A water injection and exhaust device for a motor for a boiler water circulating pump test and a method of operating the device

Abstract

The present application relates to a kind of motor water injection and exhaust device for boiler water circulating pump test and the operation method of device, the device is set according to the needs on each pipeline valve, by different opening and closing combination, the flow direction of water injection is controlled, by the opening degree variation of valve, and flowmeter is set in the front side of motor water inlet pipeline, water injection flow rate is controlled, ensure that motor cavity air is effectively discharged, flowmeter is used to monitor the circulation flow in motor when pump group operates, to be verified with the result of analysis and calculation, and timely find abnormality. By the above system and method, motor only needs to be started to determine direction, and does not need to be stationary, exhaust, water supplement operation. Using the method, multiple boiler water circulating pumps are tested, performance test and endurance test are completed, and motor operation is good, without abnormal temperature rise, vibration and other phenomena.

Description

Technical Field

[0001] This invention relates to a water injection and venting device and its operating method. Specifically, it relates to a device and its operating method for installing valves on each section of pipeline as needed, controlling the water injection flow rate by changing the valve opening, and installing a flow meter on the front side of the motor water inlet pipeline to ensure effective air discharge from the motor cavity. At the same time, the flow meter can be used to monitor the internal circulation flow of the motor during pump operation, so as to verify the results of analysis and calculation, and promptly detect abnormalities in the test motor water injection and venting device for boiler water circulation pump. Background Technology

[0002] The boiler water circulating pump features a wet stator integrated sealless design, with the pump chamber and motor chamber connected, eliminating the need for traditional mechanical seals and completely eliminating leakage points.

[0003] When the pump is operating, the pump chamber is a high-temperature, high-pressure environment, typically reaching 250℃ and exceeding 15MPa. The motor chamber pressure is the same as the pump chamber, and its temperature needs to be kept below 55℃. A heat shield between the pump chamber and the motor chamber removes heat transferred from the pump chamber to the motor chamber, keeping the motor chamber temperature within the motor's allowable operating range. After the motor starts running, the heat it generates needs to be circulated within the motor chamber by the multi-functional thrust disc inside the motor, exchanging heat with an external heat exchanger. Therefore, water needs to be added to the motor chamber before the pump unit starts operating.

[0004] The stator and rotor of the motor are immersed in liquid, and the liquid circulates during the operation of the pump set. In order to ensure the service life of the motor, it is necessary to ensure that the motor is fully vented when water is injected, and the injected water needs to be kept clean. Impurities will increase the wear inside the motor and affect its service life.

[0005] In general, when initially injecting circulating water into the motor cavity, in order to ensure that the solid suspended particles in the injected water are no more than 0.25ppm, an external filter is usually used. By ensuring that the air in the motor cavity can be completely discharged by allowing the water to stand after injection, replenishing water multiple times, or jogging the motor multiple times to help discharge the gas.

[0006] When using an external filter, if the filtration accuracy is high, the external filter is prone to clogging and requires frequent cleaning; if the filtration accuracy is low, unfiltered impurities will flow into the motor's built-in filter, resulting in poor flow capacity of the built-in filter, affecting the circulation of the liquid inside the motor, and thus affecting the temperature of the liquid inside the motor.

[0007] After the initial water filling, the air inside the motor cavity is often purged as effectively as possible by repeatedly jogging the motor and then allowing it to stand still. However, continuous starting may cause the motor to overheat, so each jog should be spaced 10-15 minutes apart, and the number of starts should be minimized. The motor starting requirements are opposite to the purging requirements, so a water filling scheme that can effectively purge air without requiring motor starting is particularly important for testing the boiler water circulating pump. Multiple jogs followed by a standby period will also increase the preparation time before the test.

[0008] Detailed explanation is as follows: See Figure 5 The existing testing method involves taking water from pool 8'. In order to ensure that the cleanliness of the liquid injected into the motor cavity meets the requirements for motor operation, a filter 5' needs to be installed in the water injection pipeline. If the filter 5' has high filtration accuracy, it is prone to clogging and needs to be cleaned frequently. If the accuracy is low, unfiltered impurities will directly enter the motor cavity 3', increasing the wear of the motor bearings, or reaching the motor's own filter and causing the motor's own circulation to be obstructed.

