A speed regulating system based on low-pressure hydrophobic pump

Abstract

The application relates to the technical field of water pump speed regulation, and particularly provides a speed regulation system based on a low-pressure heater drainage pump, which comprises a driving motor, a permanent magnet speed regulation mechanism, a low-pressure heater drainage pump, a pushing mechanism and a controller; the driving motor, the permanent magnet speed regulation mechanism and the low-pressure heater drainage pump are sequentially arranged; the permanent magnet speed regulation mechanism comprises a permanent magnet rotor, a conductor rotor and a magnetic shielding sleeve, a first rotating shaft is fixedly connected with the permanent magnet rotor, the conductor rotor and the magnetic shielding sleeve are sequentially connected with a second rotating shaft in a direction towards the driving motor, the conductor rotor is fixedly connected with the second rotating shaft, the magnetic shielding sleeve is movably connected with the second rotating shaft, the permanent magnet rotor is wrapped around the conductor rotor, and the magnetic shielding sleeve is located between the permanent magnet rotor and the conductor rotor in a circumferential direction; the magnetic shielding sleeve is connected with the pushing mechanism; the driving motor, the low-pressure heater drainage pump and the pushing mechanism are respectively communicatively connected with the controller, and the speed of the low-pressure heater drainage pump can be accurately regulated and controlled.

Description

Technical Field

[0001] This application relates to the field of water pump speed regulation technology, and in particular to a speed regulation system based on a low-pressure condensate pump. Background Technology

[0002] As an important piece of equipment in the thermal system of a power plant, the low-pressure heater condensate pump mainly functions to transport the condensate from the low-pressure heater to the deaerator or the next stage heater under the drive of the motor, ensuring the efficient operation of the thermal cycle.

[0003] Currently, variable frequency speed control (VFD) systems are a common and efficient method for retrofitting low-pressure condensate pumps. This system dynamically adjusts the power supply frequency of the drive motor by monitoring the condensate demand under different load conditions in real time, thereby changing the drive motor speed and ensuring that the speed of the low-pressure condensate pump precisely matches the actual operating conditions.

[0004] However, variable frequency speed control systems generate a large number of harmonic currents during operation. These harmonic currents not only affect the power quality of the power grid and cause voltage distortion, but may also interfere with other electrical equipment and affect its operation. Utility Model Content

[0005] To address the aforementioned issues, this application provides a speed control system based on a low-pressure condensate pump. Through the coordinated and automated control of a permanent magnet speed control mechanism, a drive mechanism, and a controller added based on the low-pressure condensate pump, the system achieves precise regulation of the pump's rotational speed.

[0006] To achieve the objectives of this application, the following technical solution is provided:

[0007] This application provides a speed regulation system based on a low-pressure condensate pump, including: a drive motor, a permanent magnet speed regulation mechanism, a low-pressure condensate pump, a drive mechanism, and a controller;

[0008] The drive motor, permanent magnet speed regulating mechanism and low-pressure condensate pump are arranged in sequence, wherein the first rotating shaft of the drive motor and the second rotating shaft of the low-pressure condensate pump are arranged opposite to each other.

[0009] The permanent magnet speed regulating mechanism includes a permanent magnet rotor, a conductor rotor, and a magnetic shielding sleeve. The first rotating shaft is fixedly connected to the permanent magnet rotor. The conductor rotor and the magnetic shielding sleeve are sequentially connected to the second rotating shaft in the direction toward the drive motor. The conductor rotor is fixedly connected to the second rotating shaft, and the magnetic shielding sleeve is movably connected to the second rotating shaft. The inner cavity of the permanent magnet rotor encloses the conductor rotor, and the magnetic shielding sleeve is located between the permanent magnet rotor and the conductor rotor in the circumferential direction.

[0010] The magnetic shielding sleeve is connected to the pushing mechanism, which is used to adjust the position of the magnetic shielding sleeve to adjust the magnetic coupling strength between the permanent magnet rotor and the conductor rotor.

