High-efficiency cooling temperature control system and control method for twin-screw oil and gas mixed delivery pump

Abstract

The application belongs to the technical field of screw pump test detection, and provides a high-efficiency cooling temperature control system and control method for a double-screw oil-gas mixed conveying pump, wherein the high-efficiency cooling temperature control system for the double-screw oil-gas mixed conveying pump comprises a pump body cooling execution unit, a medium circulation pre-cooling unit, a parameter acquisition unit and a central control unit; the pump body cooling execution unit comprises a stator cooling jacket and two groups of bearing cooling cavities, the stator cooling jacket is arranged around the outer wall of the stator of the double-screw pump, and the two groups of bearing cooling cavities are respectively arranged in the bearing seats at the two ends of the pump body; the application realizes independent cooling in different zones, improves the temperature control pertinence and temperature uniformity, adopts a decoupling closed-loop control algorithm, improves the dynamic adjustment precision and stability, combines gas-liquid pre-cooling and medium reuse of a test bench, improves the cooling efficiency and reduces energy consumption, and configures a working condition linkage pre-adjustment mechanism to improve the working condition switching stability and test efficiency.

Description

Technical Field

[0001] This invention belongs to the field of screw pump testing and inspection technology, and particularly relates to a high-efficiency cooling temperature control system and control method for twin-screw oil-gas mixed pumps. Background Technology

[0002] For example, Chinese Patent (Publication No.: CN110242558A) discloses a cooling system and control method for a single screw pump suitable for high-gas-content multiphase mixed transport. This system achieves cooling medium circulation by setting a jet cooling structure at the stator, combining a gas-liquid separator and a storage tank, and controlling the liquid spray cooling by triggering a solenoid valve through a temperature sensor. This system can provide cooling protection for the single screw pump stator under high-gas-content conditions. In the field of screw pump factory testing, existing test benches typically only have a medium storage tank and a basic heating device to meet the initial temperature requirements of the test medium, without a dedicated zoned cooling temperature control system for the pump body.

[0003] The existing technology has the following shortcomings in practical applications:

[0004] The cooling structure lacks a zoned design, and the temperature control is not targeted enough: In the existing test scenarios, heat is mostly carried away by the circulation of the medium itself, without independent zoned cooling of the stator cavity and bearing cavity. When the twin-screw oil-gas mixed pump is under high pressure loading test, the temperature rise rate and heat conduction path of the stator shear heating and bearing friction heating are different. The unified heat dissipation method cannot match the heat dissipation requirements of the two places, which is prone to local temperature exceeding the standard or uneven temperature. It is difficult to accurately assess the temperature rise characteristics of each component of the pump body, which does not meet the requirements of the test standard for pump body temperature detection.

[0005] The temperature control method is simple and the dynamic adjustment accuracy is limited: existing temperature control mostly adopts on-off control triggered by a single parameter threshold, without considering the thermal conduction coupling effect between the stator and the bearing. Temperature oscillation is prone to occur during the adjustment process, and the adjustment lag is strong. During the variable operating conditions such as pressure loading and speed switching in the factory test, the pump body heat power changes rapidly. Traditional feedback control cannot keep up in time, resulting in large temperature fluctuations, which affects the accuracy and reliability of performance test data.

[0006] The utilization efficiency of the cooling medium is low, and the test bench resources are not fully utilized: the existing cooling solutions are mostly configured with independent cooling systems, which are not combined with the medium circulation and liquid storage system of the screw pump test bench itself, resulting in equipment redundancy and increased energy consumption; at the same time, the existing gas-liquid mixing structure of the test bench is not used to enhance the cooling capacity. In the full-load test of high-pressure and high-flow pumps, the cooling power is difficult to match the heat load, and the stator temperature rise is likely to exceed the standard allowable range, which limits the product testing range of the test bench.

[0007] The cooling system lacks linkage with the test conditions, resulting in poor stability during condition switching: The existing cooling system operates independently of the test bench control system and is passively adjusted based only on the current temperature. It cannot predict the fluctuations in heat generation power caused by changes in test loading, speed adjustment, and other conditions. In the multi-level loading process of the factory test, a long temperature stabilization period is required after each condition switch, which prolongs the test time of a single pump, reduces the efficiency of factory testing, and sudden temperature changes can easily cause thermal shock to the pump stator bushing.

[0008] Therefore, a high-efficiency cooling and temperature control system and control method for twin-screw oil-gas mixed pumps are needed to solve the above problems. Summary of the Invention

[0009] The purpose of this invention is to provide a high-efficiency cooling temperature control system and control method for a twin-screw oil-gas mixed pump, so as to solve the problems mentioned in the background art.

[0010] To achieve the above objectives, the present invention provides the following technical solution: a high-efficiency cooling and temperature control system for a twin-screw oil-gas mixed pump, comprising a pump body cooling execution unit, a medium circulation pre-cooling unit, a parameter acquisition unit, and a central control unit;

[0011] The pump body cooling execution unit includes a stator cooling jacket and two sets of bearing cooling chambers. The stator cooling jacket is arranged around the outer wall of the twin-screw pump stator, and the two sets of bearing cooling chambers are respectively arranged inside the bearing seats at both ends of the pump body.

