Slag block cooling control device of dry slag extractor
By using a cooling water spraying device and sensors to control the spraying volume in the dry slag discharge machine, the problem of unstable boiler operation caused by air leakage at the furnace bottom under low load conditions was solved, achieving efficient slag cooling and boiler efficiency improvement.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-13
- Publication Date
- 2026-04-17
AI Technical Summary
Under low load conditions, the air leakage at the bottom of the dry ash discharger system increases, affecting the boiler combustion efficiency and flue gas temperature, leading to unstable boiler operation.
A cooling water spraying device is used to cool the high-temperature slag, and the spraying volume is controlled by temperature and weight sensors to reduce air leakage at the furnace bottom and avoid the negative effects of air cooling.
It effectively reduces air leakage at the furnace bottom, improves boiler combustion efficiency, prevents flue gas temperature from rising, ensures the safe operation of subsequent equipment, and does not affect the oxygen content in the furnace or the secondary air distribution volume.
Smart Images
Figure CN224135883U_ABST
Abstract
Description
Technical fields:
[0001] This utility model belongs to the field of coal-fired boiler combustion and ash removal technology, specifically relating to a ash block cooling control device for a dry ash removal machine. Background technology:
[0002] In traditional boiler systems employing dry ash removal devices, hot slag falling to the furnace bottom during boiler operation is cooled by a small amount of ambient cold air (designed to be 2% of the total air volume under rated operating conditions) entering the dry ash removal system through cooling air vents distributed around the dry ash removal machine and conveying device. This cools the high-temperature slag on the steel belt (or chain plate) of the dry ash removal machine. However, the amount of cold air required to maintain normal dry ash removal operation has already caused air leakage at the furnace bottom. In recent years, the development of new energy sources has led to a continuous decrease in the proportion of thermal power units installed, and the number of power generation utilization hours has been declining year by year. Peak-shaving operation of units has become more frequent, and the minimum peak-shaving operating load has been continuously reduced. Under low-load conditions, the proportion of furnace bottom air leakage in the total air volume of the unit has increased to 5%-8%, and its impact on the boiler can no longer be ignored.
[0003] Bottom air leakage has the following negative impacts on boiler operation: 1. Combustion requires control of the total oxygen content in the furnace. Bottom air leakage reduces the amount of secondary air passing through the burner, affecting the boiler burner air distribution and thus impacting combustion efficiency. 2. Bottom air leakage also reduces the amount of hot secondary air passing through the air preheater, causing the exhaust gas temperature to rise. 3. Bottom air leakage raises the furnace flame center, leading to an increase in the amount of superheated and reheated steam desuperheating water, and may also cause the convective heating surface metal wall temperature to exceed the limit. 4. Raising the furnace flame center also leads to an increase in the air preheater inlet flue gas temperature, thereby increasing the exhaust gas temperature. Given the significant amount of cooling air required by the dry ash removal machine in coal-fired boilers, bottom air leakage in the dry ash removal machine system must be effectively controlled to prevent it from affecting combustion. Utility model content:
[0004] The purpose of this invention is to provide a slag block cooling control device for a dry slag discharge machine to address the above-mentioned problems.
[0005] The technical solution of this utility model is implemented as follows:
[0006] A slag block cooling control device for a dry slag discharge machine includes a boiler and a dry slag discharge machine. The boiler has several slag wells at its bottom, each with a hydraulic shut-off gate at its outlet. The dry slag discharge machine includes a horizontal section and an inclined section. The horizontal section is located below the hydraulic shut-off gates. A slag crusher is located below the outlet of the inclined section, and a slag bin is located at the outlet of the crusher. A first temperature sensor is installed in each slag well above the hydraulic shut-off gates to acquire the temperature of the steam entering the boiler. Weighing rollers are installed under the conveyor belt located directly below each hydraulic shut-off gate in the horizontal section, and these weighing rollers are parallel to the horizontal section. The conveyor rollers of the horizontal section have bearing seats at both ends between them and the frame of the dry slag discharger. Weight sensors are connected to the bearing seats to obtain the weight of the slag falling on the horizontal section. A cooling water spraying device is installed above the conveyor belt of the inclined section. The cooling water spraying device can spray and cool the slag on the conveyor belt to prevent the slag temperature from being too high and affecting the safety of subsequent equipment. After spraying, the cooling water forms water vapor after contacting the slag. Under the action of the boiler negative pressure, the water vapor enters the furnace. Moreover, the specific heat capacity of water is more than 4,000 times that of air, so the amount of water required to achieve the same cooling effect is very small, and the impact on the boiler system is small.
[0007] Furthermore, the first temperature sensor is a thermocouple.
