A closed test system and method for a mechanical pump-in foam proportioning device

Abstract

This application relates to the field of mechanical testing, and in particular to a closed-loop testing system and method for a mechanically pumped foam proportioning device. It includes a closed-loop testing system comprising a closed-circuit loop, a circulation power component, and a pressure stabilizing and boosting component. The circulation power component drives the test medium to circulate and generate a pressure differential, while the pressure stabilizing and boosting component replenishes the medium to establish a base static pressure. Together, they create a test pressure in the supply pipeline that is formed by the superposition of the base static pressure and the circulation pressure differential. The system also includes various detection components and regulating valves. Furthermore, it includes a closed-loop testing method based on this system, comprising steps such as liquid injection and venting, establishing base static pressure, superimposing pressure and adjusting operating conditions, and steady-state pressure-holding cyclic testing. This application achieves the technical effect of effectively simulating the actual working pressure and flow conditions of a mechanically pumped foam proportioning device, enabling effective testing of its performance and durability.

Description

Technical Field

[0001] This application relates to the field of mechanical testing, and in particular to a closed-loop testing system and method for a mechanically pumped foam proportioning mixing device. Background Technology

[0002] Currently, foam fire suppression systems are widely used to extinguish Class B fires in industries such as petroleum, chemical, and warehousing, where large quantities of flammable liquids are present. The mechanically pumped foam proportioning unit, as the core component of this system, is responsible for steadily injecting foam concentrate into the fire-fighting water flow according to a set ratio to generate qualified extinguishing foam. To verify the reliability of this unit under extreme operating conditions, industry standards and user procurement often require rigorous durability tests on mechanically pumped foam proportioning units. Specifically, the equipment needs to maintain continuous operation for 24 hours or longer at its rated maximum operating pressure and maximum test flow rate.

[0003] In current conventional durability testing, open or semi-open water circulation test systems are typically used. During the test, a high-power, high-lift main water supply pump draws atmospheric pressure water from an atmospheric pressure tank or pool, pressurizes it directly to the calibrated maximum test pressure, and then supplies it to the inlet of the mechanically pumped foam proportioning device under test. After the water flows through the device under test and completes the test, it only overcomes the device's own flow resistance, resulting in a small pressure drop. At this point, the test medium in the pipeline still retains a relatively high pressure at the outlet of the device under test. However, this portion of high-pressure test water is directly depressurized and discharged back into the atmospheric pressure pool, releasing all residual pressure in the pipeline network. Subsequently, the main water supply pump draws test water again from the atmospheric pressure state and pressurizes it again to the maximum test pressure, thus repeating the entire durability cycle test.

[0004] The aforementioned technologies suffer from drawbacks such as wasted pressure energy and high testing energy consumption. In existing open-loop testing systems, because the residual pressure of the system after the test medium flows through the device under test cannot be recovered, the main water supply pump must bear the entire workload of directly pressurizing atmospheric water to the maximum test pressure throughout the entire test cycle. This means that the main water supply pump used for testing must have a high head, which not only places high demands on the pump hardware selection and motor rated power, but also results in significant power consumption during long-term continuous durability testing, increasing factory testing costs. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, this application provides a closed-loop testing system and method for a mechanically pumped foam proportioning device, which can achieve low-energy closed-loop operation under high-pressure and high-flow-rate testing conditions, providing a precise, efficient and energy-saving testing solution for the performance verification and long-term durability testing of mechanically pumped foam proportioning devices.

[0006] This application is achieved through the following technical solution: A closed-loop testing system for a mechanically pumped foam proportioning device includes: a closed-loop circulation system comprising a supply pipe and a return pipe, wherein the output end of the supply pipe is connected to the inlet of the mechanically pumped foam proportioning device under test, and the input end of the return pipe is connected to the outlet of the mechanically pumped foam proportioning device under test; and a circulation power component connected in series between the return pipe and the supply pipe, wherein the input end of the circulation power component is connected to the output end of the return pipe, and the output end is connected to the input end of the supply pipe, for driving the test medium in the closed-loop circulation system. The circulating flow in the closed loop generates a circulating pressure difference; the pressure stabilizing and boosting component, connected to the return pipeline, includes a liquid replenishment unit and a pressure stabilizing and relieving unit. The liquid replenishment unit is used to replenish the test medium to the closed loop to establish the system's basic static pressure. The pressure stabilizing and relieving unit is used to absorb pressure changes caused by volume fluctuations of the test medium to maintain the system's basic static pressure. The pressure stabilizing and boosting component works together with the circulating power component to ensure that the test pressure flowing through the inlet in the liquid supply pipeline is formed by the superposition of the system's basic static pressure and the circulating pressure difference.

