A low temperature test device and method for lubricating oil pipeline of deep low temperature axial flow compressor

Abstract

The invention relates to the technical field of safety protection of complex large-scale rotating mechanical equipment, and aims to solve the problem that the prior art lacks research on heat transfer of normal temperature medium in deep low temperature and supercharging coupling environment, and provides a deep low temperature axial flow compressor lubricating oil pipeline low temperature test device and method; wherein the test device comprises a lubricating oil tank, an oil pump, a high-position oil tank, a low temperature test component, a Dewar flask and a connecting pipeline; the oil outlet of the lubricating oil tank is connected to the oil pump, the oil pump is connected to the oil inlet of the high-position oil tank, the low temperature test component has a cavity inside, and the cavity is used to place the pipeline test piece; the oil outlet of the high-position oil tank is connected to the inlet end of the pipeline test piece, and the outlet end of the pipeline test piece is connected to the oil return port of the lubricating oil tank; liquid nitrogen is stored in the Dewar flask and a control valve is installed on it, and the Dewar flask is connected to the low temperature test component; a heater is arranged in the cavity; and the test method is implemented using the above-mentioned test device.

Description

Technical Field

[0001] The invention belongs to the field of safety protection of complex large-scale rotating mechanical equipment, and in particular relates to a low-temperature test device and method for a deep-cryogenic axial flow compressor lubricating oil pipeline. Background Art

[0002] Large axial compressors used in industrial production are mostly used in normal temperature, high temperature or slightly low temperature environments. During operation, the required lubricating oil is usually heated or cooled according to the natural ambient temperature, compressor operating speed or load to keep the oil at a certain temperature, thereby ensuring that the bearings are in good working condition.

[0003] The latest large-scale deep-cryogenic axial compressor developed and put into operation in China has an operating temperature range of 77K to 323K, and an operating pressure range of 20kPa(A) to 450kPa(A). During operation, it is in a complex coupled environment of 110K deep low temperature and supercharging for a long time, which has greatly exceeded the application conditions of existing industrial axial compressors. The bearing box of the deep-cryogenic axial compressor is located inside the compressor, and the lubricating oil required for operation is stored in the oil tank in the natural environment. The oil supply and return oil pipelines will pass through the deep low temperature and high pressure areas, which will generate cold transfer. In particular, due to the use of gravity natural oil return, the flow rate of the oil is slow during oil return, and the cold transfer is more sufficient, which can easily cause the lubricating oil temperature to drop suddenly, resulting in increased viscosity and poor fluidity, and even accelerated mechanical wear, oil accumulation in the bearing box, and increased load on the oil supply system. In order to reduce risks and ensure the safe and stable operation of deep-cryogenic axial compressors, it is urgent to carry out research on the heat transfer characteristics of lubricating oil and its pipelines in deep low temperature environments.

[0004] Most of the existing research technologies on heat transfer characteristics of cryogenic pipelines are aimed at cryogenic media such as liquefied natural gas, liquefied air, liquid nitrogen, and liquid helium, that is, the pipeline itself is a cryogenic medium; even for the targeted research on the impact of low-temperature environment on lubricating oil performance, the lowest temperature is only a shallow low temperature of about 228K, and it is a normal pressure environment. Therefore, there is a lack of heat transfer research devices and methods for normal temperature media in deep low temperature and pressurized coupling environments. In addition, the compressors involved in the existing technology are basically centrifugal compressors, reciprocating compressors or screw compressors, and there is a lack of related technologies for axial flow compressors. Therefore, it is urgent to propose a low-temperature test device and method for lubricating oil pipelines of large axial flow compressors suitable for deep low temperature environments. Summary of the invention

[0005] The purpose of the present invention is to provide a low-temperature test device and method for the lubricating oil pipeline of a deep-cryogenic axial flow compressor, which can be used to study the heat transfer characteristics of the lubricating oil pipeline under the deep-cryogenic and pressurized environment of 110K, provide a basis for solving the problem of sudden temperature drop of the return oil pipeline passing through the deep-cryogenic and high-pressure areas, and meet the requirements for safe and stable operation of the deep-cryogenic axial flow compressor.

[0006] The present invention provides a low-temperature test device for a deep-cryogenic axial flow compressor lubricating oil pipeline, comprising a lubricating oil tank, an oil pump, a high-position oil tank, a low-temperature test component, a dewar flask and a connecting pipeline; the oil outlet of the lubricating oil tank is connected to the oil pump, the oil pump is connected to the oil inlet of the high-position oil tank, the arrangement height of the high-position oil tank is higher than the arrangement height of the lubricating oil tank, and the arrangement height of the low-temperature test component is located between the high-position oil tank and the lubricating oil tank; the low-temperature test component has a cavity inside, and the cavity is used to place a pipeline test piece; the oil outlet of the high-position oil tank is connected to the inlet end of the pipeline test piece, and the outlet end of the pipeline test piece is connected to the oil return port of the lubricating oil tank; liquid nitrogen is stored in the dewar flask, a control valve is installed on the dewar flask, the dewar flask is connected to the low-temperature test component, and the dewar flask is used to inject liquid nitrogen into the cavity to achieve cooling; a heater is also arranged in the cavity.

[0007] Through the above structure, the lubricating oil tank, the oil pump, the high-position oil tank and the pipeline test piece are connected by the connecting pipe to form a closed lubricating oil circuit; the lubricating oil tank statically stores lubricating oil, the oil pump draws lubricating oil from the lubricating oil tank and fills it into the high-position oil tank, and the lubricating oil in the high-position oil tank relies on its own gravity to flow through the pipeline test piece and naturally return to the lubricating oil tank.

[0008] Furthermore, the components are connected via the connecting pipes.