[0012] The medium circulation precooling unit includes a main cooling circuit, a gas-liquid precooling branch, a stator branch regulating valve and a bearing branch regulating valve. The inlet of the main cooling circuit is connected to the test bench liquid storage tank, and the outlet is connected to the stator cooling jacket and the bearing cooling chamber respectively. The gas-liquid precooling branch is connected to the front end of the main cooling circuit.

[0013] The detection terminals of the parameter acquisition unit are respectively set at the pump body temperature measurement point and inside the cooling pipe, and the signal output terminal of the parameter acquisition unit is connected to the central control unit.

[0014] The control output terminals of the central control unit are respectively connected to the control terminals of the stator branch regulating valve, the bearing branch regulating valve and the gas-liquid precooling branch, and the central control unit is connected to the host computer of the test bench.

[0015] The architecture constructs a complete temperature control system with zoned cooling, gas-liquid precooling, and operating condition linkage. It can reuse the existing liquid storage, gas source, and control resources of the test bench to achieve independent temperature control and adaptive adjustment of multiple areas of the pump body. This provides stable temperature conditions for the screw pump factory test, improves the accuracy of test data and testing efficiency, and reduces the cost of test system modification.

[0016] In a further technical solution, a spiral flow guide baffle is provided inside the stator cooling jacket, and the spiral flow guide baffle extends along the stator axis to form a continuous spiral flow channel.

[0017] The spiral flow channel can extend the residence time of the cooling medium in the jacket, enhance the heat exchange effect of the stator wall, and make the axial temperature distribution of the stator more uniform. It avoids the impact of local temperature differences on the stator fitting accuracy, improves the consistency of stator temperature rise detection, and can obtain higher cooling efficiency under the same flow rate.

[0018] In a further technical solution, the bearing cooling cavity adopts an annular cavity structure, the inner wall of the annular cavity is in contact with the outer wall of the bearing outer ring, and the annular cavity is provided with a liquid inlet and a liquid outlet.

[0019] The annular bonding structure ensures uniform heat dissipation around the outer ring of the bearing, avoiding changes in bearing clearance caused by localized overheating and improving bearing operational stability. At the same time, the cooling medium directly exchanges heat with the main heat-generating area of ​​the bearing, improving the targeting and heat dissipation efficiency of bearing cooling and ensuring the accuracy of bearing temperature rise detection.

[0020] In a further technical solution, the gas-liquid precooling branch includes a compressed air source, a gas regulating valve, and a gas-liquid mixer. The liquid phase inlet of the gas-liquid mixer is connected to the main cooling circuit, and the gas phase inlet is connected to the compressed air source through the gas regulating valve.

[0021] By mixing gas and liquid, the latent heat of vaporization in the gas phase can be used to enhance cooling capacity, thereby increasing heat dissipation power without increasing the liquid phase flow rate and flexibly adapting to the cooling requirements of different loads. At the same time, the existing air compressor on the test bench can be reused as the air source, eliminating the need for additional refrigeration equipment and reducing the cost of upgrading and modifying the test bench.

[0022] In a further technical solution, a circulating pump and a filter are sequentially installed on the main cooling circuit, and the return end of the main cooling circuit is connected to the liquid storage tank of the test bench.

[0023] The circulating pump provides stable circulation power for the cooling medium, ensuring the adjustable range of cooling flow rate; the filter can remove impurities in the medium, avoiding blockage of the cooling channel and wear of pump components; the return flow into the storage tank can realize closed-loop circulation of the medium, fully reuse the medium resources of the test bench, and reduce equipment redundancy and medium consumption.

[0024] In a further technical solution, the parameter acquisition unit includes a first temperature sensor, a second temperature sensor, a third temperature sensor, and an inlet temperature sensor; the first temperature sensor is embedded in the inner wall of the stator cavity, the second and third temperature sensors are respectively embedded in the bearing seats at both ends, and the inlet temperature sensor is located at the inlet of the main cooling circuit.

[0025] Multi-point temperature acquisition can accurately obtain the actual operating temperature of the stator and bearings, providing reliable input data for closed-loop control; inlet temperature detection can correct the cooling power calculation results, improve temperature control accuracy, and all temperature data can be synchronously stored in the test system to ensure the accuracy and traceability of temperature detection data.

[0026] In a further technical solution, the parameter acquisition unit also includes a stator branch flow sensor, a bearing branch flow sensor, and an outlet pressure transmitter; the stator branch flow sensor is located downstream of the stator branch regulating valve, the bearing branch flow sensor is located downstream of the bearing branch regulating valve, and the outlet pressure transmitter is located in the outlet pipeline of the twin-screw pump.

[0027] Real-time flow detection enables closed-loop verification of cooling flow, improving the accuracy of valve flow regulation; outlet pressure acquisition helps determine the actual load on the pump body, providing a direct basis for pre-adjusting cooling power, further enhancing the accuracy of operating condition linkage control, and reducing pre-adjustment deviation.

[0028] In a further technical solution, the parameter acquisition unit also includes a vibration sensor and a sound level meter. The vibration sensor is disposed on the surface of the bearing housing, and the sound level meter is disposed on one side of the pump body.

[0029] By combining vibration and noise parameters with temperature data, the pump's operating status can be comprehensively assessed, helping to identify potential problems such as bearing failure and abnormal stator wear. This expands the condition monitoring function of the temperature control system, enhances the fault detection capability of factory tests, and ensures the quality of products leaving the factory.

