Low-pressure cylinder cooling steam bypass adjusting device
By designing a low-pressure cylinder cooling steam bypass regulating device and utilizing steam flow rate detection and cooling liquid flow rate control, the temperature difference problem caused by the direct introduction of intermediate exhaust steam into the low-pressure cylinder was solved, thus achieving stable operation of the steam turbine and extending rotor life.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- DATANG GONGYI POWER GENERATION CO LTD
- Filing Date
- 2025-06-20
- Publication Date
- 2026-05-01
AI Technical Summary
Directly introducing intermediate-discharge steam into the low-pressure cylinder results in a large temperature difference, leading to turbine vibration and reduced rotor life.
A low-pressure cylinder cooling steam bypass regulating device was designed. The cooling liquid flow rate is adjusted by detecting the steam flow rate, and the parallel and series switching of the cooling pipes is controlled by solenoid valves and flow sensors to achieve rapid cooling.
It effectively reduces the temperature difference between steam and the low-pressure cylinder, avoids turbine vibration, extends rotor life, and improves the efficiency of steam temperature regulation.
Smart Images
Figure CN224187631U_ABST
Abstract
Description
A low-pressure cylinder cooling steam bypass regulating device Technical Field
[0001] This utility model relates to the field of energy conservation and emission reduction technology for steam turbines, specifically a low-pressure cylinder cooling steam bypass regulating device. Background Technology
[0002] A thermal power plant, or coal-fired power plant for short, is a factory that uses combustible materials as fuel to produce electricity. Its basic production process is as follows: when fuel is burned, it heats water to generate steam, converting the chemical energy of the fuel into heat energy. The steam pressure drives the turbine to rotate, converting the heat energy into mechanical energy. Then, the turbine drives the generator to rotate, converting the mechanical energy into electrical energy. The prime mover is usually a steam engine or a gas turbine. In some smaller power plants, an internal combustion engine may also be used. They all generate electricity by utilizing the pressure drop in the process of high-temperature, high-pressure steam or gas being converted into low-pressure air or condensate through a turbine. By performing a zero-output modification of the low-pressure cylinder, the original steam inlet pipe of the low-pressure cylinder is cut off under high-vacuum operation conditions. A small amount of cooling steam is introduced through a new bypass pipe, achieving near-zero output operation of the low-pressure cylinder. This significantly reduces the consumption of cooling steam in the low-pressure cylinder, reduces the unit's cold source loss, and greatly improves the unit's low-load heating capacity, peak-shaving capacity, and heating economy.
[0003] The source of cooling steam is usually the exhaust from the intermediate-pressure cylinder. The exhaust temperature of the intermediate-pressure cylinder is relatively high, generally around 375 degrees Celsius, while the temperature inside the low-pressure cylinder is lower. Directly introducing the intermediate-pressure exhaust steam into the low-pressure cylinder results in a large temperature difference between the two, which can cause turbine vibration and reduce rotor life. Therefore, a device that can adjust the temperature of the cooling steam needs to be added to the bypass. Summary of the Invention
[0004] To address the shortcomings of existing technologies, this utility model provides a low-pressure cylinder cooling steam bypass regulating device, which solves the problem of turbine vibration and reduced rotor life caused by the large temperature difference between the intermediate discharge steam and the low-pressure cylinder when the intermediate discharge steam is directly introduced into the low-pressure cylinder.
[0005] Technical solution
[0006] To achieve the above objectives, this utility model is implemented through the following technical solution: a low-pressure cylinder cooling steam bypass regulating device, including a steam flow pipe, an electromagnetic regulating valve for controlling steam flow rate connected and passing through the outlet end of the steam flow pipe, a flow sensor connected and passing through the outlet end of the steam flow pipe, a cooling pipe for convective flow with the steam flow pipe on the outer surface of the steam flow pipe, and a pressurizing pump provided at the liquid inlet end of the cooling pipe, wherein the pumping speed of the pressurizing pump is proportional to the value of the flow sensor.
[0007] Furthermore, temperature sensors are installed at the inlet and middle of the steam flow pipe, and the difference between the two temperature sensors is used to control the pumping speed of the booster pump.
[0008] Furthermore, the cooling pipes are divided into multiple groups, which are evenly distributed on the outer surface of the steam flow pipes. Each group of cooling pipes has an inlet and an outlet. All the inlets of the cooling pipes are connected and connected through a connecting inlet pipe, and all the outlets of the cooling pipes are connected and connected through a connecting outlet pipe. The connecting inlet pipe is connected and connected to the pressurization pump. Each group of inlets and outlets is equipped with an electromagnetic closing valve to control the connection of the group of cooling pipes.
