Automatic continuous water supply device of vertical steam boiler

Abstract

The automatic continuous water supply device comprises a vertical boiler upper header, and an electrode type water level controller, a double-chamber balance container, a differential pressure transmitter, a water level adjusting controller, a frequency converter and a water supply pump are assembled on the outer side of the vertical boiler upper header. The water level electrode controller comprises a water level electrode cylinder, a low water level electrode, a medium water level electrode and a high water level electrode; the upper header of the vertical boiler is connected with the electrode type water level controller through a connecting mechanism; according to the automatic continuous water supply device for the vertical steam boiler, automatic continuous water supply of the boiler can be achieved, and the automatic continuous water supply device for the vertical steam boiler has the advantages of being high in response speed, stable in water level control, capable of achieving automatic continuous water supply of the boiler and capable of achieving automatic continuous water supply of the boiler. And steam pressure output is stable.

Description

Technical Field

[0001] This patent relates to the field of boiler technology, specifically an automatic continuous water supply device for a vertical steam boiler. Background Art

[0002] Vertical steam boilers have the advantages of small water capacity and quick start-up. The water level is generally controlled by position control, that is, the water level detection device generates an on-off signal to control the start and stop of the feed water pump. The most common water level control method is to start the water pump at a low water level and stop it when the water level reaches a high level. However, on-off control is not an ideal type of boiler control. When the water pump is running regularly, a large amount of cold feed water will reduce the boiler pressure, which will cause the combustion volume to fluctuate frequently with the water pump's on and off. This change will reduce the boiler's thermal efficiency and cause the steam flow rate to fluctuate in a sawtooth pattern. If the steam load is very high, the fluctuating steam flow rate will increase steam carryover, causing the water level to become increasingly unstable and may even lead to the risk of low water level interlock shutdown. Utility Model Content

[0003] The purpose of this patent is to provide an automatic continuous water supply device for a vertical steam boiler to solve the problems raised in the above background technology.

[0004] To achieve the above objectives, this patent provides the following technical solutions: an automatic continuous water supply device for a vertical steam boiler, comprising an upper header of a vertical boiler, the outer side of which is equipped with an electrode-type water level controller, a double-chamber balancing container, a differential pressure transmitter, a water level regulating controller, a frequency converter, and a water supply pump;

[0005] The electrode type water level controller comprises a water level electrode cylinder, a low water level electrode, a middle water level electrode and a high water level electrode;

[0006] A valve is installed between the vertical boiler upper header and the electrode type water level controller via a connecting mechanism;

[0007] The water level electrode cylinder is provided with a low water level line, a target water level line, a middle water level line and a high water level line from bottom to top, and the low water level electrode, the middle water level electrode and the high water level electrode are placed in the water level electrode cylinder;

[0008] The end of the low water level electrode is flush with the low water level line, the end of the middle water level electrode is flush with the middle water level line, and the end of the high water level electrode is flush with the high water level line.

[0009] Preferably, the lengths of the high water level electrode, the middle water level electrode and the low water level electrode increase sequentially.

[0010] Preferably, the connecting mechanism includes a sealing body, and both side walls of the sealing body are provided with sealing openings, a sealing tube a is inserted into the sealing opening on one side, and a sealing tube b is inserted into the sealing opening on the other side, the inner wall of the sealing body is provided with an internal thread, and the outer walls of the sealing tube a and the sealing tube b are provided with external threads.

[0011] Preferably, a connecting tube is provided at the connection between the sealing tube a and the sealing tube b and inside the sealing body, and a rubber pad a and a rubber pad b are provided outside the connecting tube, a fixing ring is installed on the side wall of the rubber pad a facing the rubber pad b, and a rubber block is installed on the side wall of the fixing ring.

[0012] Preferably, the double-chamber balancing container converts the change of the boiler water level into a differential pressure signal, the differential pressure transmitter collects the differential pressure signal and outputs a 4-20mA water level current signal, the water level regulating controller collects the water level current signal of the differential pressure transmitter and sets the PID control water level to be flush with the target water level.

[0013] Preferably, the feed water pump is arranged in the upper header of the vertical boiler, the frequency converter is electrically connected to the feed water pump, and the water level controller is electrically connected to the frequency converter.

[0014] Compared with the prior art, the beneficial effects of this patent are as follows: the automatic continuous water supply device for a vertical steam boiler adopts a water level electrode and a double-chamber balancing container to collect water level signals. The water level signal collected by the water level electrode controls the start and stop of the water supply pump. The water level signal collected by the double-chamber balancing container is used to control the continuous operation of the water supply pump. Among the three water level electrodes, one is used as the water supply pump OFF control, and two are used as the water supply pump ON control. Different water level electrodes are used to control the start of the water pump in the water level rising and falling stages. The lower water level electrode is used to control the start of the water supply pump in the water level rising stage, and the higher water level is used to control the start of the water supply pump in the water level falling stage. Because the water capacity of the vertical boiler is small, the two-stage control of the water supply pump start can avoid the rapid rise of the water level caused by the original one-stage control, so that the water pump stops. After continuous adjustment of the water level PID controller, the water level can be stabilized near the PID target water level in a short time. The use of this automatic continuous water supply device for the boiler can realize automatic continuous water supply of the boiler, which has the advantages of fast response speed, stable water level control, and stable steam pressure output. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the composition of this patent;

[0016] Figure 2 This is a schematic diagram of the sealing body of this patent;

[0017] Figure 3 This is an exploded view of the sealing body of this patent.