[0007] By adopting the above technical solution, the closed-loop circulation connects the outlet and inlet of the device under test (DUT) to recover the residual pressure of the system after the test medium flows through the DUT. The pressure stabilizing and boosting component establishes and maintains a high system base static pressure in the loop, while the circulation power component only needs to output the circulation pressure difference to overcome the flow resistance of the DUT and pipeline to maintain the circulation flow of the medium in the pipeline network. This results in the final test pressure in the supply pipeline being formed by the superposition of the system base static pressure and a lower circulation pressure difference, thereby significantly reducing the head requirement and operating load of the power source required to drive the circulation medium. This effectively solves the problem of pressure energy waste caused by the direct discharge of pressurized medium in existing open-loop testing systems, and significantly reduces the overall energy consumption and testing cost of long-term durability testing. Furthermore, the circulation power component includes a circulation pump, the inlet of which is connected to the output end of the return pipeline, and the outlet of which is connected to the input end of the supply pipeline.

[0008] By adopting the above technical solution, a circulating pump is used as the circulating power component and directly connected in series between the return pipeline and the supply pipeline. The structure is compact and easy to control. It can stably and efficiently provide the circulating pressure difference required to overcome fluid resistance for the closed loop, ensuring that the test medium maintains a continuous and constant circulating flow state in the loop.

[0009] Furthermore, the replenishment unit includes a pressurizing pump and a pressurizing branch pipe; the input end of the pressurizing pump is used to draw external liquid source, and the output end is connected to the return pipeline through the pressurizing branch pipe.

[0010] By adopting the above technical solution, the pressurizing pump draws liquid from an external liquid source through the pressure replenishment branch pipe and injects it into the return pipeline. This not only enables the rapid injection of liquid into the pipeline network at the beginning of the test to establish the basic static pressure of the system, but also timely replenishes the pressure loss caused by minor leaks or volume changes in the circuit during long-term pressure holding cycle tests, ensuring that the basic static pressure of the system is maintained stably for a long time.

[0011] Furthermore, the pressure-replenishing branch pipe includes a connecting reducer and a tee fitting; the smaller diameter end of the reducer is connected to the output end of the pressure pump, and the larger diameter end is connected to the bypass input end of the tee fitting; the main path of the tee fitting is connected in series to the return pipe.

[0012] By adopting the above technical solution, the pressure replenishment branch pipe adopts a structure combining a reducing pipe and a tee fitting. The reducing pipe enables the high-pressure fluid output by the pressurizing pump to achieve a smooth transition in flow velocity and flow pressure before entering the return pipeline, reducing the impact and disturbance of the fluid replenishment process on the main flow medium in the closed loop, and improving the uniformity and stability of the pressure distribution of the entire test pipeline network.

[0013] Furthermore, an exhaust assembly is connected to both the local high point of the closed loop and the top of the pressure-replenishing branch pipe; the exhaust assembly includes an exhaust duct and a control valve disposed on the exhaust duct.

[0014] By adopting the above technical solution, an exhaust component is installed at the top of the pressure-replenishing branch pipe, which can effectively discharge the air accumulated inside the closed pipeline during the liquid injection and pressure-building stage, prevent the occurrence of air resistance and the interference of gas compressibility on the system pressure control accuracy, ensure the accuracy of subsequent superimposed pressurization and flow regulation, and at the same time avoid cavitation damage to the circulating pump due to gas intake.

[0015] Furthermore, a flow regulating valve and a flow meter are connected in series in the closed loop. The flow regulating valve is used to regulate the circulation flow through the mechanically pumped foam proportioning device to be tested; the flow meter is used to monitor the circulation flow through the closed loop.

[0016] By adopting the above technical solution, integrating a flow meter and a flow regulating valve into a closed loop, it is possible to achieve real-time and accurate monitoring and dynamic adjustment of the circulating flow in the test pipeline network, ensuring that the test flow field conditions strictly match the working requirements of the device under test.

