Boiler liquid level monitoring system

Abstract

The utility model relates to a boiler liquid level monitoring system, belongs to the technical field of boiler liquid level control, and solves the technical problem that the measurement result fluctuates greatly when the liquid level of the boiler changes at present. The system comprises an insulating sleeve installed on the furnace top of the boiler, and the inner diameter of the insulating sleeve is smaller than that of the boiler; the two liquid level guide rods are connected to the insulating sleeve, the bottom ends of the liquid level guide rods are arranged in the insulating sleeve, and the two liquid level guide rods are arranged in a spaced mode; the top ends of the two liquid level guide rods are positioned outside the boiler and are electrically connected with the alternating current circuit; the current input end of the current transformer is electrically connected to the alternating current circuit; and the controller can control the boiler to start and stop, is electrically connected with the current output end of the current transformer, and is also electrically connected with an alarm device and a display device. Through the structure, the system can monitor the liquid level in the boiler, and when the liquid level changes, the current fluctuation in the alternating current circuit is smaller, so that observation is convenient, and accurate measurement is achieved.

Description

Technical Field

[0001] The utility model belongs to the technical field of boiler liquid level control, and particularly relates to a boiler liquid level monitoring system. Background Art

[0002] The liquid level parameters in gas boilers are extremely important, not only affecting production efficiency, but more importantly production safety. Therefore, current gas boilers are usually equipped with a liquid level monitoring system to monitor the liquid level in the boiler.

[0003] At present, the liquid level monitoring system used in boilers usually includes a liquid level guide rod inserted into the boiler and a conductor rod connected to the outer wall of the boiler. The liquid level guide rod and the conductor rod are connected together in a current loop. Since the boiler itself and the liquid in the boiler have a conductive function, when the liquid in the boiler rises to contact the liquid level guide rod, the liquid level guide rod, liquid, the boiler itself, the conductor and the external circuit together form a liquid level monitoring loop, and the resistance of the liquid level guide rod increases as the length of the section submerged in the liquid increases. With the help of this physical property, the liquid level depth in the boiler can also be monitored in real time.

[0004] However, due to the influence of the inner diameter of the boiler, the cross-sectional area of ​​the liquid in the boiler is large, and therefore the liquid resistance is relatively small. Therefore, when the liquid level changes, the current value in the liquid level monitoring circuit fluctuates greatly, resulting in large fluctuations in the output measurement results. This is not only not conducive to observation by staff, but also not convenient for accurately obtaining the liquid level information in the boiler. Utility Model Content

[0005] The utility model provides a boiler liquid level monitoring system, which is used to solve the technical problem that when the boiler liquid level changes, the measurement result output by the liquid level monitoring system used by the utility model fluctuates greatly.

[0006] The utility model is realized by the following technical scheme: a boiler liquid level monitoring system, comprising:

[0007] An insulating sleeve is installed on the furnace top of the boiler, the bottom end of the insulating sleeve is placed in the boiler, and the inner diameter of the insulating sleeve is smaller than that of the boiler;

[0008] Two liquid level guide rods are both detachably fixedly connected to the insulating sleeve, the bottom ends of the liquid level guide rods are placed in the insulating sleeve, and the two liquid level guide rods are spaced apart;

[0009] an AC circuit, the top ends of the two liquid level guide rods are both located outside the boiler, and the top ends of the two liquid level guide rods are both electrically connected to the AC circuit;

[0010] A current transformer having a current input terminal and a current output terminal, wherein the current input terminal of the current transformer is electrically connected to the AC circuit;

[0011] A controller capable of controlling the start and stop of the boiler, the controller is electrically connected to the current output end of the current transformer, and the controller is also electrically connected to an alarm device and a display device.

[0012] Furthermore, in order to better implement the present invention, a relay having a normally open contact and a normally closed contact, the normally closed contact of the relay is electrically connected to the AC circuit, and the normally open contact of the relay is electrically connected to the controller.