[0030] In a further technical solution, the central control unit includes a PLC control module and a working condition linkage interface. The working condition linkage interface is connected to the host computer of the test bench to obtain test working condition parameters.

[0031] As the core control unit, the PLC can realize synchronous acquisition of multiple parameters and logic operation control, ensuring real-time control; the working condition linkage interface can communicate with the host computer of the test bench in real time to obtain working condition commands and loading plans, providing a data channel for the working condition pre-adjustment function, and realizing synchronous linkage between the cooling system and the test process.

[0032] A high-efficiency cooling temperature control method for a twin-screw oil-gas mixed-transfer pump, applied to any of the above-described high-efficiency cooling temperature control systems for twin-screw oil-gas mixed-transfer pumps, includes the following steps:

[0033] The central control unit includes a PLC control module and a working condition linkage interface. The working condition linkage interface is connected to the host computer of the test bench to obtain test working condition parameters.

[0034] This method combines static steady-state temperature control with dynamic operating condition adaptation through a step-by-step control logic of zoned acquisition, independent adjustment, operating condition pre-adjustment, and gas-liquid synergy. This improves the temperature control response speed and stability, adapts to the multi-operating condition switching requirements of factory testing, and can effectively shorten the test temperature stabilization time.

[0035] Compared with the prior art, the beneficial effects of the present invention are:

[0036] This invention achieves independent cooling in different zones, improving the targeting and uniformity of temperature control: Through the split structure design of the stator cooling jacket and two sets of bearing cooling chambers, the core heat-generating area of ​​the pump body is divided into three independent temperature control units: the stator chamber and the bearing chambers at both ends. With the help of two independent regulating valves to control the flow rate of the cooling medium, the corresponding cooling flow rate can be matched according to the actual heat load of each area. This structure can adapt to the different temperature rise characteristics of stator shear heating and bearing friction heating, avoiding local overcooling or overheating caused by uniform cooling method, so that the temperature of each area of ​​the pump body is maintained within the set range. This helps to accurately evaluate the temperature rise performance of each component in the factory test and reduce the impact of uneven temperature on the pump body seals and fitting clearances.

[0037] This invention employs a decoupled closed-loop control algorithm to improve the accuracy and stability of dynamic adjustment. By introducing decoupled PID control logic, the two control signals are decoupled and corrected based on the thermal conduction coupling coefficient between the stator and the bearing. This effectively suppresses the interference of thermal conduction on the temperature of another area during flow regulation in one area, avoiding the temperature oscillation phenomenon that is prone to occur in traditional single-loop control. At the same time, the partitioned sampling of multiple sensors provides refined input for control, which can reduce the steady-state error of temperature regulation and reduce the amplitude of steady-state temperature fluctuations. This meets the requirements of screw pump test standards for the temperature stability of the medium and pump body, and improves the consistency and reliability of performance test data.

[0038] This invention combines gas-liquid precooling with test bench medium reuse to improve cooling efficiency and reduce energy consumption: By connecting a gas-liquid precooling branch to the front end of the main cooling circuit, the heat exchange effect is enhanced by incorporating the latent heat of vaporization of microbubbles, thereby increasing cooling capacity without adding an additional refrigeration unit, which can meet the cooling requirements of full-load tests of high-pressure, high-flow-rate pumps; at the same time, the main cooling circuit is directly connected to the test bench's liquid storage tank, reusing the test bench's medium storage and filtration system, eliminating the need for a separate coolant tank and refrigeration unit, reducing equipment redundancy and space occupation, and lowering the overall energy consumption and operation and maintenance costs of the test system;

[0039] This invention features a pre-adjustment mechanism for operating condition linkage, enhancing the stability of operating condition switching and improving testing efficiency. Through real-time communication with the host computer on the test bench via an operating condition linkage interface, operating parameters such as speed and pressure for the next stage can be obtained in advance. Based on a heat generation power model, the flow rate and gas-liquid ratio of the cooling medium are pre-adjusted, achieving synchronous matching of cooling power during operating condition switching. This mechanism overcomes the lag of traditional passive feedback regulation, significantly shortening the temperature stabilization time after operating condition switching, accelerating the multi-stage loading process of factory testing, and improving the testing efficiency of a single pump. Simultaneously, it reduces the magnitude of temperature fluctuations, minimizing the impact of thermal shock on the stator bushing and bearing assemblies, ensuring stable product performance after testing.

[0040] To more clearly illustrate the structural features and effects of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0041] Figure 1 This is a block diagram of the overall architecture of the present invention;

[0042] Figure 2 This is a block diagram showing the architecture connection between the parameter acquisition unit and the central control unit of the present invention;

[0043] Figure 3 This is a schematic diagram of the overall process of the present invention.

[0044] In the diagram: 1. Pump body cooling unit; 11. Stator cooling jacket; 111. Spiral guide baffle; 12. Bearing cooling chamber; 2. Medium circulation precooling unit; 21. Main cooling circuit; 211. Circulating pump; 212. Filter; 22. Gas-liquid precooling branch; 221. Compressed air source; 222. Gas regulating valve; 223. Gas-liquid mixer; 23. Stator branch regulating valve; 24. Bearing branch regulating valve; 3. Parameter acquisition unit; 31. First temperature sensor; 32. Second temperature sensor; 33. Third temperature sensor; 34. Inlet temperature sensor; 35. Stator branch flow sensor; 36. Bearing branch flow sensor; 37. Outlet pressure transmitter; 38. Vibration sensor; 39. Sound level meter; 4. Central control unit; 41. PLC control module; 42. Operating condition linkage interface; 5. Twin screw pump; 6. Test bench storage tank; 7. Test bench host computer. Detailed Implementation

[0045] The present invention will be further described below with reference to embodiments.

