A booster pump high pressure test system

Abstract

This invention relates to the field of booster pump testing technology, specifically a high-pressure testing system for booster pumps. The invention includes a large circulation pipeline. Along the direction of medium flow, a water storage assembly, a pre-pump, a booster pump under test, a main pipeline regulating valve, and a booster regulating valve are sequentially installed on the large circulation pipeline. A one-way return pipeline is connected in parallel to the large circulation pipeline. The first and second nodes of this one-way return pipeline are located at the output ends of the main pipeline regulating valve and the pre-pump, respectively, and the medium flow direction of the one-way return pipeline is towards the output end of the pre-pump. This invention not only provides high-pressure conditions for the booster pump inlet but also eliminates the need for continuous high-power operation of the pre-pump, significantly reducing testing costs and extending the service life of the booster pump.

Description

Technical Field

[0001] This invention relates to the field of booster pump testing technology, specifically a booster pump high-pressure testing system. Background Technology

[0002] A booster pump is a type of pump commonly used to transport high-pressure media, increasing the pressure of high-pressure fluids to a higher level before delivering them to their destination. When a booster pump is in operation, the inlet pressure is very high. Compared with conventional low-pressure inlet pumps, the local structure of a booster pump needs to be adapted and optimized to meet the high-pressure inlet operating conditions and improve the service life of the booster pump.

[0003] Therefore, during the testing and inspection of booster pumps, the high-pressure test conditions at the booster pump inlet are often simulated to test the performance reliability and high-pressure differential operation stability of the booster pump under high-pressure conditions.

[0004] like Figure 2 As shown, the existing booster pump testing system mainly includes a test pipeline d connected end-to-end. Along the direction of medium flow, a water storage tank a, a pre-pump 12, and a booster pump under test 13 are sequentially installed on the test pipeline d. In addition, a branch line b is connected to the outlet of the pre-pump 12, and a control valve c is installed on branch line b. During the test, the pre-pump 12 pressurizes and supplies water to the inlet of the booster pump under test 13, providing high-pressure test conditions for the inlet of the booster pump under test 13. Simultaneously, the control valve c on branch line b distributes the flow from the pre-pump 12 through the booster pump under test 13 and branch line b, achieving precise adjustment of the inlet pressure of the booster pump under test 13. In this layout, the pre-pump 12 needs to supply medium not only to the booster pump under test 13 but also to branch line b; therefore, the operating flow rate of the pre-pump 12 will be much greater than the test flow rate of the booster pump under test 13. Obviously, under long-term continuous testing, the test booster pump 13 needs to operate at high power continuously, which not only greatly increases the test cost, but also reduces the service life of the test booster pump 13, so it is urgent to solve this problem. Summary of the Invention

[0005] In order to avoid and overcome the technical problems existing in the prior art, the present invention provides a high-pressure test system for booster pumps. The test process can not only provide high-pressure conditions for the inlet of the booster pump, but also eliminate the need for continuous high-power operation of the pre-pump, which greatly reduces the cost of the test process and extends the service life of the booster pump.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A high-pressure test system for a booster pump includes a large circulation pipeline. Along the direction of medium flow, a water storage component, a pre-pump, a booster pump under test, a main pipeline regulating valve, and a booster regulating valve are sequentially installed on the large circulation pipeline. A one-way return pipeline is connected in parallel on the large circulation pipeline. The first node and the second node of the one-way return pipeline are located at the output end of the main pipeline regulating valve and the output end of the pre-pump, respectively, and the medium flow direction of the one-way return pipeline flows to the output end of the pre-pump.

[0008] As a further aspect of the present invention: the water storage component is a cooling tower, and the flow rate of the pre-pump under normal operating conditions is controlled according to the following formula:

[0009] ;

[0010] In the formula,

[0011] The flow rate of the booster pump under normal operating conditions is expressed in m³ / s. 3 / h;

[0012] The empirical coefficient for power consumption correction is dimensionless.

[0013] The flow rate of the booster pump under test is expressed in m³ / s. 3 / h;

[0014] The discharge pressure of the tested booster pump is expressed in Pa.

[0015] The inlet pressure of the booster pump under test is expressed in Pa.

[0016] The efficiency of the tested booster pump is dimensionless.

[0017] The length of the test pipe is in meters (m).

[0018] The temperature of the medium inside the test pipeline is expressed in °C.

[0019] The ambient temperature outside the test pipeline is expressed in °C.

[0020] The convection coefficient inside the test pipe is dimensionless.

[0021] The inner diameter of the test pipe is in meters (m).

[0022] The outer diameter of the test pipe is in meters (m).

[0023] The temperature difference is measured in °C.

[0024] As a further aspect of the present invention: the flow rate of the tested booster pump under leakage operation is controlled according to the following formula:

[0025] ;

[0026] In the formula,

[0027] The flow rate of the booster pump under leakage operation conditions is expressed in m³ / s. 3 / h;

[0028] These are empirical correction coefficients, dimensionless.

[0029] The plunger diameter is in meters (m).

[0030] This refers to the initial clearance height of the packing material, in meters (m).

[0031] The coefficient of compressibility is dimensionless.

[0032] This refers to the initial length of the packing material, in meters (m).

[0033] This is a length correction factor, dimensionless;

[0034] The dynamic viscosity of the medium is expressed in Pa·s.

[0035] As a further embodiment of the present invention: the one-way return pipeline has a one-way check valve to realize the one-way flow of the medium. The one-way check valve is provided with an exhaust port and a water inlet at its inlet and outlet, respectively, and valves are installed on both the exhaust port and the water inlet.

[0036] As a further embodiment of the present invention: a first flow stabilizing device and a second pressure sensor are sequentially installed on the pipeline between the output end of the pre-pump and the second node in the large circulation pipeline, and a first pressure sensor is installed on the pipeline between the output end of the water storage component and the input end of the pre-pump in the large circulation pipeline.

[0037] As a further embodiment of the present invention: a third pressure sensor is installed on the pipeline between the second node and the input end of the test booster pump on the large circulation pipeline, and a second flow stabilizing device and a fourth pressure sensor are sequentially installed on the pipeline between the output end of the test booster pump and the main pipeline regulating valve on the large circulation pipeline.