[0013] Furthermore, in order to better implement the present invention, the insulating sleeve includes:

[0014] An insulating pipe, detachably and fixedly mounted on the furnace top of the boiler;

[0015] The insulating plate is fixedly mounted on the top of the insulating tube and blocks the top of the insulating tube. The insulating plate is provided with two mounting holes which are axially the same as the insulating tube. The two liquid level guide rods are respectively inserted into the two mounting holes, and the two liquid level guide rods are respectively locked to the insulating plate through a locking assembly.

[0016] Furthermore, in order to better implement the utility model, a through hole is opened on the furnace top of the boiler, the insulating tube is inserted into the through hole, and the insulating tube is locked on the furnace top of the boiler through an installation component.

[0017] Furthermore, in order to better implement the present invention, the installation assembly includes:

[0018] A ring, sleeved on the insulating tube and fixedly connected to the insulating tube, the ring being provided with a through hole;

[0019] A stud is fixed on the furnace top of the boiler, and the stud passes through the through hole and is screwed with the first nut.

[0020] Furthermore, in order to better implement the present utility model, the locking assembly includes:

[0021] Two second nuts, the upper part of the liquid level guide rod is screwed to the mounting hole, the two second nuts are both screwed to the liquid level guide rod, and the two second nuts are respectively located on the upper and lower sides of the insulating plate.

[0022] Furthermore, in order to better implement the utility model, the inner diameter of the insulating tube is 50mm-60mm.

[0023] Furthermore, in order to better implement the present utility model, the inner diameter of the insulating tube is 55 mm.

[0024] Compared with the prior art, the utility model has the following beneficial effects:

[0025] The boiler liquid level monitoring system provided by the utility model comprises an insulating sleeve, two liquid level guide rods, an AC circuit, a current transformer and a controller. The insulating sleeve is installed on the furnace roof of the boiler, the bottom end of the insulating sleeve is placed in the boiler, and the inner diameter of the insulating sleeve is smaller than the boiler. Both the two liquid level guide rods are detachably fixedly connected to the insulating sleeve, and the bottom ends of the liquid level guide rods are placed in the above insulating sleeve. In this way, when the liquid in the boiler rises, it will enter the insulating sleeve and contact with both insulating guide rods. The two above liquid level guide rods are arranged at intervals to avoid short circuit. The top ends of the two liquid level guide rods are located outside the boiler, and the top ends of the two liquid level guide rods are electrically connected to the AC circuit. It is easy to understand that the two liquid level guide rods can be regarded as being connected in series in the AC circuit. The current transformer has a current input end and a current output end. Its current input end is electrically connected to the AC circuit, and its output end is electrically connected to the controller. In this way, the current transformer converts the AC power in the AC circuit into DC power and transmits it to the controller. The controller can control the start and stop of the boiler, and the controller is also electrically connected to an alarm device and a display device.

[0026] When in use, AC current flows in the AC circuit. When the liquid level in the boiler rises to contact the liquid level guide rod, the two liquid level guide rods are turned on and connected in series in the AC circuit. With the help of a current transformer, DC current is input to the controller. When the liquid level is different, the length of the liquid level guide rod submerged in the liquid is different, so the resistance in the AC circuit is different, which makes the current flowing in the AC circuit different, and thus the DC power delivered to the controller is different. The controller controls the operating status of the alarm device and controls the display device to display the current liquid level according to the different current sizes received.