[0046] The following embodiments are used to illustrate the present invention, but should not be used to limit the scope of protection of the present invention. The conditions in the embodiments can be further adjusted according to specific conditions, and simple improvements to the method of the present invention under the premise of the concept of the present invention are all within the scope of protection claimed by the present invention.

[0047] Example 1

[0048] like Figure 1-3 As shown, this embodiment of the invention provides a high-efficiency cooling and temperature control system for a twin-screw oil-gas mixed-transfer pump, which is applied to the screw pump factory test bench and works with the test bench to complete the temperature control during the factory inspection and type test of the twin-screw oil-gas mixed-transfer pump.

[0049] This system includes a pump body cooling execution unit 1, a medium circulation precooling unit 2, a parameter acquisition unit 3, and a central control unit 4.

[0050] The pump cooling unit 1 includes a stator cooling jacket 11 and two sets of bearing cooling chambers 12. The stator cooling jacket 11 is fitted around the outer wall of the stator of the twin-screw pump. A spiral guide baffle 111 is fixed inside the stator cooling jacket 11. The spiral guide baffle 111 extends continuously along the stator axial direction, dividing the inner cavity of the jacket into a single-channel spiral flow channel. The liquid inlet end of the flow channel is located at the end of the stator near the pump outlet, and the liquid outlet end is located at the end of the stator near the pump inlet, forming a heat exchange flow path that is opposite to the flow direction of the medium inside the pump, thereby improving heat exchange efficiency. Both sets of bearing cooling chambers 12 are annular cavity structures, respectively embedded in the drive end bearing housing and the non-drive end bearing housing of the twin-screw pump. The inner wall of the annular cavity is tightly fitted with the outer wall of the corresponding bearing outer ring. Each cooling chamber is provided with an independent liquid inlet and outlet. The liquid inlet faces the circumference of the bearing rolling element, so that the cooling medium preferentially flushes the main heat-generating area of ​​the bearing outer ring.

[0051] The medium circulation precooling unit 2 includes a main cooling circuit 21, a gas-liquid precooling branch 22, a stator branch regulating valve 23, and a bearing branch regulating valve 24. The inlet of the main cooling circuit 21 is connected to the test bench's liquid storage tank. The test medium in the test bench's liquid storage tank is also used as the cooling medium. A circulation pump 211 and a filter 212 are sequentially installed on the main cooling circuit 21. The filter 212 is used to filter impurities in the medium to prevent clogging of the cooling channels or damage to the internal components of the pump body. The gas-liquid precooling branch 22 is connected downstream of the filter 212 in the main cooling circuit 21 and includes a compressed air source 221, a gas regulating valve 222, and a gas-liquid mixer 223. The liquid phase inlet of the gas-liquid mixer 223 is connected to the main cooling circuit 21, and the gas phase inlet is connected to the compressed air source 221 through the gas regulating valve 222. The compressed air source 221 reuses the air compressor configured on the test bench. The outlet of the gas-liquid mixer 223 connects to subsequent branch pipelines. The main cooling circuit 21 is divided into two branches after passing through the gas-liquid mixer 223. The first branch connects to the inlet of the stator cooling jacket 11 through the stator branch regulating valve 23. The second branch is further divided into two paths after passing through the bearing branch regulating valve 24, which connect to the inlets of the two bearing cooling chambers 12 respectively. The outlets of the stator cooling jacket 11 and the two bearing cooling chambers 12 are all connected back to the test bench storage tank through return pipelines, forming a complete cooling circulation loop.

[0052] The parameter acquisition unit 3 includes a first temperature sensor 31, a second temperature sensor 32, a third temperature sensor 33, an inlet temperature sensor 34, a stator branch flow sensor 35, a bearing branch flow sensor 36, an outlet pressure transmitter 37, a vibration sensor 38, and a sound level meter 39. The first temperature sensor 31 is embedded in the middle of the inner wall of the stator cavity to detect the actual temperature of the stator working surface; the second temperature sensor 32 is embedded in the drive end bearing housing and close to the outer ring of the bearing, and the third temperature sensor 33 is embedded in the non-drive end bearing housing and close to the outer ring of the bearing, to detect the operating temperature of the bearings at both ends respectively; the inlet temperature sensor 34 is set at the inlet of the main cooling circuit 21 to detect the initial temperature of the medium entering the cooling system; the stator branch flow sensor 35 is installed downstream of the stator branch regulating valve 23, and the bearing branch flow sensor 36 is installed downstream of the bearing branch regulating valve 24 to detect the real-time flow of the two branches respectively; the outlet pressure transmitter 37 is installed on the outlet pipeline of the twin screw pump to obtain the pump outlet pressure parameters; the vibration sensor 38 is set on the surface of the bearing housing to detect the vibration parameters of the pump body during operation; and the sound level meter 39 is set on one side of the pump body to detect the noise parameters during the test process.