[0009] Furthermore, the low temperature test component comprises three sections of cylinders connected in sequence, the three sections of the cylinders are cylinder I, cylinder II and cylinder III, and two adjacent sections of the cylinders are detachably connected; the cylinder I is connected to the lubricating oil tank, and the cylinder III is connected to the high-level oil tank;

[0010] The low temperature test components are arranged obliquely, the pipeline test piece is located inside the cavity and is concentric with the central axis of the cavity, and the installation heights of the cylinder I, the cylinder II and the cylinder III increase sequentially.

[0011] Furthermore, each section of the cylinder is connected by a flange.

[0012] Furthermore, the low temperature test component maintains a certain angle with the horizontal plane. α。

[0013] Furthermore, the cylinder I is provided with a liquid nitrogen filling port, a first thermal resistor and a safety valve, the cylinder II is provided with a pressure gauge and a second thermal resistor, and the cylinder III is provided with a third thermal resistor and a nitrogen discharge port.

[0014] Furthermore, the heater is an electric heater, and the electric heater is installed inside each section of the cylinder.

[0015] Furthermore, the structure of the cylinder adopts a hollow non-insulated structure or a solid insulated structure;

[0016] When the cylinder adopts a hollow non-insulated structure, the cavity inside the cylinder is hollow and has no filler. After the pipeline test piece is placed in the cavity, a cavity exists between the pipeline test piece and the cylinder in the radial direction.

[0017] When the cylinder adopts a solid insulation structure, an insulation layer and an elastic compensation layer are provided in the cavity inside the cylinder, the pipeline test piece is located on the central axis of the cavity and between the insulation layer and the elastic compensation layer, and there is a gap between the pipeline test piece and the insulation layer and the elastic compensation layer.

[0018] The heat-insulating layer and the elastic compensation layer are a layer of structural parts sleeved on the outside of the pipeline test piece, and have the functions of heat insulation and elastic compensation.

[0019] Furthermore, the liquid nitrogen filling port is connected to the Dewar flask through a stainless steel hose, and the nitrogen exhaust port is connected to an exhaust valve through a stainless steel hose.

[0020] Furthermore, the stainless steel hose is a low-temperature stainless steel hose. The low-temperature stainless steel hose is a hose that can work in a low-temperature environment and has good flexibility and pressure resistance.

[0021] Furthermore, the pipeline test piece includes a stainless steel pipe and a double-layer corrugated hose, which are detachably connected;

[0022] The stainless steel pipe and the oil outlet of the high-position oil tank, as well as the double-layer corrugated hose and the oil return port of the lubricating oil tank are both connected by pipelines and flanges.

[0023] Furthermore, the pipelines between the stainless steel pipe and the oil outlet of the high-position oil tank and between the double-layer corrugated hose and the oil return port of the lubricating oil tank adopt high-pressure hoses.

[0024] Furthermore, the stainless steel pipe and the double-layer corrugated hose are connected by a flange.

[0025] Furthermore, the oil outlet of the high-position oil tank and the oil return port of the lubricating oil tank are both equipped with thermal resistors, and there is a height difference Δ between the oil outlet of the high-position oil tank and the oil return port of the lubricating oil tank. h ;

[0026] The lubricating oil tank is equipped with a flap type liquid level gauge and a thermal resistor;

[0027] The oil pump adopts a variable frequency speed regulating quantitative pump.

[0028] The present invention further provides a cryogenic test method for a deep cryogenic axial flow compressor lubricating oil pipeline, which is implemented using the above-mentioned cryogenic test device for a deep cryogenic axial flow compressor lubricating oil pipeline, and comprises the following steps:

[0029] S1A: Select the structure of the low temperature test component and determine the working parameters;

[0030] The working parameters include the lubricating oil flow rate, the cooling rate in the cavity of the low temperature test component, and the pressure in the cavity of the low temperature test component;

[0031] The cooling rate is calculated as follows:

[0032]

[0033] In the formula, t (n) Indicates n a moment, T (n) Indicates n The temperature inside the cavity of the low-temperature test component at a certain moment; t (n-1) Indicates n -1 moment, T (n-1) Indicates n -The temperature inside the low temperature test component cavity at one moment;

[0034] S2A: Test according to the operating parameters determined in S1A;

[0035] S2A specifically includes:

[0036] S201: record the initial state;

[0037] The initial state includes: ambient temperature, temperature of the three-section cylinder of the low-temperature test component, temperature of the lubricating oil tank, ambient pressure, and pressure in the cavity of the low-temperature test component;

[0038] S202: starting the oil pump and adjusting its speed so that the corresponding lubricating oil flow reaches the stable state of the flow value determined by S1A, and establishing a stable oil circulation in the closed loop;

[0039] S203: Open the control valve of the Dewar flask, and continuously inject liquid nitrogen into the cavity of the low-temperature test component through the Dewar flask. Monitor the cooling state of the cavity through the thermal resistor in the low-temperature test component, calculate the cooling rate according to the cooling temperature and cooling time, and adjust the opening of the control valve on the Dewar flask accordingly. When the cooling rate reaches the cooling rate value determined by S1A, keep the opening of the control valve of the Dewar flask unchanged so that the average measured temperature in the cavity The temperature is stable at no more than 110K. The pressure in the cavity is detected by a pressure gauge. The low-temperature nitrogen gas vaporized from the liquid nitrogen is dynamically discharged by adjusting the exhaust valve to establish a stable pressure inside the cavity and make the pressure reach the stable state of the pressure value determined by S1A.

[0040] S204: maintaining the stable state in S202 and S203, and waiting for a period of time to complete the heat transfer between the inner and outer layers of the double-layer corrugated hose of the pipeline test piece;

[0041] S205: Conducting a test, and recording test process parameters multiple times within the test duration;

[0042] The test process parameters recorded include the lubricating oil flow rate, the cooling rate in the low temperature test component cavity, the pressure in the low temperature test component cavity, the oil outlet temperature of the high-level oil tank, and the oil return port temperature of the lubricating oil tank;

[0043] S206: Change one of the working parameters in S1A, perform multiple tests in sequence and record the test process parameters accordingly.