[0027] In the boiler liquid level monitoring system, since the two insulating guide rods are placed in the insulating sleeve, and the insulating sleeve is inserted in the boiler, and the inner diameter of the insulating sleeve is smaller than the inner diameter of the boiler, the liquid cross-sectional area between the two guide rods is smaller and the resistance is larger. Therefore, when the liquid level in the boiler changes, the current fluctuation flowing in the AC circuit is smaller, and the DC power fluctuation delivered to the controller is also smaller. This makes it more convenient for staff to observe and it is also easier to accurately obtain the liquid level information in the boiler. Of course, the alarm threshold can also be set more accurately (wherein the alarm threshold refers to the current value corresponding to when the liquid level in the boiler drops to the low liquid point). BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 It is a structural schematic diagram of a boiler liquid level monitoring system provided by an embodiment of the utility model;

[0030] Figure 2 It is a schematic diagram of the installation structure of the insulating sleeve in the embodiment of the utility model on the boiler roof;

[0031] Figure 3 It is a schematic diagram of the installation structure of the guide rod on the insulating sleeve in the embodiment of the utility model.

[0032] In the figure:

[0033] 100- boiler, 200- insulating sleeve, 210- insulating tube, 220- insulating plate, 230- ring, 240- stud, 250- first nut, 300- liquid level guide rod, 310- second nut, 400- AC circuit, 500- current transformer, 600- controller, 700- alarm device, 800- display device, 900- relay. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the utility model.

[0035] Example:

[0036] The boiler liquid level monitoring system provided by the utility model is as follows Figure 1 As shown, it includes an insulating sleeve 200, two liquid level guide rods 300, an AC circuit 400, a current transformer 500 and a controller 600, wherein:

[0037] The insulating sleeve 200 is installed on the furnace top of the boiler 100. The insulating sleeve 200 is vertically arranged, and the bottom end of the insulating sleeve 200 is placed in the boiler 100. Preferably, the bottom end of the insulating sleeve 200 extends to the middle and lower part of the boiler 100, and the inner diameter of the insulating sleeve 200 is smaller than that of the boiler 100. The insulating sleeve 200 is made of insulating material, such as ceramics.

[0038] Both liquid level guide rods 300 are made of conductive metal (such as iron, etc.), which has conductive properties, and as the length submerged in the liquid changes, the resistance of the liquid level guide rod 300 changes in a positive correlation. Both liquid level guide rods 300 can be detachably fixedly connected to the insulating sleeve 200, and the bottom end of the liquid level guide rod 300 is placed in the above-mentioned insulating sleeve 200. Optionally, the above-mentioned liquid level guide rod 300 is a straight rod, and its length direction is also a vertical direction, that is, the axial direction of the liquid level guide rod 300 is in the same direction as the above-mentioned insulating sleeve 200. The two liquid level guide rods 300 are arranged at intervals to avoid short circuit. When the liquid in the furnace rises, it will enter the insulating sleeve 200 and contact the two insulating guide rods, so that the two liquid level guide rods 300 are turned on. The top ends of the two liquid level guide rods 300 are located outside the boiler 100, and the top ends of the two liquid level guide rods 300 are electrically connected to the AC circuit 400. It is easy to understand that the two liquid level guide rods 300 can be regarded as being connected in series in the AC circuit 400. The AC circuit 400 is electrically connected to a power source so that when the AC circuit 400 is turned on, an AC current is formed in the AC circuit 400.

[0039] The current transformer 500 has a current input terminal and a current output terminal, wherein the current input terminal is electrically connected to the AC circuit 400, and the output terminal is electrically connected to the controller 600. In this way, the current transformer 500 converts the AC power in the AC circuit 400 into DC power and transmits it to the controller 600. The controller 600 can control the start and stop of the boiler 100, and the controller 600 is also electrically connected to an alarm device 700 and a display device 800. Optionally, the controller 600 may be a PLC or a chip or a circuit board, the alarm device 700 may be a buzzer or an indicator light, and the display device 800 may be a display screen.

[0040] When in use, when the liquid level in the boiler 100 rises to contact the liquid level guide rod 300, the two liquid level guide rods 300 are turned on and connected in series in the AC circuit 400. AC current flows in the AC circuit 400, and DC power is input to the controller 600 with the help of the current transformer 500. When the liquid level is different, the length of the liquid level guide rod 300 submerged in the liquid is different, so the resistance in the AC circuit 400 is different, which makes the current flowing in the AC circuit 400 different, and thus the DC power delivered to the controller 600 is different. The controller 600 controls the operating status of the alarm device 700 and controls the display device 800 to display the current liquid level according to the different currents received, or controls the boiler 100 to shut down.