[0053] The central control unit 4 includes a PLC control module 41 and a working condition linkage interface 42. The signal input terminals of the PLC control module 41 are connected to the output terminals of each temperature sensor, flow sensor, pressure transmitter, vibration sensor 38, and sound level meter 39, respectively. The signal output terminals are connected to the control terminals of the stator branch regulating valve 23, bearing branch regulating valve 24, gas regulating valve 222, and circulating pump 211, respectively. The working condition linkage interface 42 adopts an industrial Ethernet interface and communicates with the host computer of the test bench, which can obtain the rotor speed setpoint, loading level, medium gas content, and preset parameters for the next working condition issued by the test bench in real time.

[0054] In this embodiment, the system control method is performed according to the following steps:

[0055] S1. Before the test starts, the parameters are initialized. During the test, the first temperature sensor 31, the second temperature sensor 32, and the third temperature sensor 33 collect the real-time temperature of the stator and the bearings at both ends, respectively. The inlet temperature sensor 34 collects the inlet temperature of the cooling medium. All temperature data are transmitted to the PLC control module 41 in real time. At the same time, the PLC control module 41 obtains the current speed, outlet pressure, loading gear parameters, and preset parameters of the next working condition from the host computer of the test bench through the working condition linkage interface 42.

[0056] S2 and PLC control module 41 compare the collected stator temperature with the preset stator temperature threshold, and calculate and generate the stator branch flow regulation signal through the decoupled PID algorithm; at the same time, they compare the average value of the bearing temperature at both ends with the preset bearing temperature threshold to calculate and generate the bearing branch flow regulation signal.

[0057] The flow output formula for decoupled PID control is as follows:

[0058]

[0059] In the formula:

[0060] The flow rate of the cooling medium in the stator branch is expressed in units of... ;

[0061] This refers to the flow rate of the cooling medium in the bearing branch, in units of... ;

[0062] The stator real-time temperature is collected by the first temperature sensor 31. Set the temperature for the stator, in units of ;

[0063] The bearing average temperature is obtained by averaging the values ​​collected by the second temperature sensor 32 and the third temperature sensor 33. Set the temperature for the bearing, in units of ;

[0064] These are the proportional, integral, and derivative coefficients of the PID controller in the stator circuit, which are calibrated through testing and debugging.

[0065] These are the proportional, integral, and derivative coefficients of the PID controller in the bearing circuit, which are calibrated through testing and debugging.

[0066] The decoupling coefficient of bearing temperature on the stator circuit, with a value ranging from 0 to 0.3, represents the degree of coupling of bearing heat conduction to the stator, and is calibrated through pump body thermal simulation and actual measurement.

[0067] The decoupling coefficient of stator temperature to bearing circuit is 0~0.2, representing the degree of coupling of stator heat conduction to bearing. It is calibrated through pump body thermal simulation and actual measurement.

[0068] This formula reduces the control interference caused by heat conduction between the stator and bearing by subtracting the influence of coupling terms from each other in the two PID loops, enabling the two temperature regulation circuits to operate independently and stably.

[0069] S3, PLC control module 41 calculates the pre-adjusted cooling power required for the next operating condition based on the acquired preset parameters of the next operating condition through the pump body heating power model, and performs pre-correction on the two flow adjustment signals generated in step S2 to obtain the final two cooling medium flow commands.

[0070] The formula for calculating the pre-adjusted cooling power is as follows:

[0071]

[0072] In the formula:

[0073] To pre-adjust the total flow rate of the cooling medium, the unit is... ;

[0074] The pump shaft input power is calculated from the torque and speed measured by the torque and speed sensors on the test bench, in units of... ;

[0075] The volumetric efficiency of the pump is calculated from the ratio of the theoretical flow rate to the actual flow rate under the current operating conditions. The actual flow rate is collected by the electromagnetic flowmeter on the test bench.

[0076] This is a viscosity correction factor for the medium, obtained by looking up a table based on the current medium temperature and viscosity curve, with a value range of 0.8 to 1.2.

[0077] This is a pressure correction factor, calculated based on the ratio of outlet pressure to rated pressure, with a value ranging from 0.7 to 1.3.

[0078] This refers to the isobaric specific heat capacity of the cooling medium, in units of... ;

[0079] The density of the cooling medium is expressed in units of 1000 kJ / m³. ;

[0080] The allowable temperature difference between the inlet and outlet of the cooling medium, in units of... The temperature is preset according to the test temperature requirements.

[0081] This formula is derived based on the physical relationship between the pump's energy loss and its conversion into heat. It can quantitatively calculate the required cooling flow rate through operating parameters, providing a quantitative basis for pre-adjustment control.

[0082] S4 and PLC control module 41 output the final flow command to stator branch regulating valve 23 and bearing branch regulating valve 24 respectively, adjust the valve opening of the corresponding branch, and control the flow of cooling medium; at the same time, according to the total cooling power requirement, adjust the opening of gas regulating valve 222, adjust the gas-liquid mixing ratio of gas-liquid precooling branch 22, strengthen or weaken the cooling effect, and finally realize pump body zone cooling and operating condition adaptive temperature control.

[0083] The formula for adjusting the gas-liquid mixing ratio is as follows:

[0084]

[0085] In the formula:

[0086] This is the gas-liquid volume mixing ratio, with a value ranging from 0 to 0.3.