[0009] Furthermore, an electromagnetic three-way directional valve is connected and passes through the inlet, the connecting inlet, and the previous outlet. The electromagnetic three-way directional valve is also located between the outlet, the connecting outlet, and the next inlet.
[0010] Furthermore, an isolation box is provided on the outside of the steam flow pipe and the cooling pipe, and the electromagnetic regulating valve, the flow sensor and the pressurizing pump are all located on the outside of the isolation box.
[0011] Furthermore, the steam flow pipe has vertical bends, and the cooling pipe is spirally distributed on the outer surface of the steam flow pipe.
[0012] The beneficial effects of this utility model are as follows:
[0013] 1. The low-pressure cylinder cooling steam bypass regulating device is set to detect the steam flow rate and adjust the cooling liquid flow rate according to the steam flow rate. When the steam flow rate increases, the cooling liquid flow rate is increased, thereby enabling the steam to cool down quickly and avoiding the problem of insufficient cooling when the steam flow rate increases, which leads to a large temperature difference with the low-temperature cylinder.
[0014] 2. The low-pressure cylinder cooling steam bypass regulating device uses a steam flow pipeline to slowly cool the steam through a series of cooling pipelines during normal use to meet the supply demand. When additional steam is needed, the steam flow rate increases, and the original cooling pipelines cannot effectively process the steam to a suitable temperature. Therefore, by increasing the flow rate of the coolant in the cooling pipelines, the heat exchange efficiency with the steam is accelerated, thereby enabling the steam to be cooled to a suitable temperature. Attached Figure Description
[0015] Figure 1 is a schematic diagram of the structure of this utility model;
[0016] Figure 2 is a schematic diagram of the cooling pipe of this utility model;
[0017] Figure 3 is a schematic diagram of the parallel connection of the cooling pipes of this utility model;
[0018] Figure 4 is a schematic diagram of the series connection of this utility model.
[0019] The components include: 1. Steam flow pipe; 2. Electromagnetic regulating valve; 3. Flow sensor; 4. Cooling pipe; 5. Pressurization pump; 6. Temperature sensor; 7. Inlet pipe; 8. Outlet pipe; 9. Connecting inlet pipe; 10. Connecting outlet pipe; 11. Electromagnetic closing valve; 12. Electromagnetic three-way reversing valve; and 13. Isolation box. Detailed Implementation
[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. 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] Referring to Figures 1-4, a low-pressure cylinder cooling steam bypass regulating device includes a steam flow pipe 1, an electromagnetic regulating valve 2 for controlling steam flow rate connected and passing through the outlet end of the steam flow pipe 1, a flow sensor 3 connected and passing through the outlet end of the steam flow pipe 1, a cooling pipe 4 for counterflow with the steam flow pipe 1 on the outer surface of the steam flow pipe 1, a pressurizing pump 5 at the inlet end of the cooling pipe 4, the pumping speed of the pressurizing pump 5 being proportional to the value of the flow sensor 3, by detecting the steam flow rate and adjusting the cooling liquid flow rate accordingly, the cooling liquid flow rate can be increased when the steam flow rate increases, thereby enabling the steam to cool down quickly and avoiding the problem of insufficient cooling and large temperature difference caused by the increased steam flow rate.
[0022] Temperature sensors 6 are installed at the inlet and middle of the steam flow pipe 1. The difference between the two temperature sensors 6 is used to control the pumping speed of the pressurization pump 5. The inlet temperature is detected by the temperature sensor 6, and the temperature after cooling in the middle is detected by the temperature sensor 6 in the middle. The difference between the two is compared. When the difference is small, it means that the cooling is slow and the flow rate of the cooling liquid needs to be increased. When the difference is large, the flow rate of the cooling liquid can be reduced.
[0023] The cooling pipes 4 are divided into multiple groups, which are evenly distributed on the outer surface of the steam flow pipe 1. Each group of cooling pipes 4 has an inlet 7 and an outlet 8. All the inlets 7 of the cooling pipes 4 are connected and connected through the connecting inlet pipe 9, and all the outlets 8 of the cooling pipes 4 are connected and connected through the connecting outlet pipe 10. The connecting inlet pipe 9 is connected and connected to the pressurizing pump 5. Each group of inlets 7 and outlets 8 is equipped with an electromagnetic closing valve 11 to control the connection of the group of cooling pipes 4. Through this arrangement, the cooling pipes 4 can be connected in parallel to circulate the coolant at different locations, so as to quickly cool down the steam flow pipe 1.
