Water spraying and temperature reducing device for boiler superheater
By designing the Venturi-type pipe and nozzle in the boiler superheater water spray and cooling device, combining the main path and bypass to adjust the temperature of the reducing water, the problem of deterioration of the vaporization effect caused by the increase in pressure difference under low load conditions is solved, and the boiler is ensured Safe operation under different load conditions.
Patent Information
- Application Number
- CN202420781188.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-15
- Publication Date
- 2024-12-10
- Estimated Expiration
- 2034-04-15
AI Technical Summary
During the boiler startup process, when the steam load is less than 30%, the pressure difference between the water supply pump outlet and the boiler superheater increases, resulting in poor vaporization effect of the water spray cooling device, which may lead to clogging of the superheater pipeline and falling off the scale. Threat the safe operation of the boiler.
A boiler superheater water spray and cooling device is designed, including a Venturi-type pipe, main nozzle and secondary nozzle. The main and bypasses are adjusted by reducing the temperature water to control the flow of the temperature water, and is equipped with a constant pressure pressure reducing valve and bypass locking. Valves, regulating valves, stop valves and check valves ensure that the steam flow rate matches the cooling water flow rate under different load ranges, and avoids poor vaporization.
While ensuring the temperature reduction effect, it avoids the overheater pipeline blockage caused by poor vaporization of the temperature reduction water, and improves the safe operation stability of the boiler under different load conditions.
Smart Images
Figure CN222143026U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of boilers, and in particular relates to a water spraying and temperature reducing device for a boiler superheater. Background Art
[0002] The temperature regulation of boiler superheated steam (such as the steam temperature regulation in the steam pipe between the low-temperature superheater outlet and the screen superheater inlet) mainly adopts the water spray cooling regulation method, and the cooling water source is taken from the outlet main pipe of the feed water pump. The water spray cooling device adopts the structure of a venturi tube plus a single flute nozzle. The superheated steam flow rate is increased through the venturi tube, and then the water column sprayed into the steam pipe by the flute nozzle is crushed and mixed with high-speed steam, and then vaporized to achieve the purpose of superheating steam. The cooling and vaporization effect of the water column sprayed into the steam pipe depends on the ideal degree of matching between the steam flow rate and the cooling water flow rate at the flute nozzle outlet.
[0003] When the boiler steam load (flow) is above 30%, the boiler uses the main water supply to control the drum water level. At this time, the pressure difference between the feed water pump outlet and the boiler superheater is small and stable. When the steam flow rate in the Venturi tube of the water spray cooling device and the cooling water flow rate at the flute nozzle outlet are at the ideal flow rate, the water spray cooling device has a good cooling and vaporization effect. However, during the boiler startup process, the boiler evaporation volume is small (steam load is less than 30%), and water supply needs to be supplied by feedwater bypass. Due to the small diameter of the boiler feedwater bypass pipe (only 30% of the main line), the pressure difference between the feedwater pump outlet and the boiler superheater increases significantly and is accompanied by a large fluctuation in the feedwater flow rate, resulting in a significant increase and fluctuation in the cooling water flow rate at the flute nozzle outlet. At this time, the steam flow rate in the Venturi tube is extremely low, which leads to a poor vaporization effect of the water spray cooling device. Part of the cooling water cannot be vaporized, which easily leads to steam-water stratification, and difficulty in controlling the superheater metal wall temperature and superheated steam temperature. Sometimes it even causes a sudden change in the superheater metal wall temperature, resulting in oxide scale shedding. Once the oxide scale peels off, it may cause furnace tube blockage, over-temperature failure, and unit non-stop. Utility Model Content
[0004] In view of this, the purpose of the utility model is to provide a boiler superheater water spray cooling device so as to ensure the cooling effect while avoiding the situation where the superheater pipe is blocked due to poor vaporization of cooling water, which threatens the safe operation of the boiler.
[0005] The utility model solves the above problems through the following technical means:
[0006] A boiler superheater water spray cooling device comprises a steam pipe, a venturi tube built in the steam pipe, a main nozzle extending into the venturi tube, and a cooling water regulating main path connected to the main nozzle; and also comprises a secondary nozzle extending into the venturi tube and a cooling water regulating bypass connected to the secondary nozzle.
[0007] Furthermore, the main nozzle and the auxiliary nozzle are both fixed by nozzle fasteners.
[0008] Furthermore, a constant pressure reducing valve is installed on the desuperheating water regulating bypass.
[0009] Furthermore, a bypass locking valve, a bypass regulating valve, a bypass stop valve and a bypass check valve are also installed on the desuperheating water regulating bypass.
[0010] Furthermore, a main circuit closing valve, a main circuit regulating valve, a main circuit stop valve and a main circuit check valve are installed on the main circuit for regulating the cooling water.
[0011] Furthermore, a drain cylinder is provided at the rear side of the venturi tube, and the drain cylinder is communicated with the steam pipeline.
[0012] Beneficial effects of the utility model:
[0013] The present application provides a boiler superheater water spray cooling device, comprising a steam pipe, a venturi tube built into the steam pipe, a main nozzle extending into the venturi tube, and a cooling water regulating main path connected to the main nozzle; and also comprising a secondary nozzle extending into the venturi tube and a cooling water regulating bypass connected to the secondary nozzle. The water spray cooling device of the present application can select the cooling water regulating main path or the cooling water regulating bypass to control the cooling water flow rate according to the boiler load range, while ensuring the cooling effect, avoiding the situation that the superheater pipe is blocked due to poor cooling water vaporization, which threatens the safe operation of the boiler. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The utility model is further described below in conjunction with the accompanying drawings and embodiments.