[0009] There is only valve 6' in the pipeline. After the valve is opened, the water injection pipeline injects water into the motor and the heat exchanger at the same time. Because the tube side volume of the heat exchanger is much smaller than the motor cavity, the heat exchanger will fill with water first. The water will enter the motor 3' from the connecting pipe between the motor and the heat exchanger 4'. The water is injected from the top and bottom of the motor at the same time, which can easily form cavities inside the motor, resulting in incomplete exhaust. Figure 5 The labels in the diagram correspond to the following names: Pump body 1', Motor 3', Heat exchanger 4', Filter 5', Valve 6', Pump 7', and Water tank 8'. Summary of the Invention

[0010] To address the aforementioned problems, the main objective of this invention is to provide a device for injecting and venting water into a boiler water circulation pump, which involves installing valves on each section of the pipeline as needed, controlling the water injection rate by varying the valve opening, and installing a flow meter on the front side of the motor inlet pipeline to ensure effective air discharge from the motor cavity. Simultaneously, this flow meter can be used to monitor the internal circulation flow of the motor during pump operation, allowing for verification with analytical calculations and timely detection of abnormalities.

[0011] The present invention solves the above-mentioned technical problems through the following technical solution: a water injection and venting device for a boiler water circulating pump test motor. The water injection and venting device for a boiler water circulating pump test motor has valves installed on each section of the pipeline as needed. By different opening and closing combinations, the flow direction of the water injection is controlled. By changing the opening degree of the valves, and by installing a flow meter on the front side of the motor inlet pipeline, the water injection flow rate is controlled to ensure that the air in the motor cavity is effectively discharged. When the pump unit is running, the flow meter is used to monitor the internal circulation flow of the motor to verify the results of analysis and calculation, and to detect abnormalities in a timely manner.

[0012] In a specific embodiment of the present invention, the test motor water injection and exhaust device for the boiler water circulating pump includes: a pump body, a motor, a heat exchanger, a first shut-off valve, a second shut-off valve, a third shut-off valve, a fourth shut-off valve, a fifth shut-off valve, a flow meter, a pressurized pump, a water tank, and the heat exchanger and motor are connected together by pipes. The press pump is connected to the water tank via a main pipe. A fifth shut-off valve is installed on the main pipe. The water in the tank is divided into two paths after passing through the press pump. The first path is the inlet pipe through the heat exchanger, which is equipped with a fourth shut-off valve. The second path is the inlet pipe for the motor. After passing through the motor and entering the pump body, the second path is discharged through the outlet pipe, which is equipped with a first shut-off valve. The motor's inlet pipe is divided into a front side and a rear side. A flow meter is installed on the front side of the inlet pipe. The rear side of the inlet pipe is divided into two branches. One branch is equipped with a second shut-off valve and is connected to the motor via a pipe. The other branch is equipped with a third shut-off valve.

[0013] In a specific embodiment of the present invention, the first shut-off valve, the second shut-off valve, the third shut-off valve, the fourth shut-off valve, and the fifth shut-off valve are all shut-off valves of the same model, and the material of the flow-through components is stainless steel.

[0014] In a specific embodiment of the present invention, the impeller and shaft of the press pump are made of stainless steel; the water tank is made entirely of stainless steel.

[0015] In a specific embodiment of the present invention, a viewing window is installed on the water tank.

[0016] An operating method for a test motor water injection and venting device for a boiler water circulation pump, the operating method comprising the following steps: Step 1: When filling the motor with water, first make the first and third shut-off valves fully open, and the second, fourth, and fifth shut-off valves fully closed. Step 2: Start the press pump, slowly open the fifth shut-off valve, observe the flow rate of the flow meter, and open the fourth shut-off valve for 10-15 seconds by adjusting the opening of the fifth shut-off valve to discharge the gas in the pipeline from the fifth shut-off valve to the fourth shut-off valve into the heat exchanger; close the third and fourth shut-off valves, fully open the second shut-off valve, and inject water into the motor cavity; observe the flow rate of the flow meter, and inject water at a low flow rate through the fifth adjusting shut-off valve. The water level in the motor cavity rises slowly, allowing the gas in the complex space inside the motor to be effectively discharged through the first shut-off valve above. Step 3: When the water level in the motor cavity reaches the connection point with the heat exchanger tubes, the water will flow into the coils inside the heat exchanger and expel the air from the coils. This process cannot be observed during water filling because the water enters the heat exchanger coils from top to bottom, and the air may not be completely expelled. Further venting is required afterward. Step 4: Continue until the water flows out in a continuous column from the first shut-off valve. At this point, close the second shut-off valve. This process may take anywhere from tens of minutes to several hours, depending on the size of the motor. Step 5: Fully open the third shut-off valve to prevent the pressurizing pump from running at zero flow, which would cause the temperature to rise. Once no more liquid flows out of the first shut-off valve, close the third shut-off valve and fully open the fourth shut-off valve to inject water into the tube side of the heat exchanger. Because the coil structure in the heat exchanger is relatively regular, the water injection process can effectively remove residual air until the water flows out continuously in a columnar manner from the first shut-off valve again. Step 6: Fully open the second shut-off valve, and adjust the opening of the fifth shut-off valve until the flow meter reading is 0.2–0.5 m³ / h. 3 / h, add water for 5-10 minutes. Under the action of the relatively fast water flow, if there is air in the motor and heat exchanger tube side, it can be further discharged; Step 7: Close the fifth shut-off valve, stop the press pump, and complete the water injection and air venting of the motor.