[0041] In the boiler liquid level monitoring system, since the two insulating guide rods are placed in the insulating sleeve 200, and the insulating sleeve 200 is inserted in the boiler 100, and the inner diameter of the insulating sleeve 200 is smaller than the inner diameter of the boiler 100, the liquid cross-sectional area between the two guide rods is smaller and the resistance is larger. Therefore, when the liquid level in the boiler 100 changes, the current flowing in the AC circuit 400 fluctuates less, and the DC power supplied to the controller 600 also fluctuates less. This makes it more convenient for staff to observe and it is also easier to accurately obtain the liquid level information in the boiler 100. Of course, the alarm threshold can also be set more accurately (wherein the alarm threshold refers to the current value corresponding to when the liquid level in the boiler 100 drops to the low liquid point).

[0042] For a more detailed description, this embodiment is described by assumption, as follows:

[0043] Assume that when the boiler liquid level monitoring system was used before, when the liquid level changed by Δh, the corresponding current value changed by 5ΔI. In this way, when the liquid level changed continuously, the current value changed with a gradient of 5ΔI. For example, from Δh to 2Δh, the current change was 5ΔI. There would be no situations of ΔI, 2ΔI, 3ΔI, and 4ΔI.

[0044] When the boiler liquid level monitoring system provided in this embodiment is used, when the liquid level changes by Δh, the corresponding current value changes by ΔI. In this way, when the liquid level changes continuously, the current value changes with a gradient of ΔI. For example, from Δh to 2Δh, the current change is ΔI. At this time, the current change value is smaller than that of the boiler liquid level monitoring system used before.

[0045] Optionally, the boiler liquid level monitoring system provided in this embodiment also includes a relay 900 having a normally open contact and a normally closed contact, and the normally closed contact of the relay 900 is electrically connected to the above-mentioned alternating current. In this way, it can be ensured that as long as the liquid level rises to contact the bottom ends of both guide rods, the AC circuit 400 is immediately turned on, and the normally open contact of the relay 900 is electrically connected to the controller 600.

[0046] In this embodiment, a suitable liquid point (i.e., point A in the figure), a bottom liquid point (i.e., point B in the figure), and an extremely low liquid point (i.e., point C in the figure) are sequentially arranged in the boiler 100 from top to bottom. The extremely low liquid point corresponds to the bottom end of the liquid level guide rod 300. That is, when the liquid in the boiler 100 rises to the extremely low liquid point, the liquid is easy to contact the liquid level guide rod 300. At this time, a very low alternating current is generated in the AC circuit 400. When the liquid level continues to rise to the bottom liquid point, the current in the AC circuit 400 becomes larger than the median value. In this case, The current cannot close the normally open contact of the relay 900; and when the liquid level continues to rise to the appropriate liquid level point, the current in the AC circuit 400 further increases to a high value. The current in this case closes the normally open contact of the relay 900. Since the normally open contact of the relay 900 is electrically connected to the controller 600, the normally open contact after closing sends a corresponding current signal to the controller 600. When the controller 600 receives the current signal, it determines that the liquid level in the boiler 100 is at a high value, indicating that the boiler 100 is suitable for normal operation. In the above process, the controller 600 will receive the direct current sent from the AC transformer, and the display device 800 will display the corresponding liquid level value. Only when the liquid level in the boiler 100 rises to the appropriate liquid level point will the controller 600 receive the current signal sent by the relay 900.

