Centrifugal pump linear constant power module and series washing system for variable load working conditions

Abstract

The utility model discloses a linear constant power module and series washing system for centrifugal pump of variable load working condition relates to motor control technical field, including motor, shaft coupling, centrifugal pump, proportional speed regulating valve, flowmeter and controller, the motor with controller electricity is connected and is connected with centrifugal pump through shaft coupling, the motor will current information feedback to controller and drives centrifugal pump through shaft coupling, flowmeter is located the export position of proportional speed regulating valve and with controller electricity is connected, is used for detecting the flow information of proportional speed regulating valve output, and will flow information feedback to controller, proportional speed regulating valve is located the export position of centrifugal pump and with controller electricity is connected, and the controller is used for adjusting the opening of proportional speed regulating valve according to current information and flow information. The utility model can guarantee normal use and the stable output of flow of motor under the premise of not changing motor rotating speed.

Description

Technical Field

[0001] This utility model relates to the field of motor control technology, and in particular to a linear constant power module and series washing system for centrifugal pumps under variable load conditions. Background Technology

[0002] Before the commissioning of existing large hydraulic systems, all hydraulic pipelines need to be flushed and tested to ensure that they are thoroughly clean, thus eliminating any contaminants or foreign objects remaining in the pipelines.

[0003] With the continuous development of industry, the types of hydraulic systems have increased. Different hydraulic pumps are required for different working conditions, and existing hydraulic pump technology can no longer meet market demands. Some specific working conditions can only be handled by centrifugal pumps, but due to some drawbacks, centrifugal pumps are not suitable for certain special conditions (such as variable load conditions). Specifically:

[0004] 1) Centrifugal pumps operate under variable load conditions, resulting in unstable output: The flow rate of a centrifugal pump is easily affected by the outlet load pressure. When the outlet load increases, the pump flow rate will decrease, and when the outlet load decreases, the pump flow rate will increase.

[0005] 2) Centrifugal pumps are prone to motor overload when operating under variable load conditions: When a centrifugal pump operates in an environment with unstable load, if the outlet load decreases, the pump flow rate will increase. When the flow rate increases to a certain value, it is easy to cause motor overload.

[0006] Therefore, existing pipeline flushing technology cannot overcome the shortcomings of centrifugal pumps. Directly applying centrifugal pumps to pipeline flushing results in unsatisfactory flushing effects. Utility Model Content

[0007] The technical problem to be solved by this utility model is to provide a linear constant power module and series washing system for centrifugal pumps under variable load conditions, which can ensure the normal use of the motor and the stable output of flow.

[0008] To address the aforementioned technical problems, this utility model provides a linear constant power module for a centrifugal pump under variable load conditions, comprising a motor, a coupling, a centrifugal pump, a proportional speed control valve, a flow meter, and a controller. The motor is electrically connected to the controller and to the centrifugal pump via the coupling. The motor feeds back current information to the controller and drives the centrifugal pump through the coupling. The flow meter is located at the outlet of the proportional speed control valve and is electrically connected to the controller, used to detect the flow information output by the proportional speed control valve and feed the flow information back to the controller. The proportional speed control valve is located at the outlet of the centrifugal pump and is electrically connected to the controller, which adjusts the opening degree of the proportional speed control valve according to the current and flow information.

[0009] As an improvement to the above solution, the linear constant power module for centrifugal pumps under variable load conditions also includes a bell-shaped cover for encapsulating the coupling.

[0010] As an improvement to the above solution, the proportional speed control valve is connected in series at the outlet position of the centrifugal pump.

[0011] As an improvement to the above solution, the flow meter is connected in series at the outlet position of the proportional speed control valve.

[0012] Accordingly, this utility model also provides a series washing system based on a centrifugal pump linear constant power module, which includes a housing, a first oil circuit, and a second oil circuit; the first oil circuit includes a pulse valve group and the aforementioned centrifugal pump linear constant power module connected to each other; the input end of the centrifugal pump linear constant power module is connected to the housing, and the output end of the centrifugal pump linear constant power module is connected to the input end of the pulse valve group, the centrifugal pump linear constant power module is used to output working medium to the pulse valve group; the output end of the pulse valve group is provided with an oil outlet, and the pulse valve group is used to control the flow state of the working medium; the input end of the second oil circuit is provided with an oil return port, and the output end of the second oil circuit is connected to the housing.