[0038] As a further aspect of the present invention: a flow meter is installed on the pipeline between the output end of the main pipeline regulating valve and the first node on the large circulation pipeline.

[0039] As a further embodiment of the present invention: safety overflow pipelines connecting water storage components are installed on the rear pipeline of the second node on the large circulation pipeline and on the pipeline between the tested booster pump and the main pipeline regulating valve, and safety overflow valves are installed on the safety overflow pipelines.

[0040] As a further aspect of the present invention: the water storage component is connected to a water replenishment pipeline for replenishing the water storage component with a medium, and an automatic water replenishment valve is installed on the water replenishment pipeline.

[0041] Compared with the prior art, the beneficial effects of the present invention are:

[0042] 1. During the test, the pre-pump is started first, allowing the medium to circulate in the main circulation pipeline. Due to the pressure drop caused by resistance in the main circulation pipeline, the pressure at the first node of the one-way return pipeline will be lower than the pressure at the second node, meaning the one-way return pipeline does not participate in the medium circulation at this point. Next, the opening of the booster regulating valve is reduced until the pressure at the input end of the booster pump under test reaches the required set pressure. Then, the booster pump under test is started. Because the pressure generated by the booster pump is much greater than the pressure drop caused by the pressure decrease, the pressure at the first node of the one-way return pipeline momentarily exceeds the pressure at the second node. Therefore, the one-way return pipeline will circulate the medium from the outlet of the booster pump under test to the outlet end of the pre-pump. Finally, the opening of the main pipeline regulating valve is adjusted to adjust the pressure at the output end of the booster pump under test to the required set pressure value. The test process is clear, orderly, and stable.

[0043] Based on the above experimental process, this application utilizes a unidirectional return pipeline to circulate and converge the medium at the output end of the pre-pump to supply the input end of the test booster pump. This reduces the flow rate supplied by the pre-pump, making the section of the pipeline containing the test booster pump in the unidirectional return pipeline and the main circulation pipeline the main flow pipeline for the medium. This significantly reduces the flow rate of the medium in the section of the pipeline containing the pre-pump and the water storage component in the main circulation pipeline, thus requiring the pre-pump to supply only a small flow rate during the test, significantly reducing the power of the pre-pump.

[0044] 2. The water storage component is a cooling tower that can be used to dissipate heat and cool down the medium, avoiding the medium temperature rise caused by long-term continuous circulation tests in the large circulation pipeline and unidirectional return pipeline, so as to avoid large fluctuations in the test temperature of the tested booster pump.

[0045] 3. This application also provides a flow control algorithm for the pre-pump, which optimizes the flow rate distributed to the cooling tower. While minimizing the flow rate of the pre-pump, it avoids large fluctuations in the temperature of the medium in the pipeline compared to the set temperature of the test, thereby achieving precise control of the temperature of the medium in the pipeline.

[0046] 4. This application also provides a flow control algorithm for the booster pump under pipeline leakage conditions, which can achieve precise control of the medium temperature in the pipeline even under leakage conditions, avoiding the increase in test time caused by downtime maintenance due to leakage during the test. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the test system of the present invention.

[0048] Figure 2 This is a schematic diagram of an existing experimental system.

[0049] In the diagram: 10. Main circulation pipeline; 11. Cooling tower; 12. Pre-pump; 121. First pressure sensor; 122. First flow stabilizing device; 123. Second pressure sensor; 13. Test booster pump; 131. Third pressure sensor; 132. Second flow stabilizing device; 133. Fourth pressure sensor; 14. Main pipeline regulating valve; 15. Flow meter; 16. Booster regulating valve; 17. Safety overflow pipeline; 171. Safety overflow valve; 20. One-way return pipeline; 21. One-way check valve; 22. Exhaust port; 23. Water inlet; e. First node; f. Second node;

[0050] a. Water storage tank; b. Branch line; c. Control valve; d. Testing pipeline. Detailed Implementation

[0051] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0052] For ease of understanding, the specific structure and operation of the present invention will be further described below with reference to the accompanying drawings:

[0053] The specific structure of this invention is as follows: Figure 1As shown, its main structure includes a large circulation pipeline 10. Along the direction of medium flow, a water storage component, a pre-pump 12, a test booster pump 13, a main pipeline regulating valve 14, and a booster regulating valve 16 are installed sequentially on the large circulation pipeline 10. A one-way return pipeline 20 is connected in parallel on the large circulation pipeline 10. The first node e and the second node f of the one-way return pipeline 20 are located at the output end of the main pipeline regulating valve 14 and the output end of the pre-pump 12, respectively, and the medium flow direction of the one-way return pipeline 20 flows to the output end of the pre-pump 12.

[0054] During the test, the pre-pump 12 is started first. The medium circulates in the main circulation pipeline 10. Due to the pressure drop caused by resistance in the main circulation pipeline 10, the pressure at the first node e of the one-way return pipeline 20 is less than the pressure at the second node f; that is, the one-way return pipeline 20 does not participate in the medium circulation at this time. Then, the opening of the booster regulating valve 16 is reduced so that the pressure at the input end of the tested booster pump 13 reaches the required set pressure. Afterward, the tested booster pump 13 starts. Because the pressure generated by the tested booster pump 13 is much greater than the pressure drop caused by the pressure decrease, the pressure at the first node e of the one-way return pipeline 20 momentarily exceeds the pressure at the second node f. Therefore, the one-way return pipeline 20 will circulate the medium from the outlet of the tested booster pump 13 to the outlet end of the pre-pump 12. Finally, the opening of the main pipeline regulating valve 14 is adjusted to adjust the pressure at the output end of the tested booster pump 13 to the required set pressure value.

[0055] This application utilizes the medium circulating and converging at the output end of the pre-pump 12 through the unidirectional return pipeline 20 to supply the input end of the test booster pump 13. By reducing the flow rate supplied by the pre-pump 12, the section of pipeline containing the unidirectional return pipeline 20 and the test booster pump 13 in the large circulation pipeline 10 becomes the main flow pipeline for the medium. This significantly reduces the flow rate of the medium in the section of pipeline containing the pre-pump 12 and the water storage component in the large circulation pipeline 10. Consequently, the pre-pump 12 only needs to supply a smaller flow rate during the test, significantly reducing the power of the pre-pump 12.