[0017] The positive and progressive effects of the present invention are as follows: The water injection and venting device for the test motor of the boiler water circulating pump provided by the present invention and the operation method of the device have the following advantages: valves are set on each section of the pipeline as needed, and the flow direction of water injection is controlled by different opening and closing combinations.

[0018] By adjusting the valve opening and installing a flow meter upstream of the motor's inlet pipe, the water injection rate is controlled to ensure effective air removal from the motor cavity. Simultaneously, this flow meter can monitor the internal circulation flow rate of the motor during pump operation, allowing for verification with analytical calculations and timely detection of anomalies.

[0019] Using the above system and method for water injection, the motor only needs to be jogged to determine the direction, eliminating the need for further static setting, venting, and water replenishment. Multiple boiler water circulation pumps were tested using this method, completing performance and durability tests. The motors all operated well, with no abnormal temperature rises or vibrations. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0021] Figure 2 This is one of the directions of water flow in this invention.

[0022] Figure 3 This is the second direction of water flow in this invention.

[0023] Figure 4 This is the third direction of water flow in this invention.

[0024] Figure 5 A schematic diagram of the structure of similar technologies commonly used today.

[0025] The following are the names corresponding to the reference numerals in this invention: In the figure: pump body (1), motor (3), heat exchanger (7), first shut-off valve (2), second shut-off valve (4), third shut-off valve (5), fourth shut-off valve (8), fifth shut-off valve (9), flow meter (6), press pump (10), water tank (11). Detailed Implementation

[0026] The preferred embodiments of the present invention are given below with reference to the accompanying drawings to illustrate the technical solution of the present invention in detail.

[0027] Figure 1 This is a schematic diagram of the overall structure of the present invention, as shown below. Figure 1 As shown: This invention proposes a water injection and venting device for a boiler water circulating pump test motor. This device has valves installed on each section of the pipeline as needed. Different opening and closing combinations control the flow direction of the injected water. The water injection velocity is controlled by changing the valve opening, and a flow meter is installed upstream of the motor's water inlet pipeline to ensure effective air removal from the motor cavity. During pump operation, the flow meter monitors the internal circulation flow rate of the motor, verifying the results with analytical calculations and promptly detecting any abnormalities.

[0028] The water injection and venting device for the test motor of the boiler water circulation pump proposed in this invention includes: pump body 1, motor 3, heat exchanger 7, first stop valve 2, second stop valve 4, third stop valve 5, fourth stop valve 8, fifth stop valve 9, flow meter 6, pressurized pump 10, water tank 11, and heat exchanger 7 and motor 3 are connected together by pipeline.

[0029] The press pump 10 is connected to the water tank 11 through a main pipe. A fifth shut-off valve 9 is installed on the main pipe. The water in the water tank 11 is divided into two paths after passing through the press pump 10. The first path is the inlet pipe through the heat exchanger 7, which is equipped with a fourth shut-off valve 8. The second path is the inlet pipe of the motor. The second path enters the pump body through the motor and is discharged through the outlet pipe, which is equipped with a first shut-off valve 2. The motor inlet pipe is divided into a front side and a rear side. The flow meter 6 is installed on the front side of the inlet pipe. The rear side of the inlet pipe is divided into two branches. One branch is equipped with a second shut-off valve 4 and is connected to the motor 3 through a pipe. The other branch is equipped with a third shut-off valve 5.

[0030] The above-mentioned parts are connected by welding through steel pipes, tees, flanges, etc. All steel pipes, tees, and flanges are made of stainless steel. They are thoroughly cleaned and dried before use, and no solid particles will be generated due to rust during the test.

[0031] The first shut-off valve 2, the second shut-off valve 4, the third shut-off valve 5, the fourth shut-off valve 8, and the fifth shut-off valve 9 are all shut-off valves of the same model. The flow-through components are made of stainless steel, and no solid particles will be generated due to corrosion during the test.