[0044] Furthermore, in S1A, the structure of the low temperature test component includes a hollow non-insulated structure and a solid insulated structure. The test methods corresponding to the two structures are a non-insulated test method and an insulated test method. For each test method, the working parameters include: the lubricating oil flow rate is Q 1 and Q 2. The cooling rate in the low temperature test component cavity is v T1 and v T2 , the pressure inside the low temperature test component cavity is P 1 and P 2, and Q 1< Q 2. v T1 < v T2 , P 1< P 2;

[0045] The non-insulation test method includes the following steps:

[0046] S0: Record the initial state: the ambient temperature, the temperature of the three-section cylinder of the low-temperature test component and the temperature of the lubricating oil tank are all at room temperature 288.7K, and the ambient pressure and the pressure in the cavity of the low-temperature test component are both at normal pressure 101.3kPa;

[0047] S1: Start the oil pump and adjust the speed to n 1, the corresponding flow rate is Q 1. Establish a stable oil circulation in the closed lubricating oil circuit so that the lubricating oil flow reaches Q 1 is a stable state, during which the high-level oil tank is required to have no oil accumulation;

[0048] S2: Open the control valve on the Dewar flask and set the temperature at the cooling rate. v T1 Liquid nitrogen is continuously injected into the cavity of the cryogenic test component from the Dewar flask, and the temperature drop in the cavity is monitored by the thermal resistor in the cryogenic test component, so that the average measured temperature in the cavity is The temperature is stable at no more than 110K. The pressure in the cavity of the low-temperature test component is monitored by a pressure gauge, and the low-temperature nitrogen is discharged by adjusting the exhaust valve to establish a stable pressure inside the cavity. P 1;

[0049] S3: Keep S1 and S2 stable and continue to wait for the time t 1. Until the heat transfer between the inner and outer layers of the double-layer corrugated hose of the pipeline test piece is completed and the temperature is Δ T 1 stable state within the range;

[0050] S4: Maintain the stable state of S3, interval time t 2. Monitor and confirm that there is no oil accumulation in the high-level oil tank, and record Q 1. , P 1、 High oil tank outlet temperature T 1 and lubricating oil tank return port temperature T 2. Duration reaches t The test was completed at 3 o'clock;

[0051] S5: Keep the stable state of S1, close the exhaust valve, and continue to cool down at the rate of the Dewar flask. v T1 Inject liquid nitrogen into the cavity until the pressure gauge detects that the pressure in the cavity reaches P 2. Keep the control valve opening on the Dewar flask unchanged, gradually open the exhaust valve to a certain opening, and keep the pressure inside the chamber at P 2 stable state;

[0052] S6: Maintain the stable state of S5 and continue to wait for the time t4. Until the heat transfer between the inner and outer layers of the double-layer corrugated hose of the pipeline test piece is completed and the temperature is Δ T 1 stable state within the range;

[0053] S7: Maintain the stable state of S6, interval time t 2. Monitor and confirm that there is no oil accumulation in the high-level oil tank, and record Q 1. , P 2. High oil tank outlet temperature T 3. Temperature of oil return port of lubricating oil tank T 4. Duration Arrival t The test was completed at 3 o'clock;

[0054] S8: Keep the stable state of S1, close the control valve on the Dewar flask, keep the opening of the exhaust valve unchanged, and release the pressure in the chamber until the pressure returns to P 1. Close the exhaust valve;

[0055] S9: Keep the stable state of S1 and the closed state of the control valve and exhaust valve in S8, turn on the heater, and heat the inside of the low-temperature test component cavity until the average measured temperature in the low-temperature test component cavity reaches At 155K±Δ T 2 temperature range;

[0056] S10: Keep S1 stable, open the control valve on the Dewar flask, and follow the cooling rate. v T2 Liquid nitrogen is injected into the cavity, and the temperature drop in the cavity is monitored by the thermal resistor in the low-temperature test component, so that the average measured temperature in the cavity The temperature is stable at no more than 110K. The pressure in the cavity is monitored by a pressure gauge, and low-temperature nitrogen is discharged through the exhaust valve to establish a stable pressure inside the cavity. P 1. Use thermal resistors to monitor the temperature of the oil outlet of the high-position oil tank and the oil return port of the lubricating oil tank, and record the temperature changes Δ T 3 and Δ T 4;

[0057] S11: Keep S10 stable and continue to wait t 5. Until the heat transfer between the inner and outer layers of the double-layer corrugated hose of the pipeline test piece is completed and the temperature is Δ T 1 stable state within the range;

[0058] S12: maintain the stable state of S11, interval time t 2. Monitor and confirm that there is no oil accumulation in the high-level oil tank, and record Q 1. , P 1. High oil tank outlet temperatureT 5. Temperature of oil return port of lubricating oil tank T 6. Duration reaches t The test was completed at 3 o'clock;

[0059] S13: Adjust the oil pump speed to n 2, the corresponding flow is Q 2. Re-establish a stable oil circulation in the closed lubricating oil circuit so that the lubricating oil flow reaches Q 2. The stable state requires that there is no oil accumulation in the high-level oil tank during the process;

[0060] S14: Keep S13 and S12 stable, interval time t 2. Monitor and confirm that there is no oil accumulation in the high-level oil tank, and record Q 2. , P 1. High oil tank outlet temperature T 7 and lubricating oil tank return port temperature T 8, duration reaches t The test was completed at 3 o'clock;

[0061] S15: Keep the stable state of S13, and the remaining steps and states are consistent with S5;

[0062] S16: Maintain the stable state of S15 and continue to wait for the time t 6. Until the heat transfer between the inner and outer layers of the double-layer corrugated hose of the pipeline test piece is completed and the temperature is Δ T 1 stable state within the range;

[0063] S17: Maintain the stable state of S16, interval time t 2. Monitor and confirm that there is no oil accumulation in the high-level oil tank, and record Q 2. , P 2. High oil tank outlet temperature T 9 and lubricating oil tank return port temperature T 10 , duration reached t The test was completed at 3 o'clock;