[0056] In addition, since the flow rate through the large circulation pipe 10 is very small, the water storage component does not need a large volume during the test, thus reducing the space occupied by the water storage component.

[0057] Specifically, such as Figure 1 As shown, the one-way return pipeline 20 has a one-way check valve 21 to realize the one-way flow of the medium. The one-way check valve 21 has an exhaust port 22 and a water inlet 23 at its inlet and outlet, respectively, and valves are installed on both the exhaust port 22 and the water inlet 23.

[0058] In the pipeline structure, the exhaust port 22 and the water inlet 23 are respectively set at the inlet and outlet of the one-way check valve 21. By opening the valves of the exhaust port 22 and the water inlet 23 and injecting the medium into the water inlet 23, the pipelines to the large circulation pipeline 10 and the one-way return pipeline 20 can be filled with the medium before the test, ensuring that the air in the pipeline is emptied.

[0059] Based on the above, such as Figure 1 As shown, a first flow stabilizing device 122 and a second pressure sensor 123 are sequentially installed on the pipeline of the large circulation pipeline 10 between the output end of the pre-pump 12 and the second node f. A first pressure sensor 121 is installed on the pipeline of the large circulation pipeline 10 between the output end of the water storage component and the input end of the pre-pump 12. The second pressure sensor 123 and the first pressure sensor 121 are used to directly obtain the pressure at the output and input ends of the pre-pump 12, respectively. The first flow stabilizing device 122 can be a prior art Chinese Tully-type flow stabilizer, which is used when the pre-pump 12 is a reciprocating pump, and aims to eliminate turbulence, reduce eddies, and reduce uneven flow velocity distribution. If the pre-pump 12 is a centrifugal pump, the first flow stabilizing device 122 is not required.

[0060] Based on the above, such as Figure 1 As shown, a third pressure sensor 131 is installed on the pipeline of the large circulation pipeline 10 between the second node f and the input end of the test booster pump 13. A second flow stabilizing device 132 and a fourth pressure sensor 133 are sequentially installed on the pipeline of the large circulation pipeline 10 between the output end of the test booster pump 13 and the main pipeline regulating valve 14. The fourth pressure sensor 133 and the third pressure sensor 131 are used to directly acquire the pressure at the output and input ends of the test booster pump 13, respectively. The second flow stabilizing device 132 can also be a Venturi-type flow stabilizer as in the prior art, which is used when the test booster pump 13 is a reciprocating pump, aiming to eliminate turbulence, reduce eddies, and reduce uneven flow velocity distribution. If the test booster pump 13 is a centrifugal pump, the second flow stabilizing device 132 is not required.

[0061] Based on the above, such as Figure 1 As shown, a flow meter 15 is installed on the pipeline between the output end of the main pipeline regulating valve 14 and the first node e on the large circulation pipeline 10, which is used to quickly obtain the flow value of the test booster pump 13 during the test.

[0062] In addition, to ensure safety during pipeline testing, such as Figure 1 As shown, safety overflow pipes 17 connecting the water storage components are installed on the pipeline behind the second node f on the large circulation pipeline 10 and on the pipeline between the test booster pump 13 and the main pipeline regulating valve 14. Safety overflow valves 171 are installed on the safety overflow pipes 17.

[0063] In addition, such as Figure 1 As shown, a water supply pipeline for replenishing the medium in the water storage component is connected to the water storage component. An automatic water supply valve is installed on the water supply pipeline, thereby realizing the replenishment of the medium in the water storage component in case of leakage or other situations.

[0064] Based on the above, to prevent the medium temperature from rising due to prolonged continuous circulation in the large circulation pipeline 10 and the one-way return pipeline 20, which would interfere with the test temperature of the booster pump 13, the water storage component in this application is a cooling tower 11, which can be used for heat dissipation and cooling of the medium. Simultaneously, to reduce the energy consumption of the booster pump 12 while preventing large fluctuations in the medium temperature, the flow rate of the booster pump 12 under normal operating conditions is controlled according to the following formula:

[0065] ;

[0066] In the formula,

[0067] The flow rate of the pre-pump 12 under normal operating conditions is expressed in m³ / s. 3 / h;

[0068] The empirical coefficient for power consumption correction is dimensionless and ranges from 0.90 to 0.95.

[0069] The flow rate of the tested booster pump 13 is expressed in m³ / s. 3 / h;

[0070] The discharge pressure of the tested booster pump 13 is expressed in Pa.

[0071] The inlet pressure of the tested booster pump 13 is expressed in Pa.

[0072] The efficiency of the tested booster pump 13 is dimensionless.

[0073] The length of the test pipe is in meters (m).

[0074] The temperature of the medium inside the test pipeline is expressed in °C.

[0075] The ambient temperature outside the test pipeline is expressed in °C.

[0076] The convection coefficient inside the test pipe is dimensionless and is taken as 100 to 300.

[0077] The inner diameter of the test pipe is in meters (m).

[0078] The outer diameter of the test pipe is in meters (m).

[0079] The temperature difference is measured in °C.

[0080] The derivation of the above formula is as follows:

[0081] (1) Overview

[0082] Since the experiment involves continuous power consumption by the test booster pump 13, most of this power consumption is converted into heat energy, continuously heating the test medium and inevitably causing its temperature to rise. Because the main circulation system is a high-pressure system, direct heat exchange is inefficient, costly, and poses safety hazards; therefore, direct cooling is not recommended. Cooling can be achieved by using a pre-pump 12 to deliver hot water from the cooling tower 11 for displacement, thus reaching thermal equilibrium. In this case, another task of the pre-pump 12 is to provide sufficient cooling displacement liquid; therefore, the cooling displacement rate of the pre-pump 12 needs to be calculated.

[0083] As the test medium circulates in the pipeline, it continuously exchanges heat with the surrounding atmosphere through the pipeline, which dissipates some of the heat.

[0084] Therefore, during the test, part of the heat generated by the test booster pump 13 was naturally dissipated through the pipeline, while the remaining heat that was not dissipated needed to be transported to the cooling tower 11 by the pre-pump 12 for direct cooling.

