will contact the first stop 34. Under the action of the baffle 27, the second stop 41 cannot rotate, thus preventing the spring 26 from being released automatically.

[0056] When the bimetallic strip 7 bends due to the heat of the equipment, it pushes the upright 8 upward. The upright 8 then moves the support rod 33 via the fixed rod 32, causing the support rod 33 to move the first stop 34 away from the second stop 41. When the second stop 41 is no longer obstructed, the spring 26 drives the gear set 21 to rotate. Under the transmission of the gear set 21, the connecting rod 18 rotates rapidly. While rotating, the connecting rod 18 drives the connecting rod 29 to swing. When one end of the connecting rod 18 rotates away from the gear set 21, the connecting rod 29 swings due to the weight and inertia of the end hammer 20, causing the hammer 20 to collide with the warning bell 17 to produce a continuous warning sound until the spring 26 is fully released. The through hole 2 allows the warning sound to travel further, and the through slot 9 in the upright 8 prevents the rocker arm 4 from obstructing the upright 8 when it is lifted.

[0057] When the upright pole 8 is lifted, the warning sign 10 will move the interior of the outer casing 1 to the top of the outer casing 1 to provide a visual warning, thereby achieving a dual warning of sight and sound. The upright pole 8 slides in the middle of the slide groove 22. The upright pole 8 drives the limiting rod 28 to slide in the middle of the limiting hole 23 through the horizontal plate 3. Under the limiting action of the limiting rod 28, the limiting hole 23 and the slide groove 22, the force applied by the second stop 41 to the first stop 34 under the torque of the spring 26 can be avoided, which would cause the upright pole 8 to slide easily.

[0058] Since the heat-conducting plate 30 is in contact with the bimetallic strip 7, the heat from the bimetallic strip 7 can be directly conducted to the thermometer 29. When the bimetallic strip 7 bends due to heat and lifts the upright 8, the thermometer 29 can extend from the inside of the outer casing 1 along with the upright 8. By comparing the temperature on the thermometer 29 with the reading on the scale 31, it can be determined whether the bimetallic strip 7 maintains sufficient deformation capacity. When the temperature reading on the thermometer 29 is sufficient, but the reading on the scale 31 is insufficient to slide out from the outer casing 1, it indicates that the bimetallic strip 7 has experienced metal fatigue after prolonged use, thus... Rotating knob 6 causes rotating rod 37 to drive gear 36 to rotate, which in turn moves rack 15. As rack 15 moves, it causes movable plate 13 to slide around the outer circumference of rod 12, thereby causing insert 39 to slide out from the middle of insertion hole 38. This allows bimetallic strip 7 to be quickly removed and replaced. As movable plate 13 moves, it compresses spring 14. After knob 6 is released, spring 14 pushes insert 39 and rack 15 back to their original positions, allowing for quick installation of new bimetallic strip 7.

Claims

1. An automatic overheat detection and alarm device for thermal power plants based on the principle of thermal expansion, comprising a housing (1) and a bimetallic strip (7), characterized in that, A vertical rod (8) is slidably connected to the middle of the outer shell (1), and a horizontal plate (3) is fixedly connected to the top of the vertical rod (8). A locking assembly is provided inside the outer shell (1), and a bimetallic strip (7) is provided in the middle of the locking assembly. The bottom of the vertical rod (8) is in contact with the top of the bimetallic strip (7). A visual warning assembly is provided in the middle of the vertical rod (8), and an auditory warning assembly is provided on the rear side of the inner wall of the outer shell (1). A hanging rod (16) is fixedly connected to the rear side of the inner wall of the outer shell (1), and a warning bell (17) is provided at the end of the hanging rod (16). A transparent glass (5) is provided on the front side of the outer shell (1). The auditory warning component includes a gear set (21), an anti-reverse component, and a striking component. The gear set (21) is located on the rear side of the inner wall of the housing (1). A sleeve (25) is fixedly connected to the rear side of the inner wall of the housing (1). A spring (26) is provided on the inner wall of the sleeve (25). The end of the spring (26) is located on the outside of one of the shafts of the gear set (21). A rocker arm (4) is fixedly connected to the outside of the gear set (21). The end of the rocker arm (4) away from the gear set (21) passes through the front wall of the housing (1). The anti-reverse component is located on the outer periphery of the rocker arm (4). The striking component is located on the front side of the gear set (21).