[0008] Furthermore, the cooling water spraying device includes a water supply pipe, on which a water outlet valve is provided; the outlet of the water supply pipe is connected to a plurality of spray heads, and the outlet of the spray heads is aligned with the inclined section.
[0009] Furthermore, it also includes a controller; the signal input terminal of the controller is connected to the weight sensor and the first temperature sensor, and the signal output terminal of the controller is connected to the water outlet valve. The controller controls the opening degree of the water outlet valve based on the slag weight measured by the weight sensor and the temperature of the steam in the slag inlet measured by the first temperature sensor. If the controller is not available, the opening degree of the water outlet valve can also be adjusted manually based on the data.
[0010] Furthermore, a second temperature sensor is installed above the conveyor belt of the inclined section. The second temperature sensor is located on the side of the cooling water spray device away from the boiler. Located after the cooling water spray device, the second temperature sensor can be used to monitor the temperature of the slag after spraying and cooling, determine whether the spraying rate is appropriate, and if the temperature is too high, the spraying rate needs to be increased.
[0011] Furthermore, the second temperature sensor is an infrared temperature sensor.
[0012] Furthermore, the signal input terminal of the controller is connected to the signal of the second temperature sensor. Based on the temperature of the slag block after spraying measured by the second temperature sensor, the controller further controls the opening degree of the outlet valve.
[0013] Beneficial effects:
[0014] This invention provides a slag block cooling control device for a dry slag discharge machine. It uses cooling water spray to cool the high-temperature slag, preventing excessively high slag temperatures from affecting the normal operation of the subsequent slag crusher. Furthermore, compared to traditional air cooling, this device reduces air leakage at the furnace bottom, avoiding the unorganized air leakage at the furnace bottom that affects boiler combustion, as mentioned in the background art. It also alleviates problems such as flame center elevation, increased flue gas temperature, and reduced boiler efficiency caused by excessive air leakage at the furnace bottom. In addition, the water sprayed forms steam that enters the furnace but does not participate in combustion, thus not interfering with the oxygen content in the furnace and not reducing the secondary air distribution volume. Attached image description:
[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0016] Figure 1 A schematic diagram of a slag block cooling control device for a dry slag discharge machine;
[0017] Figure 2 This is a schematic diagram of the horizontal section of the dry slag discharge machine;
[0018] Figure 3 This is a schematic diagram of the controller's signal connections.
[0019] The attached diagrams are described as follows: 1. Boiler; 11. Slag well; 12. Hydraulic shut-off valve; 13. First temperature sensor; 2. Dry slag discharge machine; 21. Horizontal section; 22. Inclined section; 23. Conveyor belt; 24. Weighing idler; 25. Bearing seat; 26. Weight sensor; 3. Slag crusher; 4. Slag bin; 5. Spray head; 51. Water supply pipe; 52. Water outlet valve; 6. Second temperature sensor; 7. Controller. Detailed implementation method:
[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. In the description of the present utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present utility model. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0021] Example 1
[0022] A slag block cooling control device for a dry slag discharge machine, such as Figure 1 As shown, it includes a boiler 1 and a dry ash discharger 2. The bottom of the boiler 1 has several ash wells 11. Each ash well 11 has a hydraulic shut-off valve 12 at its outlet. A first temperature sensor 13, which is a thermocouple, is installed inside the ash well 11 above the hydraulic shut-off valve 12. The dry ash discharger 2 includes a horizontal section 21 and an inclined section 22. The horizontal section 21 is located below the hydraulic shut-off valve 12. A ash crusher 3 is installed below the outlet end of the inclined section 22. A ash bin 4 is installed at the outlet of the ash crusher 3.
[0023] A weighing idler roller 24 is installed under each conveyor belt 23 located directly below each hydraulic shut-off gate 12 in the horizontal section 21. The top surface of the weighing idler roller 24 contacts the conveyor belt 23. The weighing idler roller 24 is parallel to the conveyor idler rollers of the horizontal section 21. Bearing seats 25 are installed between both ends of the weighing idler roller 24 and the frame of the dry slag discharger 2. That is, the section of the bearing seat 25 away from the weighing idler roller 24 is set on the frame of the dry slag discharger 2. Figure 2 As shown, a weight sensor 26 is connected to the bearing housing 25. In this embodiment, the weight sensor 26 is a strain gauge sensor. When the slag falls onto the conveyor belt 23 of the horizontal section 21, the weighing roller 24 and the frame will be subjected to the pressure of the slag weight, resulting in slight deformation or stress changes. This allows the weight sensor 26 connected to the bearing housing 25 to detect these changes and convert them into weight signals.