[0013] As an improvement to the above solution, the housing includes an oil tank, a heater, and a temperature sensor. The heater and the temperature sensor are both located inside the oil tank. The oil tank is used to store the working medium, the temperature sensor is used to detect the temperature information of the working medium inside the oil tank, and the heater is used to heat the working medium inside the oil tank.

[0014] As an improvement to the above solution, the housing also includes a gas filter for filtering the gas entering the tank.

[0015] As an improvement to the above solution, the housing also includes a level gauge and / or a level relay, both disposed within the oil tank. The level gauge is used to detect the liquid level of the working medium in the oil tank, and the level relay is used to output an alarm signal when the liquid level of the working medium in the oil tank is abnormal.

[0016] As an improvement to the above solution, the second oil circuit includes a contamination detection group, an oil flow meter, a filter group, and a cooler; the input end of the contamination detection group is connected to the oil return port, and the output end of the contamination detection group is connected to the oil tank. The contamination detection group is used to detect the contamination information of the working medium; the input end of the oil flow meter is connected to the oil return port, and the output end of the oil flow meter is connected to the input end of the cooler through the filter group. The output end of the cooler is connected to the housing. The oil flow meter is used to detect the flow rate of the working medium, the filter group is used to filter the working medium after rinsing, and the cooler is used to cool the working medium.

[0017] As an improvement to the above solution, the second oil circuit also includes a bypass valve connected in parallel with the cooler.

[0018] The beneficial effects of implementing this utility model are as follows:

[0019] This invention correlates the flow rate information at the outlet of the proportional speed control valve, the current information of the motor, and the opening degree of the proportional speed control valve. By adjusting the opening degree of the proportional speed control valve in real time through the flow rate information and the current information, the output flow rate at the outlet of the proportional speed control valve can be effectively adjusted without changing the motor speed. This allows the centrifugal pump to determine whether the motor is overloaded in real time under variable load conditions to ensure the normal operation of the motor and to ensure stable flow output.

[0020] Furthermore, this utility model applies a linear constant power module for centrifugal pumps to pipeline flushing, which solves the shortcomings of unstable output and easy motor overload of centrifugal pumps under variable load conditions. It outputs a stable flow rate in a linear manner, thereby enabling the centrifugal pump to adapt to various low-viscosity media at a lower cost. Attached Figure Description

[0021] Figure 1 This is a structural diagram of an embodiment of the linear constant power module for a centrifugal pump under variable load conditions according to this utility model;

[0022] Figure 2 This is a schematic diagram of an embodiment of the series washing system based on the linear constant power module of a centrifugal pump of this utility model;

[0023] Figure 3 This is a structural diagram of an embodiment of the series washing system based on a linear constant power module of a centrifugal pump according to this utility model. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this utility model clearer, the following will describe this utility model in further detail with reference to the accompanying drawings. It is hereby declared that the terms "up," "down," "left," "right," "front," "back," "inner," and "outer," etc., appearing or about to appear in this document, are based solely on the accompanying drawings and are not intended to specifically limit this utility model.

[0025] See Figure 1 , Figure 1 The specific structure of the linear constant power module 22 for centrifugal pumps under variable load conditions of this utility model is shown. It includes a motor 221, a coupling 222, a centrifugal pump 223, a proportional speed control valve 224, a flow meter 225, and a controller 226. Specifically:

[0026] Centrifugal pump 223 has a low delivery pressure and is mainly used to deliver media that do not require high pressure. It also experiences significant frictional losses when delivering liquids.

[0027] The motor 221 is electrically connected to the controller 226 and connected to the centrifugal pump 223 through the coupling 222. The motor 221 feeds back the current information to the controller 226 and drives the centrifugal pump 223 through the coupling 222. In this utility model, the motor 221 can be an ordinary motor.

[0028] The flow meter 225 is located at the outlet of the proportional speed control valve 224 and is electrically connected to the controller 226. It is used to detect the flow information output by the proportional speed control valve 224 and feed the flow information back to the controller 226. Preferably, the flow meter 225 is connected in series at the outlet of the proportional speed control valve 224 to detect the flow information at the outlet of the proportional speed control valve 224 in real time.