[0017] Furthermore, a pressure detection component is provided on the closed loop, the pressure detection component including an inlet pressure detection element and an outlet pressure detection element; the inlet pressure detection element is disposed on the liquid supply pipeline and located between the output end of the circulation power component and the inlet of the mechanical pump-in foam proportioning device to be tested; the outlet pressure detection element is disposed on the return pipeline and located between the outlet of the mechanical pump-in foam proportioning device to be tested and the input end of the circulation power component.

[0018] By adopting the above technical solution, pressure detection devices are installed on the liquid supply pipeline at the inlet and the return pipeline at the outlet of the device under test. The inlet pressure detection device can directly monitor whether the test fluid before entering the device under test reaches the set target test pressure, while the outlet pressure detection device can provide real-time feedback on the pressure status of the return pipeline network after the test medium flows through the device under test. This provides key data feedback for the precise start-up, shutdown and pressure replenishment of the pressure stabilizing and boosting components, ensuring that the closed loop can always stably maintain the required system base static pressure during long-term dynamic testing.

[0019] Furthermore, the pressure stabilizing and relieving unit includes a safety relief valve and an accumulator connected in parallel; the safety relief valve and the accumulator are connected to the closed loop and are used to absorb pressure fluctuations of the test medium in the pipeline during constant pressure cyclic testing to prevent overpressure in the pipeline.

[0020] By adopting the above technical solution, the pressure stabilization and pressure relief unit utilizes the compressibility of the gas inside the accumulator to provide a flexible volume compensation space for the rigid closed pipeline network. It can effectively absorb and buffer the pressure surge caused by volume changes or mechanical disturbances of the test medium, and smooth the fluctuation of the system's basic static pressure. Combined with the mechanical pressure relief mechanism of the safety relief valve, it can quickly release part of the medium when the pipeline network faces the risk of overpressure. The two work together in parallel to construct a dual protection system of pressure stabilization and buffering and ultimate explosion protection, which significantly improves the system stability and equipment operation safety of the high-pressure constant pressure test process.

[0021] A closed-loop testing method for a mechanically pumped foam proportioning mixing device is applied to a closed-loop testing system. The closed-loop testing system includes a closed-loop circulation circuit, a circulation power component, and a pressure stabilizing and boosting component. The closed-loop circulation circuit is also equipped with an exhaust component, a static pressure detection element, an inlet pressure detection element, an outlet pressure detection element, a flow meter, and a flow regulating valve. The method includes the following steps: S1, Liquid injection and venting: The exhaust component is activated, and the liquid replenishment unit is controlled to draw external liquid source and continuously inject test medium into the closed-loop circulation circuit. Based on the injection of test medium into the pipeline, the circulation power component is activated to drive the test medium to flow in the closed-loop circulation circuit, and the air in the pipeline is discharged through the exhaust component until the closed-loop circulation circuit is filled with the test medium, after which the exhaust component is closed; S2, Establishing basic static pressure: The liquid replenishment unit is controlled to continue replenishing the test medium into the closed-loop circulation circuit and to acquire pressure monitoring data from the static pressure detection element; When the monitoring data of the static pressure detection element reaches the preset system basic static pressure value, the system basic static pressure is established and maintained at the input end of the circulation power component; S3, Superimposed pressure boosting and... Condition adjustment: Maintain the pressure replenishment state of the pressure stabilizing and boosting component to maintain the system's basic static pressure; control the operation of the circulating power component to generate a circulating pressure difference; adjust the flow regulating valve to make the circulating flow reach the preset target test flow, and simultaneously acquire the monitoring data of the inlet pressure detection element and the flow meter; based on the superposition effect of the system's basic static pressure and the circulating pressure difference, make the test pressure before the inlet of the mechanical pump-in foam proportioning mixing device under test reach the preset target test pressure; S4, steady-state constant pressure circulation test: the test medium flows through the mechanical pump-in foam proportioning mixing device under test. The foam proportioning device is pumped in and generates a circulating pressure drop before entering the return pipeline. During continuous circulation testing, monitoring data from the outlet pressure sensor is acquired, and the closed loop is pressurized through the replenishment unit. When the system is overpressured, the pressure is relieved and buffered through the pressure stabilizing and relieving unit to maintain the pressure at the outlet pressure sensor at the preset system baseline static pressure value. The circulation power component continuously outputs the circulating pressure difference that matches the circulating pressure drop to maintain the circulation flow of the test medium in the closed loop until the preset durability test duration is reached.