[0011] The drive motor, the low-pressure condensate pump, and the push mechanism are respectively communicatively connected to the controller.

[0012] In one possible implementation, the actuating mechanism includes a hydraulic mechanism, a hydraulic lock, and a lever, wherein the hydraulic lock is disposed within the hydraulic mechanism, and the actuating mechanism is communicatively connected to the controller;

[0013] One end of the pull rod is connected to the telescopic end of the hydraulic mechanism, and the other end of the pull rod is connected to the magnetic shielding sleeve;

[0014] The hydraulic mechanism is used to drive the pull rod to move linearly along the axial direction of the second rotation axis, thereby driving the magnetic shielding sleeve to move linearly along the axial direction of the second rotation axis;

[0015] The hydraulic lock is used to lock the position of the hydraulic cylinder, thereby fixing the magnetic shielding sleeve.

[0016] In one possible implementation, a cooling fan is also included, the outlet of which faces the permanent magnet speed control mechanism. A temperature sensor is disposed within the permanent magnet speed control mechanism, and the cooling fan and the temperature sensor are respectively communicatively connected to the controller.

[0017] In one possible implementation, a displacement sensor is also included, which is used to collect the position information of the magnetic shielding sleeve, and the displacement sensor is communicatively connected to the controller.

[0018] In one possible implementation, a magnetic shielding mechanism is also included, which is a shell structure made of a magnetic material with high permeability and low coercivity, and the shell structure covers the outside of the permanent magnet speed regulating mechanism.

[0019] In one possible implementation, the controller is used to collect the current operating parameters of the drive motor and the low-pressure condensate pump;

[0020] It is also used to receive hydrophobic load demand signals, convert the hydrophobic load demand into the target speed of the low-pressure hydrophobic pump through a built-in algorithm, calculate the required magnetic coupling region size by combining the current operating state of the low-pressure hydrophobic pump with the target speed, and convert it into the displacement command of the push mechanism. Finally, according to the displacement command, the push mechanism is driven to move the magnetic shielding sleeve to the corresponding position, thereby changing the magnetic coupling region between the permanent magnet rotor and the conductor rotor and adjusting the speed of the low-pressure hydrophobic pump.

[0021] In one possible implementation, the central axes of the first rotating shaft, the second rotating shaft, the permanent magnet rotor, the conductor rotor, and the magnetic shielding sleeve coincide.

[0022] The speed control system based on the low-pressure condensate pump provided in this application sets a permanent magnet speed control mechanism between the drive motor and the low-pressure condensate pump. The position of the magnetic shielding sleeve is automatically adjusted by the controller and the push mechanism, thereby changing the transmission torque of the second rotating shaft, achieving efficient and stable speed control of the low-pressure condensate pump. At the same time, the non-contact magnetic coupling transmission method between the permanent magnet rotor and the conductor rotor avoids the friction loss of traditional mechanical speed control, extends the service life of the equipment, and the structure has a fast response speed and fewer failure points, which can effectively improve the operating efficiency and stability of the low-pressure condensate pump. In addition, the use of a permanent magnet speed control mechanism to replace the traditional variable frequency speed control technology can effectively solve the problems of harmonic pollution and inverter self-loss in variable frequency speed control. Attached Figure Description

[0023] The accompanying drawings are provided to further understand this application and form part of the specification. They are used together with the embodiments of this application to explain this application and do not constitute a limitation thereof.