[0087] The total heat output of the pump body is expressed in units of... It is calculated from the shaft input power and volumetric efficiency;

[0088] This represents the maximum heat dissipation power of pure liquid phase cooling, expressed in units of... It is calculated from the maximum liquid flow rate and the inlet and outlet temperature difference;

[0089] The contribution of latent heat of vaporization of air per unit volume to heat dissipation, in units of Calibration was achieved through testing;

[0090] As a safety factor, a value of 0.8 to 0.9 is used to avoid over-adjustment.

[0091] This formula is used to quantitatively calculate the gas-liquid mixing ratio, and to supplement vaporization cooling when the liquid phase cooling capacity is insufficient, so as to achieve continuous and adjustable cooling capacity.

[0092] This embodiment includes two typical use cases:

[0093] Scenario 1: Steady-state loading scenario during factory testing. In the steady-state performance test at rated speed and rated pressure, the system uses partitioned decoupled PID control to stably control the stator temperature and bearing temperature near the set value. The gas-liquid precooling branch maintains a low mixing ratio to ensure stable temperature, providing stable temperature conditions for testing performance parameters such as flow rate and efficiency, and meeting the requirements for test environment temperature in JB / T8091-2014 screw pump test methods.

[0094] Scenario 2: Multi-stage continuous loading test. In the multi-stage progressive loading test from no-load to rated pressure, the system obtains the loading command for each stage in advance through the working condition linkage interface. Before the pressure is increased, the cooling flow rate and gas-liquid mixing ratio are increased in advance to make the pump body temperature rise slowly during the loading process, avoiding sudden temperature rise. After the loading is completed, it can quickly enter a steady state, shortening the total test time of a single pump.

[0095] Example 2

[0096] The difference between this embodiment and embodiment 1 is that: the internal flow channel of the stator cooling jacket 11 is replaced by multiple sets of axial flow dividers instead of spiral flow guides 111. The axial flow dividers are evenly arranged along the circumference of the stator, dividing the inner cavity of the jacket into multiple parallel axial flow channels. The liquid inlet end of each flow channel is uniformly connected to the liquid inlet collecting ring, and the liquid outlet end is uniformly connected to the liquid outlet collecting ring.

[0097] In this embodiment, the axial flow channel structure has lower flow resistance, enabling a larger cooling medium flow rate under the same output pressure of the circulating pump 211. This makes it suitable for testing large-diameter, long-length twin-screw oil-gas mixed-transfer pumps. The circumferentially uniform flow channel distribution ensures a more uniform stator circumferential temperature, avoiding uneven stator deformation caused by circumferential temperature differences, and is more suitable for high-precision stator temperature rise characteristic testing. The remaining structures and control methods in this embodiment are consistent with those in Embodiment 1, and can also achieve zoned cooling and operating condition-linked temperature control functions to meet the testing cooling requirements of pumps of different specifications.

[0098] Example 3

[0099] The difference between this embodiment and embodiment 1 is that: the two bearing cooling chambers 12 are each equipped with an independent branch regulating valve, that is, the bearing branch is equipped with two independent regulating valves, corresponding to the driving end and the non-driving end cooling chamber respectively, and the two regulating valves are independently controlled by the PLC control module 41.

[0100] In this embodiment, the cooling flow rate can be adjusted separately for the different heating levels of the bearings at both ends. For example, the drive end, due to its connection to the transmission mechanism, experiences a greater bearing load and generates more heat, thus requiring a larger cooling flow rate. Conversely, the non-drive end, with a relatively smaller load, can be allocated a smaller flow rate. This structure further enhances the precision of bearing temperature control, preventing temperature differences between the bearings at both ends. It is particularly suitable for testing scenarios involving high-power, high-speed twin-screw oil-gas mixed-transfer pumps, ensuring that both bearings operate within a suitable temperature range and improving the accuracy of bearing temperature rise detection.

[0101] Example 4

[0102] The difference between this embodiment and embodiment 1 is that the gas-liquid mixer 223 of the gas-liquid precooling branch 22 is set after the branch point of the stator branch and the bearing branch. That is, each of the stator branch and the bearing branch is equipped with an independent gas-liquid mixer 223 and a gas regulating valve 222, which can adjust the gas-liquid mixing ratio of the two branches respectively.

[0103] In this embodiment, the corresponding gas-liquid mixing ratio can be matched according to the different cooling requirements of the stator and bearing. For example, if the stator has a high heat load, a higher gas-liquid ratio can be set to enhance cooling, while if the bearing has a low heat load, a lower gas-liquid ratio or even pure liquid phase cooling can be set. This structure can further improve the flexibility and precision of zoned cooling, allowing the cooling capacity of both cooling branches to be adjusted independently, adapting to pump components with different heat dissipation characteristics.

[0104] Example 5

[0105] The difference between this embodiment and embodiment 1 is that a magnetic suction cleaner is also provided downstream of the filter 212 of the main cooling circuit 21. The magnetic suction cleaner is equipped with a permanent magnet inside, which is used to adsorb ferromagnetic impurities in the medium. A heat dissipation finned tube is provided at the return end of the main cooling circuit 21 to help reduce the temperature of the return medium.