[0064] S18: Keep the stable state of S13, and the remaining steps and states are consistent with S8;

[0065] S19: Keep the stable state of S13 and the closed state of the control valve and the exhaust valve in S8, and the remaining steps and states are consistent with S9;

[0066] S20: Keep the stable state of S13, and keep the other steps and states consistent with S10, and record the temperature changes of the oil outlet of the high-level oil tank and the oil return port of the lubricating oil tank Δ T 5 and ΔT 6;

[0067] S21: Keep S20 stable and continue to wait t 7. Until the heat transfer between the inner and outer layers of the double-layer corrugated hose of the pipeline test piece is completed and the temperature is Δ T 1 stable state within the range;

[0068] S22: maintain the stable state of S21, interval time t 2. Monitor and confirm that there is no oil accumulation in the high-level oil tank, and record Q 2. , P 1. High oil tank outlet temperature T 11 and lubricating oil tank return port temperature T 12 , the duration reaches t The test was completed at 3 o'clock;

[0069] The steps of the adiabatic test method are the same as those of the non-insulated test method described above.

[0070] Compared with the prior art, the present invention has the following beneficial effects:

[0071] 1. The test medium used in the present invention is room temperature lubricating oil, which fills the technical gap in the existing deep-cryogenic pipeline heat transfer characteristics research technology, which mostly uses low-temperature media such as liquefied natural gas, liquefied air, liquid nitrogen, and liquid helium, and expands the scope of application of the existing technology.

[0072] 2. The test temperature proposed in the present invention is no more than 110K, which expands the test temperature in the existing low-temperature environment effect research technology on lubricating oil performance from shallow low temperature to deep low temperature, greatly improving the test temperature range.

[0073] 3. The environmental test pressure proposed in the present invention is a supercharged state, which expands the test pressure in the existing technology for studying the influence of low-temperature environment on lubricating oil performance from normal pressure to supercharged conditions, filling the technical gap in the prior art.

[0074] 4. The test process adopted by the present invention covers two temperature domains: normal temperature and deep low temperature. The proposed device and method can effectively verify the temperature change process of the lubricating oil within a large temperature range. The fluidity of the lubricating oil in a deep low temperature environment is verified by monitoring the oil accumulation in the high-level oil tank, and beneficial results of normal temperature media in a deep low temperature environment are obtained.

[0075] 5. The test device and method adopted in the present invention are based on a large axial flow compressor, which fills the technical gap in the prior art which basically adopts centrifugal compressors, reciprocating compressors or screw compressors, and beneficially expands the equipment objects involved in the prior art.

[0076] 6. The lubricating oil brand, three-stage cylinder solid insulation structure, pipeline test piece structure and installation position and other device states adopted in the present invention, the proposed test conditions such as the cooling rate in the cavity of the low-temperature test component, the steady-state temperature, the steady-state pressure, and the test steps taken are all consistent with the operating conditions of the deep cryogenic axial flow compressor. The set lubricating oil flow rate covers the working flow of the deep cryogenic axial flow compressor, and can provide sufficient technical support for the operation of the deep cryogenic axial flow compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] Figure 1 It is a schematic diagram of the composition of the test device proposed by the present invention.

[0078] Figure 2 It is a schematic diagram of the installation of instruments and meters in the test device proposed by the present invention.

[0079] Figure 3 It is a schematic diagram of the installation of the test device proposed by the present invention.

[0080] Figure 4 It is the overall flow chart of the test method proposed by the present invention.

[0081] Figure 5 Flow chart of the non-adiabatic test method of the present invention.

[0082] Figure 6 It is a schematic diagram of the heat transfer calculation model of the double-layer corrugated hose proposed by the present invention.

[0083] Icons: 1-liquid nitrogen filling port; 2-first thermal resistor; 3-safety valve; 4-pressure gauge; 5-second thermal resistor; 6-third thermal resistor; 7-nitrogen discharge port; 8-fourth thermal resistor; 9-fifth thermal resistor; 10-electric heater; 11-cylinder I; 12-cylinder II; 13-cylinder III; 14-lubricating oil tank; 15-high-level oil tank; 16-oil pump; 17-low-temperature test component; 18-Dewar flask; 19-pipeline test piece; 20-corrugated hose outer layer; 21-corrugated hose interlayer; 22-corrugated hose inner layer. DETAILED DESCRIPTION

[0084] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0085] Example 1

[0086] like Figure 1-Figure 3As shown, this embodiment provides a cryogenic test device for a deep cryogenic axial compressor lubricating oil pipeline, comprising a lubricating oil tank 14, an oil pump 16, a high-level oil tank 15, a cryogenic test component 17, a Dewar flask 18 and connecting pipelines.

[0087] The lubricating oil tank 14 stores lubricating oil statically, the oil outlet of the lubricating oil tank 14 is connected to the oil pump 16, the oil pump 16 is connected to the oil inlet of the high-position oil tank 15, the high-position oil tank 15 is arranged at a higher height than the lubricating oil tank 14, the low-temperature test component 17 is arranged at a height between the high-position oil tank 15 and the lubricating oil tank 14, and the low-temperature test component 17 is arranged in an inclined manner. The low-temperature test component 17 has a cavity inside, and the pipeline test piece 19 is placed in the cavity of the low-temperature test component 17 during the test. The oil outlet of the high-position oil tank 15 is connected to the inlet end of the pipeline test piece 19, and the outlet end of the pipeline test piece 19 is connected to the oil return port of the lubricating oil tank 14. The Dewar flask 18 stores liquid nitrogen for testing, and the Dewar flask 18 is connected to the low-temperature test component 17, so as to transport the low-temperature liquid nitrogen to the cavity of the low-temperature test component 17. The above-mentioned components are connected through connecting pipes.