[0015] Figure 1 It is a schematic diagram of a preferred embodiment of the utility model. DETAILED DESCRIPTION
[0016] The utility model will be described in detail below with reference to the accompanying drawings. Figure 1 As shown: The boiler superheater water spraying and cooling device of the utility model comprises a steam pipe 4, a venturi tube 1 built in the steam pipe, a main nozzle 3 extending into the venturi tube, a cooling water regulating main path connected to the main nozzle, a secondary nozzle 2 extending into the venturi tube, and a cooling water regulating bypass connected to the secondary nozzle. The main nozzle and the secondary nozzle are fixed by a nozzle fastener 5.
[0017] The desuperheating water regulating bypass is also equipped with a bypass closing valve 7, a bypass regulating valve 9, a bypass stop valve 10 and a bypass check valve 11. The desuperheating water regulating main circuit is equipped with a main circuit closing valve 12, a main circuit regulating valve 13, a main circuit stop valve 14 and a main circuit check valve 15. The closing valve is used to open and close the corresponding pipeline, the regulating valve is used to adjust the flow of the corresponding pipeline, the stop valve is used to stop the flow of the corresponding pipeline, and the check valve is used to prevent the corresponding pipeline from backflow.
[0018] The function of the Venturi tube is as follows: the Venturi tube has an ejection effect. When superheated steam passes through the Venturi tube, a pressure drop is generated at its throat, and the steam velocity increases instantly. At this time, cooling water is ejected from the flute nozzle at a constant speed, and after entering the Venturi tube, it is quickly atomized by the steam and fully combined with the steam to achieve the purpose of cooling the superheated steam.
[0019] The diameter of the desuperheating water regulating bypass is reduced to about 20% of the desuperheating water regulating main path. Correspondingly, the size of the spray hole of the auxiliary nozzle is also reduced to about 20% of the size of the spray hole of the main nozzle.
[0020] During the operation, when the boiler steam load is above 30%, the main nozzle cooperates with the Venturi tube to make the sprayed cooling water and superheated steam mixed and atomized more evenly, thereby ensuring the cooling vaporization effect and ensuring the smooth operation of the boiler; when the boiler steam load is below 30% (such as during the boiler startup process), the auxiliary nozzle cooperates with the Venturi tube to make the sprayed cooling water and superheated steam mixed and atomized more evenly, thereby ensuring the cooling vaporization effect, thereby ensuring that the steam flow rate and the cooling water flow rate are ideally matched when the pressure difference between the feed water pump outlet and the boiler superheater increases significantly.
[0021] In summary, the water spray cooling device of the present application can select the cooling water regulation main path or the cooling water regulation bypass according to the boiler load range to control the cooling water flow rate. While ensuring the cooling effect, it avoids the situation where the superheater pipe is blocked due to poor vaporization of the cooling water, which threatens the safe operation of the boiler.
[0022] As a further improvement to the above technical solution, a constant pressure reducing valve 8 is installed on the desuperheating water regulating bypass to reduce the instability of the pressure difference between the feed water pump outlet and the boiler superheater caused by feed water regulation, thereby improving the regulation stability of the superheater desuperheating water regulating bypass.
[0023] As a further improvement to the above technical solution, a drain cylinder 6 is provided at the rear side of the venturi tube, and the drain cylinder is connected to the steam pipe. The drain cylinder collects the condensed water after water spraying and cooling, and then flows into the boiler fixed discharge expansion tank through the corresponding pipeline, so as to prevent the cooling water from entering the superheater pipe and causing blockage in the event of an accident, thereby threatening the safe and stable operation of the boiler.
[0024] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.
Claims
1. A boiler superheater water spraying and cooling device, characterized in that: It includes a steam pipe, a venturi tube built in the steam pipe, a main nozzle extending into the venturi tube, and a main cooling water regulation path connected to the main nozzle; it also includes a secondary nozzle extending into the venturi tube and a cooling water regulation bypass connected to the secondary nozzle.
2. The boiler superheater water spraying and cooling device according to claim 1 is characterized in that: The main nozzle and the auxiliary nozzle are both fixed by nozzle fasteners.
3. The boiler superheater water spraying and cooling device according to claim 2 is characterized in that: A constant pressure reducing valve is installed on the desuperheating water regulating bypass.
4. The boiler superheater water spraying and cooling device according to claim 3 is characterized in that: The desuperheating water regulating bypass is also equipped with a bypass locking valve, a bypass regulating valve, a bypass stop valve and a bypass check valve.
5. The boiler superheater water spraying and cooling device according to claim 4 is characterized in that: The main cooling water regulating main circuit is equipped with a main circuit locking valve, a main circuit regulating valve, a main circuit stop valve and a main circuit check valve.
6. The boiler superheater water spraying and cooling device according to claim 5, characterized in that: A drain cylinder is arranged at the rear side of the venturi tube, and the drain cylinder is communicated with the steam pipeline.