[0106] In this embodiment, the magnetic decontaminator can further improve the cleanliness of the cooling medium, preventing impurities such as iron filings from entering the pump body or cooling channel and causing wear or blockage. It forms a multi-stage filtration protection with the magnetic structure in the test bench's storage tank. The heat dissipation finned tubes at the return end can utilize ambient air to assist in heat dissipation, reduce the temperature of the return medium, alleviate the thermal load on the storage tank, extend the running time of continuous tests, and meet the cooling requirements of long-term type tests.

[0107] Example 6

[0108] The difference between this embodiment and embodiment 1 is that the parameter acquisition unit 3 also includes a medium viscosity sensor. The medium viscosity sensor is installed in the liquid storage tank of the test bench and is used to detect the viscosity parameters of the test medium in real time. The signal output terminal of the viscosity sensor is connected to the PLC control module 41.

[0109] In this embodiment, viscosity data of the medium can be obtained in real time by a viscosity sensor, replacing the original lookup table method to obtain the viscosity correction coefficient. This makes the calculation of the pre-adjusted cooling power more consistent with the actual medium state and improves the accuracy of the pre-adjustment control. Especially in scenarios where the medium temperature changes significantly and the viscosity fluctuates significantly during the test, real-time viscosity detection can effectively improve the temperature control accuracy and ensure the reliability of the cooling power calculation at different temperatures.

[0110] Example 7

[0111] The difference between this embodiment and embodiment 1 is that the PLC control module 41 is equipped with a status warning module. The status warning module is connected to the detection signals of the vibration sensor 38 and the sound level meter 39, and can make a comprehensive judgment on the pump's operating status by combining temperature data.

[0112] In this embodiment, when the bearing temperature rises and the vibration value exceeds the standard, the status early warning module can send an early warning signal to the host computer of the test bench to indicate the potential risk of bearing failure; when the stator temperature rises and abnormal noise occurs, a corresponding early warning can also be triggered. This configuration can expand the system's status monitoring function, assisting in the prediction of pump body failures while controlling temperature, improving the failure detection rate of factory tests, and ensuring the quality of products leaving the factory.

[0113] Example 8

[0114] The difference between this embodiment and embodiment 1 is that the central control unit 4 also includes a data storage module and a report generation module. The data storage module is used to store historical data such as temperature, flow rate, and pressure for each test. The report generation module can automatically generate characteristic curves such as temperature-time curves and cooling flow rate-pressure curves, and can export test temperature control reports.

[0115] In this embodiment, the system can independently complete the data recording and analysis of the cooling process. The generated temperature characteristic curve can be directly used as part of the factory test report, simplifying the test data processing process. At the same time, historical data can be used to optimize PID control parameters and decoupling coefficients, continuously improve the temperature control effect, and also provide data support for the improvement of pump body thermal design.

[0116] Example 9

[0117] The difference between this embodiment and embodiment 1 is that the central control unit 4 is connected to the electric heater control circuit of the liquid storage tank of the test bench, and can control the start, stop and power of the electric heater in conjunction with the cooling reflux temperature and the medium temperature of the liquid storage tank.

[0118] In this embodiment, when the cooling reflux causes the temperature of the storage tank to drop below the set temperature of the test medium, the system can activate the storage tank electric heater to maintain a stable test medium temperature. When the storage tank temperature is too high, the cooling loop circulation flow can be increased to lower the storage tank temperature through reflux heat dissipation. This structure achieves overall linkage between the cooling system and the test bench medium temperature control system, ensuring that the medium temperature of the entire test system remains within the standard requirements range, further improving the stability of the test conditions.

[0119] Example 10

[0120] The difference between this embodiment and embodiment 1 is that the control method also includes a manual control mode. In the manual control mode, the operator can manually set the opening degree of the stator branch regulating valve 23, the bearing branch regulating valve 24 and the gas regulating valve 222 through the human-machine interface of the central control unit 4, and manually control the cooling flow rate and the gas-liquid ratio.

[0121] In this embodiment, the manual mode can be used as a backup operation for equipment debugging, special test conditions, or automatic control failures, improving the system's applicability and reliability. The automatic and manual modes can be seamlessly switched, maintaining a smooth transition in valve opening during the switching process to avoid temperature fluctuations. The automatic control process in this embodiment is consistent with that in Embodiment 1, balancing the convenience of automated operation with the flexibility of manual operation.

[0122] The working principle and usage process of this invention are as follows: Before the test starts, parameter initialization and threshold setting are completed. During the test, the parameter acquisition unit acquires the temperature of each part of the pump body and pipeline parameters in real time. The central control unit generates flow regulation signals for the two cooling branches through a decoupled PID algorithm. At the same time, it performs pre-adjustment and correction in combination with the operating parameters issued by the test bench. Finally, the cooling flow rate and gas-liquid mixing ratio are controlled by the regulating valve to achieve precise cooling of the pump body in zones and adaptive temperature control under operating conditions.