[0024] An electromagnetic three-way reversing valve 12 is connected and runs through the inlet 7, the connecting inlet 9, and the previous outlet 8. The electromagnetic three-way reversing valve 12 is also set between the outlet 8, the connecting outlet 10, and the next inlet 7. This setting enables the switching between series cooling and parallel cooling of the cooling pipe 4, and different combinations can be switched according to the cooling requirements of the steam flow pipe 1.
[0025] An isolation box 13 is installed on the outside of the steam flow pipe 1 and the cooling pipe 4. The electromagnetic regulating valve 2, the flow sensor 3, and the pressurizing pump 5 are all located on the outside of the isolation box 13. The temperature of the steam flow pipe 1 is high. By setting up the isolation box 13, heat radiation can be isolated to avoid workers being burned by high temperature. Setting the detection device and the regulating device on the outside of the isolation box 13 makes it easy to make adjustments.
[0026] The steam flow pipe 1 has bends at the top and bottom, and the cooling pipe 4 is spirally distributed on the outer surface of the steam flow pipe 1. This arrangement allows the cooling pipe 4 and the steam flow pipe 1 to make full contact, increasing the heat exchange area.
[0027] In use, the steam in the steam flow pipe 1 is normally cooled down slowly through the cooling pipe 4 in series to meet the supply demand. When the steam demand increases, the steam flow rate increases, and the original cooling pipe 4 cannot effectively process the steam to a suitable temperature. Therefore, by increasing the flow rate of the coolant in the cooling pipe 4, the heat exchange efficiency with the steam is accelerated, thereby enabling the steam to be cooled to a suitable temperature.
[0028] Meanwhile, the cooling pipe 4 can be changed from a series mode to a parallel mode by switching the electromagnetic three-way reversing valve 12. In the parallel mode, the contact distance between the cooling water and the steam is reduced, and the temperature difference between them increases, thereby enabling the steam to be cooled down more quickly.
[0029] It should be noted that in this paper, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.
[0030] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.
Claims
1. A low-pressure cylinder cooling steam bypass regulating device, comprising a steam flow pipe (1), characterized in that: The outlet end of the steam flow pipe (1) is connected to and penetrates an electromagnetic regulating valve (2) for controlling the steam flow rate. The outlet end of the steam flow pipe (1) is connected to and penetrates a flow sensor (3). A cooling pipe (4) is provided on the outer surface of the steam flow pipe (1) to flow against the steam flow pipe (1). A pressure pump (5) is provided at the inlet end of the cooling pipe (4). The pumping speed of the pressure pump (5) is proportional to the value of the flow sensor (3).
2. The low-pressure cylinder cooling steam bypass regulating device according to claim 1, characterized in that: Temperature sensors (6) are installed at the inlet and middle of the steam flow pipe (1). The difference between the two temperature sensors (6) is used to control the pumping speed of the pressurization pump (5).
3. The low-pressure cylinder cooling steam bypass regulating device according to claim 1, characterized in that: The cooling pipes (4) are divided into multiple groups, and the multiple groups of cooling pipes (4) are evenly distributed on the outer surface of the steam flow pipe (1). Each group of cooling pipes (4) is divided into an inlet (7) and an outlet (8). The inlets (7) of all cooling pipes (4) are connected and connected through a connecting inlet pipe (9). The outlets (8) of all cooling pipes (4) are connected and connected through a connecting outlet pipe (10). The connecting inlet pipe (9) is connected and connected to the pressurizing pump (5). Each group of inlets (7) and outlets (8) is equipped with an electromagnetic closing valve (11) to control the connection of the group of cooling pipes (4).
4. The low-pressure cylinder cooling steam bypass regulating device according to claim 3, characterized in that: An electromagnetic three-way reversing valve (12) is connected and passes through the inlet (7), the connecting inlet (9), and the previous outlet (8). The electromagnetic three-way reversing valve (12) is simultaneously located between the outlet (8), the connecting outlet (10), and the next inlet (7).
5. A low-pressure cylinder cooling steam bypass regulating device according to any one of claims 1-4, characterized in that: An isolation box (13) is provided on the outside of the steam flow pipe (1) and the cooling pipe (4). The electromagnetic regulating valve (2), the flow sensor (3), and the pressurizing pump (5) are all located on the outside of the isolation box (13).
6. The low-pressure cylinder cooling steam bypass regulating device according to claim 5, characterized in that: The steam flow pipe (1) is distributed with bends at the top and bottom, and the cooling pipe (4) is distributed spirally on the outer surface of the steam flow pipe (1).