[0024] Figure 1 A schematic diagram of a speed regulation system based on a low-pressure condensate pump provided in an embodiment of this application;

[0025] Figure 2 A block diagram illustrating the communication connections between various mechanisms in a speed control system based on a low-pressure condensate pump, provided for embodiments of this application;

[0026] Figure 3 A flowchart illustrating the working principle of a speed regulation system based on a low-pressure condensate pump, provided for embodiments of this application;

[0027] Illustration:

[0028] 1. Second rotating shaft; 2. Magnetic shielding sleeve; 3. Permanent magnet rotor; 4. Conductor rotor; 5. First rotating shaft; 6. Pushing mechanism. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0030] In the description of this utility model, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; in the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0031] In a thermal system, the core function of the low-pressure heater condensate pump is to pressurize the condensate (i.e., the water produced after condensate and steam exchange) accumulated in the low-pressure heater, driven by a motor, and then transport it to the deaerator or the next stage heater. This process ensures the continuity of the thermal cycle and avoids reduced heat exchange efficiency or equipment safety hazards caused by excessively high water levels in the low-pressure heater. The drive motor provides power to the condensate pump, converting mechanical energy into fluid kinetic energy, enabling the condensate to overcome pipe resistance and elevation differences, achieving directional flow. The low-pressure heater, as a heat exchange device, uses steam extracted from the turbine to heat the condensate, while the condensate pump is responsible for promptly discharging the heated condensate, maintaining pressure and liquid level balance within the heater, thereby ensuring the thermal efficiency of the entire regenerative system.

[0032] Since the rotational speed of the low-pressure condensate pump directly affects its flow rate and head, in traditional methods, the low-pressure condensate pump and the drive motor are rigidly connected via a coupling, and the rotational speed of the low-pressure condensate pump is equal to that of the drive motor. However, in actual operation, the condensate load demand of the low-pressure condensate pump may vary, thus requiring adjustment of the pump's rotational speed. This application employs a permanent magnet speed control mechanism to achieve non-contact, autonomous adjustment of the low-pressure condensate pump's rotational speed without changing the drive motor's speed.

[0033] Figure 1 A schematic diagram of a speed regulation system based on a low-pressure condensate pump provided in an embodiment of this application; Figure 2 A communication connection block diagram between various mechanisms in a speed regulation system based on a low-pressure condensate pump, provided for embodiments of this application; Figure 3 A flowchart illustrating the working principle of a speed control system based on a low-pressure condensate pump, provided in an embodiment of this application, is shown below. Figures 1 to 3 The following embodiments illustrate the technical solutions of this application.

[0034] This application provides a speed control system based on a low-pressure condensate pump, comprising: a drive motor, a permanent magnet speed control mechanism, a low-pressure condensate pump, a push mechanism 6, and a controller.

[0035] Specifically, such as Figure 1 As shown, the drive motor, permanent magnet speed regulating mechanism and low-pressure condensate pump are arranged in sequence, wherein the first rotating shaft 5 of the drive motor and the second rotating shaft 1 of the low-pressure condensate pump are arranged opposite to each other.

[0036] The permanent magnet speed regulating mechanism includes a permanent magnet rotor 3, a conductor rotor 4, and a magnetic shielding sleeve 2. The first rotating shaft 5 of the drive motor is fixedly connected to the permanent magnet rotor 3. The conductor rotor 4 and the magnetic shielding sleeve 2 are sequentially connected to the second rotating shaft 1 in the direction toward the drive motor. The conductor rotor 4 is fixedly connected to the second rotating shaft 1, and the magnetic shielding sleeve 2 is movably connected to the second rotating shaft 1. The inner cavity of the permanent magnet rotor 3 encloses the conductor rotor 4, and the magnetic shielding sleeve 2 is located between the permanent magnet rotor 3 and the conductor rotor 4.

[0037] The magnetic shielding sleeve 2 is connected to the pushing mechanism 6, which is used to adjust the position of the magnetic shielding sleeve 2 to adjust the magnetic coupling strength between the permanent magnet rotor 3 and the conductor rotor 4.

[0038] The drive motor, the low-pressure condensate pump, and the push mechanism 6 are respectively connected to the controller via communication.