[0085] The following calculations will cover the heat generation power, the natural heat dissipation of the pipeline, and the heat delivered by the pre-pump 12 to the cooling tower 11.

[0086] (2) Calculation of heating power

[0087] In the test system of booster pump 13, the power consumption during operation of booster pump 13 is mainly due to heating the test medium. The operating power consumption of booster pump 13 is... (Unit: kW) can be expressed using the output power of the tested booster pump 13. (Unit: kW) Divide by the efficiency of the tested booster pump 13 get.

[0088] Right now:

[0089] ;

[0090] The power consumption of the tested booster pump 13 also accounts for a portion of the lubricating oil temperature rise in the oil tank, which is corrected using an empirical power consumption correction coefficient y, taken as 0.95-0.98. Other factors, such as seal temperature rise, can be ignored in the calculation.

[0091] Output power of the tested booster pump 13 The standard calculation formula is:

[0092] ;

[0093] The pressure difference between the inlet and outlet of the tested booster pump 13 is, i.e. ;

[0094] The discharge pressure of the tested booster pump 13 is expressed in MPa.

[0095] The inlet pressure of the tested booster pump 13 is in MPa.

[0096] Therefore, we can conclude that: ;

[0097] Since the right side of the equation is multiplied by 10 at this point... -6 Therefore, the discharge pressure of the tested booster pump 13 at this time... The unit is Pa;

[0098] The inlet pressure of the tested booster pump 13 is The unit is Pa.

[0099] Power consumption for heating the test medium Part of it dissipates naturally through the surface of the pipes, while the other part is transported to the cooling tower 11 for direct cooling via the pre-pump 12.

[0100] (3) Natural heat dissipation of the pipeline Calculation

[0101] When the temperature of the medium in the test pipe exceeds the ambient temperature, the medium will exchange heat with the air in the environment through the pipe, and some energy will be naturally dissipated. The power consumption for heating the test medium... Subtract natural heat dissipation from the pipes This refers to the energy that needs to be delivered by the pre-pump 12 to the cooling tower 11 for cooling. .

[0102] The liquid inside the pipe is at a high temperature, and it dissipates heat to the surrounding environment through the pipe wall. This generally follows the process: heat from inside the liquid is transferred to the pipe wall, conducted from the inner surface to the outer surface through the pipe wall, and then dissipated from the outer surface to the surrounding environment through convection and radiation.

[0103] 1) Determination of basic calculation conditions

[0104] A. The test pipe is circular.

[0105] B. Heat is lost in the following ways.

[0106] Internal convection: convective heat transfer between the liquid and the inner wall of the pipe;

[0107] Heat conduction through the pipe wall: Heat is conducted to the outer surface through the pipe wall;

[0108] External heat dissipation: The outer surface of the pipe dissipates heat into the environment through convection and radiation.

[0109] C. The calculation is based on the following basic boundary conditions.

[0110] Steady-state heat transfer: the temperature distribution does not change over time;

[0111] One-dimensional radial heat transfer: heat is transferred only along the radial direction of the pipe, and is symmetrical in both the circumferential and axial directions;

[0112] Linearization of radiative heat transfer: Equivalent to the convection coefficient .

[0113] 2) Thermal resistance calculation for each stage

[0114] Internal convection thermal resistance Calculate (the convective heat transfer resistance between the liquid and the inner wall of the pipe) using units of K / W:

[0115] ;

[0116] In the formula, The heat exchange area is expressed in m², and ;

[0117] The internal convection coefficient is expressed in W / (m²·K).

[0118] This is the inner radius of the pipe, in meters (m).

[0119] The length of the test pipeline is in meters (m).

[0120] Pipe wall thermal resistance (Unit: K / W) Calculation:

[0121] ;

[0122] in, The thermal conductivity of the pipe wall is expressed in W / (m·K).

[0123] This is the outer radius of the pipe, in meters (m).

[0124] External convection and radiation thermal resistance (Unit: K / W) Calculation:

[0125] ;

[0126] This is the external convection coefficient, expressed in W / (m³). 2 ·K);

[0127] The radiation equivalence factor is expressed in W / (m²). 2 ·K):

[0128] ;

[0129] This refers to the ambient temperature, expressed in °C.

[0130] The temperature of the pipe surface is expressed in °C.

[0131] The emissivity of the pipe surface;

[0132] It is the Stefan-Boltzmann constant;

[0133] This refers to the outer surface area of ​​the pipe, expressed in m²; where, ;

[0134] This represents the outer diameter of the pipe, in meters (m).

[0135] 3) Thermal resistance of each component, total thermal resistance and heat transfer system

[0136] A. Thermal resistance of each component and total thermal resistance calculate

[0137] The total thermal resistance is the sum of the series thermal resistances:

[0138] ;

[0139] External convection and radiation are in parallel because they act simultaneously on the same temperature difference.

[0140] B. Heat Transfer System Calculation

[0141] The natural heat dissipation of the pipeline is:

[0142] ;

[0143] The temperature of the medium inside the test pipeline;

[0144] at this time, The unit is W.

[0145] Calculating the overall heat transfer system requires converting all thermal resistances to a common reference area, typically the outer surface, and then converting each thermal resistance to a heat transfer coefficient based on that outer surface. This is related to the overall heat transfer coefficient. The formula is:

[0146] ;

[0147] Therefore, the overall heat transfer coefficient for:

[0148] ;

[0149] Therefore, we can conclude that:

[0150] ;

[0151] Right now:

[0152] ;

[0153] Therefore, we can conclude that:

[0154] .

[0155] 4) Engineering simplification

[0156] Since the above formula is quite complex, we can draw on the actual working conditions and application experience of various parameters in the test practice of booster pumps to simplify the heat dissipation power formula accordingly.

[0157] In practical engineering, low-carbon steel is generally used for test pipelines, with a thermal conductivity k of 45 W / (m·K). During pump testing, the flow velocity within the pipeline is generally controlled within 1 m / s to 5 m / s, and its internal convection coefficient is... The range can be selected from 100-500; the booster pump test pipeline is generally indoors, with horizontal pipes and automatic convection, and the external convection coefficient is... Select 50W / (m²·K); under normal circumstances, to ensure safety, the temperature difference between the booster pump test pipeline and the environment is very small, the thermal radiation is very small, and the radiation equivalence coefficient is small. A value of 3 W / (m²·K) is generally selected.