[0047] When the liquid level in the boiler 100 starts to drop from the appropriate liquid point, the direct current sent by the current transformer 500 received by the controller 600 gradually decreases. When the liquid level in the boiler 100 drops to the low liquid point, the current signal received by the controller 600 becomes smaller than the set value (the set value is the alarm threshold set in the controller 600). At this time, due to the mechanical characteristics of the relay 900, the normally open contact of the relay 900 will also remain in a closed state, that is, the controller 600 will also receive the current signal sent by the relay 900. Therefore, in this case (that is, the controller 600 simultaneously receives the current signal sent by the relay 900 and the current signal sent by the current transformer 500 is lower than the alarm threshold), the controller 600 controls the alarm device 700 to send an alarm signal to remind the staff that the boiler 100 is in a water shortage state. When the liquid level in the boiler 100 further decreases, causing the liquid level in the boiler 100 to be lower than the above alarm threshold, the current in the AC circuit 400 further decreases so that the current is insufficient to close the normally open contact of the relay 900. At this time, the normally open contact of the relay 900 will be disconnected, and the controller 600 will not receive the current signal sent by the relay 900. In this case (that is, the controller 600 only receives the current lower than the alarm threshold transmitted by the AC transformer, and will not receive the relevant current signal sent by the relay 900), the controller 600 controls the boiler 100 to stop. In the above process, the display device 800 will display the current liquid level.

[0048] An optional implementation of this embodiment is as follows: the above-mentioned insulating sleeve 200 includes an insulating tube 210 and an insulating plate 220, wherein:

[0049] The insulating tube 210 is a straight tube structure made of insulating material (such as ceramic). The insulating tube 210 can be detachably fixedly installed on the furnace roof of the boiler 100, and the entire insulating sleeve 200 can be detachably installed on the furnace roof of the boiler 100. The insulating plate 220 is integrally formed and arranged on the top of the insulating tube 210 and blocks the top of the insulating tube 210. Two mounting holes are provided on the insulating plate 220, and the axial direction of the mounting holes is coaxial with the insulating tube 210. Two liquid level guide rods 300 are respectively inserted into the two mounting holes, and the two liquid level guide rods 300 are respectively locked to the insulating plate 220 by a locking assembly, so that the liquid level guide rods 300 can be detachably fixedly installed on the insulating sleeve 200. Through the above structure, it is convenient to disassemble and install the insulating sleeve 200 on the boiler 100, and it is also convenient to disassemble and install the liquid level guide rod 300 on the insulating sleeve 200. The inner diameter of the insulating tube 210 (ie, the inner diameter of the main body of the insulating sleeve 200) is 50 mm to 60 mm. Preferably, the inner diameter of the insulating tube 210 is 55 mm.

[0050] Optionally, in this embodiment, a threaded hole may be opened on the furnace top of the boiler 100, and the insulating tube 210 is screwed into the threaded hole.

[0051] As a best implementation of this embodiment, Figure 2 As shown, in this embodiment, a through hole is provided on the furnace top of the boiler 100, the insulating tube 210 is inserted into the through hole, and the insulating tube 210 is locked on the furnace top of the boiler 100 through the mounting assembly. In this way, the insulating sleeve 200 can be more firmly mounted on the furnace top of the boiler 100.

[0052] Optionally, the mounting assembly includes a ring 230 and a stud 240, the ring 230 is sleeved on the insulating tube 210 and fixedly connected to the insulating tube 210, for example, the ring 230 and the insulating tube 210 are integrally formed, a through hole is provided in the ring 230, the axial direction of the through hole is in the vertical direction, the stud 240 is welded and fixed to the furnace top of the boiler 100, and the first nut 250 is screwed after the stud 240 passes through the through hole, so that the ring 230 can be pressed against the furnace top of the boiler 100 by using the first nut 250. A plurality of through holes can be provided, and correspondingly, a plurality of studs 240 are also provided.

[0053] As another implementation of this embodiment, in this embodiment, the above-mentioned installation component can also be a pipe clamp arranged on the furnace top of the boiler 100, and the above-mentioned insulating tube 210 is clamped by using the pipe clamp.