[0022] By adopting the above technical solution, the testing method operates according to a rigorous logical sequence: liquid injection and venting, establishing basic static pressure, superimposed pressurization adjustment, and steady-state pressure holding cyclic testing. First, air is eliminated to remove system interference. Then, a high basic static pressure is established and maintained using the pressure stabilization and boosting component. Finally, the circulating power component is activated to output an extremely low circulating pressure differential to compensate for pipeline flow resistance. This cleverly transforms the original test mode, which required high-power direct pressure from a single pump, into a composite and coordinated test mode that combines static pressure maintenance with dynamic pressure circulation. This method allows the circulating power component to only bear a small workload in overcoming the pressure drop of the device under test and pipelines throughout the entire long-term test cycle. It fundamentally changes the energy consumption path of direct pressure relief of high-pressure fluid in traditional testing, significantly reducing the energy cost of long-duration endurance testing and achieving efficient recycling of the pressure potential energy of the test medium.

[0023] In summary, this application includes at least one of the following beneficial technical effects: This application recovers the residual pressure of the test medium after it flows through the device under test through a closed loop, and establishes the basic static pressure of the system using a pressure stabilizing and boosting component. In conjunction with the circulating power component, it provides a circulating pressure difference to overcome flow resistance. The target test pressure is formed by the superposition of static pressure and pressure difference, which greatly reduces the head requirement and power load of the main circulation equipment, fundamentally solves the problem of energy waste in existing test systems, and significantly reduces the power consumption of long-term durability tests. This application achieves the smooth inflow of high-pressure fluid and reduces fluid disturbance in the main pipeline network by setting up a pressure-replenishing branch pipe with a reducing pipe and an exhaust assembly. At the same time, it effectively vents the gas in the pipeline in the early stage of testing to prevent gas lock phenomenon, ensuring the rapid establishment of basic static pressure in the closed loop and steady-state pressure maintenance during long-term operation. This application achieves precise monitoring of test pressure and flexible dynamic adjustment of circulating flow at various stages within the pipeline network by rationally arranging inlet pressure detection devices, outlet pressure detection devices, static pressure detection devices, flow meters, and flow regulating valves at pipeline nodes. This ensures the accuracy and reliability of the durability test monitoring data of the device under test under extreme operating conditions. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the closed-loop testing system of a mechanically pumped foam proportioning mixing device described in Embodiment 1; Figure 2 This is a partially enlarged view of the voltage stabilizing and boosting component described in Embodiment 1.

[0025] In the diagram: 1. Closed-loop circulation circuit; 11. Liquid supply line; 12. Return line; 13. Static pressure sensor; 14. Inlet pressure sensor; 15. Outlet pressure sensor; 16. Flow regulating valve; 17. Flow meter; 2. Circulation power assembly; 3. Pressure stabilizing and boosting assembly; 31. Booster pump; 32. Pressure replenishing branch pipe; 321. Reducer; 322. Tee fitting; 33. Accumulator; 34. Safety relief valve; 4. Mechanically pumped foam proportioning device; 5. Exhaust assembly; 51. Exhaust duct; 52. Control valve. Detailed Implementation

[0026] The technical solutions of various embodiments 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, and 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. Example 1

[0027] Reference Figure 1 This application discloses a closed-loop testing system for a mechanically pumped foam proportioning device, comprising: a closed-loop circulation loop 1, including a supply pipe 11 and a return pipe 12, wherein the output end of the supply pipe 11 is connected to the inlet of the mechanically pumped foam proportioning device 4 to be tested, and the input end of the return pipe 12 is connected to the outlet of the mechanically pumped foam proportioning device 4 to be tested; and a circulation power component 2, connected in series between the return pipe 12 and the supply pipe 11, wherein the input end of the circulation power component 2 is connected to the output end of the return pipe 12, and the output end is connected to the input end of the supply pipe 11. The end connection is used to drive the test medium to circulate in the closed loop 1 and generate a circulating pressure difference; the pressure stabilizing and boosting component 3 is connected to the return pipeline 12 and includes a liquid replenishment unit and a pressure stabilizing and depressurizing unit. The liquid replenishment unit is used to replenish the test medium to the closed loop 1 to establish the system's basic static pressure. The pressure stabilizing and depressurizing unit is used to absorb the pressure changes caused by volume fluctuations of the test medium to maintain the system's basic static pressure. The pressure stabilizing and boosting component 3 and the circulating power component 2 work together to make the test pressure flowing through the inlet in the liquid supply pipeline 11 formed by the superposition of the system's basic static pressure and the circulating pressure difference.