[0158] In conclusion, It can be simplified to:

[0159] ;

[0160] The convection coefficient inside the test pipe is dimensionless and is taken as 100 to 300.

[0161] Since the right side of the equation is divided by 1000 at this point, The unit is kW.

[0162] (4) Cooling calculation of cooling tower

[0163] 1) Equilibrium equations

[0164] A. Thermodynamic equilibrium equation

[0165] Cooling tower 11 cools the energy (Unit: kW) Discharged from the process system, it needs to be dissipated through water evaporation and air heating:

[0166] ;

[0167] In the formula: This refers to the circulating water mass flow rate, expressed in kg / s.

[0168] is the specific heat capacity of water, expressed in kJ / kg·℃;

[0169] The inlet water temperature of the cooling tower is expressed in °C.

[0170] The outlet water temperature of the cooling tower is expressed in °C.

[0171] Evaporation loss mass flow rate, in kg / s;

[0172] The latent heat of vaporization of water is expressed in kJ / kg.

[0173] B. Mass Balance Equation

[0174] Evaporation loss is equal to the amount of moisture absorbed by the air:

[0175] ;

[0176] In the formula: This is the dry air mass flow rate, expressed in kg / s.

[0177] Moisture content of inlet air, expressed in kg / kg dry air;

[0178] Moisture content at the air outlet, expressed in kg / kg dry air.

[0179] 2) Enthalpy difference equation on the air side

[0180] The total heat absorbed by the air includes sensible heat. and latent heat ,but

[0181] ;

[0182] Enthalpy of moist air (Unit: kJ / kg) The calculation formula is:

[0183] ;

[0184] in, This refers to the dry-bulb temperature of air, expressed in °C.

[0185] W is the humidity content, which is the mass of water vapor contained in the air.

[0186] 3) Calculation of circulating water volume

[0187] Substituting the mass balance equation into the heat balance equation:

[0188] ;

[0189] Meanwhile, the enthalpy difference equation on the air side is:

[0190] ;

[0191] but:

[0192] ;

[0193] Where Q is the total heat transfer.

[0194] This equation needs to be solved iteratively in conjunction with air parameters, and simplified methods are often used in engineering.

[0195] 4) Simplified Engineering Formula

[0196] In the design, the sensible heat portion of the latent heat of vaporization is ignored (with an error of approximately 5%), and the circulating water volume is approximated using only sensible heat:

[0197] ;

[0198] The temperature difference is measured in °C.

[0199] The above formula can be converted to the following using common units:

[0200] ;

[0201] The specific heat capacity of water is 4200 J / (kg·℃).

[0202] The flow rate of the pre-pump 12 under normal operating conditions is expressed in m³ / s. 3 / h.

[0203] It can be further simplified to:

[0204] .

[0205] (5) Calculation of flow rate of pre-pump 12

[0206] From the above formula, we can obtain:

[0207] ;

[0208] And because ;

[0209] The above and Substituting the calculation results, the flow rate of the pre-pump 12 under normal operating conditions is finally obtained. for:

[0210] ;

[0211] This yields the flow rate used for cooling in the cooling tower 11, which is the flow rate drawn from the cooling tower 11 by the inlet of the booster pump 12 under normal operating conditions. .

[0212] During the practice, the conditions were divided into three groups:

[0213] In the first set of experiments, the efficiency of the tested booster pump 13 was... The convection coefficient inside the test pipe was 87%. Take 300, power consumption correction empirical coefficient Take 0.92; the flow rate of the tested booster pump 13 30m 3 / h; Discharge pressure of the tested booster pump 13 The inlet pressure of the tested booster pump 13 is 32,000,000 Pa. The Pa value is 15,000,000; the length of the test pipe is... The length is 30m; the temperature of the medium inside the test pipe is... Ambient temperature outside the test pipeline The difference is 10℃; the inner diameter of the test pipe The outer diameter of the test pipe is 0.0325m. It is 0.043m; cooling temperature difference The temperature is 10.00℃.

[0214] The flow rate of cooling in cooling tower 11 is obtained, that is, the flow rate drawn from cooling tower 11 by the inlet of booster pump 12 under normal operating conditions. Specifically, it is 12.52m 3 / h. If a traditional piping layout is used, the flow rate of the pre-pump 12 must be greater than the flow rate of the tested booster pump 13. That is, greater than 30m 3 / h, and obviously, using the pipeline layout method of this application, the flow rate of the pre-pump 12 under normal operating conditions is... Significantly reduced.

[0215] Furthermore, under normal pipeline conditions, in practice, the pre-pump 12 is installed at a length of 12.52m. 3 The system operates at a flow rate of / h, and the temperature of the medium near the test booster pump 13 in the large circulation pipeline 10 is measured in real time. Table 1 below shows a comparison of the real-time temperature range of the first medium with the expected test temperature at different operating times during normal operation.

[0216] Table 1 Comparison of Real-time Temperature Range and Expected Test Temperature of the First Medium

[0217] ;

[0218] In the second set of experiments, the efficiency of the tested booster pump 13 was... The convection coefficient inside the test pipe was 88%. The value is 300; power consumption correction empirical coefficient. The flow rate of the tested booster pump 13 was 0.92. 35m 3 / h; Discharge pressure of the tested booster pump 13 The inlet pressure of the tested booster pump 13 is 39,000,000 Pa. The Pa value is 17,000,000; the length of the test pipe is... The length is 30m; the temperature of the medium inside the test pipe is... Ambient temperature outside the test pipeline The difference is 10℃; the inner diameter of the test pipe The outer diameter of the test pipe is 0.0325m. It is 0.043m; cooling temperature difference The temperature is 10.00℃.

[0219] The flow rate of cooling in cooling tower 11 is obtained, that is, the flow rate drawn from cooling tower 11 by the inlet of booster pump 12 under normal operating conditions. Specifically, it is 18.87m 3 / h. If a traditional piping layout is used, the flow rate of the pre-pump 12 must be greater than the flow rate of the tested booster pump 13. That is, greater than 35m 3 / h, and obviously, using the pipeline layout method of this application, the flow rate of the pre-pump 12 under normal operating conditions is... Significantly reduced.