[0018] In the figure: 1 electrode type water level controller, 101 water level electrode cylinder, 102 low water level electrode, 103 middle water level electrode, 104 high water level electrode, 2 double chamber balance container, 3 differential pressure transmitter, 4 water level regulation controller, 5 frequency converter, 6 feed water pump, 7 vertical boiler upper header, 8 sealing body, 9 sealing pipe a, 10 sealing pipe b, 11 sealing port, 12 internal thread, 13 external thread, 14 rubber pad a, 15 fixing ring, 16 rubber block, 17 connecting pipe, 18 rubber pad b, 19 valve. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of this patent to clearly and completely describe the technical solutions in the embodiments of this patent. Obviously, the embodiments described are only part of the embodiments of this patent, not all of them. Based on the embodiments of this patent, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this patent.

[0020] See also Figure 1 、 Figure 2 and Figure 3 This patent provides a technical solution: an automatic continuous water supply device for a vertical steam boiler, comprising a vertical boiler upper header 7, the outer side of which is equipped with an electrode-type water level controller 1, a double-chamber balancing container 2, a differential pressure transmitter 3, a water level adjustment controller 4, a frequency converter 5 and a water supply pump 6;

[0021] The electrode type water level controller 1 comprises a water level electrode cylinder 101, a low water level electrode 102, a middle water level electrode 103 and a high water level electrode 104;

[0022] A valve is installed between the vertical boiler upper header 7 and the electrode-type water level controller 1 through a connecting mechanism, the electrode-type water level controller 1, the double-chamber balancing container 2, the differential pressure transmitter 3, the water level regulating controller 4, the frequency converter 5 and the water feed pump 6. The electrode-type water level controller 1 sends a switching signal according to the change of the water level. The water level regulating controller 4 collects the water level signals of the differential pressure transmitter 3 and the electrode-type water level controller 1 and sends a start-stop switching control signal, a power frequency speed signal and a variable frequency speed signal to control the operation of the water feed pump 6.

[0023] The water level electrode cylinder 101 is provided with a low water level line, a target water level line, a middle water level line and a high water level line from bottom to top, and the low water level electrode 102, the middle water level electrode 103 and the high water level electrode 104 are placed in the water level electrode cylinder 101;

[0024] The end of the low water level electrode 102 is flush with the low water level line, the end of the middle water level electrode 103 is flush with the middle water level line, and the end of the high water level electrode 104 is flush with the high water level line.

[0025] The lengths of the high water level electrode 104, the middle water level electrode 103 and the low water level electrode 102 increase sequentially. When the middle water level electrode 103 is lower than the middle water level during the water level drop stage, the water level regulation controller 4 outputs a low frequency signal to the frequency converter 5 to control the water supply pump 6 to operate at the lowest frequency.

[0026] The connecting mechanism includes a sealing body 8, and sealing openings 11 are provided on both side walls of the sealing body 8. A sealing tube a9 is inserted into the sealing opening 11 on one side, and a sealing tube b10 is inserted into the sealing opening 11 on the other side. The inner wall of the sealing body 8 is provided with an internal thread 12, and the outer walls of the sealing tubes a9 and b10 are provided with external threads 13.

[0027] The connection between the sealing tube a9 and the sealing tube b10 is provided with a connecting tube 17 inside the sealing body 8, and the outside of the connecting tube 17 is provided with a rubber pad a14 and a rubber pad b18. The side wall of the rubber pad a14 facing the rubber pad b18 is provided with a fixing ring 15, and the side wall of the fixing ring 15 is provided with a rubber block 16. The two sealing tubes are connected through the sealing body 8, and the upper header of the vertical boiler is connected to other equipment through the sealing tube. The connecting tube 17 is a prefabricated part and is installed in the sealing body 8. After the sealing tubes a9 and the sealing tubes b10 are installed in the sealing body 8, they are connected to the connecting tube 10.

[0028] The double-chamber balancing container 2 converts the change of the boiler water level into a differential pressure signal. The differential pressure transmitter 3 collects the differential pressure signal and outputs a 4-20mA water level current signal. The water level regulating controller collects the water level current signal of the differential pressure transmitter and sets the PID control water level to be level.

[0029] The feed water pump 6 is arranged outside the upper header 7 of the vertical boiler, the frequency converter 5 is electrically connected to the feed water pump 6 , and the water level controller 4 is electrically connected to the frequency converter 5 .