2. The automatic overheat detection and alarm device for thermal power plants based on the principle of thermal expansion as described in claim 1, characterized in that, The anti-reverse assembly includes a wheel (24), which is fixedly connected to the outer periphery of the rocker arm (4). A second stop (41) is rotatably connected to the middle of the wheel (24). A baffle (27) is fixedly connected to the middle of the wheel (24). The second stop (41) is in contact with the baffle (27). A retaining ring (40) is fixedly connected to the middle of the wheel (24) and the outer side of the second stop (41). A tension spring (42) is sleeved between the two retaining rings (40). A fixing rod (32) is fixedly connected to the rear side of the upright (8). A support rod (33) is fixedly connected to the rear side of the fixing rod (32). A first stop (34) is fixedly connected to the outer periphery of the support rod (33).

3. The automatic overheat detection and alarm device for thermal power plants based on the principle of thermal expansion as described in claim 1, characterized in that, The striking assembly includes a connecting rod one (18), which is fixedly connected to the front side of the gear set (21). A connecting rod two (19) is rotatably connected to the end of the connecting rod one (18) away from the gear set (21), and a hammer (20) is fixedly connected to the end of the connecting rod two (19) away from the connecting rod one (18).

4. The automatic overheat detection and alarm device for thermal power plants based on the principle of thermal expansion as described in claim 1, characterized in that, The visual warning component includes a warning sign (10), which is located on the front side of the pole (8). A thermometer (29) is fixedly connected to the middle of the pole (8), and a heat-conducting plate (30) is fixedly connected to the bottom of the pole (8). The end of the thermometer (29) is in contact with the heat-conducting plate (30), and a scale (31) is provided on the front side of the pole (8).

5. The automatic overheat detection and alarm device for thermal power plants based on the principle of thermal expansion as described in claim 1, characterized in that, The engaging assembly includes a rotating rod (37), an elastic component, and an engaging component. The rotating rod (37) is rotatably connected to the middle of the front wall of the outer shell (1). A knob (6) is fixedly connected to the front end of the rotating rod (37). Round rods (12) are fixedly connected to the left and right sides of the inner wall of the outer shell (1). A movable plate (13) is slidably connected to the outer periphery of the round rod (12). The engaging component is disposed between the movable plate (13) and the rotating rod (37). An insert block (39) is fixedly connected to the outer side of the movable plate (13). A connecting block (11) is fixedly connected to the top of the bimetallic strip (7). An insertion hole (38) is opened in the middle of the connecting block (11). The insert block (39) is slidably connected to the middle of the insertion hole (38). The elastic component is disposed on the outer periphery of the round rod (12).

6. The automatic overheat detection and alarm device for thermal power plants based on the principle of thermal expansion as described in claim 5, characterized in that, The meshing assembly includes a spur gear (36), which is fixedly connected to the outer periphery of the rotating rod (37). A rack (15) is fixedly connected to the outer side of the movable plate (13), and the rack (15) meshes with the spur gear (36).

7. The automatic overheat detection and alarm device for thermal power plants based on the principle of thermal expansion as described in claim 5, characterized in that, The elastic component includes a stop block (35), which is fixedly connected to the outer periphery of the round rod (12), and a compression spring (14) is sleeved on the outer periphery of the round rod (12).

8. The automatic overheat detection and alarm device for thermal power plants based on the principle of thermal expansion as described in claim 1, characterized in that, The upright (8) has a through groove (9) in the middle, and the rocker arm (4) is located in the middle of the through groove (9) so that the rocker arm (4) will not cause obstruction when the bimetallic strip (7) pushes the upright (8).

9. The automatic overheat detection and alarm device for thermal power plants based on the principle of thermal expansion as described in claim 1, characterized in that, The top of the outer casing (1) is provided with a sliding groove (22), the upright (8) is slidably connected to the middle of the sliding groove (22), the bottom of the horizontal plate (3) is fixedly connected with a limiting rod (28), the top of the outer casing (1) is provided with a limiting hole (23), and the limiting rod (28) is slidably connected to the middle of the limiting hole (23) to ensure the stability of the sliding of the upright (8).

10. The automatic overheat detection and alarm device for thermal power plants based on the principle of thermal expansion according to claim 1, characterized in that, The outer side of the outer casing (1) is provided with a through hole (2), and the warning bell (17) is vertically centered with the through hole (2) to ensure the propagation of the warning sound when the warning bell (17) is struck.

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