[0054] Alternatively, if Figure 3 As shown, the locking assembly includes two second nuts 310, the upper part of the liquid level guide rod 300 is screwed to the mounting hole, and the two second nuts 310 are screwed to the liquid level guide rod 300, that is, each liquid level guide rod 300 is screwed to two second nuts 310, and the two second nuts 310 are respectively located at the upper and lower sides of the insulating plate 220, so that the two second nuts 310 can lock the liquid level guide rod 300 on the insulating plate 220. The second nuts 310 are made of insulating material.

[0055] As another implementation of this embodiment, the locking assembly in this embodiment may also be a clip disposed on the insulating plate 220 , and the liquid level guide rod 300 is clamped by the clip.

[0056] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope recorded in the utility model, which should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A boiler liquid level monitoring system, characterized in that: include: An insulating sleeve (200) is installed on the furnace roof of the boiler (100), the bottom end of the insulating sleeve (200) is placed in the boiler (100), and the inner diameter of the insulating sleeve (200) is smaller than that of the boiler (100); Two liquid level guide rods (300) are both detachably fixedly connected to the insulating sleeve (200), the bottom ends of the liquid level guide rods (300) are placed in the insulating sleeve (200), and the two liquid level guide rods (300) are arranged at intervals; an AC circuit (400), the top ends of the two liquid level guide rods (300) are both located outside the boiler (100), and the top ends of the two liquid level guide rods (300) are both electrically connected to the AC circuit (400); A current transformer (500) having a current input end and a current output end, wherein the current input end of the current transformer (500) is electrically connected to the AC circuit (400); A controller (600) capable of controlling the start and stop of the boiler (100), wherein the controller (600) is electrically connected to the current output end of the current transformer (500), and the controller (600) is also electrically connected to an alarm device (700) and a display device (800).

2. The boiler liquid level monitoring system according to claim 1, characterized in that: Also includes: A relay (900) having a normally open contact and a normally closed contact, wherein the normally closed contact of the relay (900) is electrically connected to the AC circuit (400), and the normally open contact of the relay (900) is electrically connected to the controller (600).

3. The boiler liquid level monitoring system according to claim 1 or 2, characterized in that: The insulating sleeve (200) comprises: An insulating tube (210) is detachably fixedly mounted on the furnace top of the boiler (100); An insulating plate (220) is fixedly mounted on the top end of the insulating tube (210) and blocks the top end of the insulating tube (210); the insulating plate (220) is provided with two mounting holes having the same axial direction as the insulating tube (210); the two liquid level guide rods (300) are respectively inserted into the two mounting holes, and the two liquid level guide rods (300) are respectively locked to the insulating plate (220) via a locking assembly.

4. The boiler liquid level monitoring system according to claim 3, characterized in that: A through hole is provided on the furnace top of the boiler (100), the insulating tube (210) is inserted into the through hole, and the insulating tube (210) is locked on the furnace top of the boiler (100) through a mounting assembly.

5. The boiler liquid level monitoring system according to claim 4, characterized in that: The installation assembly includes: A ring (230) is sleeved on the insulating tube (210) and fixedly connected to the insulating tube (210), and the ring (230) is provided with a through hole; A stud (240) is fixedly mounted on the furnace top of the boiler (100); the stud (240) passes through the through hole and is screwed to the first nut (250).

6. The boiler liquid level monitoring system according to claim 3, characterized in that: The locking assembly comprises: Two second nuts (310), the upper part of the liquid level guide rod (300) is screwed to the mounting hole, the two second nuts (310) are both screwed to the liquid level guide rod (300), and the two second nuts (310) are respectively located on the upper and lower sides of the insulating plate (220).

7. The boiler liquid level monitoring system according to claim 3, characterized in that: The inner diameter of the insulating tube (210) is 50 mm-60 mm.

8. The boiler liquid level monitoring system according to claim 6, characterized in that: The inner diameter of the insulating tube (210) is 55 mm.

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