[0028] For details, please refer to Figure 1The circulating power assembly 2 employs a circulating pump. The inlet of the circulating pump is connected to the output flange of the return pipeline 12, and the outlet is connected to the input flange of the supply pipeline 11. The circulating pump is selected as a high-flow-rate, low-head centrifugal pump, specifically designed to overcome the frictional and local resistance generated by the flow of the test medium in the pipeline network and the device under test. Since the input of the circulating pump receives the test medium, which still has a relatively high pressure in the return pipeline 12, rather than a non-pressure medium, the circulating pump only needs to provide the head required to overcome the flow resistance, without needing to directly pressurize the test medium from atmospheric pressure to the target test pressure.

[0029] refer to Figure 1 and Figure 2 The pressure stabilizing and boosting assembly 3 includes a booster pump 31 and a pressure replenishing branch pipe 32. The input end of the booster pump 31 extends below the liquid surface of the external liquid source, specifically an external water storage tank, and the output end is connected to the return pipeline 12 via the pressure replenishing branch pipe 32. The booster pump 31 is selected as a low-flow, high-head vertical multistage pump or plunger pump, used to pressurize the liquid from the external liquid source into the closed loop 1. Since the booster pump 31 only operates during the initial liquid injection and pressure building phase of the test and during the replenishment of minor leaks during the test, its average flow rate is much smaller than the circulation flow rate of the circulation pump, but it must have the output capacity to reach or exceed the target test pressure. To reduce the impact of the replenishment process on the flow pattern of the main pipeline, the pressure replenishment branch pipe 32 includes a connecting reducer pipe 321 and a tee fitting 322. The smaller diameter end of the reducer pipe 321 is connected to the output end of the booster pump 31, and the larger diameter end is connected to the bypass input end of the tee fitting 322. The main path of the tee fitting 322 is connected in series to the return pipeline 12. By gradually increasing the cross-sectional area, the reducer pipe 321 forces the high-speed fluid output by the booster pump 31 to gradually reduce its velocity and convert it into static pressure energy, thereby preventing the high-pressure liquid in the thin tube from directly entering the main pipeline and causing flow field turbulence and severe vibration.

[0030] refer to Figure 2 To ensure no gas accumulation within the system, an exhaust assembly 5 is connected to the top of the pressure-replenishing branch pipe 32. The exhaust assembly 5 includes a vertically upward exhaust conduit 51 and a control valve 52 mounted on the exhaust conduit 51. When the pipeline is filled with liquid, opening the control valve 52 allows air to be released from the pipeline. Simultaneously, a static pressure sensor 13 is installed on the pressure-replenishing branch pipe 32. Specifically, the static pressure sensor 13 is a pressure transmitter, with its probe extending into the pipe to monitor the system's base static pressure within the closed-loop circuit 1 in real time. Because the gas density is less than that of the test medium, the air accumulated in the pipeline naturally converges at the highest local point in the closed-loop circuit 1 under buoyancy. Positioning the exhaust assembly 5 at this highest local point allows for targeted removal of residual gas in the system, eliminating air bubbles in the fluid, thus preventing cavitation damage to the circulating pump during operation and avoiding disturbances to the pipeline's static pressure control caused by gas compressibility.

[0031] refer to Figure 1 The pressure stabilizing and pressure-relief unit in the pressure stabilizing and boosting assembly 3 includes a safety relief valve 34 and an accumulator 33 connected in parallel on the closed loop 1. During continuous constant pressure cyclic testing, the test medium inside the closed pipeline will expand in volume due to ambient temperature or mechanical heating. Due to the incompressibility of the liquid itself, even a small volume expansion will cause a violent pressure surge in the rigid closed pipeline network. The accumulator 33 has a pre-pressurized gas bladder structure, which uses the compressibility of gas to provide volume compensation space, absorb and buffer the volume fluctuations caused by the thermal expansion of the fluid, and smooth out normal pressure fluctuations in the pipeline network. When the system pressure is subjected to an abnormal impact exceeding the calibrated set value, the safety relief valve 34 automatically opens to discharge part of the medium, preventing pipeline overpressure damage through physical pressure relief and ensuring the operational safety of the entire test system under basic static pressure conditions.