[0032] The impeller, shaft and other flow-through components of the stamping pump 10 are all made of stainless steel, and no solid particles will be generated due to corrosion during the test.

[0033] Water tank 11 is made entirely of stainless steel, preventing the generation of solid particles due to corrosion during testing. The tank has a closed structure with an openable window to prevent external impurities from entering the testing system, but media can be added to the tank through this window.

[0034] The water tank 11 of the present invention is equipped with a viewing window. Before the test, the water tank 11 is opened and sufficient Grade A water is added into it.

[0035] The above water injection system can meet the motor's requirements for solid particle content, and no additional filtration device is needed between water tank 11 and motor 3.

[0036] The operation method of the present invention includes the following steps: When filling the motor with water, first ensure that the first shut-off valve 2 and the third shut-off valve 5 are fully open, and the second shut-off valve 4, the fourth shut-off valve 8, and the fifth shut-off valve 9 are fully closed.

[0037] Start the press pump 10, slowly open the fifth shut-off valve 9, observe the flow rate of the flow meter 6, and adjust the opening of the fifth shut-off valve 9 until the flow meter reading is 0.1 m³ / s. 3 / h, open the fourth shut-off valve for 10-15 seconds to vent the gas in the pipeline from the fifth shut-off valve 9 to the fourth shut-off valve 8 into the heat exchanger 7. Close the third shut-off valve 5 and the fourth shut-off valve 8, and fully open the second shut-off valve 4 to fill the motor cavity with water. Observe the flow rate of the flow meter 6. If necessary, adjust the fifth shut-off valve 9 to make the reading of the flow meter 6 0.1-0.2m. 3 / h, low-flow water injection, the water level in the motor cavity rises slowly, allowing the gas in the complex space inside the motor to be effectively discharged through the first shut-off valve 2 above. The direction of water flow during this process is shown in [the diagram]. Figure 2 .

[0038] When the water level in the motor chamber 3 reaches the connection point with the tube side of the heat exchanger 7, the water will flow into the coil inside the heat exchanger 7, expelling the air inside the coil. This process cannot be observed during water filling. Because the water enters the coil of the heat exchanger 7 from top to bottom, the air may not be completely expelled, requiring further venting later.

[0039] The process continues until the water flows out in a continuous column from the first shut-off valve 2. At this point, the second shut-off valve 4 is closed. This process may take anywhere from tens of minutes to several hours, depending on the size of the motor.

[0040] Fully open the third shut-off valve 5 to prevent the pressure pump 10 from operating at zero flow, which would cause the temperature to rise. Once no more liquid flows out from the first shut-off valve 2, close the third shut-off valve 5 and fully open the fourth shut-off valve 8 to inject water into the tube side of the heat exchanger 7. Because the coil structure in the heat exchanger 7 is relatively regular, the water injection process can effectively expel residual air until water flows out continuously in a column from the first shut-off valve 2 again. The direction of water flow during this process is shown in the diagram. Figure 3 .

[0041] Fully open the second shut-off valve 4, and adjust the opening of the fifth shut-off valve 9 until the flow meter 6 reads 0.2–0.5 m³ / s. 3 At a flow rate of / h, water is injected for 5-10 minutes. Under the action of the relatively fast water flow, any air present in the tubes of motor 2 and heat exchanger 7 can be further expelled. The direction of water flow during this process is shown in the diagram. Figure 4 .

[0042] Close the fifth shut-off valve 9, stop the press pump 10, and complete the water injection and air venting of the motor.

[0043] Using the above system and method for water injection, the motor only needs to be jogged to determine the direction, eliminating the need for further static setting, venting, and water replenishment. Multiple boiler water circulation pumps were tested using this method, completing performance and durability tests. The motors all operated well, with no abnormal temperature rises or vibrations.

[0044] This invention provides an independent water injection system, in which all components and flow-through parts are made of stainless steel.

[0045] The present invention uses Grade A water as the test medium, which does not require filtration by filters or other products.

[0046] The present invention installs valves on each section of pipeline as needed, and controls the flow direction of water injection through different opening and closing combinations.

[0047] This invention controls the water injection rate by varying the valve opening and installing a flow meter upstream of the motor's water inlet pipe, ensuring effective air removal from the motor cavity. Simultaneously, this flow meter can monitor the internal circulation flow rate of the motor during pump operation, allowing for verification with analytical calculations and timely detection of anomalies.

[0048] The basic principles, main features, and advantages of the present invention have been shown and described. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as defined by the appended claims and their equivalents.

