Boiler reheater protection and control device

Abstract

The invention discloses a boiler reheater protection and control device, and relates to the technical field of boiler heat supply machinery, the boiler reheater protection and control device comprises a horizontal inlet and vertical outlet L-shaped pipeline main body, a horizontal elbow is formed on the L-shaped pipeline main body, and a water collector is arranged at the position, close to the horizontal elbow, of the L-shaped pipeline main body in the horizontal direction; the water collector is provided with a liquid level measuring device and a matched drain valve set in a matched mode, an atomizing nozzle is arranged in the vertical direction of the L-shaped pipeline body and connected with a desuperheating water pipeline system, and the position, located above the atomizing nozzle, of the L-shaped pipeline body is provided with a temperature monitoring point. And the control system is connected with and controls the attemperation water pipeline control system, the water delivery valve group and the liquid level measuring device. The atomization nozzle is used for spraying water for atomization and making contact with the hot steam to be mixed into the hot steam, the purpose of increasing the air exhaust flow can be achieved, meanwhile, the temperature of the hot steam can be reduced, overtemperature of the reheater is avoided, the heating area of the reheater does not need to be adjusted, and cost can be effectively saved.

Description

Technical Field

[0001] The present application relates to the technical field of boiler heating machinery, and in particular to a boiler reheater protection and control device. Background Art

[0002] The coal-fired power units have implemented heating transformation, using the main steam perforation extraction and reheat cold section perforation extraction scheme, which has changed the flow ratio of the heating surface of the boiler reheater and the superheater. Under normal circumstances, the maximum amount of steam extraction that the boiler reheater can operate is about 5% to 8% of the total flow of the reheater. If you want to increase the steam extraction volume, you must transform the boiler and reduce the heating area of ​​the reheater. The investment is large and the construction period is long. However, once the heating area of ​​the reheater is reduced, when the steam extraction volume is reduced, the reheat steam parameters will be reduced and the rated output cannot be reached. If the heating area of ​​the boiler reheater is not changed, increasing the extraction volume will inevitably lead to overheating of the reheater. Summary of the invention

[0003] The main purpose of this application is to provide a boiler reheater protection and control device to solve the above-mentioned technical problems.

[0004] The technical solutions adopted in this application are as follows:

[0005] A boiler reheater protection and control device comprises an L-shaped pipe body with a horizontal inlet and a vertical outlet, the L-shaped pipe body is formed with a horizontal elbow, a water collector is arranged near the horizontal elbow in the horizontal direction of the L-shaped pipe body, the water collector is equipped with a liquid level measuring device and a matching steam trap group, an atomizing nozzle is arranged in the vertical direction of the L-shaped pipe body, the atomizing nozzle is connected to a cooling water pipeline system, and a temperature monitoring point is arranged on the L-shaped pipe body above the atomizing nozzle;

[0006] It also includes a control system, which is connected to and controls the cooling water pipeline control system, the water delivery valve group and the liquid level measuring device.

[0007] Optionally, the cooling water pipeline system includes a cooling water inlet pipeline, and the cooling water inlet pipeline is provided with a flow valve, an electric shut-off valve, an electric regulating valve and a check valve.

[0008] Optionally, the atomizing nozzle is located at an upward elevation of more than 3 m from the central axis of the horizontal section of the L-shaped pipe body.

[0009] Optionally, the temperature monitoring point is located at an elevation greater than 3m from the atomizing nozzle.

[0010] Optionally, there are multiple temperature monitoring points, which are arranged in a ring around the L-shaped pipeline body.

[0011] Optionally, at least two liquid level measuring devices are provided to monitor different liquid level heights.

[0012] Optionally, the steam trap group includes a shut-off valve A1, a steam trap, a shut-off valve A2, an electric steam trap and a shut-off valve A3; the shut-off valve A1, the steam trap and the shut-off valve A2 are connected in series; the electric steam trap and the shut-off valve A3 are connected in series; the shut-off valve A1, the steam trap and the shut-off valve A2 are connected in parallel with the electric steam trap and the shut-off valve A3.

