Device for improving variable load rate of generator set
By setting a gap between the inner cylinder and the thick-walled boiler element and using pressure balance holes to achieve pressure balance between the inner and outer sides, the problems of temperature difference and transient stress between the inner and outer walls of the thick-walled boiler element are solved, and the load change rate of the thermal power unit is improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-16
- Publication Date
- 2026-04-14
AI Technical Summary
Existing technologies are insufficient to effectively reduce the temperature difference between the inner and outer walls of thick-walled boiler components during rapid load changes and the resulting transient stress, thus limiting the load change rate of thermal power units.
An inner cylinder is installed inside the thick-walled boiler element to form a gap space between the inner cylinder and the thick-walled boiler element. Pressure balance between the inner and outer sides is achieved through pressure balance holes, which reduces steam flow and heat transfer capacity and lowers the temperature difference between the inner and outer walls.
It effectively reduces the temperature difference between the inner and outer walls of thick-walled boiler components, reduces transient stress, and improves the load change rate of thermal power units.
Smart Images
Figure CN224120301U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of generator set technology, and more specifically, to a device for improving the variable load rate of a generator set. Background Technology
[0002] New energy sources, primarily wind and solar power, have the disadvantages of randomness and intermittency. Therefore, the rapid growth and large-scale integration of renewable energy installations place higher demands on the flexible operation of thermal power units. Thermal power units need to meet the requirements of a wider range of load changes and a higher rate of load change.
[0003] Due to the randomness and intermittency of new energy sources, primarily wind and solar power, the rapid increase in installed capacity of these unstable power sources, particularly wind and solar power, places higher demands on the peak-shaving rate and operational flexibility of thermal power plants. Currently, the load increase rate of domestic thermal power units is generally only 1-2%, but newly built demonstration units need to reach over 4%. During rapid load changes in boilers, the heat storage effect of thick-walled boiler components and their heat exchange with the working fluid cause temperature differences between the inner and outer walls of these components, resulting in transient thermal stress. This leads to a surge in stress levels in the thick-walled boiler components, severely impacting their safety and lifespan. Therefore, to adapt to the requirements of the new power system for rapid load changes in coal-fired power and to better leverage the role of thermal power as a "ballast" and "pillar" of energy security, it is necessary to take economical and effective measures to reduce the transient stress in thick-walled boiler components during rapid load changes.
[0004] Currently, there are two main methods for stress control of thick-walled boiler components: 1) using compensation devices to offset the effects of thermal stress, and 2) increasing the metal wall temperature and reducing the temperature difference between the inner and outer walls by heating with electricity or working fluid. For thick-walled boiler components, the former is often difficult to use; while the latter has limited effectiveness for boilers with high load change rates, and the heating scheme is not suitable for rapid load reduction (when the wall temperature of the thick-walled boiler components is higher than the working fluid temperature). Utility Model Content
[0005] The technical problem to be solved by this utility model is to provide a device for improving the load change rate of a generator set. This utility model can effectively reduce the temperature difference between the inner and outer walls of thick-walled boiler components and the transient stress caused by it, thereby no longer restricting the boiler load increase rate.
[0006] The solution adopted by this utility model to solve the technical problem is:
[0007] A device for improving the variable load rate of a generator set, used in conjunction with a thick-walled boiler element, includes an inner cylinder fitted inside the thick-walled boiler element and forming a gap space between the inner cylinder and the thick-walled boiler element, and a pressure balance hole for connecting the gap space and the interior of the inner cylinder.
[0008] Steam enters the inner cylinder through the steam inlet. Due to the pressure balance hole, the pressure on the inner and outer sides of the inner cylinder is balanced. The steam entering the gap space has poor fluidity and poor heat transfer capacity, which leads to an increase in the heat exchange resistance between the steam and the thick-walled components of the boiler and a decrease in the heat exchange capacity. As a result, even when the steam temperature changes significantly, the thick-walled components of the boiler can maintain a very small temperature difference between the inner and outer walls.
[0009] In some possible implementations, in order to effectively prevent steam condensation and water accumulation in the gap space, a drainage hole communicating with the drain outlet of the boiler thick-walled element and the gap space is also included.
[0010] In some possible implementations, in order to effectively fix the inner cylinder to the boiler thick-walled component, both ends of the inner cylinder are respectively connected to the inner sidewall of the boiler thick-walled component; the inner cylinder and the boiler thick-walled component are coaxially arranged.
[0011] In some possible implementations, the drainage holes and pressure balance holes are both located at the connection point between the inner cylinder and the boiler thick-walled element near the drain port of the boiler thick-walled element. This arrangement can reduce the flow of steam in the gap space.