[0039] For example, the central axes of the first rotating shaft 5, the second rotating shaft 1, the permanent magnet rotor 3, the conductor rotor 4, and the magnetic shielding sleeve 2 coincide.

[0040] The conductor rotor 4, magnetic shielding sleeve 2, and permanent magnet rotor 3 are all cylindrical structures with one open end and the other closed. The closed end of the conductor rotor 4 is fixedly connected to the second rotating shaft 1, and the closed end of the magnetic shielding sleeve 2 is movably connected to the second rotating shaft 1. This movement includes rotation about the second rotating shaft 1 and linear motion along the second rotating shaft 1 driven by the push mechanism 6. The open end of the conductor rotor 4 and the open end of the magnetic shielding sleeve 2 face the same direction, while the open end of the permanent magnet rotor 3 faces opposite to the open end of the conductor rotor 4. The closed end of the permanent magnet rotor 3 is fixedly connected to the first rotating shaft 5. Furthermore, the cylindrical inner cavity of the permanent magnet rotor 3 encloses the conductor rotor 4, and a magnetic coupling region is formed between the inner wall of the permanent magnet rotor 3 and the outer wall of the conductor rotor 4 through an air gap. The side wall of the magnetic shielding sleeve 2 is located between the inner wall of the permanent magnet rotor 3 and the outer wall of the conductor rotor 4.

[0041] Based on this structure, the magnetic coupling region between the permanent magnet rotor 3 and the conductor rotor 4 can be adjusted by moving the magnetic shielding sleeve 2 axially along the driving mechanism 6. When the magnetic shielding sleeve 2 moves, the magnetic shielding effect changes accordingly, causing a change in the magnetic flux cut by the conductor rotor 4, which directly affects the magnitude of the eddy current induced in the conductor rotor 4. This allows for precise control of its output electromagnetic torque, ultimately achieving stepless adjustment of the speed of the second rotating shaft 1 (low-pressure condensate pump side) without changing the speed of the first rotating shaft 5 (drive motor side). The entire process is completed through non-contact magnetic coupling, avoiding mechanical wear while achieving rapid response and stable speed regulation.

[0042] For example, when the condensate load demand of the low-pressure condensate pump decreases, the controller controls the drive mechanism 6 to move the magnetic shielding sleeve 2 a preset distance closer to the conductor rotor 4, reducing the magnetic coupling area, decreasing the electromagnetic force on the conductor rotor 4, and reducing the speed of the low-pressure condensate pump; conversely, when the condensate load demand of the low-pressure condensate pump increases, the controller controls the drive mechanism 6 to move the magnetic shielding sleeve 2 a preset distance away from the conductor rotor 4, increasing the magnetic coupling area, increasing the electromagnetic force on the conductor rotor 4, and increasing the speed of the low-pressure condensate pump.

[0043] It should be noted that the controller can collect the current operating parameters of the drive motor and the low-pressure condensate pump in real time, and can also receive the condensate load demand signal. Through the built-in algorithm, the condensate load demand is converted into the target speed of the low-pressure condensate pump. Then, combined with the current operating status of the low-pressure condensate pump, the required magnetic coupling area size is calculated, and finally converted into a precise displacement command for the drive mechanism 6. Through this displacement command, the drive mechanism is controlled to adjust the position of the magnetic shielding sleeve 2, thereby changing the effective magnetic coupling area between the permanent magnet rotor 3 and the conductor rotor 4, thus realizing closed-loop control of the speed of the low-pressure condensate pump, ensuring that the low-pressure condensate pump always delivers condensate according to the condensate load demand.

[0044] Meanwhile, after the magnetic shielding sleeve 2 moves to the designated position, the second rotating shaft 1 drives it to rotate. However, due to factors such as mechanical transmission or assembly clearance, axial displacement may occur during rotation, affecting the speed stability of the second rotating shaft 1. To ensure speed consistency, the controller can monitor the axial displacement of the magnetic shielding sleeve 2 in real time through a displacement sensor, and dynamically compensate the position of the magnetic shielding sleeve 2 through the drive mechanism 6, keeping it always in the working position, thereby reducing speed fluctuations and improving operating accuracy and system reliability.