[0013] Optionally, the horizontal section of the L-shaped pipeline body is welded to a reheat cold section pipeline, the reheat cold section pipeline is connected to the exhaust port of the high-pressure cylinder of the steam turbine, and the vertical section of the L-shaped pipeline is welded to the reheater of the boiler, and the reheater is connected to the air inlet of the intermediate-pressure cylinder of the steam turbine through the reheat hot section pipeline.

[0014] Optionally, a pressure sensor and a temperature sensor are provided on the reheat cold section pipeline.

[0015] Optionally, a main steam pipe is connected between the boiler and the high-pressure cylinder of the steam turbine.

[0016] Compared with the prior art, the beneficial effects of this application are:

[0017] A boiler reheater protection and control device proposed in an embodiment of the present application can supply water to the atomizing nozzle through a cooling water pipeline system when the reheater is overheated, and use the atomizing nozzle to spray water to atomize and contact with hot steam to mix into hot steam, which can not only achieve the purpose of increasing the exhaust flow rate, but also reduce the hot steam temperature to avoid overheating of the reheater. There is no need to adjust the heating area of ​​the reheater, which can effectively save costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of the structure of a boiler reheater protection and control device provided in an embodiment of the present application;

[0019] Figure 2 A schematic diagram of the connection between the boiler reheater protection and control device provided in the embodiment of the present application and the boiler heating system;

[0020] Figure 3 for Figure 1 Schematic diagram of the cross section along the AA direction.

[0021] Description of the reference numerals in the accompanying drawings: Measuring device

[0022] 1- boiler, 2- turbine high-pressure cylinder, 3- turbine medium-pressure cylinder, 4- control system, 5- flow valve, 6- electric shut-off valve, 7- electric regulating valve, 8- check valve, 9- boiler reheater protection and control device, 10- atomizing nozzle, 11- water collector, 12- liquid level measuring device, 13- shut-off valve A1, 14- drain valve, 15- shut-off valve A2, 16- electric drain valve, 17- shut-off valve A3, 18- temperature monitoring point, 19- pressure sensor, 20- temperature sensor, 21- L-type pipeline body. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0024] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0025] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0026] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0027] See attached Figure 1 and Figure 2 As shown, an embodiment of the present application provides a boiler reheater protection and control device, including an L-shaped pipe body 21 with horizontal inlet and vertical outlet, the horizontal section of the L-shaped pipe body 21 is welded to the reheat cold section pipeline, the reheat cold section pipeline is connected to the exhaust port of the turbine high-pressure cylinder 2, and a pressure sensor 19 and a temperature sensor 20 are arranged on the reheat cold section pipeline for monitoring the extraction temperature and flow rate. The vertical section of the L-shaped pipe body 21 is welded to the boiler reheater, and the reheater is connected to the air inlet of the turbine intermediate-pressure cylinder 3 through the reheat hot section pipeline. At the same time, a main steam pipe is connected between the boiler 1 and the turbine high-pressure cylinder 2.

[0028] like Figure 1 As shown, the L-shaped pipe body 21 is formed with a horizontal elbow 9, and the horizontal elbow 9 connects the horizontal section and the vertical section. The L-shaped pipe body 21 is provided with an atomizing nozzle 10 in the vertical direction. The atomizing nozzle 10 is connected to a cooling water pipeline system, and the cooling water pipeline system includes a cooling water inlet pipeline. The cooling water inlet pipeline is provided with a flow valve 5, an electric shut-off valve 6, an electric regulating valve 7 and a check valve 8. The cooling water has a high-pressure water system outlet, and after being atomized by the atomizing nozzle 10, it contacts with the hot steam passing through the L-shaped pipe body 21, thereby reducing the temperature of the hot steam and achieving the effect of protecting the reheater. It can be imagined that the atomizing nozzle 10 atomizes the cooling water and then sprays it upward. Due to power reasons, the atomized liquid first mixes with the steam upstream, becomes steam and moves upward with it, and continues to mix, which can achieve the purpose of increasing the flow rate and reduce the temperature of the hot steam at the same time, protecting the reheater from overheating. When the atomized liquid does not turn into steam, it changes from upward to downward due to gravity, and is then heated by the lower steam countercurrent, and after turning into steam, it moves upward to reach the target of the predetermined temperature and flow rate. At the same time, a temperature monitoring point 18 is set on the L-shaped pipe body 21 located above the atomizing nozzle 10, and the temperature monitoring point 18 is set with multiple, such as Figure 3 As shown, this embodiment takes three as an example, which are distributed in an annular manner around the L-shaped pipe body 21. Through the temperature monitoring point 18, the temperature of the mixed steam can be mastered, and the flow rate of the cooling water can be adjusted in time to mix it with the extracted steam to reach a predetermined temperature.