[0012] In some possible implementations, in order to effectively form a gap space, the cylinder in the thick-walled boiler element can be effectively protected; the thick-walled boiler element includes a cylinder and an auxiliary pipe joint disposed on the cylinder and communicating with the inside of the cylinder; the inner cylinder includes a main body fitted inside the cylinder.
[0013] In some possible implementations, in order to effectively protect the auxiliary pipe joints on the thick-walled components of the boiler, the inner cylinder also includes a secondary pipe connected to the main body and fitted inside the auxiliary pipe joint; an inlet communicating with the secondary pipe is provided on the inner cylinder.
[0014] In some possible implementations, the secondary pipe and the auxiliary pipe joint are coaxially arranged, and a small gap cavity communicating with the gap space is formed between them; the end of the small gap cavity away from the main body is a closed structure (unless a drainage hole is provided).
[0015] In some possible implementations, the boiler thick-walled element is any one of a steam-water separator, a boiler header, or a pipe.
[0016] During use, after steam enters the thick-walled components of the boiler, a small portion of the steam enters the gap space through the drainage holes to form a protective layer.
[0017] Most of the steam enters the inner cylinder and is discharged from the steam outlet; the flow rate of a small portion of the steam located in the gap space is originally less than that of the steam in the inner cylinder, resulting in poor heat transfer capacity. This increases the thermal resistance between the steam and the thick-walled components of the boiler, and reduces the heat transfer capacity. As a result, the thick-walled components of the boiler can maintain a very small temperature difference between the inner and outer walls when the steam temperature changes significantly.
[0018] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0019] Compared with the prior art, this utility model adopts a main body set in the thick-walled element of the boiler, and allows steam to enter the gap space formed by the main body and the side of the thick-walled element of the boiler to form a protective layer. Due to the poor steam flow and heat transfer capacity in the gap space, the heat exchange resistance between the steam and the steam-water separator cylinder is very large and the heat exchange is very small. As a result, when the steam temperature changes drastically, the separator cylinder can maintain a small temperature difference between the inner and outer walls, thereby reducing the transient stress caused by the temperature difference between the inner and outer walls, and thus no longer restricting the boiler load increase rate.
[0020] This invention provides protection for the auxiliary pipe joint by setting a secondary pipe inside the auxiliary pipe joint and forming a small gap cavity between the secondary pipe and the auxiliary pipe joint. The small gap cavity is connected to the gap space, and steam will enter the small gap cavity to form a protective layer. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the structure of this utility model connected to the steam-water separator;
[0022] Figure 2 This is a schematic diagram of a structure for connecting the secondary pipe and the auxiliary pipe joint in this utility model;
[0023] Figure 3 This is a schematic diagram of another structure for the connection between the secondary pipe and the auxiliary pipe joint in this utility model;
[0024] Figure 4 A comparison of radial steam temperature and wall temperature distribution curves between the steam-water separator of this invention and the steam-water separator in the prior art when the steam temperature changes significantly.
[0025] Among them: 1. Boiler thick-walled components; 11. Shell; 12. Auxiliary pipe joints; 101. Steam outlet; 102. Drain outlet; 2. Inner cylinder; 21. Main body; 22. Secondary pipe; 3. Drain hole; 10. Gap space; 20. Small gap cavity. Detailed Implementation
[0026] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. The terms "first," "second," and similar terms used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, "a" or "one," etc., do not indicate a quantity limitation, but rather indicate the existence of at least one. In the implementation of this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more. For example, multiple positioning posts refer to two or more positioning posts. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0027] The present invention will now be described in detail.
[0028] It should be noted that the thick-walled components of the boiler are equipment products such as steam-water separators, headers, and pipelines;
[0029] like Figures 1-3 As shown:
[0030] A device for improving the variable load rate of a generator set, used in conjunction with a boiler thick-walled element 1, wherein the boiler thick-walled element 1 is provided with a steam inlet, a steam outlet 101 and a drain outlet 102;
[0031] Includes an inner cylinder 2 that is fitted inside the boiler thick-walled element 1 and forms a gap space 10 with the boiler thick-walled element 1, and a pressure balance hole for connecting the gap space 10 and the interior of the inner cylinder 2;
[0032] The inner cylinder 2 is provided with a steam inlet for use with the steam inlet, a steam outlet for use with the steam outlet 101, and a water outlet connected to the drain outlet 102 at corresponding positions;
[0033] Steam enters the inner cylinder 2 through the steam inlet and steam outlet. Due to the pressure balance hole, the pressure on the inner and outer sides of the inner cylinder 2 is balanced. Since the inner cylinder 2 is connected to the boiler thick-walled element 1, the steam entering the gap space 10 has poor flow and heat transfer capacity, which leads to an increase in the heat exchange resistance between the steam and the boiler thick-walled element 1 and a decrease in the heat exchange capacity. As a result, even when the steam temperature changes significantly, the boiler thick-walled element 1 can maintain a very small temperature difference between the inner and outer walls. The inner cylinder 2 and the boiler thick-walled element 1 only need to be able to accommodate the expansion difference between the two.