[0029] The proportional speed control valve 224 is located at the outlet of the centrifugal pump 223 and is electrically connected to the controller 226. The controller 226 is used to adjust the opening of the proportional speed control valve 224 according to the current information and flow information, thereby controlling the flow rate of the fluid output by the proportional speed control valve 224 in real time.

[0030] It should be noted that this utility model associates the flow information at the outlet of the proportional speed control valve 224, the current information of the motor 221, and the opening degree of the proportional speed control valve 224.

[0031] During operation, the flow meter 225 detects the flow information at the outlet position of the proportional speed control valve 224 in real time and sends the flow information to the controller 226 in the form of an electrical signal. At the same time, the motor 221 feeds back the current information to the controller 226 in real time. Therefore, the controller 226 can adjust the opening of the proportional speed control valve 226 according to the electrical signal (i.e., the flow information) and the current information, thereby effectively adjusting the output flow at the outlet position of the proportional speed control valve 226 without changing the speed of the motor 221. Specifically, when the current information exceeds the preset maximum current value, it indicates that the motor 221 is overloaded. At this time, the controller 226 reduces the opening of the proportional speed control valve 226, thereby increasing the load at the outlet of the centrifugal pump 223 and reducing the output flow of the proportional speed control valve 226. Consequently, the current information fed back by the motor 221 decreases. When the electrical signal (i.e., the flow information) is less than the preset minimum electrical signal, the controller 226 increases the opening of the proportional speed control valve 226, thereby increasing the output flow of the proportional speed control valve 226. When the electrical signal (i.e., the flow information) exceeds the preset maximum electrical signal, the controller 226 reduces the opening of the proportional speed control valve 226, thereby reducing the output flow of the proportional speed control valve 226, thus ensuring the stability of the output flow of the proportional speed control valve 226.

[0032] Therefore, this utility model enables the centrifugal pump 223 to determine in real time whether the motor 221 is overloaded under variable load conditions, ensuring the normal use of the motor 221 and ensuring stable flow output.

[0033] Accordingly, the controller 226 may include a first comparator, a first buffer (such as a 74HC125 tri-state buffer chip), a second comparator, a second buffer, a third comparator, a third buffer, and a main control circuit. The first comparator's non-inverting input is connected to a preset maximum current value, its inverting input is connected to real-time detected current information, its output is connected to the enable terminal of the first buffer, the input of the first buffer is grounded, and its output is connected to the main control circuit. The second comparator's non-inverting input is connected to a preset minimum electrical signal, its inverting input is connected to a real-time detected electrical signal (i.e., flow information), its output is connected to the enable terminal of the second buffer, the input of the second buffer is connected to the power supply, and its output is connected to the main control circuit. The third comparator's non-inverting input is connected to a preset maximum electrical signal, its inverting input is connected to a real-time detected electrical signal (i.e., flow information), its output is connected to the enable terminal of the third buffer, the input of the third buffer is grounded, and its output is connected to the main control circuit. Specifically:

[0034] (1) When the real-time detected current information is greater than the maximum current value, the first comparator outputs a low level. At this time, the first buffer is activated and outputs a low level to the main control circuit. The main control circuit outputs a low-level PWM control signal to reduce the opening of the proportional speed control valve 226.

[0035] (2) When the real-time detected electrical signal (i.e. flow information) is less than the minimum electrical signal, the second comparator outputs a high level. At this time, the second buffer is activated and outputs a high level to the main control circuit. The main control circuit outputs a high-level PWM control signal to increase the opening of the proportional speed control valve 226.

[0036] (3) When the real-time detected electrical signal (i.e. flow information) is greater than the maximum electrical signal, the third comparator outputs a low level. At this time, the third buffer is activated and outputs a low level to the main control circuit. The main control circuit outputs a low-level PWM control signal to reduce the opening of the proportional speed control valve 226.

[0037] Therefore, by setting / combining comparators, the logic control of controller 226 can be achieved, thereby controlling the opening degree of proportional speed control valve 226 through the level signal output by the comparator. It should be noted that in practical applications, the main control circuit can use existing technology to adjust the opening degree of proportional speed control valve 226. For details, please refer to the circuit structure of patent "CN116696828B" or other existing technologies; no limitations are imposed here.