[0123] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-efficiency cooling and temperature control system for a twin-screw oil-gas mixed-transfer pump, characterized in that, It includes a pump body cooling execution unit (1), a medium circulation precooling unit (2), a parameter acquisition unit (3), and a central control unit (4). The pump body cooling execution unit (1) includes a stator cooling jacket (11) and two sets of bearing cooling chambers (12). The stator cooling jacket (11) is arranged around the outer wall of the stator of the twin screw pump, and the two sets of bearing cooling chambers (12) are respectively arranged inside the bearing seats at both ends of the pump body. The medium circulation precooling unit (2) includes a main cooling circuit (21), a gas-liquid precooling branch (22), a stator branch regulating valve (23) and a bearing branch regulating valve (24). The inlet of the main cooling circuit (21) is connected to the liquid storage tank of the test bench, and the outlet is connected to the stator cooling jacket (11) and the bearing cooling chamber (12) respectively. The gas-liquid precooling branch (22) is connected to the front end of the main cooling circuit (21). The detection end of the parameter acquisition unit (3) is respectively set in the pump body temperature measurement point and the cooling pipe, and the signal output end of the parameter acquisition unit (3) is connected to the central control unit (4). The control output terminal of the central control unit (4) is connected to the control terminals of the stator branch regulating valve (23), the bearing branch regulating valve (24) and the gas-liquid precooling branch (22), respectively. The central control unit (4) is connected to the host computer of the test bench.

2. The high-efficiency cooling and temperature control system for the twin-screw oil-gas mixed-transfer pump according to claim 1, characterized in that, The stator cooling jacket (11) is provided with a spiral flow guide baffle (111) inside, which extends along the stator axis to form a continuous spiral flow channel.

3. The high-efficiency cooling and temperature control system for the twin-screw oil-gas mixed-transfer pump according to claim 1, characterized in that, The bearing cooling cavity (12) adopts an annular cavity structure. The inner wall of the annular cavity is in contact with the outer wall of the bearing outer ring. The annular cavity is provided with a liquid inlet and a liquid outlet.

4. The high-efficiency cooling and temperature control system for the twin-screw oil-gas mixed-transfer pump according to claim 1, characterized in that, The gas-liquid precooling branch (22) includes a compressed air source (221), a gas regulating valve (222) and a gas-liquid mixer (223). The liquid phase inlet of the gas-liquid mixer (223) is connected to the main cooling circuit (21), and the gas phase inlet is connected to the compressed air source (221) through the gas regulating valve (222).

5. The high-efficiency cooling and temperature control system for the twin-screw oil-gas mixed-transfer pump according to claim 1, characterized in that, The main cooling circuit (21) is equipped with a circulating pump (211) and a filter (212) in sequence, and the return end of the main cooling circuit (21) is connected to the liquid storage tank of the test bench.

6. The high-efficiency cooling and temperature control system for the twin-screw oil-gas mixed-transfer pump according to claim 1, characterized in that, The parameter acquisition unit (3) includes a first temperature sensor (31), a second temperature sensor (32), a third temperature sensor (33), and an inlet temperature sensor (34); the first temperature sensor (31) is embedded in the inner wall of the stator cavity, the second temperature sensor (32) and the third temperature sensor (33) are respectively embedded in the bearing seats at both ends, and the inlet temperature sensor (34) is located at the inlet of the main cooling circuit (21).

7. The high-efficiency cooling and temperature control system for the twin-screw oil-gas mixed-transfer pump according to claim 6, characterized in that, The parameter acquisition unit (3) also includes a stator branch flow sensor (35), a bearing branch flow sensor (36), and an outlet pressure transmitter (37); the stator branch flow sensor (35) is located downstream of the stator branch regulating valve (23), the bearing branch flow sensor (36) is located downstream of the bearing branch regulating valve (24), and the outlet pressure transmitter (37) is located in the outlet pipeline of the twin screw pump.

8. The high-efficiency cooling and temperature control system for the twin-screw oil-gas mixed-transfer pump according to claim 6, characterized in that, The parameter acquisition unit (3) also includes a vibration sensor (38) and a sound level meter (39). The vibration sensor (38) is disposed on the surface of the bearing housing, and the sound level meter (39) is disposed on one side of the pump body.

9. The high-efficiency cooling and temperature control system for the twin-screw oil-gas mixed-transfer pump according to claim 1, characterized in that, The central control unit (4) includes a PLC control module (41) and a working condition linkage interface (42). The working condition linkage interface (42) is connected to the host computer of the test bench to obtain test working condition parameters.

10. A high-efficiency cooling temperature control method for a twin-screw oil-gas mixed-transfer pump, applied to the high-efficiency cooling temperature control system for the twin-screw oil-gas mixed-transfer pump as described in any one of claims 1-9, characterized in that, Includes the following steps: S1. The stator cavity temperature, the bearing temperatures at both ends, and the inlet temperature of the cooling medium are collected by the parameter acquisition unit. At the same time, the current operating condition parameters and the preset parameters for the next operating condition are obtained by the central control unit from the host computer of the test bench. S2. Compare the stator cavity temperature with the preset stator temperature threshold to generate a stator branch flow regulation signal, and compare the bearing temperatures at both ends with the preset bearing temperature threshold to generate a bearing branch flow regulation signal. S3. Calculate the pre-adjusted cooling power based on the preset parameters of the next operating condition, perform pre-correction on the stator branch flow regulation signal and the bearing branch flow regulation signal, and output the final two cooling medium flow commands. S4. Adjust the opening of the stator branch regulating valve and the bearing branch regulating valve according to the flow command, and adjust the gas-liquid mixing ratio of the gas-liquid precooling branch to complete the pump body zone cooling and operating condition adaptive temperature control.

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