[0029] In a preferred embodiment, Figure 1As shown, the atomizing nozzle 10 is more than 3m above the horizontal section center axis of the L-shaped pipe body 21, and the temperature monitoring point 18 is more than 3m above the atomizing nozzle 10, thereby providing sufficient length for the mixing of cooling water and hot steam. It can be seen that this structure fully mixes steam and cooling water by means of downstream and countercurrent, and by setting a mixing section of sufficient length. After the atomized liquid is evenly diffused around, it only moves up and down, avoiding the safety risks such as the temperature difference between the upper and lower walls, water accumulation in the lower part, and the upward warping of the pipe caused by insufficient mixing and heating of the horizontal desuperheater.

[0030] In this implementation, if Figure 1 As shown, a water collector 11 is provided near the horizontal elbow in the horizontal direction of the L-shaped pipe body 21, and the water collector 11 is equipped with a liquid level measuring device 12 and a matching steam trap group. Among them, at least two liquid level measuring devices 12 are provided, which are used to monitor different liquid level heights, which are counted as high-high liquid level monitoring points and high liquid level monitoring points. The steam trap group includes a shut-off valve A113, a steam trap 14, a shut-off valve A215, an electric steam trap 16 and a shut-off valve A317. The shut-off valve A113, the steam trap 14, and the shut-off valve A215 are connected in series, the electric steam trap 16 and the shut-off valve A317 are connected in series, and the shut-off valve A113, the steam trap 14, and the shut-off valve A215 are connected in parallel with the electric steam trap 16 and the shut-off valve A317. It can be imagined that if there is insufficient mixing of the cooling water, when it falls into the horizontal section, the horizontal elbow 9 adopts a wear-resistant elbow with a wall thickness of 3mm thicker than the traditional elbow. A water collector 11 is arranged near the horizontal elbow 9 to prevent the accumulated water from entering the steam turbine through the reheat cold section pipeline. Two liquid level measuring devices 12 are arranged on the side of the water collector 11, and one regular drain and one emergency drain are arranged at the lower part of the water collector 11. The regular drain is composed of the shut-off valve A113, the drain valve 14, the shut-off valve A215 and the pipeline where they are located, and the emergency drain is composed of the electric drain valve 16 and the shut-off valve A317 and the pipeline where they are located. When the liquid level is high, the control system alarms. When the liquid level is high, the control system opens the electric drain valve 16, and the shut-off valve A317 is in the normally open state.

[0031] In this embodiment, if Figure 1 As shown, the boiler reheater protection and control device also includes a control system 4, which is connected to each temperature monitoring element, each flow pressure monitoring element, and valve element to form a logic control.

[0032] In combination with the above content, the boiler reheater protection and control device provided in the embodiment of the present application is put into use when any of the following conditions is met:

[0033] First: Protect the reheat cold section pipeline extraction steam volume> 8%

[0034] Second: Reheat steam outlet overtemperature

[0035] During the heating process, the pressure photosensitive device 19 and the temperature sensor 20 transmit the measured values ​​to the control system 4. The control system 4 calculates the steam superheat according to the measured pressure (P) and temperature (T), and sets the reheat protection device system operation target value T1 in the control system.

[0036] The temperature of the reheated steam is adjusted to the target value T1 for commissioning by regulating the desuperheating water. The control system 4 opens the electric shut-off valve 6 and the electric regulating valve 7, and the desuperheating water system is put into operation. The three temperature measuring points 18 set at the end of the reheat protection device monitor the reheated steam outlet temperature T2, and send the signal to the control system 4. The control system 4 controls the opening of the electric regulating valve 7 by measuring the T2 value to adjust the desuperheating water volume, and finally realizes the supplement of the flow of the reheated steam system and the adjustment of the steam temperature, so as to achieve the purpose of protecting the reheater. The water volume Q measured by the flow sensor 5 is the flow of the supplementary reheating system, and is sent to the control system 4. Through the calculation of the control system 4, it is checked whether the water spray is excessive or small, and a prompt is given in the control system. Of course, if the commissioning conditions are not met, the reheat protection device in the control system 4 is in the cut-off state, the electric shut-off valve 6 and the electric regulating valve 7 are closed, and the water collector 11 is put into operation normally, which can be used as part of the normal use of the system.