[0088] Through the above structure, a closed lubricating oil circuit is formed between the lubricating oil tank 14, the oil pump 16, the high-level oil tank 15 and the pipeline test piece 19, and the lubricating oil stored in the lubricating oil tank 14 meets the oil supply and return requirements of the entire circulating oil circuit. Figure 1 In the closed loop, the lubricating oil circulates counterclockwise. During the test, the oil pump 16 is in operation to extract lubricating oil from the lubricating oil tank 14. The lubricating oil is pressurized by the oil pump 16 to overcome the pipe resistance and its own gravity, and is filled into the high-position oil tank 15 through the connecting pipe. The lubricating oil in the high-position oil tank 15 then relies on its own gravity to flow from the oil outlet of the high-position oil tank 15 through the pipe test piece 19 in the low-temperature test component 17, and then naturally returns to the lubricating oil tank 14.

[0089] In this embodiment, the low temperature test component 17 adopts a three-section cylinder structure. Specifically, the low temperature test component 17 includes three sections of cylinders, namely cylinder I 11, cylinder II 12 and cylinder III 13. Each section of the cylinder is connected by a flange. The cylinder I 11 is connected to the lubricating oil tank 14, and the cylinder III 13 is connected to the high-position oil tank 15. The installation heights of the cylinder I 11, the cylinder II 12 and the cylinder III 13 increase in sequence.

[0090] like Figure 2As shown, a liquid nitrogen filling port 1, a first thermal resistor 2 and a safety valve 3 are installed on the shell of the cylinder Ⅰ11. Liquid nitrogen is added to the cavity of the low-temperature test component 17 through the liquid nitrogen filling port 1, so as to cool the cavity to reach the temperature required by the test; the first thermal resistor 2 is used to monitor the internal temperature of the cylinder Ⅰ11; the safety valve 3 is used to achieve emergency pressure relief when the cavity is over-pressured, so as to ensure the safety of the test equipment and personnel.

[0091] A pressure gauge 4 and a second thermal resistor 5 are installed on the shell of the cylinder II 12 . The pressure gauge 4 is used to monitor the dynamic pressure inside the entire cavity during the test; the second thermal resistor 5 is used to monitor the internal temperature of the cylinder II 12 .

[0092] A third thermal resistor 6 is installed on the shell of the cylinder III13 and a nitrogen exhaust port 7 is provided. The third thermal resistor 6 is used to monitor the internal temperature of the cylinder III13, and the nitrogen exhaust port 7 is used to discharge the gasified liquid nitrogen (i.e. nitrogen) to maintain the pressure balance of the entire cavity.

[0093] In this embodiment, the liquid nitrogen filling port 1, the first thermal resistor 2, the pressure gauge 4, the second thermal resistor 5, the third thermal resistor 6 and the nitrogen exhaust port 7 are installed directly above the low-temperature test component 17, and the safety valve 3 is installed on the side of the low-temperature test component 17, but is not limited to this installation method.

[0094] In addition, an electric heater 10 is installed inside each section of the cylinder, and the electric heater 10 is used to heat the inside of the cylinder to increase the temperature inside the cylinder.

[0095] In this embodiment, an electric heater 10 is installed inside each section of the cylinder, with a total of three electric heaters 10; the electric heater 10 uses a heating ring, which is fixed on the inner wall surface of each section of the cylinder shell to heat the inside of the cylinder, thereby increasing the temperature in the entire cavity. The electric heater 10 is not limited to the selection of the above-mentioned number and type.

[0096] The structure of the cylinder adopts a hollow non-insulated structure or a solid insulating structure.

[0097] The hollow non-insulated structure means that the cavity inside the cylinder is hollow and has no filler. After the pipeline test piece 19 is placed in the cavity, there is a cavity in the radial direction between the pipeline test piece 19 and the cylinder.

[0098] The solid insulation structure refers to an insulation layer and an elastic compensation layer provided in the cavity inside the cylinder, the pipeline test piece 19 is located on the central axis of the cavity and between the insulation layer and the elastic compensation layer, and a partial gap is reserved between the pipeline test piece 19 and the insulation layer and the elastic compensation layer.

[0099] In this embodiment, the thickness of the thermal insulation layer and the elastic compensation layer is 180 mm, but is not limited to this thickness.

[0100] Regarding the connecting pipeline, the liquid nitrogen filling port 1 is connected to the Dewar flask 18 through a low-temperature stainless steel hose. A control valve is installed on the Dewar flask 18. After opening the control valve, liquid nitrogen is injected into the cavity through the liquid nitrogen filling port 1, thereby cooling the interior of the cavity; by adjusting the opening of the control valve, the flow rate of the injected liquid nitrogen can be controlled, thereby controlling the cooling rate of the cavity.

[0101] The nitrogen exhaust port 7 is connected to the exhaust valve through a low-temperature stainless steel hose. The liquid nitrogen in the cavity becomes low-temperature nitrogen after gasification. After the exhaust valve is opened, the excess nitrogen is discharged from the cavity through the nitrogen exhaust port 7, thereby maintaining the pressure in the cavity stable.

[0102] In this embodiment, the pipeline test piece 19 includes a stainless steel pipe and a double-layer corrugated hose, which are connected by a flange. The entire double-layer corrugated hose is located in the cavity, and the stainless steel pipe and the oil outlet of the high-position oil tank 15, and the double-layer corrugated hose and the oil return port of the lubricating oil tank 14 are connected by a high-pressure hose and connected by a flange. Specifically, a flange interface is installed at the end of the shell of the cylinder I11, and one end of the double-layer corrugated hose is connected to the flange interface; one end of the stainless steel pipe is connected to the double-layer corrugated hose, and the other end passes through the end of the shell of the cylinder III13, and a flange interface is installed in the normal temperature area.

[0103] To ensure the validity of the test results, the design of the lubricating oil return pipeline of the test device of the present invention is consistent with the design of the oil return pipeline of the cryogenic axial compressor.