[0045] In this embodiment, the controller is exemplary configured as a DCS automatic control system, equipped with an FPGA programmable logic chip. A DCS automatic control system, also known as a distributed control system, is a new generation of instrument automatic control system developed based on microprocessors, with the design principle of distributed control functions and centralized display operations. A DCS automatic control system consists of field control stations composed of dedicated cabinets, a control host, and display modules, as well as other distributed control stations.

[0046] The introduction of this automatic control system monitors various parameters in the power plant's thermal production process, especially the operating parameters of the low-pressure heater condensate pump and drive motor. It can also automatically adjust the operating parameters of the drive mechanism 6 according to the condensate load requirements and provide accident prediction when the speed control system malfunctions (such as excessively high temperature of the permanent magnet speed control mechanism or failure of the drive mechanism 6). This can better maintain the safe and stable operation of the speed control system and the power production process.

[0047] In some embodiments, the actuating mechanism 6 in the speed regulation system based on the low-pressure condensate pump provided in this application includes a hydraulic mechanism, a hydraulic lock, and a pull rod. The hydraulic lock is connected to the hydraulic mechanism and is specifically installed between the throttle valve and the slide valve of the hydraulic mechanism through an oil pipeline. The actuating mechanism 6 is communicatively connected to the controller.

[0048] One end of the pull rod is connected to the telescopic end of the hydraulic mechanism, and the other end of the pull rod is connected to the magnetic shielding sleeve 2. The hydraulic mechanism is used to drive the pull rod to move linearly along the axial direction of the second rotating shaft 1, thereby driving the magnetic shielding sleeve 2 to move linearly along the axial direction of the second rotating shaft 1. The hydraulic lock is used to lock the position of the oil cylinder of the hydraulic mechanism, thereby fixing the magnetic shielding sleeve 2.

[0049] The pull rod, acting as a force transmission component, connects at both ends to the piston rod end of the hydraulic mechanism and the magnetic shielding sleeve 2, forming a rigid transmission chain. When the hydraulic mechanism receives a controller command, the linear stroke of its piston rod is converted into a precise axial displacement of the magnetic shielding sleeve 2 along the second rotating axis 1 via the pull rod. The hydraulic lock then locks the cylinder position by blocking the hydraulic oil circuit, thereby mechanically fixing the movement trajectory of the magnetic shielding sleeve 2.

[0050] The hydraulic mechanism is exemplified by a hydraulic oil pump. The hydraulic oil pump will only operate when it receives a push command from the controller. Its maximum pressure is 6.5 MPa. If there is no push command within a predetermined time (e.g., 10 seconds), the hydraulic oil pump will automatically stop.

[0051] In some embodiments, the speed control system based on the low-pressure condensate pump provided in this application further includes a displacement sensor, which is used to collect the position information of the magnetic shielding sleeve 2, and the displacement sensor is communicatively connected to the controller.

[0052] One example of a displacement sensor is a laser displacement sensor. This sensor collects the position information of the magnetic shielding sleeve 2 and sends it to the controller. The controller uses this position information to determine whether the size of the magnetic coupling area matches the drainage load requirements of the low-pressure condensate pump. Furthermore, before and after the driving mechanism 6 moves the magnetic shielding sleeve 2, the displacement sensor collects the position information of the magnetic shielding sleeve 2. The controller can then use the difference in this position information to determine whether the driving mechanism 6 is operating normally, thereby ensuring that the speed control system operates within a safe range.

[0053] In some embodiments, the speed control system based on the low-pressure hydrophobic pump provided in this application further includes a cooling fan, the air outlet of the cooling fan facing the permanent magnet speed control mechanism, a temperature sensor being disposed in the permanent magnet speed control mechanism, and the cooling fan and the temperature sensor being communicatively connected to the controller.