[0032] refer to Figure 1 To quantitatively monitor and adjust the test conditions, a pressure detection assembly is installed on the closed loop 1, comprising an inlet pressure sensor 14 and an outlet pressure sensor 15. The inlet pressure sensor 14 is located on the supply line 11, between the output of the circulation power assembly 2 and the inlet of the mechanically pumped foam proportioning device 4 under test. The outlet pressure sensor 15 is located on the return line 12, between the outlet of the mechanically pumped foam proportioning device 4 under test and the input of the circulation power assembly 2. Furthermore, a flow regulating valve 16 is connected in series on the closed loop 1. The flow regulating valve 16 is either electrically or pneumatically operated and is used to change the total resistance of the pipeline, thereby regulating the circulating flow rate through the mechanically pumped foam proportioning device 4 under test. A flow meter 17, specifically an electromagnetic flow meter, is installed on the straight section of the main pipeline of the closed loop 1 to accurately monitor the circulating flow rate through the closed loop 1.

[0033] In addition, the closed-loop testing system also includes a control system, which is connected to the static pressure sensor 13, inlet pressure sensor 14, outlet pressure sensor 15, flow meter 17, booster pump 31, circulating pump, and flow regulating valve 16. The control system controls the operation of the booster pump 31 based on the feedback signal from the static pressure sensor 13 to maintain a constant system baseline static pressure; the control system controls the rotational speed of the circulating pump and the opening degree of the flow regulating valve 16 based on the feedback signal from the flow meter 17 to maintain a constant circulating flow rate. The control system is implemented using a programmable logic controller or an industrial computer.

[0034] The implementation principle of this embodiment is as follows: During system operation, the pressurization pump 31 of the replenishment unit draws liquid from an external liquid source and pumps it into the closed pipeline network. When the pipeline network is full and the exhaust components 5 at each local high point have purged the air, the pressurization pump 31 continues to work, establishing a high system base static pressure in the entire closed loop 1. At this time, the circulation pump starts, pushing the pressurized test medium to circulate in the closed loop 1. The circulation pump only needs to provide the circulating pressure difference to overcome the resistance of the pipeline and the device under test. The system base static pressure and the circulating pressure difference are superimposed, so that the test pressure entering the inlet of the device under test reaches the target working pressure. During continuous operation, the accumulator 33 of the pressure stabilization and pressure relief unit absorbs liquid volume fluctuations in real time. The static pressure detection element 13 monitors the pipeline side pressure in real time and controls the pressurization pump 31 to perform micro-liquid replenishment and pressure maintenance through feedback control. Combined with the pressure limiting protection of the safety relief valve 34, the balance of the long-term durability test is maintained. Example 2

[0035] A closed-loop testing method for a mechanically pumped foam proportioning mixing device is applied to a closed-loop testing system. The closed-loop testing system includes a closed-loop circulation loop 1, a circulation power component 2, and a pressure stabilizing and boosting component 3. The closed-loop circulation loop 1 is also equipped with an exhaust component 5, a static pressure detection element 13, an inlet pressure detection element 14, an outlet pressure detection element 15, a flow meter 17, and a flow regulating valve 16. The method includes the following steps: S1. Liquid injection and venting: Turn on the venting component 5, control the liquid replenishment unit to draw external liquid source, and continuously inject the test medium into the closed loop 1; on the basis of injecting the test medium into the pipeline, start the circulation power component 2 to drive the test medium to flow in the closed loop 1, and exhaust the air in the pipeline through the venting component 5 until the closed loop 1 is full of test medium, and then turn off the venting component 5. S2. Establishing basic static pressure: The control unit continues to replenish the test medium into the closed loop 1 and acquires the pressure monitoring data of the static pressure detection element 13; when the monitoring data of the static pressure detection element 13 reaches the preset system basic static pressure value, the system basic static pressure is established and maintained at the input end of the circulating power component 2. S3, Superimposed Pressure Boosting and Operating Condition Adjustment: Maintain the pressure boosting component 3 to maintain the system's basic static pressure, control the operation of the circulating power component 2 to generate a circulating pressure difference; adjust the flow regulating valve 16 to make the circulating flow reach the preset target test flow, and simultaneously acquire the monitoring data of the inlet pressure detection element 14 and the flow meter 17. Based on the superimposed effect of the system's basic static pressure and the circulating pressure difference, make the test pressure before the inlet of the mechanical pump-in foam proportioning mixing device 4 to be tested reach the preset target test pressure. S4. Steady-state constant pressure cycling test: The test medium flows through the mechanically pumped foam proportioning device 4 under test and generates a circulating pressure drop before entering the return pipeline 12. During the continuous cycling test, the monitoring data of the outlet pressure detection element 15 is acquired, and the pressure is replenished to the closed loop 1 through the liquid replenishment unit. When the system is over-pressured, the pressure is relieved and buffered through the pressure stabilization and pressure relief unit to maintain the pressure at the outlet pressure detection element 15 at the preset system basic static pressure value. The cycling power component 2 continuously outputs a circulating pressure difference that matches the circulating pressure drop to maintain the circulating flow of the test medium in the closed loop 1 until the preset durability test duration is reached.