[0104] To ensure the validity of the test results, Figure 3 As shown, the pipeline test piece 19 is concentric with the central axis of the internal cavity of the low temperature test component 17 and maintains a certain angle with the horizontal plane. α In this embodiment, α Set it to 50°, which is consistent with the angle of the oil return pipe of the cryogenic axial compressor.

[0105] The installation position of the low temperature test component 17 is as follows Figure 4As shown, the axis of the internal cavity of the low-temperature test component 17 is coaxial with the axis of the pipeline test piece 19, so the angle between the low-temperature test component 17 and the horizontal plane is also 50°; according to the installation order from low to high, they are the cylinder I 11, the cylinder II 12 and the cylinder III 13.

[0106] like Figure 4 As shown, in order to ensure that the pipeline test piece 19, the low temperature test component 17 form an angle of 50° with the horizontal plane, and also to create conditions for the natural return of the lubricating oil by gravity, the oil outlet of the high-position oil tank 15 and the oil return port of the lubricating oil tank 14 need to maintain a certain height difference Δ h To ensure the validity of the test results, Δ h It is set to 3360±10mm, which is consistent with the oil return height difference of the deep low temperature axial flow compressor.

[0107] like Figure 2 As shown, the oil outlet of the high-level oil tank 15 and the oil return port of the lubricating oil tank 14 are respectively installed with a fourth thermal resistor 8 and a fifth thermal resistor 9. The fourth thermal resistor 8 and the fifth thermal resistor 9 are respectively used to monitor the temperature of the lubricating oil before and after flowing through the pipeline test piece 19.

[0108] The lubricating oil tank 14 is equipped with a flap level gauge and a thermal resistor. The level gauge is marked with three positions: shutdown level, maximum operating level and minimum operating level, so as to intuitively monitor the level of the lubricating oil tank 14. The thermal resistor is used to measure the temperature of the lubricating oil tank 14.

[0109] The shutdown liquid level represents the lowest oil level allowed when the oil pump 16 is not running, the maximum operating liquid level represents the highest oil level allowed when the oil pump 16 is running, and the minimum operating liquid level represents the lowest oil level allowed when the oil pump 16 is running. Before the test, the liquid level of the lubricating oil tank 14 should be higher than the shutdown liquid level to prevent the oil pump 16 from being unable to continue pumping oil due to the lubricating oil filling the closed circuit during operation, causing the liquid level of the lubricating oil tank 14 to be lower than the oil suction port of the oil pump 16; during the test, the liquid level of the lubricating oil tank 14 should be between the highest operating liquid level and the lowest operating liquid level.

[0110] In this embodiment, the oil pump 16 is a variable frequency speed regulating quantitative pump. By adjusting the speed, the lubricating oil flow rate is correspondingly adjusted, and the speed and flow rate correspond one to one. For example, the speed of the oil pump 16 is n 1, the corresponding lubricating oil flow rate is Q 1; The speed of the oil pump 16 is n 2, the corresponding lubricating oil flow rate is Q2. To ensure the validity of the test results, the lubricating oil flow rate of the oil pump 16 is in the range of 40L / min to 100L / min, covering the normal oil return flow rate range of the deep cryogenic axial flow compressor.

[0111] The present invention fills the lubricating oil into the high-position oil tank 15 at the highest point of the entire test device through the oil pump 16. The lubricating oil in the high-position oil tank 15 relies on its own gravity to flow to the pipeline test piece 19 through the oil outlet, that is, it flows through the stainless steel pipe and the double-layer corrugated hose in sequence, and then returns to the oil through the oil return port of the lubricating oil tank 14. The cycle is repeated in this way, so that the entire closed loop can achieve stable oil circulation flow. During the process, the high-position oil tank 15 has smooth oil discharge and no oil accumulation at the bottom. The liquid level in the lubricating oil tank 14 is between the highest operating liquid level and the lowest operating liquid level.

[0112] Example 2

[0113] like Figure 4 As shown, this embodiment proposes a low-temperature test method for a deep-cryogenic axial flow compressor lubricating oil pipeline, which is implemented using the deep-cryogenic axial flow compressor lubricating oil pipeline low-temperature test device described in Example 1, and includes the following steps:

[0114] S1A: Select the structure of the low temperature test component 17 and determine the working parameters;

[0115] The working parameters include the lubricating oil flow rate, the cooling rate in the cavity of the low temperature test component 17, and the pressure in the cavity of the low temperature test component 17;

[0116] The cooling rate is calculated as follows:

[0117]

[0118] In the formula, t (n) Indicates n a moment, T (n) Indicates n The temperature in the cavity of the low temperature test component 17 at a certain moment; t (n-1) Indicates n -1 moment, T (n-1) Indicates n -The temperature inside the low temperature test component cavity at 1 moment.

[0119] In this embodiment, the structure of the low temperature test component 17 adopts two types: hollow non-insulated structure and solid insulation structure. The lubricating oil flow rate adopts Q 1 and Q 2Two types ( Q 1< Q 2) The cooling rate isv T1 and v T2 Two types ( v T1 < v T2 ), pressure is adopted P 1 and P 2Two types ( P 1< P 2).

[0120] To ensure that the test results are of reference significance, the cooling rate is consistent with the cooling rate of the environment where the deep cryogenic axial compressor is located. v T1 Take the normal cooling rate of 0.015K / s (±0.002K / s), v T2 Take the rapid cooling rate within the range of 40K as 0.5K / s (±0.01K / s). v T1 When cooling down, each moment is 5 minutes apart; when using v T2 When cooling down, each moment is 5s apart.

[0121] The lubricating oil flow rate is selected from the working flow rate of the deep low temperature axial flow compressor 80L / min and the maximum flow rate of the oil pump 16 100L / min, that is, Q 1=80L / min, Q 2=100L / min.

[0122] The pressure is selected as normal pressure 115kPa and boost pressure 225kPa within the operating range of the deep cryogenic axial compressor, that is, P 1 = 115 kPa (± 1 kPa), P 2=225kPa (±2kPa).