[0030] Working process and principle: When the boiler is started, when the water level is lower than the low water level line, the water level regulating controller 4 controls the frequency converter 5 to output the industrial frequency operation signal to control the water feed pump 6 to operate. When the water level is higher than the low water level line, it switches to the matching frequency operation. When the water level continues to rise to the high water level line, the water feed pump 6 stops running. As the boiler continues to output steam, the water level drops below the middle water level line. When the middle water level electrode is OFF, the water level regulating controller 4 enters the PID control mode, and controls the frequency conversion operation of the water feed pump 6 by outputting a frequency signal matching the water level change to the frequency converter 5, so as to control the water level to always fluctuate around the target water level line. The conventional setting of the target water level is the midpoint of the high water level and the low water level. The utility model sets a middle water level line that is higher than the target water level line. The reason for this setting is that the water capacity between the high and low water levels of the vertical steam boiler is small and far away. It is much smaller than other types of steam boilers. If the conventional water level control method is used, the feed water pump 6 will run at the rated frequency when the water level is lower than the low water level, and will stop when the water level reaches the high water level. Because the water volume between the high and low water levels is small, although the water pump will enter the variable frequency operation when the water level exceeds the low water level line, the water level will soon reach the high water level line due to inertia, which will cause the feed water pump 6 to start and stop frequently, and the water level cannot be controlled to be stable near the target water level line. After setting a middle water level line higher than the target water level line, when the water level is lower than the middle water level in the water level drop stage, the water level regulation controller 4 outputs a low-frequency signal to the inverter 5 to control the feed water pump 6 to run at the lowest frequency. When the water level drops to the target water level line, the water level regulation controller 4 enters PID regulation to make the water supply equal to the steam output, so that the water level is stabilized near the "target water level line" to ensure smooth operation of the boiler and steam quality.

[0031] It will be apparent to those skilled in the art that this patent is not limited to the details of the exemplary embodiments described above, and that this patent can be implemented in other specific forms without departing from the spirit or essential characteristics of this patent. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of this patent is defined by the appended claims rather than the foregoing description, and it is intended that all changes that fall within the meaning and range of equivalents of the claims be encompassed within this patent. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0032] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. An automatic continuous water supply device for a vertical steam boiler, comprising an upper header (7) of a vertical boiler, characterized in that: The outer side of the vertical boiler upper header (7) is equipped with an electrode-type water level controller (1), a double-chamber balancing container (2), a differential pressure transmitter (3), a water level regulating controller (4), a frequency converter (5) and a water feed pump (6); The electrode-type water level controller (1) comprises a water level electrode cylinder (101), a low water level electrode (102), a middle water level electrode (103) and a high water level electrode (104); A valve (19) is installed between the vertical boiler upper header (7) and the electrode type water level controller (1) via a connecting mechanism; The water level electrode cylinder (101) is provided with a low water level line, a target water level line, a middle water level line and a high water level line from bottom to top, and the low water level electrode (102), the middle water level electrode (103) and the high water level electrode (104) are placed in the water level electrode cylinder (101); The end of the low water level electrode (102) is flush with the low water level line, the end of the middle water level electrode (103) is flush with the middle water level line, and the end of the high water level electrode (104) is flush with the high water level line.

2. The automatic continuous water supply device for a vertical steam boiler according to claim 1, characterized in that: The lengths of the high water level electrode (104), the middle water level electrode (103) and the low water level electrode (102) increase sequentially.

3. The automatic continuous water supply device for a vertical steam boiler according to claim 1, characterized in that: The connecting mechanism comprises a sealing body (8), both side walls of the sealing body (8) are provided with sealing openings (11), a sealing tube a (9) is inserted into the sealing opening (11) on one side, and a sealing tube b (10) is inserted into the sealing opening (11) on the other side, an inner wall of the sealing body (8) is provided with an internal thread (12), and the outer walls of the sealing tube a (9) and the sealing tube b (10) are both provided with external threads (13).

4. The automatic continuous water supply device for a vertical steam boiler according to claim 3, characterized in that: A connecting tube (17) is provided at the connection point between the sealing tube a (9) and the sealing tube b (10) and is located inside the sealing body (8). A rubber pad a (14) and a rubber pad b (18) are provided outside the connecting tube (17). A fixing ring (15) is provided on the side wall of the rubber pad a (14) facing the rubber pad b (18), and a rubber block (16) is provided on the side wall of the fixing ring (15).

5. The automatic continuous water supply device for a vertical steam boiler according to claim 1, characterized in that: The double-chamber balancing container (2) converts the change of the boiler water level into a differential pressure signal, the differential pressure transmitter (3) collects the differential pressure signal and outputs a 4-20mA water level current signal, and the water level regulating controller collects the water level current signal of the differential pressure transmitter and sets the PID control water level to be flush with the target water level.

6. The automatic continuous water supply device for a vertical steam boiler according to claim 1, characterized in that: The feed water pump (6) is arranged outside the upper header (7) of the vertical boiler, the frequency converter (5) is electrically connected to the feed water pump (6), and the water level adjustment controller (4) is electrically connected to the frequency converter (5).

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