[0220] Furthermore, under normal pipeline conditions, in practice, the pre-pump 12 is installed at 18.87m. 3The system operates at a flow rate of / h, and the temperature of the medium near the tested booster pump 13 in the large circulation pipeline 10 is measured in real time. Table 2 below shows a comparison between the real-time temperature range of the second medium and the expected test temperature at different operating times during normal operation.

[0221] Table 2 Comparison of Real-time Temperature Range and Expected Test Temperature of the Second Medium

[0222] ;

[0223] In the third set of experiments, the efficiency of the tested booster pump 13 was... The convection coefficient inside the test pipe was 89%. The value is 300; power consumption correction empirical coefficient. The flow rate of the tested booster pump 13 was 0.92. 40m 3 / h; Discharge pressure of the tested booster pump 13 The inlet pressure of the tested booster pump 13 is 44,000,000 Pa. The Pa is 21,000,000; the length of the test pipe is... The length is 30m; the temperature of the medium inside the test pipe is... Ambient temperature outside the test pipeline The difference is 10℃; the inner diameter of the test pipe The outer diameter of the test pipe is 0.0325m. It is 0.043m; cooling temperature difference The temperature is 10.00℃.

[0224] The flow rate of cooling in cooling tower 11 is obtained, that is, the flow rate drawn from cooling tower 11 by the inlet of booster pump 12 under normal operating conditions. Specifically, it is 22.35m 3 / h. If a traditional piping layout is used, the flow rate of the pre-pump 12 must be greater than the flow rate of the tested booster pump 13. That is, greater than 40m 3 / h, and obviously, using the pipeline layout method of this application, the flow rate of the pre-pump 12 under normal operating conditions is... Significantly reduced.

[0225] When the pipeline is in normal operating condition, in practice, the pre-pump 12 is set at 22.35m. 3 The system operates at a flow rate of / h, and the temperature of the medium near the tested booster pump 13 in the large circulation pipeline 10 is measured in real time. Table 3 below shows a comparison of the real-time temperature range of the third medium with the expected test temperature at different operating times during normal operation.

[0226] Table 3 Comparison of Real-time Temperature Range and Expected Test Temperature of the Third Medium

[0227] ;

[0228] As shown in Table 1, the pre-pump 12 operates according to the flow rate calculation formula provided in this application under normal operating conditions, which can stably maintain the temperature of the medium in the pipeline and avoid excessive fluctuations in the temperature of the medium in the pipeline, which would reduce the accuracy of the test results of the test booster pump 13.

[0229] Based on the above, further consideration is given to potential leaks in the pipeline. Since the tested booster pump 13 requires prolonged testing, leaks may occur during the test. If it were to be shut down for maintenance and retested at this time, the testing time would obviously be greatly increased. Therefore, this application considers the possibility of leakage in the tested booster pump 13 and provides the following formula for calculating the flow rate of the tested booster pump 13 under leaky operating conditions:

[0230] ;

[0231] In the formula,

[0232] The flow rate of the booster pump 12 under leakage operation is expressed in m³ / s. 3 / h;

[0233] This is an empirical correction factor, dimensionless, ranging from 0.7 to 1.0;

[0234] The plunger diameter is in meters (m).

[0235] This refers to the initial clearance height of the packing material, in meters (m).

[0236] The coefficient of compressibility is dimensionless.

[0237] This refers to the initial length of the packing material, in meters (m).

[0238] This is a length correction factor, dimensionless;

[0239] The dynamic viscosity of the medium is expressed in Pa·s.

[0240] The derivation of the above formula is as follows:

[0241] (1) Overview

[0242] In existing traditional booster pump test systems, the flow rate of the pre-pump 12 must be greater than that of the booster pump 13 under test. That is, the same flow rate must be provided for the booster pump 13 under test, and sufficient flow rate must also be provided for the bypass booster. Generally, it is selected to be configured at 1.5 times the flow rate of the pump under test to ensure the normal conduct of the test.

[0243] The flow rate of the pre-pump 12 in this invention is not necessarily related to that of the test booster pump 13. Its flow rate is designed mainly to obtain the displaced cooling test medium through the cooling tower 11. In addition, it is also used to supplement the losses incurred by the test booster pump 13 during the process.

[0244] (2) Calculation of the flow rate to compensate for losses during the test of the booster pump 13

[0245] The tested booster pump 13 is a reciprocating pump, and during operation, it experiences mechanical losses, hydraulic losses, and volumetric losses. Mechanical and hydraulic losses do not affect the pump's flow rate and are not considered in this calculation. Volumetric losses include those caused by liquid compression and expansion, those caused by delayed closure of check valves, those caused by valves not closing tightly, and those caused by leakage through seals. The first three are the main causes of decreased pump volumetric efficiency, but they are all internal losses and do not cause a decrease in pump flow rate, so they are not considered in the calculation. Volumetric losses caused by leakage through seals are external leaks. Although they account for a small proportion, once they occur, the system flow rate will decrease accordingly, disrupting the flow and pressure balance of the test system. This makes the test process complex, variable, difficult to control, and unstable, so the system losses must be compensated. This invention only needs to calculate the volumetric losses caused by the fourth type of leakage through seals.

[0246] 1) Determination of basic calculation conditions

[0247] A. The leakage gap can be considered an annular gap, with a parabolic velocity distribution, and the maximum velocity is in the middle. A coordinate system is established with the seal as the object of calculation and study. The plunger is cylindrical, and its radius is set. (Unit: m) Inner radius of stuffing box (Unit: m), then the gap Total length of packing (Unit: m), leakage occurs along the axial direction z.

[0248] B. Geometric parameters

[0249] plunger diameter (Unit: m), packing gap height is (Unit: m), Initial packing gap height (Unit: m) Compressive force (Unit: N), Elastic modulus of filler material Poisson's ratio The initial length of the packing is (Unit: m).

[0250] C. Dynamic conditions

[0251] piston reciprocating speed ;

[0252] Pressure difference on both sides of the seal Because the leak was detected as atmospheric leakage during the test, , .