[0054] During operation, the permanent magnet speed regulating mechanism generates heat. The heat generation is mainly due to the heat generated by the permanent magnet eddy current and the mechanical friction loss inside the equipment. Especially when the distance between the open end of the magnetic shielding sleeve and the closed end of the permanent magnet rotor is 130mm during the test (at which time the inner wall of the permanent magnet rotor and the outer wall of the conductor rotor are connected) and the cooling fan stops running, the heat accumulation is more obvious (the highest temperature can reach 97℃).

[0055] Because heat generation can accelerate the aging of equipment insulation, reduce the magnetic performance of permanent magnets, and even cause component burnout or mechanical deformation, it seriously affects the reliability and service life of the equipment. Therefore, this embodiment is equipped with a cooling fan to dissipate the heat generated by the permanent magnet speed regulation mechanism during operation through forced convection, maintaining the temperature within a safe range (usually below 130°C) and avoiding the risk of equipment failure or burns due to overheating. Furthermore, this embodiment also includes a temperature sensor to detect the temperature of the permanent magnet speed regulation mechanism and transmit the temperature to the controller. The controller determines whether the temperature is within the safe range and, if the temperature exceeds the safe range, increases the operating power of the cooling fan or directly shuts down the drive motor and issues an alarm.

[0056] Based on the above embodiments, this application provides a working process for a speed regulation system based on a low-pressure condensate pump, including the following steps:

[0057] First, a routine check is performed before starting the speed control system. The check items include:

[0058] The power indicator of the controller for the speed control system based on the low-pressure condensate pump is normal.

[0059] Check that the remote / local knob on the controller of the speed control system based on the low-pressure condensate pump is switched to the local position;

[0060] Start the cooling fan and check that it is operating normally;

[0061] The low-pressure heater condensate pump was checked and found to be operating normally with cooling water supply.

[0062] Then, the control panel of the display module is equipped with a "local / remote" selection switch for switching between local and remote modes, allowing users to select the operating mode as needed.

[0063] Next, the controller confirms whether the outlet valve of the low-pressure condensate pump is closed and whether the magnetic shielding sleeve is in its initial position. This initial position includes either the fully shielded position (lowest pump speed) or a permanent magnet coupling position (e.g., the distance between the open end of the magnetic shielding sleeve and the closed end of the permanent magnet rotor is 90mm). If the above conditions are met, and the temperature of the permanent magnet speed control mechanism is within a safe range and the air cooler is running, the controller sends a permanent magnet start signal and starts the drive motor.

[0064] Then, when the condensate load demand of the low-pressure condensate pump changes, the controller sets the distance between the open end of the magnetic shielding sleeve and the closed end of the permanent magnet rotor according to the condensate load demand of the low-pressure condensate pump, and drives the push mechanism to move the magnetic shielding sleeve until it moves into place and maintains the current position. The push mechanism then enters automatic compensation until it receives the next push command.

[0065] It should be noted that when the inner cavity of the magnetic shielding sleeve completely encloses the conductor rotor, the distance between the open end of the magnetic shielding sleeve and the closed end of the permanent magnet rotor is zero, and the magnetic coupling area is zero. At this time, the speed of the low-pressure condensate pump is the lowest, generally 30% of the rated speed (the shielding effect of the magnetic shielding sleeve is not absolute, and there may still be a small amount of magnetic leakage, so the conductor rotor is subjected to a weak magnetic field and generates residual torque), corresponding to a DCS signal of 4mA. When the magnetic shielding sleeve is outside the conductor rotor and the permanent magnet rotor, the speed of the low-pressure condensate pump is the highest, generally 97% of the rated speed. At this time, the distance between the open end of the magnetic shielding sleeve and the closed end of the permanent magnet rotor is 130mm (that is, the magnetic shielding sleeve has moved 130mm away from the permanent magnet rotor), corresponding to a DCS signal of 20mA. Through extensive calculations and practice, the relationship between the condensate load requirement of the low-pressure condensate pump and the distance between the magnetic shielding sleeve and the permanent magnet rotor has been obtained (Table 1).