[0036] The implementation principle of this embodiment is as follows: This method decomposes the high-power fluid testing process into two independent sub-processes: static pressure maintenance control and dynamic pressure circulation control, through control logic. Steps S1 and S2 utilize low-power booster equipment to raise the entire closed pipeline network to a reference high-pressure state, completing static pressure energization; Step S3 utilizes a high-flow circulation device to impart kinetic energy to the fluid, completing dynamic pressure superposition and operating condition matching; Step S4 uses a dual closed-loop control mechanism, specifically controlling the replenishment volume through data feedback from the static pressure detection device 13 and controlling the circulation pump speed and valve opening through data feedback from the flow meter 17, so that after the test medium experiences pressure consumption by the device under test, the remaining pressure can be directly fed back to the input end of the circulation pump. Throughout the entire testing cycle, the externally input energy is only used to compensate for the friction loss along the pipeline network, local resistance loss, and the pressure drop generated by the device under test itself. From the control method perspective, energy loss caused by high-pressure fluid venting is completely avoided, achieving accurate reproduction of the actual operating conditions of the mechanically pumped foam proportioning mixing device 4 and energy saving and consumption reduction in the durability testing process.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of this application.

Claims

1. A closed-loop testing system for a mechanically pumped foam proportioning mixing device, characterized in that, include: The closed loop (1) includes a liquid supply line (11) and a return line (12). The output end of the liquid supply line (11) is used to connect to the inlet of the mechanical pump-in foam proportioning device (4) to be tested, and the input end of the return line (12) is used to connect to the outlet of the mechanical pump-in foam proportioning device (4) to be tested. A circulating power assembly (2) is connected in series between the return pipeline (12) and the supply pipeline (11). The input end of the circulating power assembly (2) is connected to the output end of the return pipeline (12), and the output end is connected to the input end of the supply pipeline (11). It is used to drive the test medium to circulate in the closed loop (1) and generate a circulating pressure difference. The pressure stabilizing and boosting component (3) is connected to the return pipeline (12) and includes a liquid replenishment unit and a pressure stabilizing and depressurizing unit. The liquid replenishment unit is used to replenish the test medium to the closed loop (1) to establish the basic static pressure of the system. The pressure stabilizing and depressurizing unit is used to absorb the pressure change caused by the volume fluctuation of the test medium to maintain the basic static pressure of the system. The pressure stabilizing and boosting component (3) and the circulating power component (2) work together to make the test pressure in the liquid supply pipeline (11) before flowing through the inlet formed by the superposition of the system's basic static pressure and the circulating pressure difference.

2. The closed-loop testing system for the mechanically pumped foam proportioning mixing device according to claim 1, characterized in that, The circulating power assembly (2) includes a circulating pump, the inlet of which is connected to the output end of the return pipeline (12), and the outlet of which is connected to the input end of the supply pipeline (11).

3. The closed-loop testing system for the mechanically pumped foam proportioning mixing device according to claim 1, characterized in that, The replenishment unit includes a pressurizing pump (31) and a pressurizing branch pipe (32); the input end of the pressurizing pump (31) is used to draw external liquid source, and the output end is connected to the return pipeline (12) through the pressurizing branch pipe (32).

4. The closed-loop testing system for the mechanically pumped foam proportioning mixing device according to claim 3, characterized in that, The pressure-replenishing branch pipe (32) includes a connecting reducer pipe (321) and a tee fitting (322); the small diameter end of the reducer pipe (321) is connected to the output end of the booster pump (31), and the large diameter end is connected to the bypass input end of the tee fitting (322); the main path of the tee fitting (322) is connected in series to the return pipe (12).