[0253] D. Fluid properties

[0254] Under normal circumstances, the test medium for booster pumps is water, and the test pressure is less than 50 MPa. Therefore, the compressibility of the test medium can be ignored, and it can be considered an incompressible Newtonian fluid. The dynamic viscosity of the medium is... .

[0255] Under normal operating conditions where the seal is intact, the test medium flows in the sealing gap as a laminar flow. There is slight inertia at the edge of the plunger, indicating an inertial term. The flow is driven by both pressure and shear force.

[0256] 2) Establishment of the computational model

[0257] Assuming the packing is uniformly compressed, forming an annular gap, under the compression force... This results in a gap height of The length after compression is .

[0258] 3) Fluid flow analysis

[0259] The flow in the gap is caused by the pressure difference. and piston movement speed (Unit: m / s) Driven by both. Assuming the flow is laminar, incompressible Newtonian fluid, the Navier-Stokes equations simplify to:

[0260] ;

[0261] in Flow velocity (unit: m / s) It is a coordinate perpendicular to the flow direction (from the packing surface to the plunger surface). These are coordinates along the flow direction. The boundary conditions are: In place, (The packing is stationary); in place, (Plunger speed); p is pressure.

[0262] Solving this equation yields the velocity distribution:

[0263] ;

[0264] From the above equation, we can conclude that the flow velocity is composed of the superposition of pressure-driven and shear-driven terms.

[0265] 4) Leakage Calculation

[0266] Leakage (The unit here is m) 3 ( / s) is the integral of the flow velocity over the cross-sectional area of ​​the gap:

[0267] ;

[0268] Will Substitute into the integral:

[0269] ;

[0270] Calculate the integral:

[0271] ;

[0272] ;

[0273] This is the expression for instantaneous leakage, which includes leakage driven by pressure difference and leakage driven by plunger motion.

[0274] 5) Correction for packing compression effect

[0275] A. Gap height correction:

[0276] The clamping force reduces the gap height. According to mechanics of materials, the deformation after clamping can be approximated by Hooke's law, and the compressive strain can be obtained. (Dimensionless). Among them, In the formula, This is the elastic modulus, expressed in Pa. The cross-sectional area of ​​the packing material is expressed in meters (m²). 2 ,and .

[0277] Therefore, gap height for:

[0278] ;

[0279] To simplify calculations, a compression factor is introduced. :

[0280] .

[0281] B. Sealing length correction:

[0282] Lateral expansion of the packing increases its effective length. Due to the Poisson effect, the packing expands laterally during compaction, resulting in an increase in length.

[0283] ,

[0284] therefore:

[0285] ;

[0286] To simplify calculations, a length correction factor is introduced. :

[0287] ;

[0288] Then the total length of the packing for:

[0289] ;

[0290] Substitution :

[0291] .

[0292] C. Dynamic Effects Analysis

[0293] The plunger reciprocates, and its speed It is a simple harmonic motion: ,in For maximum speed, It's angular frequency, period. .

[0294] Due to leakage Includes and For terms that are proportional, the average value of the shear flow component is zero when integrated and averaged over the period, because the positive and negative half-cycles cancel each other out. Therefore, the average leakage rate... Contributed solely by the pressure difference term:

[0295] .

[0296] D. Coefficient Correction

[0297] In practical applications, theoretical formulas need to be modified due to factors such as packing wear, temperature changes, and non-Newtonian fluid characteristics. Empirical coefficients are typically introduced in these cases. and will Unit conversion to m 3 / h, the corrected loss of the pre-pump 12 is as follows:

[0298] ;

[0299] The pre-pump 12 is used to replenish the flow required for energy loss.

[0300] Therefore, the flow rate calculation formula for the tested booster pump 13 under leakage operation is obtained:

[0301] ;

[0302] Right now: ;

[0303] The flow rate of the booster pump 12 under leakage operation is expressed in m³ / s. 3 / h.

[0304] In practice, follow the aforementioned procedures respectively. The parameter conditions in the first, second, and third sets of practices are obtained by inheriting the conditions from the first, second, and third sets of practices, respectively. The specific result is 12.52m. 3 / h, 18.87m 3 / h and 22.35m 3 / h.

[0305] Among the other parameters, the empirical correction coefficient 0.7; plunger diameter It is 0.085m; initial gap height of the packing. It is 0.0005m; the compressibility coefficient is 0.0005m. The initial height of the packing is 0.643. It is 0.05m; length correction factor The dynamic viscosity of the medium is 4.122. The value was 1 Pa·s; and the pipeline was tested in three groups to simulate leakage under the above parameters.

[0306] As mentioned above In the first set of experiments, corresponding to the leakage in the fourth set of experiments, the flow rate of the pre-pump 12 under leakage operating conditions was calculated. It is 12.81m 3 / h. Clearly, under leak conditions, the flow rate of the pre-pump 12 is still far less than the flow rate of the tested booster pump 13 (30m³ / h). 3 / h.

[0307] When the pipeline is operating under leakage conditions, in practice, the booster pump 12 is set at 12.81m. 3 The system operates at a flow rate of / h, and the temperature of the medium near the test booster pump 13 in the large circulation pipeline 10 is measured in real time. Table 4 below shows a comparison of the real-time temperature range of the fourth medium with the expected test temperature at different operating times during leakage operation:

[0308] Table 4 Comparison of Real-time Temperature Range and Expected Test Temperature of the Fourth Medium

[0309] ;

[0310] Clearly, as shown in Table 4, even if the pipeline is in a leaking state, the temperature of the medium in the pipeline can be maintained stably. This not only eliminates the need for shutdown and maintenance for re-measurement, but also avoids excessive fluctuations in the temperature of the medium in the pipeline, which would reduce the accuracy of the test results of the tested booster pump 13.

[0311] As mentioned above In the second set of practices corresponding to the fifth set of practices, the flow rate of the pre-pump 12 under leakage operating conditions was calculated. It is 19.22m 3 / h. Clearly, under leak conditions, the flow rate of the pre-pump 12 is much smaller than the flow rate of the tested booster pump 13 (35m³ / h). 3 / h.

