Auxiliary steam pre-heating device of waste heat boiler
By designing the auxiliary steam preheating device of waste heat boiler and preheating the high-pressure steam drum, the problem of excessive temperature difference between high-pressure steam drum during cold start is solved, and faster start-up speed and lower thermal stress are achieved, and the equipment life is extended.
Patent Information
- Application Number
- CN202421536614.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-02
- Publication Date
- 2025-05-20
- Estimated Expiration
- 2034-07-02
AI Technical Summary
During the cold start-up of the F-class gas-steam combined power generation project, the temperature difference between the upper and lower walls of the high-pressure steam drum was too large, which affected the safety of the equipment operation and the start-up speed was not enough to meet the peak shaving requirements of the power grid.
A waste heat boiler auxiliary steam preheating device is designed, including preheating components, low-pressure steam drum auxiliary steam pipe interface, high-pressure evaporator drop pipe, steam heater, auxiliary steam nozzle and valve control, which is used to preheat the high-pressure steam drum and reduce the thermal stress during cold start.
It effectively reduces the temperature difference between the upper and lower walls of the high-pressure steam drum during cold start, shortens the cold start time, reduces the thermal stress, extends the life of the waste heat boiler, and accelerates the cold start speed of the unit.
Smart Images
Figure CN222887391U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of preheating of waste heat boilers, in particular to an auxiliary steam preheating device for waste heat boilers. Background Art
[0002] Gas-steam combined cycle units mainly play a peak shaving role in the power grid. To meet the peak shaving requirements of the power grid, the units need to have the function of rapid start-up and shutdown. The gas turbine in the combined cycle unit can achieve the start-up and shutdown of the unit in a short time, but the steam turbine and waste heat boiler are often limited by thermal stress, and the heating and pressure increase rates need to be strictly restricted. Under the condition of ensuring the safe operation of the equipment, the start-up and shutdown also need to be achieved in a short time. For the waste heat boilers of many early F-class gas-steam combined power generation projects, during the cold start process, the temperature difference between the upper and lower walls of the high-pressure steam drum is too large. In some projects, the temperature difference between the upper and lower walls of the high-pressure steam drum even reaches more than 90°C, far exceeding the maximum allowable value of 50°C for the boiler safety, seriously affecting the safe operation of the equipment.
[0003] As an important pressure-bearing equipment in the combined cycle, how to ensure the equipment safety of the waste heat boiler while also maximizing the start-up and shutdown speed of the unit to meet the peak shaving requirements of the power grid is the key problem to be solved now. Therefore, we propose an auxiliary steam preheating device for waste heat boilers to solve the above-mentioned problems. Summary of the Utility Model
[0004] The purpose of the utility model is to provide an auxiliary steam preheating device for waste heat boilers to solve the problems mentioned in the above background art.
[0005] To achieve the above purpose, the utility model provides the following technical solutions:
[0006] An auxiliary steam preheating device for waste heat boilers, comprising:
[0007] The waste heat boiler body and the high-pressure steam drum, the high-pressure steam drum is arranged on the waste heat boiler body;
[0008] The waste heat boiler preheating steam pipelines, and there are two paths thereof;
[0009] The preheating assembly, which is used for preheating the high-pressure steam drum and is located on the waste heat boiler body.
[0010] As a further scheme of the utility model: the preheating assembly includes an interface of the auxiliary steam pipe of the low-pressure steam drum, the interface of the auxiliary steam pipe of the low-pressure steam drum is connected to one path of the waste heat boiler preheating steam pipeline, the other path of the waste heat boiler preheating steam pipeline is connected with a downcomer of the high-pressure evaporator, the other end of the downcomer of the high-pressure evaporator is connected with a steam heater, and an auxiliary steam spray pipe is arranged in the downcomer of the high-pressure evaporator.
[0011] As a further solution of the present utility model: a regulating valve is provided on the preheating steam pipeline of the waste heat boiler.
[0012] As a further solution of the present utility model: one ends of the two paths of the preheating steam pipeline of the waste heat boiler are both connected to the auxiliary steam main pipe.
[0013] As a further solution of the present utility model: a deaerator is further provided on the waste heat boiler body.
[0014] As a further solution of the present utility model: the other end of the auxiliary steam spray pipe is connected to the steam heater.
[0015] Compared with the prior art, the beneficial effects of the present utility model are:
[0016] For the waste heat boiler auxiliary steam preheating device, through the preheating component, the temperature difference between the upper and lower walls of the high-pressure steam drum during cold start can be reduced, the cold start time can be shortened, the thermal stress during startup can be reduced, the service life of the waste heat boiler body can be extended, and the cold start speed of the unit can be accelerated; at the same time, when the unit is operating normally, after the deaerator on the waste heat boiler body removes oxygen, during the startup stage of the unit, an auxiliary steam heater is set up to heat the feed water of the deaerator by heating the condensate, pre-heating the feed water to the saturated state before the unit starts, reducing the dissolved oxygen content in the feed water, making the oxygen content of the feed water reach the qualified range, enabling the deaerator to be put into operation in advance, thereby shortening the time without deaeration steam during startup and shortening the time of corrosion of the waste heat boiler body due to excessive oxygen content in the condensate during startup, which is relatively practical. Description of the Drawings
[0017] Figure 1 It is a schematic structural diagram of the waste heat boiler auxiliary steam preheating device in the present utility model.