5. The closed-loop testing system for the mechanically pumped foam proportioning mixing device according to claim 3, characterized in that, The exhaust assembly (5) is connected to the local high point of the closed loop (1) and the top of the pressure-replenishing branch pipe (32); the exhaust assembly (5) includes an exhaust duct (51) and a control valve (52) disposed on the exhaust duct (51).

6. The closed-loop testing system for the mechanically pumped foam proportioning mixing device according to claim 3, characterized in that, The pressure-replenishing branch pipe (32) is equipped with a static pressure detection device (13), which is used to monitor the basic static pressure of the system in the closed loop (1).

7. The closed-loop testing system for the mechanically pumped foam proportioning mixing device according to claim 1, characterized in that, The closed loop (1) is provided with a pressure detection component, which includes an inlet pressure detection element (14) and an outlet pressure detection element (15). The inlet pressure detection element (14) is set on the liquid supply line (11) and is located between the output end of the circulation power component (2) and the inlet of the mechanical pump-in foam proportioning device (4) to be tested. The outlet pressure detection element (15) is set on the return line (12) and is located between the outlet of the mechanical pump-in foam proportioning device (4) to be tested and the input end of the circulation power component (2).

8. The closed-loop testing system for the mechanically pumped foam proportioning mixing device according to claim 1, characterized in that, A flow regulating valve (16) and a flow meter (17) are connected in series on the closed loop (1). The flow regulating valve (16) is used to regulate the circulating flow through the mechanical pump-in foam proportioning device (4) to be tested; the flow meter (17) is used to monitor the circulating flow through the closed loop (1).

9. The closed-loop testing system for the mechanically pumped foam proportioning mixing device according to claim 1, characterized in that, The pressure stabilizing and pressure relief unit includes a safety relief valve (34) and an accumulator (33) connected in parallel; the safety relief valve (34) and the accumulator (33) are connected to the closed loop (1) and are used to absorb pressure fluctuations of the test medium in the pipeline during constant pressure cycle testing to prevent overpressure in the pipeline.

10. A closed-loop test method for a mechanically pumped foam proportioning mixing device, characterized in that, The method is applied to a closed-loop testing system, which includes a closed-loop circuit (1), a circulating power component (2), and a pressure stabilizing and boosting component (3) as described in claim 1; and the closed-loop circuit (1) is further provided with an exhaust component (5), a static pressure detection element (13), an inlet pressure detection element (14), an outlet pressure detection element (15), a flow meter (17), and a flow regulating valve (16); the method includes the following steps: S1. Liquid injection and venting: Open the venting assembly (5), control the liquid replenishment unit to draw external liquid source, and continuously inject test medium into the closed loop (1); on the basis of injecting test medium into the pipeline, start the circulation power assembly (2) to drive the test medium to flow in the closed loop (1), and exhaust the air in the pipeline through the venting assembly (5) until the closed loop (1) is full of test medium, and then close the venting assembly (5); S2. Establishing basic static pressure: Control the replenishment unit to continue replenishing the test medium into the closed loop (1) and obtain the pressure monitoring data of the static pressure detection device (13); when the monitoring data of the static pressure detection device (13) reaches the preset system basic static pressure value, establish and maintain the system basic static pressure at the input end of the circulating power component (2); S3, Superimposed Pressure Boosting and Operating Condition Adjustment: Maintain the pressure boosting component (3) to maintain the basic static pressure of the system, control the operation of the circulating power component (2) to generate a circulating pressure difference; adjust the flow regulating valve (16) to make the circulating flow reach the preset target test flow, and simultaneously acquire the monitoring data of the inlet pressure detection element (14) and the flow meter (17). Based on the superimposed effect of the basic static pressure of the system and the circulating pressure difference, make the test pressure before the inlet of the mechanical pump-in foam proportioning mixing device (4) to be tested reach the preset target test pressure. S4. Steady-state constant pressure cycle test: The test medium flows through the mechanical pump-in foam proportioning device (4) to be tested and generates a cycle pressure drop before entering the return pipeline (12); During the continuous cycle test, the monitoring data of the outlet pressure detection device (15) is obtained, and the closed loop (1) is pressurized through the liquid replenishment unit, and the pressure is relieved and buffered through the pressure stabilization and pressure relief unit when the system is over-pressured, so that the pressure at the outlet pressure detection device (15) is maintained at the preset system basic static pressure value; The cycle power component (2) continuously outputs the cycle pressure difference that matches the cycle pressure drop to maintain the cycle flow of the test medium in the closed loop (1) until the preset durability test duration is reached.

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