[0123] S2A: Test according to the operating parameters determined in S1A;

[0124] Step S2A specifically includes:

[0125] S201: record the initial state;

[0126] The initial state includes: the ambient temperature, the temperature of the three-section cylinder of the low-temperature test component 17 , the temperature of the lubricating oil tank 14 , the ambient pressure, and the pressure in the cavity of the low-temperature test component 17 .

[0127] In this embodiment, the ambient temperature, the temperature of the three-stage cylinder of the low-temperature test component 17 and the temperature of the lubricating oil tank 14 are all normal temperature 288.7K, and the ambient pressure and the pressure in the cavity of the low-temperature test component 17 are all normal pressure 101.3 kPa.

[0128] S202: starting the oil pump 16 and adjusting its rotation speed so that the corresponding lubricating oil flow rate reaches the stable state of the flow value determined in S1, and establishing a stable oil circulation in the closed loop;

[0129] The stable state means that the oil flow from the high-level oil tank 15 is smooth, there is no oil accumulation at the bottom, and the oil level of the lubricating oil tank 14 is between the maximum operating liquid level and the minimum operating liquid level;

[0130] S203: Open the control valve of the Dewar flask 18, and continuously inject liquid nitrogen into the cavity of the low-temperature test component 17 through the Dewar flask 18. The temperature drop state of the cavity is monitored by the thermal resistor in the low-temperature test component 17. The cooling rate is calculated according to the cooling temperature and the cooling time, and the opening of the control valve of the Dewar flask 18 is adjusted accordingly. When the cooling rate reaches the cooling rate value determined in step S1, the opening of the control valve of the Dewar flask 18 is kept unchanged, so that the average measured temperature in the cavity The temperature is in a stable state not higher than 110K; the pressure in the cavity is detected by a pressure gauge, and the low-temperature nitrogen gas after liquid nitrogen vaporization is dynamically discharged by adjusting the exhaust valve connected to the nitrogen exhaust port 7 of the low-temperature test component 17, so that a stable pressure is established inside the cavity, and the pressure reaches a stable state of the pressure value determined by S1;

[0131] S204: maintaining the stable state in S202 and S203, and waiting for a period of time to complete the heat transfer between the inner and outer layers of the double-layer corrugated hose of the pipeline test piece 19;

[0132] S205: Conducting a test, and recording test process parameters multiple times within the test duration;

[0133] The test process parameters recorded include the lubricating oil flow rate, the cooling rate in the cavity of the low-temperature test component 17, the pressure in the cavity of the low-temperature test component 17, the oil outlet temperature of the high-level oil tank 15 and the oil return port temperature of the lubricating oil tank 14.

[0134] S206: Change one of the working parameters in S1A to adjust to different test conditions, perform multiple tests in sequence and record the test process parameters accordingly.

[0135] The low-temperature test method for the deep-cryogenic axial flow compressor lubricating oil pipeline can be divided into two methods: non-insulated test and insulated test. When the cylinder of the low-temperature test component 17 adopts a hollow non-insulated structure, it is a non-insulated test; when the cylinder of the low-temperature test component 17 adopts a solid insulated structure, it is an insulated test.

[0136] Next, the non-insulated test method is described in detail:

[0137] The six test conditions of the non-insulated test method are shown in Table 1; the test process parameters are shown in Table 2, and data is recorded accordingly; the overall test process is shown in Figure 4 As shown, the initial state is first recorded, and then the state 1 to state 6 are implemented in sequence.

[0138] Table 1 Test status table

[0139]

[0140] Table 2 Test process parameters

[0141]

[0142] like Figure 5 As shown, the specific steps include:

[0143] S0: Record the initial state: the ambient temperature, the temperature of the three sections of the low temperature test component 17 and the temperature of the lubricating oil tank 14 are all at room temperature 288.7K, and the ambient pressure and the pressure in the cavity of the low temperature test component 17 are both at normal pressure 101.3 kPa.

[0144] S1: Start the oil pump 16 and adjust the speed to n 1, corresponding to the lubricating oil flow rate is Q 1. Establish a stable oil circulation in the closed lubricating oil circuit so that the flow reaches a stable state. The stable state means that the oil flow from the high-level oil tank 15 is smooth, there is no oil accumulation at the bottom, and the oil level of the lubricating oil tank 14 is between the highest operating level and the lowest operating level. To ensure the validity of the test results, Q 1 Adjust to 80L / min, which is consistent with the normal oil return flow of the deep low temperature axial flow compressor.

[0145] S2: Open the control valve on the Dewar flask 18, and continuously inject liquid nitrogen into the cavity of the low-temperature test component 17 through the Dewar flask 18. The temperature drop state in the cavity is monitored by the thermal resistor in the low-temperature test component 17. The temperature drop rate is calculated in real time according to the temperature drop and the temperature drop time through the temperature drop rate calculation formula and the opening of the control valve is adjusted. When the temperature drop rate reaches v T1 Keep the opening of the control valve unchanged, so that the average measured temperature in the cavity The temperature is in a stable state not higher than 110K. The pressure in the cavity of the low-temperature test component 17 is monitored by a pressure gauge, and the low-temperature nitrogen gas after liquid nitrogen vaporization is dynamically discharged by adjusting the exhaust valve to establish a stable pressure inside the cavity. P 1. When P When 1=115kPa (±1kPa), the pressure is judged to be stable.

[0146] S3: Maintain the stable state of S1 and S2, that is, the lubricating oil circulation is smooth,Q 1=80L / min, ≤110K, P 1=115kPa (±1kPa), continue waiting time t 1, until the heat transfer between the inner and outer layers of the double-layer corrugated hose of the pipeline test piece 19 is completed and the temperature is Δ T 1 stable state within the range.