[0018] Wherein: 1. Waste heat boiler body; 2. High-pressure steam drum; 3. Waste heat boiler preheating steam pipeline; 4. Auxiliary steam main pipe; 5. Deaerator; 6. Low-pressure steam drum auxiliary steam pipe interface; 7. High-pressure evaporator downcomer; 8. Steam heater; 9. Auxiliary steam spray pipe; 10. Regulating valve. Detailed Embodiments
[0019] In one embodiment, as Figure 1 shown, a waste heat boiler auxiliary steam preheating device includes: a waste heat boiler body 1 and a high-pressure steam drum 2, and the high-pressure steam drum 2 is arranged on the waste heat boiler body 1; a waste heat boiler preheating steam pipeline 3, which has two paths; a preheating component, which is used for preheating the high-pressure steam drum 2 and is located on the waste heat boiler body 1;
[0020] The preheating assembly includes a low-pressure steam drum auxiliary steam pipe interface 6, which is connected to a waste heat boiler preheating steam pipeline 3. The other path of the waste heat boiler preheating steam pipeline 3 is connected to a high-pressure evaporator downcomer 7. The other end of the high-pressure evaporator downcomer 7 is connected to a steam heater 8. An auxiliary steam spray pipe 9 is arranged in the high-pressure evaporator downcomer 7. One ends of the two paths of the waste heat boiler preheating steam pipeline 3 are both connected to an auxiliary steam main pipe 4. A deaerator 5 is also arranged on the waste heat boiler body 1. The other end of the auxiliary steam spray pipe 9 is connected to the steam heater 8.
[0021] In this embodiment, before the cold start of the unit, the deaerator 5 is supplied with heating steam to heat the boiler feed water and accelerate the compliance of the oxygen content in the feed water. During the cold start, the heating steam of the high-pressure evaporator downcomer 7 is put into use in a timely manner, and the boiler water in the high-pressure evaporator and the steam drum is heated to higher than 100 °C through the auxiliary steam spray pipe 9, which can effectively reduce the upper and lower wall temperatures of the high-pressure steam drum 2 during startup, reduce the thermal stress during startup, extend the service life of the waste heat boiler body 1, and accelerate the cold start speed of the unit. During the normal operation of the unit, after the deaerator 5 on the waste heat boiler body 1 removes oxygen, during the startup stage of the unit, auxiliary steam is set to heat the deaerator 5. The purpose is to heat the feed water of the condensate water to the deaerator 5, preheat the feed water to the saturated state before the unit starts, reduce the dissolved oxygen content in the feed water, make the oxygen content of the feed water reach the qualified range, enable the deaerator 5 to be put into operation in advance, thereby shortening the time without deaeration steam during startup and shortening the time of corrosion of the waste heat boiler body 1 due to excessive oxygen content in the condensate water during startup. It is quite practical. A regulating valve 10 is arranged on the waste heat boiler preheating steam pipeline 3, and the flow rate of the heating steam can be adjusted as needed.
[0022] The above embodiment discloses a waste heat boiler auxiliary steam preheating device. Before the cold start of the unit, the deaerator 5 is supplied with heating steam to heat the boiler feed water and accelerate the compliance of the oxygen content in the feed water. During the cold start, the heating steam of the high-pressure evaporator downcomer 7 is put into use in a timely manner, and the boiler water in the high-pressure evaporator and the steam drum is heated to higher than 100 °C through the auxiliary steam spray pipe 9, which can effectively reduce the upper and lower wall temperatures of the high-pressure steam drum 2 during startup, reduce the thermal stress during startup, extend the service life of the waste heat boiler body 1, and accelerate the cold start speed of the unit. During the normal operation of the unit, after the deaerator 5 on the waste heat boiler body 1 removes oxygen, during the startup stage of the unit, auxiliary steam is set to heat the deaerator 5. The purpose is to heat the feed water of the condensate water to the deaerator 5, preheat the feed water to the saturated state before the unit starts, reduce the dissolved oxygen content in the feed water, make the oxygen content of the feed water reach the qualified range, enable the deaerator 5 to be put into operation in advance, thereby shortening the time without deaeration steam during startup and shortening the time of corrosion of the waste heat boiler body 1 due to excessive oxygen content in the condensate water during startup.
[0023] The above are only the preferred specific embodiments of the present utility model, but the protection scope of the present utility model is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present utility model, according to the technical solution and the inventive concept of the present utility model, making equivalent substitutions or changes should be covered within the protection scope of the present utility model.
Claims
1. A waste heat boiler auxiliary steam preheating device, characterized in that: include: A waste heat boiler body (1) and a high-pressure steam drum (2), wherein the high-pressure steam drum (2) is arranged on the waste heat boiler body (1); The waste heat boiler preheating steam pipeline (3) is provided with two paths; A preheating component is used to preheat the high-pressure steam drum (2) and is located on the waste heat boiler body (1).
2. The waste heat boiler auxiliary steam preheating device according to claim 1, characterized in that: The preheating assembly comprises a low-pressure drum auxiliary steam pipe interface (6), wherein the low-pressure drum auxiliary steam pipe interface (6) is connected to one path of a waste heat boiler preheating steam pipeline (3), the other path of the waste heat boiler preheating steam pipeline (3) is connected to a high-pressure evaporator downcomer (7), the other end of the high-pressure evaporator downcomer (7) is connected to a steam heater (8), and an auxiliary steam nozzle (9) is provided in the high-pressure evaporator downcomer (7).
3. The waste heat boiler auxiliary steam preheating device according to claim 1, characterized in that: The waste heat boiler preheating steam pipeline (3) is provided with a regulating valve (10).
4. The waste heat boiler auxiliary steam preheating device according to claim 1, characterized in that: One end of each of the two routes of the waste heat boiler preheating steam pipeline (3) is connected to the auxiliary steam main pipeline (4).
5. The waste heat boiler auxiliary steam preheating device according to claim 1, characterized in that: The waste heat boiler body (1) is also provided with a deaerator (5).
6. The waste heat boiler auxiliary steam preheating device according to claim 2, characterized in that: The other end of the auxiliary steam spray pipe (9) is connected to the steam heater (8).