[0066] Table 1. Relationship between hydrophobic load requirement and distance between magnetic shielding sleeve and permanent magnet rotor

[0067]

[0068] Finally, start the low-pressure heater condensate pump on the control panel and check that the pump's current and pressure are normal. During operation, the controller also needs to monitor whether the temperature of the permanent magnet speed regulator is within a safe range and shut down the speed regulation system if it exceeds the safe range. Additionally, the control unit is equipped with an "accelerate / decelerate" knob to adjust the speed of the low-pressure heater condensate pump. When the knob is switched to "accelerate," the pump's speed increases; when switched to "decelerate," the pump's speed decreases; and when the knob is in the "middle position," the pump maintains its current speed.

[0069] The beneficial effects achievable by the embodiments of this application are as follows: The speed regulation system based on the low-pressure condensate pump provided in this application sets a permanent magnet speed regulation mechanism between the drive motor and the low-pressure condensate pump. The position of the magnetic shielding sleeve is automatically adjusted by the controller and the push mechanism, thereby changing the transmission torque of the second rotating shaft, achieving efficient and stable speed regulation of the low-pressure condensate pump. Simultaneously, the non-contact magnetic coupling transmission method between the permanent magnet rotor and the conductor rotor avoids the frictional losses of traditional mechanical speed regulation, extending the service life of the equipment. Furthermore, this structure has a fast response speed and fewer failure points, effectively improving the operating efficiency and stability of the low-pressure condensate pump. Moreover, using a permanent magnet speed regulation mechanism instead of traditional frequency conversion speed regulation technology can effectively solve the problems of harmonic pollution and inverter self-loss associated with frequency conversion speed regulation. Specifically, it includes:

[0070] Significant energy-saving effect: Through the precise speed control of the controller, the low-pressure condensate pump can adjust its speed in real time according to the actual condensate load demand, avoiding the energy waste under the traditional constant speed operation mode;

[0071] No harmonic interference: The magnetically shielded permanent magnet speed regulation technology uses non-contact electromagnetic transmission, which does not generate harmonic current and will not cause harmonic interference to the power grid and other electrical equipment, thus improving the power quality of the power system.

[0072] Significant cost advantages: Compared to variable frequency speed control technology, the magnetically shielded permanent magnet speed control mechanism of this application has a simple structure, requiring no complex electronic components and circuit boards, thus significantly reducing manufacturing and maintenance costs. Furthermore, its high reliability reduces downtime losses due to equipment failure, further improving economic efficiency.

[0073] High operational stability: The permanent magnet speed control mechanism adopts non-contact transmission, eliminating mechanical wear and vibration issues. Furthermore, the magnetic shielding mechanism effectively protects internal components from external environmental influences, extending the equipment's service life and improving system operational stability and reliability. It should be noted that the magnetic shielding mechanism is a shell structure made of high-permeability, low-coercivity magnetic material, which encloses the permanent magnet speed control mechanism.

[0074] In summary, the speed regulation system based on the low-pressure condensate pump provided in this application has significant advantages in energy-saving retrofitting of the low-pressure condensate pump by utilizing magnetically shielded permanent magnet speed regulation technology and fully automated control technology. It can effectively solve the problems existing in the prior art and has broad application prospects and promotion value.