[0034] In some possible implementations, in order to effectively prevent steam condensation and water accumulation in the gap space 10, a drain hole is also included that communicates with the drain outlet 102 of the boiler thick-walled element 1 and the gap space 10; the steam condensation and water accumulation in the gap space 10 will be discharged from the drain outlet 102 through the drain hole.
[0035] In some possible implementations, in order to effectively fix the inner cylinder 2 and the boiler thick-walled element 1, both ends of the inner cylinder 2 are respectively connected to the inner sidewall of the boiler thick-walled element 1; the inner cylinder 2 and the boiler thick-walled element 1 are coaxially arranged; the air outlet of the inner cylinder 2 is located at one end of the inner cylinder 2 near the steam outlet 101, and the water outlet of the inner cylinder 2 is located at one end of the inner cylinder 2 near the drain outlet 102.
[0036] Furthermore, the two ends of the inner cylinder 2 can be connected by welding or snap-fit structure.
[0037] In some possible implementations, the drainage hole and the pressure balance hole are both located at the connection between the inner cylinder 2 and the boiler thick-walled element 1 near the drain port 102 of the boiler thick-walled element 1.
[0038] When the drainage hole and the pressure balance hole are connected, they can be combined into one, and there is no need to distinguish between the pressure balance hole and the drainage hole.
[0039] This configuration significantly reduces the flow of steam in the gap space 10. During steam treatment, since the drain hole and pressure balance hole are located on the side away from the steam outlet 101, most of the treated steam will be discharged directly from the upper steam outlet 101, while only a small portion will enter the gap space 10 from the lower drain hole and pressure balance hole. The steam flow in the gap space 10 will be much lower than the flow of steam flowing to the steam outlet 101. Due to the poor steam flow and heat transfer capacity in the gap space 10, the heat exchange resistance between the steam and the steam-water separator cylinder 11 increases, and the heat exchange capacity decreases. Consequently, even when the steam temperature changes drastically, the steam-water separator cylinder 11 can maintain a very small temperature difference between the inner and outer walls.
[0040] In some possible implementations, in order to effectively form the gap space 10, the cylinder 11 in the boiler thick-walled element 1 can be effectively protected; the boiler thick-walled element 1 includes a cylinder 11 and an auxiliary pipe joint 12 disposed on the cylinder 11 and communicating with the inside of the cylinder 11; the inner cylinder 2 includes a main body 21 fitted inside the cylinder 11.
[0041] In some possible implementations, in order to effectively protect the auxiliary pipe joint 12 on the thick-walled component 1 of the boiler, the inner cylinder 2 also includes a secondary pipe 22 connected to the main body 21 and fitted inside the auxiliary pipe joint 12; an inlet communicating with the secondary pipe 22 is provided on the inner cylinder 2.
[0042] In some possible implementations, the secondary pipe 22 and the auxiliary pipe joint 12 are coaxially arranged, and a small gap cavity 20 communicating with the gap space 10 is formed between them; the end of the small gap cavity 20 away from the main body 21 is a closed structure (except for the presence of a water-draining hole 3), and the closed structure prevents steam from flowing out of the small gap cavity 20.
[0043] In some possible implementations, the boiler thick-walled element 1 is any one of a steam-water separator, a boiler header, or a pipe.
[0044] Working principle:
[0045] After steam enters the thick-walled element 1 of the boiler, a small portion of the steam enters the gap space 10 through the drainage hole to form a protective layer.
[0046] Most of the steam enters the inner cylinder 2 and is discharged from the steam outlet 101. The flow rate of a small portion of the steam located in the gap space 10 is much lower than that of the steam in the inner cylinder 2 and has poor heat transfer capacity. This increases the heat exchange resistance between the steam and the boiler thick-walled element 1 and reduces the heat exchange capacity. As a result, the boiler thick-walled element 1 can maintain a very small temperature difference between the inner and outer walls when the steam temperature changes significantly.
[0047] Example 1:
[0048] like Figure 1 As shown, this embodiment takes a steam-water separator as an example. The steam-water separator includes a cylinder 11 with a steam outlet 101 at the top and a drain outlet 102 at the bottom, and an auxiliary pipe joint 12 on the side of the cylinder 11. Steam enters the cylinder 11 through the auxiliary structure, is treated, and is discharged from the steam outlet 101. The treated water will be discharged from the drain outlet 102.
