Grid-connected control device suitable for high-rotating-speed ORC and SRC power generation
By setting up primary and secondary control pipelines and sensor controller systems in the turbine units, smooth grid connection of high-speed ORC and SRC generator sets is achieved, solving the synchronization and accuracy issues of large turbine speed control, and improving system stability and component life.
Patent Information
- Application Number
- CN202423160789.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-20
- Publication Date
- 2025-09-26
- Estimated Expiration
- 2034-12-20
AI Technical Summary
The existing large turbine speed control has the problem that coarse and fine adjustments are difficult to perform synchronously, the control time difference leads to system instability, and the adjustment accuracy is low, making it difficult to achieve accurate matching with the grid frequency.
Two parallel regulating pipelines, the main control pipeline and the secondary control pipeline, are used to adjust the second regulating valve and the first regulating valve in real time through sensors and controllers respectively, so as to achieve fine control of the heat source flow and eliminate regulation hysteresis.
It achieves smooth grid connection of high-speed ORC and SRC generator sets, improves regulation accuracy, reduces system complexity, extends component life, and avoids energy waste.
Smart Images
Figure CN223387385U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of ORC unit power generation control, in particular to a power generation grid-connected control device suitable for high-speed ORC and SRC. Background Art
[0002] SRC (Steam Rankine Cycle) is the abbreviation for the Steam Rankine Cycle. When utilizing waste heat in an SRC generator set, high-temperature, high-pressure steam generated in an upstream process is converted into mechanical energy through expansion in a turbine, which then drives the generator to generate electricity. ORC (Organic Rankine Cycle) is the abbreviation for the Organic Rankine Cycle. This Rankine cycle uses low-boiling-point organic matter as the working fluid. It consists of four main components: an evaporator, a turbine, a condenser, and a working fluid pump. Its operating principle is as follows: In the evaporator, the organic working fluid absorbs heat from waste heat, generating steam at a certain pressure and temperature. This steam enters the turbine, expands, and performs work, thereby driving the generator to generate electricity. Steam discharged from the turbine releases heat to the cooling water in the condenser, condensing into a liquid state. Finally, it is returned to the evaporator by the working fluid pump, repeating the cycle. As a key component in the unit's power generation and grid connection, the turbine generator is required to ensure smooth startup, speed regulation, grid connection, and power regulation during the unit's startup and operation. The electricity generated by the unit must be connected to the grid before it can be used and put into use. During this connection, the unit's output frequency must be consistent with the grid's 50Hz. The allowable grid-connected frequency deviation for synchronous generators in my country's power system is normally ±0.2Hz. When the system capacity is small, the frequency deviation can be as low as ±0.5Hz. The speed is determined by the heat source flow rate. Therefore, accurately controlling the heat source flow rate is crucial to ensure smooth and stable grid connection of the unit.
[0003] Currently, there are technical deficiencies in the speed control of large turbines in waste heat utilization (SRC) and ORC generator sets. For small turbines, due to the low heat source flow rate, flow fluctuations and turbine speed fluctuations are relatively small when adjusting the valve opening, making speed control easier. However, large turbines have a higher heat source flow rate, and changes in the valve opening cause large fluctuations in flow rate and speed, making precise control more difficult. Existing control methods typically employ a coarse-and-fine approach, employing two control valves: a large one for the main line and a smaller one for the bypass line. The smaller valve has a much smaller diameter, typically 1 / 5 to 1 / 3 the larger one. In this coarse-and-fine heat source control method, the "coarse" stage often struggles to precisely control heat output, resulting in low accuracy. Furthermore, because coarse and fine adjustments are performed in separate steps, there is a time lag. Switching between the two control modes during the coarse-and-fine adjustment process can cause system instability. Utility Model Content
[0004] The purpose of the utility model is to address the shortcomings of existing large turbines that are regulated through two parallel regulating pipelines, where coarse and fine adjustments are difficult to perform synchronously, there is a control time difference, and it is easy to cause system instability during switching. To address this shortcoming, a grid-connected control device suitable for high-speed ORC and SRC power generation is proposed.
[0005] In order to achieve the above objectives, the present invention adopts the following technical solutions:
[0006] A control device for high-speed ORC and SRC power generation grid connection includes a turbine and a generator, wherein a gearbox and a bearing housing are sequentially disposed between the generator and the turbine. A primary control line for load regulation is connected to the end of the turbine remote from the generator. A sensor is disposed in the primary control line. A secondary control line for precision adjustment is disposed on the primary control line. A second regulating valve is disposed on the secondary control line. The sensor, the second regulating valve, the generator, and the turbine are all connected to a controller.
[0007] Among them, the sensor collects the temperature, pressure and flow rate in the main control pipeline and sends the collected data to the controller. The controller obtains the speed of the turbine and generator in real time and adjusts the precision of the second control valve according to the speed.
[0008] As a further preferred embodiment of the present invention, a first regulating valve is provided on the main control pipeline.
[0009] As a further preferred embodiment of the present invention, both ends of the secondary control pipeline are respectively connected to the main control pipeline and are respectively arranged on both sides of the first regulating valve.
[0010] As a further preferred embodiment of the present invention, the diameter of the main control pipeline is larger than that of the secondary control pipeline; and the diameter of the second regulating valve is smaller than that of the first regulating valve.