[0075] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0076] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A speed regulation system based on a low-pressure condensate pump, characterized in that, include: Drive motor, permanent magnet speed regulation mechanism, low-pressure condensate pump, push mechanism (6) and controller; The drive motor, permanent magnet speed regulating mechanism and low-pressure condensate pump are arranged in sequence, wherein the first rotating shaft (5) of the drive motor and the second rotating shaft (1) of the low-pressure condensate pump are arranged opposite to each other; The permanent magnet speed regulating mechanism includes a permanent magnet rotor (3), a conductor rotor (4), and a magnetic shielding sleeve (2). The first rotating shaft (5) is fixedly connected to the permanent magnet rotor (3). The conductor rotor (4) and the magnetic shielding sleeve (2) are sequentially connected to the second rotating shaft (1) in the direction toward the drive motor. The conductor rotor (4) is fixedly connected to the second rotating shaft (1), and the magnetic shielding sleeve (2) is movably connected to the second rotating shaft (1). The inner cavity of the permanent magnet rotor (3) encloses the conductor rotor (4), and the magnetic shielding sleeve (2) is located between the permanent magnet rotor (3) and the conductor rotor (4) in the circumferential direction. The magnetic shielding sleeve (2) is connected to the pushing mechanism (6), which is used to adjust the position of the magnetic shielding sleeve (2) to adjust the magnetic coupling strength between the permanent magnet rotor (3) and the conductor rotor (4); The drive motor, the low-pressure condensate pump, and the push mechanism (6) are respectively connected to the controller via communication.

2. The speed regulation system based on a low-pressure condensate pump according to claim 1, characterized in that, The pushing mechanism (6) includes a hydraulic mechanism, a hydraulic lock and a pull rod, the hydraulic lock is configured in the hydraulic mechanism, and the pushing mechanism (6) is communicatively connected to the controller; One end of the pull rod is connected to the telescopic end of the hydraulic mechanism, and the other end of the pull rod is connected to the magnetic shielding sleeve (2); The hydraulic mechanism is used to drive the pull rod to move linearly along the axial direction of the second rotating shaft (1), thereby driving the magnetic shielding sleeve (2) to move linearly along the axial direction of the second rotating shaft (1); The hydraulic lock is used to lock the position of the hydraulic cylinder of the hydraulic mechanism, thereby fixing the magnetic shielding sleeve (2).

3. The speed regulation system based on a low-pressure condensate pump according to claim 1, characterized in that, It also includes a cooling fan, the air outlet of which faces the permanent magnet speed regulating mechanism. The permanent magnet speed regulating mechanism is equipped with a temperature sensor, and the cooling fan and the temperature sensor are respectively communicatively connected to the controller.

4. The speed regulation system based on a low-pressure condensate pump according to claim 1, characterized in that, It also includes a displacement sensor, which is used to collect the position information of the magnetic shielding sleeve (2), and the displacement sensor is communicatively connected to the controller.

5. The speed regulation system based on a low-pressure condensate pump according to claim 1, characterized in that, It also includes a magnetic shielding mechanism, which is a shell structure made of a magnetic material with high permeability and low coercivity, and the shell structure covers the outside of the permanent magnet speed regulating mechanism.

6. The speed regulation system based on a low-pressure condensate pump according to any one of claims 1-5, characterized in that, The controller is used to collect the current operating parameters of the drive motor and the low-pressure condensate pump; It is also used to receive hydrophobic load demand signals, convert the hydrophobic load demand into the target speed of the low-pressure hydrophobic pump through the built-in algorithm, and then calculate the required magnetic coupling area size by combining the current operating state of the low-pressure hydrophobic pump with the target speed and convert it into the displacement command of the push mechanism (6). Finally, according to the displacement command, the push mechanism (6) is driven to move the magnetic shielding sleeve (2) to the corresponding position, so as to change the magnetic coupling area between the permanent magnet rotor (3) and the conductor rotor (4) and adjust the speed of the low-pressure hydrophobic pump.

7. The speed regulation system based on a low-pressure condensate pump according to claim 1, characterized in that, The central axes of the first rotating shaft (5), the second rotating shaft (1), the permanent magnet rotor (3), the conductor rotor (4), and the magnetic shielding sleeve (2) coincide.

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