Claims

1. An operating method for a water injection and venting device for a boiler water circulating pump test motor, wherein the water injection and venting device for the boiler water circulating pump test motor comprises: Pump body (1), motor (3), heat exchanger (7), first shut-off valve (2), second shut-off valve (4), third shut-off valve (5), fourth shut-off valve (8), fifth shut-off valve (9), flow meter (6), press pump (10), water tank (11), heat exchanger (7) and motor (3) are connected together by pipes; The press pump (10) is connected to the water tank (11) through the main pipe. The main pipe is equipped with a fifth shut-off valve (9). The water in the water tank (11) is divided into two paths after passing through the press pump (10). The first path is the inlet pipe through the heat exchanger (7). The inlet pipe through the heat exchanger (7) is equipped with a fourth shut-off valve (8). The second path is the inlet pipe of the motor. The second path enters the pump body through the motor and is discharged through the outlet pipe. The outlet pipe is equipped with a first shut-off valve (2). The inlet pipe of the motor is divided into the front side of the inlet pipe and the rear side of the inlet pipe. The flow meter (6) is set on the front side of the inlet pipe. The rear side of the inlet pipe is divided into two branches. One branch is equipped with a second shut-off valve (4) and is connected to the motor (3) through a pipe. The other branch is equipped with a third shut-off valve (5). The method is characterized by the following steps: Step 1: When filling the motor with water, first make the first shut-off valve (2) and the third shut-off valve (5) fully open, and the second shut-off valve (4), the fourth shut-off valve (8), and the fifth shut-off valve (9) fully closed. Step 2: Start the press pump (10), slowly open the fifth shut-off valve (9), observe the flow rate of the flow meter (6), and open the fourth shut-off valve (8) for 10-15 seconds by adjusting the opening of the fifth shut-off valve (9) to discharge the gas in the pipeline from the fifth shut-off valve (9) to the fourth shut-off valve (8) into the heat exchanger (7); close the third shut-off valve (5) and the fourth shut-off valve (8), fully open the second shut-off valve (4), and inject water into the motor cavity; observe the flow rate of the flow meter (6), and inject water at a low flow rate by adjusting the fifth shut-off valve (9). The water level in the motor cavity rises slowly, so that the gas in the complex space inside the motor can be effectively discharged through the first shut-off valve (2) above. Step 3: When the water level in the motor (3) cavity reaches the connection point with the heat exchanger (7) tube side, the water will flow into the coil inside the heat exchanger (7) and expel the air in the coil. It cannot be observed during the water filling process. Because the water enters the coil of the heat exchanger (7) from top to bottom, the gas cannot be completely expelled, and further venting is required afterward. Step 4: Continue until the water flows out in a continuous column from the first shut-off valve (2). At this point, close the second shut-off valve (4). Depending on the size of the motor, this process may take tens of minutes to several hours. Step 5: Fully open the third shut-off valve (5) to prevent the pressure pump (10) from running at zero flow and causing the temperature to rise. When no more liquid flows out from the first shut-off valve (2), close the third shut-off valve (5) and fully open the fourth shut-off valve (8) to inject water into the tube side of the heat exchanger (7). Because the coil structure in the heat exchanger (7) is relatively regular, the water injection process can effectively remove residual air until the water flows out continuously in a columnar shape from the first shut-off valve (2) again. Step 6: Fully open the second shut-off valve (4), and adjust the opening of the fifth shut-off valve (9) so that the reading of the flow meter (6) is 0.2 to 0.5 m³ / h. Pour water for 5 to 10 minutes. Under the action of the fast water flow, if there is air in the tube side of the motor (3) and heat exchanger (7), it can be further discharged. Step 7: Close the fifth shut-off valve (9), stop the press pump (10), and complete the water injection and air venting of the motor.

2. The operating method of the water injection and venting device for the boiler water circulating pump test motor according to claim 1, characterized in that: The first shut-off valve (2), the second shut-off valve (4), the third shut-off valve (5), the fourth shut-off valve (8), and the fifth shut-off valve (9) are all shut-off valves of the same model, and the material of the flow-through components is stainless steel.

3. The operating method of the water injection and venting device for the boiler water circulating pump test motor according to claim 1, characterized in that: The impeller and shaft of the stamping pump (10) are made of stainless steel; the water tank (11) is made of all stainless steel.

4. The operating method of the water injection and venting device for the boiler water circulating pump test motor according to claim 1 or 3, characterized in that: A viewing window is installed on the water tank (11).

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