[0038] Furthermore, the linear constant power module 22 for centrifugal pumps under variable load conditions of this invention also includes a bell-shaped cover 227 for encapsulating the coupling 222, thereby protecting the coupling 222 and ensuring the safety of operators.

[0039] Therefore, by introducing a flow meter 225 to collect flow information in real time, and by using the flow information and current information to achieve flexible control of the opening of the proportional speed control valve 226, the centrifugal pump 223 overcomes its own shortcomings, can prevent the motor 221 from overloading under variable load conditions, and can stably output flow, thus increasing the application range and occasions of the centrifugal pump 223.

[0040] See Figure 2 , Figure 2 This diagram shows an embodiment of the series washing system based on a linear constant power module of a centrifugal pump according to the present invention. It includes a housing 1, a first oil passage 2, and a second oil passage 3. Specifically:

[0041] The first oil circuit 2 includes a pulse valve assembly 21 and the aforementioned centrifugal pump linear constant power module 22, which are interconnected. The input end of the centrifugal pump linear constant power module 22 is connected to the housing 1, and the output end of the centrifugal pump linear constant power module 22 is connected to the input end of the pulse valve assembly 21. The centrifugal pump linear constant power module 22 is used to output the working medium to the pulse valve assembly 21. The output end of the pulse valve assembly 21 is provided with an oil outlet.

[0042] The input end of the second oil circuit 3 is equipped with an oil return port, and the output end of the second oil circuit 3 is connected to the housing 1.

[0043] Unlike existing technologies, this invention introduces a unique linear constant power module for centrifugal pumps, which can output a stable flushing flow rate in a linear manner even under variable load conditions.

[0044] During the flushing operation, the two ends of the flushed pipeline 4 are connected to the "oil outlet" of the first circuit and the "oil return" of the second circuit, respectively. The working medium in the tank 1 enters the flushed pipeline through the first circuit, then passes through the second circuit, and finally returns to the tank 1.

[0045] See Figure 3 , Figure 3 The diagram shows an embodiment of the washing system of this utility model. The following is a detailed description of the housing 1, the first oil circuit 2, and the second oil circuit 3:

[0046] I. Box 1

[0047] The housing 1 includes an oil tank 11, a heater 12, and a temperature sensor 13. The heater 12 and the temperature sensor 13 are both located inside the oil tank 11. Specifically:

[0048] Oil tank 11 is used to store the working medium;

[0049] Temperature sensor 13 is used to detect the temperature information of the working medium in oil tank 11;

[0050] Heater 12 is used to heat the working medium in oil tank 11.

[0051] More preferably, the housing 1 also includes a gas filter 14, which is used to filter the gas entering the oil tank 11, thereby preventing particulate impurities from entering the oil tank 11.

[0052] Furthermore, the housing 1 also includes a level gauge 15 and / or a level relay 16, both disposed within the oil tank 11, wherein:

[0053] The level gauge 15 is used to detect the liquid level of the working medium in the oil tank 11;

[0054] The liquid level relay 16 is used to output an alarm signal when the liquid level of the working medium in the oil tank 11 is abnormal (e.g., the liquid level is too high or too low).

[0055] II. First oil line 2

[0056] The description of the linear constant power module 22 for the centrifugal pump can be found above and will not be repeated here.

[0057] The pulse valve assembly 21 is used to control the flow state of the working medium. The pulse valve assembly 21 generates turbulence through pulses, thereby creating a pressure difference to remove contaminants and foreign objects from the pipeline.

[0058] III. Second oil line 3

[0059] The second oil circuit 3 includes a contamination detection group 31, an oil flow meter 32, a filter group 33, and a cooler 34. Specifically:

[0060] The input end of the contamination detection group 31 is connected to the oil return port, and the output end of the contamination detection group 31 is connected to the oil tank 11. The contamination detection group 31 is used to detect the contamination information (e.g., contamination level) of the working medium.

[0061] The input end of the oil flow meter 32 is connected to the return oil port, and the output end of the oil flow meter 32 is connected to the input end of the cooler 34 through the filter group 33. The output end of the cooler 34 is connected to the housing 1.

[0062] The oil flow meter 32 is used to detect the flow rate of the working medium;

[0063] Filter assembly 33 is used to filter impurities from the working medium after rinsing.