[0037] It can be found that by adopting the boiler reheater protection and control device, when the reheat cold section steam extraction and main steam extraction are carried out, the heating area of ​​the reheater is not changed, the reheat steam flow is supplemented, the boiler reheater and the overall operation safety of the system are protected, and large-scale changes to the heating surface are avoided. The investment is small, the operation is more flexible, and the enterprise investment and construction period are reduced.

[0038] The boiler reheater protection and control device adopts an L-shaped structure. Through the downstream and countercurrent methods, and with a mixing section of sufficient length, the steam and the desuperheating water are fully mixed. After the atomized liquid is evenly diffused around, it only moves up and down, avoiding the safety risks such as the temperature difference between the upper and lower walls, water accumulation in the lower part, and pipe warping caused by insufficient mixing and heating of the horizontal desuperheater. The setting of the water collector and its water delivery valve group avoids the safety risk of water inflow to the turbine during the water spraying or startup stage. The device structure interface adopts welding, which is practical and has low investment.

[0039] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A boiler reheater protection and control device, characterized in that: It comprises an L-shaped pipeline body with horizontal inlet and vertical outlet, the L-shaped pipeline body is formed with a horizontal elbow, a water collector is arranged near the horizontal elbow in the horizontal direction of the L-shaped pipeline body, the water collector is equipped with a liquid level measuring device and a matching steam trap group, an atomizing nozzle is arranged in the vertical direction of the L-shaped pipeline body, the atomizing nozzle is connected to a cooling water pipeline system, and a temperature monitoring point is arranged on the L-shaped pipeline body above the atomizing nozzle; It also includes a control system, which is connected to and controls the cooling water pipeline control system, the water delivery valve group and the liquid level measuring device.

2. The boiler reheater protection and control device according to claim 1, characterized in that: The cooling water pipeline system comprises a cooling water inlet pipeline, on which a flow valve, an electric shut-off valve, an electric regulating valve and a check valve are arranged.

3. The boiler reheater protection and control device according to claim 2, characterized in that: The atomizing nozzle is located at an upward elevation of more than 3m from the central axis of the horizontal section of the L-shaped pipe body.

4. The boiler reheater protection and control device according to claim 1, characterized in that: The temperature monitoring point is greater than 3m above the atomizing nozzle.

5. The boiler reheater protection and control device according to claim 1 or 4, characterized in that: There are multiple temperature monitoring points, which are arranged in a ring around the L-shaped pipeline body.

6. The boiler reheater protection and control device according to claim 1, characterized in that: At least two liquid level measuring devices are provided to monitor different liquid level heights.

7. The boiler reheater protection and control device according to claim 1, characterized in that: The steam trap group includes a shut-off valve A1, a steam trap, a shut-off valve A2, an electric steam trap and a shut-off valve A3. The shut-off valve A1, the steam trap and the shut-off valve A2 are connected in series. The electric steam trap and the shut-off valve A3 are connected in series. The shut-off valve A1, the steam trap and the shut-off valve A2 are connected in parallel with the electric steam trap and the shut-off valve A3.

8. The boiler reheater protection and control device according to claim 1, characterized in that: The horizontal section of the L-shaped pipeline body is welded to the reheat cold section pipeline, and the reheat cold section pipeline is connected to the exhaust port of the high-pressure cylinder of the turbine. The vertical section of the L-shaped pipeline is welded to the reheater of the boiler, and the reheater is connected to the air inlet of the intermediate-pressure cylinder of the turbine through the reheat hot section pipeline.

9. The boiler reheater protection and control device according to claim 8, characterized in that: The reheat cold section pipeline is provided with a pressure sensor and a temperature sensor.

10. The boiler reheater protection and control device according to claim 8, characterized in that: A main steam pipeline is connected between the boiler and the high-pressure cylinder of the steam turbine.

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