[0011] The utility model proposes a grid-connected control device for high-speed ORC and SRC power generation, which has the following beneficial effects compared with the existing technology:
[0012] 1. The utility model sets a second regulating valve. When the flow rate is small, the second regulating valve can be controlled to finely control the flow rate change, avoid large fluctuations in the speed of the turbine and generator, and facilitate the stable grid connection of the generator;
[0013] 2. By setting up sensors and controllers, the flow of the main control pipeline can be automatically adjusted after the unit is running stably to ensure the stable operation of the generator and turbine;
[0014] 3. The utility model separates the grid-connected process from the load regulation process by setting a secondary control pipeline, which not only improves the regulation accuracy, but also effectively eliminates the hysteresis of the regulation, avoids energy waste, reduces the complexity of the system, improves stability, and extends the life of the unit components. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 It is a structural diagram of the present utility model.
[0016] The meanings of the reference numerals in the figure are: 1. turbine, 2. generator, 3. main control line, 4. first regulating valve, 5. secondary control line, 6. second regulating valve, 7. bearing box, 8. gear box, 9. sensor, 10. controller. DETAILED DESCRIPTION
[0017] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.
[0018] The utility model provides a heat source regulating device capable of more accurately controlling grid connection, and the device can accurately adjust the heat source flow rate and quickly and smoothly connect to the grid.
[0019] Example 1: Combination Figure 1 A control device for high-speed ORC and SRC power generation grid connection includes a turbine 1 and a generator 2. A gearbox 8 and a bearing box 7 are sequentially arranged between the generator 2 and the turbine 1. The end of the turbine away from the generator 2 is connected to a main control pipeline 3 for load regulation. A sensor 9 is arranged in the main control pipeline 3. A first regulating valve 4 is arranged on the main control pipeline 3. A secondary control pipeline 5 for precision adjustment is arranged on the main control pipeline 3. The two ends of the secondary control pipeline 5 are respectively connected to the main control pipeline 3 and are respectively arranged on both sides of the first regulating valve 4. The diameter of the main control pipeline 3 is larger than that of the secondary control pipeline 5; the diameter of the second regulating valve 6 is smaller than that of the first regulating valve 4. A second regulating valve 6 is arranged on the secondary control pipeline 5. The sensor 9, the second regulating valve 6, the generator 2 and the turbine 1 are all connected to a controller 10.
[0020] Among them, the sensor 9 collects the temperature, pressure and flow rate in the main control pipeline 3, and sends the collected data to the controller 10. The controller 10 obtains the rotation speed of the turbine 1 and the generator 2 in real time, and accurately adjusts the second regulating valve 6 according to the rotation speed.
[0021] The diameter of the secondary control pipeline 5 and the diameter of the second regulating valve 6 are both small, which can finely adjust the flow rate of the heat source.
[0022] Working principle: S1. During the startup of the unit, due to the small flow rate, the second regulating valve 6 is gradually opened to complete the motor's rushing work. By continuously increasing the opening, the unit's speed gradually approaches the grid-connected speed.
[0023] S2. When the frequency of the turbine 1 and the generator 2 is close to the grid frequency requirement, the second regulating valve 6 is no longer adjusted.
[0024] S3. When the load of the unit changes, the first regulating valve 4 is adjusted to change the heat source flow rate and control the load of the unit.
[0025] S4. When the unit is running stably, gradually close the second regulating valve 6 and control the stable operation of the unit by controlling the opening of the first regulating valve 4.
[0026] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the above embodiments do not limit the present invention in any form, and any technical solution obtained by equivalent replacement or equivalent transformation falls within the scope of protection of the present invention.
Claims
1. A control device for high-speed ORC and SRC power generation grid connection, comprising a turbine (1) and a generator (2), characterized in that: A gear box (8) and a bearing box (7) are sequentially arranged between the generator (2) and the turbine (1); a main control line (3) for load regulation is connected to the end of the turbine away from the generator (2); a sensor (9) is arranged in the main control line (3); a secondary control line (5) for precision regulation is arranged on the main control line (3); a second regulating valve (6) is arranged on the secondary control line (5); the sensor (9), the second regulating valve (6), the generator (2) and the turbine (1) are all connected to a controller (10); The sensor (9) collects the temperature, pressure and flow rate in the main control pipeline (3) and sends the collected data to the controller (10). The controller (10) obtains the rotation speed of the turbine (1) and the generator (2) in real time and adjusts the precision of the second regulating valve (6) according to the rotation speed.
2. The control device for high-speed ORC and SRC power generation grid connection according to claim 1, characterized in that: A first regulating valve (4) is provided on the main control pipeline (3).
3. The control device for high-speed ORC and SRC power generation grid connection according to claim 2, characterized in that: Both ends of the secondary control pipeline (5) are respectively connected to the main control pipeline (3) and are respectively arranged on both sides of the first regulating valve (4).
4. The control device for high-speed ORC and SRC power generation grid connection according to claim 3, characterized in that: The diameter of the main control pipeline (3) is larger than the diameter of the secondary control pipeline (5); and the diameter of the second regulating valve (6) is smaller than the diameter of the first regulating valve (4).