[0064] Cooler 34 is used to cool the working medium.

[0065] Furthermore, the second oil circuit 3 also includes a bypass valve connected in parallel with the cooler 34.

[0066] Therefore, this utility model applies the linear constant power module of the centrifugal pump to pipeline flushing, which solves the shortcomings of unstable output and easy motor overload of the centrifugal pump under variable load conditions. It outputs a stable flow rate in a linear manner, so that the centrifugal pump can adapt to various low viscosity media and has a low cost.

[0067] The above description is the preferred embodiment of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications are also considered to be within the protection scope of this utility model.

Claims

1. A linear constant power module for centrifugal pumps under variable load conditions, characterized in that, Includes motors, couplings, centrifugal pumps, proportional speed control valves, flow meters, and controllers; The motor is electrically connected to the controller and connected to the centrifugal pump through the coupling. The motor feeds back current information to the controller and drives the centrifugal pump through the coupling. The flow meter is located at the outlet of the proportional speed control valve and is electrically connected to the controller. It is used to detect the flow information output by the proportional speed control valve and feed the flow information back to the controller. The proportional speed control valve is located at the outlet of the centrifugal pump and is electrically connected to the controller. The controller is used to adjust the opening degree of the proportional speed control valve according to the current information and flow information.

2. The linear constant power module for centrifugal pumps under variable load conditions as described in claim 1, characterized in that, It also includes a bell-shaped cover for encapsulating the coupling.

3. The linear constant power module for centrifugal pumps under variable load conditions as described in claim 1, characterized in that, The proportional speed control valve is connected in series at the outlet of the centrifugal pump.

4. The linear constant power module for centrifugal pumps under variable load conditions as described in claim 1, characterized in that, The flow meter is connected in series at the outlet of the proportional speed control valve.

5. A series washing system based on a linear constant power module of a centrifugal pump, characterized in that, Includes the housing, the first oil passage, and the second oil passage; The first oil circuit includes an interconnected pulse valve group and a centrifugal pump linear constant power module as described in any one of claims 1 to 4; The input terminal of the centrifugal pump linear constant power module is connected to the housing, and the output terminal of the centrifugal pump linear constant power module is connected to the input terminal of the pulse valve group. The centrifugal pump linear constant power module is used to output working medium to the pulse valve group. The output end of the pulse valve assembly is provided with an oil outlet, and the pulse valve assembly is used to control the flow state of the working medium; The input end of the second oil circuit is provided with an oil return port, and the output end of the second oil circuit is connected to the housing.

6. The series washing system based on a linear constant power module of a centrifugal pump as described in claim 5, characterized in that, The housing includes an oil tank, a heater, and a temperature sensor. The heater and temperature sensor are both located inside the oil tank. The oil tank is used to store the working medium. The temperature sensor is used to detect the temperature information of the working medium inside the oil tank. The heater is used to heat the working medium inside the oil tank.

7. The series washing system based on a linear constant power module of a centrifugal pump as described in claim 6, characterized in that, The housing also includes a gas filter for filtering the gas entering the tank.

8. The series washing system based on a linear constant power module of a centrifugal pump as described in claim 6, characterized in that, The housing also includes a level gauge and / or a level relay, both installed inside the oil tank. The level gauge is used to detect the liquid level of the working medium in the oil tank, and the level relay is used to output an alarm signal when the liquid level of the working medium in the oil tank is abnormal.

9. The series washing system based on a linear constant power module of a centrifugal pump as described in claim 5, characterized in that, The second oil circuit includes a contamination detection group, an oil flow meter, a filter group, and a cooler; The input end of the contamination detection group is connected to the oil return port, and the output end of the contamination detection group is connected to the oil tank. The contamination detection group is used to detect the contamination information of the working medium. The input end of the oil flow meter is connected to the return oil port, the output end of the oil flow meter is connected to the input end of the cooler through the filter group, and the output end of the cooler is connected to the housing. The oil flow meter is used to detect the flow rate of the working medium, the filter group is used to filter the working medium after rinsing, and the cooler is used to cool the working medium.

10. The series washing system based on a linear constant power module of a centrifugal pump as described in claim 9, characterized in that, The second oil circuit also includes a bypass valve connected in parallel with the cooler.

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