[0312] The pre-pump 12 is designed for 19.22m. 3 The system operates at a flow rate of / h, and the temperature of the medium near the test booster pump 13 in the large circulation pipeline 10 is measured in real time. Table 5 below shows a comparison of the real-time temperature range of the fifth medium with the expected test temperature at different operating times during leakage operation:

[0313] Table 5 Comparison of Real-time Temperature Range and Expected Test Temperature of the Fifth Medium

[0314] ;

[0315] The pre-pump 12 is 22.75m 3 When operating at a flow rate of / h, other parameters are still adjusted using empirical coefficients. 0.7; plunger diameter It is 0.085m; initial gap height of the packing. It is 0.0005m; the compressibility coefficient is 0.0005m. The initial height of the packing is 0.643. It is 0.05m; The length correction factor is 4.122; and leakage under the above parameter conditions is simulated in practice.

[0316] As mentioned above In the third set of practices corresponding to the sixth set of practices, the leakage was obtained. The specific result is 22.75m. 3 / h. Clearly, under leak conditions, the flow rate of the pre-pump 12 is much smaller than the flow rate of the tested booster pump 13 (40m³ / h). 3 / h.

[0317] The pre-pump 12 is designed for a length of 22.75m. 3 During operation at a flow rate of / h, the temperature of the medium near the tested booster pump 13 in the large circulation pipeline 10 was measured in real time. Table 6 below shows a comparison of the real-time temperature range of the sixth medium with the expected test temperature at different operating times during leakage operation:

[0318] Table 6 Comparison of Real-time Temperature Range and Expected Test Temperature for the Sixth Medium

[0319] ;

[0320] Similarly, as shown in Table 6, even if the pipeline is in a leaking state, the temperature of the medium in the pipeline can be maintained stably. This not only eliminates the need for shutdown and maintenance for re-measurement, but also avoids excessive fluctuations in the temperature of the medium in the pipeline, which would reduce the accuracy of the test results of the tested booster pump 13.

[0321] Of course, those skilled in the art will recognize that the present invention is not limited to the details of the exemplary embodiments described above, but also includes the same or similar structures that can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0322] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0323] The technologies, shapes, and structures not described in detail in this invention are all known technologies.

Claims

1. A high-pressure testing system for a booster pump, characterized in that, The system includes a large circulation pipeline (10). Along the direction of medium flow, a water storage component, a pre-pump (12), a test booster pump (13), a main pipeline regulating valve (14), and a booster regulating valve (16) are installed sequentially on the large circulation pipeline (10). A one-way return pipeline (20) is connected in parallel on the large circulation pipeline (10). The first node (e) and the second node (f) of the one-way return pipeline (20) are located at the output end of the main pipeline regulating valve (14) and the output end of the pre-pump (12), respectively. The medium flow direction of the one-way return pipeline (20) flows to the output end of the pre-pump (12).

2. The booster pump high-pressure testing system according to claim 1, characterized in that, The water storage component is a cooling tower (11), and the flow rate of the pre-pump (12) under normal operating conditions is controlled according to the following formula: ； In the formula, The flow rate of the booster pump (12) under normal operating conditions is expressed in m³ / s. 3 / h; The empirical coefficient for power consumption correction is dimensionless. The flow rate of the tested booster pump (13) is expressed in m³ / s. 3 / h; The discharge pressure of the tested booster pump (13) is expressed in Pa. The inlet pressure of the test booster pump (13) is in Pa; The efficiency of the tested booster pump (13) is dimensionless; The length of the test pipe is in meters (m). The temperature of the medium inside the test pipeline is expressed in °C. The ambient temperature outside the test pipeline is expressed in °C. The convection coefficient inside the test pipe is dimensionless. The inner diameter of the test pipe is in meters (m). The outer diameter of the test pipe is in meters (m). The temperature difference is measured in °C.

3. The booster pump high-pressure test system according to claim 2, characterized in that, The flow rate of the tested booster pump (13) under leakage operation is controlled according to the following formula: ； In the formula: The flow rate of the booster pump (12) under leakage operation conditions is expressed in m³ / s. 3 / h; These are empirical correction coefficients, dimensionless. The plunger diameter is in meters (m). This refers to the initial gap height of the packing material, in meters (m). The compressibility factor is dimensionless. This refers to the initial length of the packing material, in meters (m). This is a length correction factor, dimensionless; The dynamic viscosity of the medium is expressed in Pa·s.

4. A high-pressure testing system for a booster pump according to claim 1, 2, or 3, characterized in that, The one-way return pipeline (20) has a one-way check valve (21) to realize the one-way flow of the medium. The one-way check valve (21) has an exhaust port (22) and a water inlet (23) at its inlet and outlet, respectively, and valves are installed on both the exhaust port (22) and the water inlet (23).

5. A high-pressure testing system for a booster pump according to claim 1, 2, or 3, characterized in that, A first flow stabilizing device (122) and a second pressure sensor (123) are sequentially installed on the pipeline between the output end of the pre-pump (12) and the second node (f) on the large circulation pipeline (10), and a first pressure sensor (121) is installed on the pipeline between the output end of the water storage component and the input end of the pre-pump (12) on the large circulation pipeline (10).

6. A high-pressure testing system for a booster pump according to claim 1, 2, or 3, characterized in that, A third pressure sensor (131) is installed on the pipeline between the second node (f) and the input end of the test booster pump (13) on the large circulation pipeline (10). A second flow stabilizing device (132) and a fourth pressure sensor (133) are installed sequentially on the pipeline between the output end of the test booster pump (13) and the main pipeline regulating valve (14) on the large circulation pipeline (10).

7. A high-pressure testing system for a booster pump according to claim 1, 2, or 3, characterized in that, A flow meter (15) is installed on the pipeline between the output end of the main pipeline regulating valve (14) and the first node (e) on the large circulation pipeline (10).

8. A high-pressure testing system for a booster pump according to claim 1, 2, or 3, characterized in that, Safety overflow pipes (17) connecting the water storage components are installed on the pipeline behind the second node (f) on the large circulation pipeline (10) and on the pipeline between the test booster pump (13) and the main pipeline regulating valve (14). Safety overflow valves (171) are installed on the safety overflow pipes (17).

9. A high-pressure testing system for a booster pump according to claim 1, 2, or 3, characterized in that, The water storage component is connected to a water supply pipeline for replenishing the water storage component with a medium, and an automatic water supply valve is installed on the water supply pipeline.

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