[0024] In the prior art, dry slag discharge machines have a cold air inlet in the inclined section. The dry slag discharge machine 2 of this application does not have a cold air inlet. Instead, a cooling water spray device and a second temperature sensor 6 are arranged sequentially above the conveyor belt 23 of the inclined section 22 along the walking direction of the conveyor belt 23. The second temperature sensor 6 is an infrared temperature sensor. The cooling water spray device includes a water supply pipe 51, and a water outlet valve 52 is provided on the water supply pipe 51. The outlet of the water supply pipe 51 is connected to several spray heads 5. The outlet of the spray heads 5 is aligned with the conveyor belt 23 of the inclined section 22, so that cooling water can be sprayed onto the slag on the conveyor belt 23 through the spray heads 5.
[0025] Example 2
[0026] A slag block cooling control device for a dry slag discharge machine is generally the same as that in Embodiment 1, except that, as Figure 3 As shown, it also includes a controller 7, which is a PID controller in this embodiment; the signal input terminal of the controller 7 is connected to the first temperature sensor 13, the weight sensor 26, and the second temperature sensor 6, and the signal output terminal of the controller 7 is connected to the water outlet valve 52.
[0027] When boiler 1 is operating normally, the slag falling from the furnace enters the slag pit 11. With the hydraulic shut-off door 12 open, the slag falls onto the slowly moving conveyor belt 23 and is transported from the horizontal section 21 to the inclined section 22. As the conveyor belt 23 moves, it receives water spray from the spray head 5 in the inclined section 22 for cooling. Then, it enters the slag crusher 3 located below the outlet end of the inclined section 22 for crushing. After cooling and crushing, the slag falls into the slag bin 4 and is stored to a designated height or for a period of time before being transported away for disposal. The water spray volume of the spray head 5 is controlled by the opening of the outlet valve 52. The opening of the outlet valve 52 is adjusted manually or by the controller 8 based on the weight of the slag on the conveyor belt 23 monitored by the weight sensor 26. The greater the weight of the slag, the larger the opening of the outlet valve 52, resulting in a greater spray volume. At the same time, when the first temperature sensor 13 detects that the temperature of the steam entering the furnace is low, the opening of the outlet valve 52 can be reduced to ensure that the temperature of the steam entering the furnace is high, which is beneficial to improving the boiler operating efficiency. Furthermore, the steam entering the furnace does not participate in combustion and will not interfere with the oxygen content in the furnace, nor will it reduce the secondary air distribution volume. In addition, there is a preset upper limit value for the temperature of the slag after spray cooling. When the second temperature sensor 6 detects that the temperature of the slag after spray cooling exceeds this upper limit value, the opening of the outlet valve 52 is immediately increased to achieve rapid cooling.
[0028] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.
Claims
1. A slag block cooling control device for a dry slag discharge machine, comprising a boiler and a dry slag discharge machine, wherein the bottom of the boiler is provided with a plurality of slag wells, and the slag outlet of each slag well is provided with a hydraulic shut-off valve; the dry slag discharge machine comprises a horizontal section and an inclined section, the horizontal section being located below the hydraulic shut-off valve, and a slag crusher being provided below the outlet end of the inclined section, the slag outlet of the slag crusher being provided with a slag bin, characterized in that, A first temperature sensor is installed in the slag well above the hydraulic shut-off gate; a weighing idler is installed under the conveyor belt located directly below each hydraulic shut-off gate in the horizontal section, the weighing idler is parallel to the conveyor idler in the horizontal section, and a bearing seat is installed between the two ends of the weighing idler and the frame of the dry slag discharge machine, and a weight sensor is connected to the bearing seat; a cooling water spray device is installed above the conveyor belt in the inclined section.
2. A device for controlling the cooling of the slag blocks of a dry slag discharging machine according to claim 1, characterized in that The first temperature sensor is a thermocouple.
3. A device for controlling the cooling of the slag blocks of a dry slag discharging machine according to claim 1, characterized in that, The cooling water spraying device includes a water supply pipe with an outlet valve; the outlet of the water supply pipe is connected to a plurality of spray heads, and the outlet of the spray heads is aligned with the conveyor steel belt of the inclined section.
4. A slag block cooling control device for a dry slagging machine according to claim 3, characterized in that, It also includes a controller; the signal input terminal of the controller is connected to the weight sensor and the first temperature sensor, and the signal output terminal of the controller is connected to the water outlet valve.
5. A slag block cooling control device for a dry slagging machine according to claim 4, characterized in that, A second temperature sensor is installed above the conveyor belt of the inclined section, and the second temperature sensor is located on the side of the cooling water spray device away from the boiler.
6. A slag block cooling control device of a dry slagging machine according to claim 5, characterized in that, The second temperature sensor is an infrared temperature sensor.
7. A slag block cooling control device for a dry slagging machine according to claim 5, characterized in that, The signal input terminal of the controller is connected to the signal of the second temperature sensor.