[0049] The inner cylinder 2 is installed inside the cylinder 11 of the steam-water separator. The inner tube is coaxially arranged with the cylinder 11 and forms a gap space 10 between the inner tube and the side of the cylinder 11. The width of the gap space 10 is 4mm and the thickness of the inner cylinder 2 is 6mm. A drainage hole or pressure balance hole is provided on the inner cylinder 2 to connect the inner cylinder 2 with the gap space 10, so that the pressure on the inner and outer sides of the inner cylinder 2 is balanced.
[0050] Therefore, the pressure balance hole is set at the lower end of the steam-water separator and combined with the drain hole, so that the gap space 10 is connected with the drain outlet 102 at the bottom of the steam-water separator. This can effectively drain water from the gap space 10 and prevent steam condensation from causing water accumulation.
[0051] The connection between the inner cylinder 2 and the cylinder 11 prevents steam from flowing rapidly after entering the gap space 10 through the pressure balance hole. The steam outside the inner cylinder 2 and located in the gap space 10 has poor flowability and heat transfer capacity, which increases the heat exchange resistance between this part of the steam and the cylinder 11 and reduces the heat exchange capacity. As a result, when the steam temperature changes significantly, the cylinder 11 can maintain a small temperature difference between the inner and outer walls of the cylinder 11, effectively protecting the cylinder 11 and thus effectively improving the service life of the steam-water separator cylinder 11.
[0052] Example 2:
[0053] like Figure 1 , Figure 3 As shown, this embodiment is a further optimization based on embodiment 1. The inner cylinder 2 includes a main body 21 fitted inside the steam-water separator cylinder 11, and a secondary pipe 22 connected to the main body 21 and fitted inside the auxiliary structure. Specifically, one end of the secondary pipe 22 is connected to the main body 21 and communicates through a through hole. The secondary pipe 22 is fitted inside the auxiliary pipe joint 12 and forms a small gap cavity 20 between the secondary pipe 22 and the auxiliary pipe joint 12. The end of the small gap cavity 20 away from the main body 21 will be a closed structure (except for the drainage hole 3). The small gap cavity 20 is connected to the gap space 10, and steam can enter the small gap cavity 20. Because the steam has poor fluidity and poor heat transfer capacity, the auxiliary pipe joint 12 can also maintain a very small temperature difference between the inner and outer walls, effectively protecting the auxiliary pipe joint 12.
[0054] The radial steam temperature and wall temperature distribution curves obtained by the technical solution developed in Example 2 and the existing steam-water separator when the steam temperature changes significantly are as follows: Figure 4 As shown, temperature distribution curve 2 is derived from this invention, while temperature distribution curve 1 is derived from an existing steam-water separator; from Figure 3 It can be concluded that using this utility model will effectively reduce the temperature difference between the inner and outer walls of the steam-water separator.
[0055] This invention is not limited to the specific embodiments described above. This invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.
Claims
1. A device for improving the load change rate of a generator set, used in conjunction with thick-walled boiler components, characterized in that, It includes an inner cylinder that is fitted inside the thick-walled components of the boiler and forms a gap space between them, and a pressure balance hole for connecting the gap space with the interior of the inner cylinder.
2. The device for improving the load change rate of a generator set according to claim 1, characterized in that, It also includes drainage holes that communicate with the drain outlets and gap spaces of the boiler's thick-walled components.
3. The device for improving the load change rate of a generator set according to claim 1, characterized in that, The two ends of the inner cylinder are respectively connected to the inner sidewall of the boiler thick-walled element; the inner cylinder and the boiler thick-walled element are coaxially arranged.
4. The device for improving the load change rate of a generator set according to claim 2, characterized in that, Both the drainage hole and the pressure balance hole are located at the connection point between the inner cylinder and the boiler thick-walled element, near the drain port of the boiler thick-walled element.
5. The device for improving the load change rate of a generator set according to claim 1, characterized in that, The boiler thick-walled component includes a cylinder and an auxiliary pipe joint disposed on the cylinder and communicating with the interior of the cylinder. The inner cylinder includes a main body fitted inside the cylinder body.
6. The device for improving the load change rate of a generator set according to claim 5, characterized in that, The inner cylinder also includes a secondary pipe connected to the main body and fitted inside the auxiliary pipe joint; an inlet communicating with the secondary pipe is provided on the inner cylinder.
7. The device for improving the load change rate of a generator set according to claim 6, characterized in that, The secondary pipe and the auxiliary pipe joint are coaxially arranged, and a small gap cavity communicating with the gap space is formed between them; the end of the small gap cavity away from the main body is a closed structure.
8. The device for improving the load change rate of a generator set according to any one of claims 1-7, characterized in that, The thick-walled boiler component can be any one of a steam-water separator, a boiler header, or a pipeline.