[0147] The heat transfer process between the inner and outer layers of the double-layer corrugated hose is obtained by calculation. The calculation model is as follows: Figure 6 As shown. The double-layer corrugated hose is made of 304L ultra-low carbon stainless steel. The outer layer 20 of the corrugated hose is low-temperature nitrogen, the inner layer 22 of the corrugated hose is filled with circulating lubricating oil, and the corrugated hose interlayer 21 between the outer layer 20 of the corrugated hose and the inner layer 22 of the corrugated hose is air. The heat transfer process is the process of low-temperature nitrogen transferring to the interlayer air and then to the inner layer. Through calculation, After reaching 110K, the air layer temperature changes rapidly in the first 15 minutes, gradually stabilizes after 25 minutes, and does not exceed 1K after 30 minutes. T 1 = 1K, that is, it has reached a stable state within the required range. In order to ensure sufficient heat transfer and accurate and reliable test results, t 1=40min, at this time, the heat transfer between the inner and outer layers of the double-layer corrugated hose is considered to be completed.

[0148] S4: Maintain the stable state of S3, that is, the lubricating oil circulation is smooth, Q 1=80L / min, ≤110K, P 1=115kPa (±1kPa), Δ T 1=1K, interval time t 2. Monitor and confirm that there is no oil accumulation in the high-level oil tank 15, and record Q 1. , P 1. Oil outlet temperature of high oil tank 15 T 1 and lubricating oil tank 14 return oil port temperature T 2. Duration reaches t The test was completed at 3:00. The oil accumulation monitoring of the high-level oil tank 15 requires that the bottom oil outlet is unobstructed and there is no excess oil accumulation. t 2=10min, that is, status monitoring and data recording are performed every 10 minutes; t 3=2h, that is, the test duration is 2 hours. Test state 1 completes 12 data records in total.

[0149] S5: Maintain the stable state of S1, that is, the lubricating oil circulation is smooth, Q1=80L / min, close the exhaust valve, and continue to cool down at the rate of 1000L / min through the control valve on the Dewar flask 18. v T1 Injecting liquid nitrogen into the cavity pressurizes the cavity until the pressure in the cavity monitored by the pressure gauge reaches P 2. Then keep the opening of the control valve on the Dewar flask 18 unchanged, and gradually open the exhaust valve to a certain opening to keep the pressure inside the cavity at P 2. When P When 2=225kPa (±2kPa), the pressure is judged to be stable.

[0150] S6: Maintain the stable state of S5, that is, the lubricating oil circulation is smooth, Q 1=80L / min, P 2 = 225 kPa (± 2 kPa), at this time the average measured temperature in the cavity remains ≤110K, continue waiting t 4. Until the heat transfer between the inner and outer layers of the double-layer corrugated hose of the pipe test piece 19 is completed and the temperature is Δ T 1 = Stable state within 1K. The temperature is kept below 110K, and only the pressure inside the cavity changes. Therefore, no obvious heat transfer will occur between the inner and outer layers of the double-layer corrugated hose. t 4=10min, which means that Δ T 1 = Stable state within 1K range.

[0151] S7: Maintain the stable state of S6, that is, the lubricating oil circulation is smooth, Q 1=80L / min, ≤110K, P 2 = 225 kPa (± 2 kPa), Δ T 1=1K, interval time t 2 = 10min, monitor and confirm that there is no oil accumulation in the high-level oil tank 15, and record Q 1. , P 2. Oil outlet temperature of high oil tank 15 T 3 and lubricating oil tank 14 return oil port temperature T 4. Duration Arrival t 3 = 2 hours to complete the test. Test state 2 completes 12 data records in total.

[0152] S8: Maintain the stable state of S1, that is, the lubricating oil circulation is smooth, Q1=80L / min, close the control valve on the Dewar flask 18, stop injecting liquid nitrogen into the cavity, keep the opening of the exhaust valve unchanged, and the cavity begins to release pressure, and the pressure inside the cavity gradually decreases until the pressure returns to P 1 = 115kPa (±1kPa) and then close the exhaust valve.

[0153] S9: Maintain the stable state of S1, that is, the lubricating oil circulation is smooth, Q 1=80L / min, and the closed state of the control valve and the exhaust valve in S8, turn on the electric heater, and heat the three sections of the low-temperature test component 17 at the same time until the average measured temperature of the thermal resistor in the cavity reaches At 155K±Δ T 2 temperature range. This process uses an electric heater to heat the cavity temperature from no higher than 110K to 155K±Δ T 2. As long as the temperature change exceeds 40K, the temperature control accuracy is not required, and Δ T 2 = 5 K. During the temperature recovery process, heat transfer will occur between the inner and outer layers of the double-layer corrugated hose of the pipeline test piece 19, thereby also increasing the temperature of the lubricating oil.

[0154] S10: Maintain the stable state of S1, that is, the lubricating oil circulation is smooth, Q 1=80L / min, open the control valve, and continuously inject liquid nitrogen into the cavity through the Dewar flask 18. The temperature drop state of the cavity is monitored by the thermal resistor in the low-temperature test component 17. The temperature drop rate is calculated in real time through the temperature drop rate calculation formula and the opening of the control valve is adjusted. When the temperature drop rate reaches v T2 Keep the opening of the control valve unchanged, so that the average measured temperature in the cavity The temperature is kept stable at no more than 110K. The pressure in the cavity is monitored by a pressure gauge, and the low-temperature nitrogen gas after liquid nitrogen vaporization is dynamically discharged by adjusting the exhaust valve to establish a stable pressure inside the cavity. P 1. When P When 1=115kPa (±1kPa), the pressure is judged to be stable.

[0155] The cavity temperature is =155K (±5K) Rapidly cool to ≤110K, the temperature drop exceeds 40K, which has covered the rapid cooling range of the deep low temperature axial compressor. During the rapid cooling process, heat transfer will occur between the inner and outer layers of the double-layer corrugated hose of the pipeline test piece 19, thereby reducing the temperature of the lubricating oil. The temperature state of the oil outlet of the high oil tank 15 and the oil return port of the lubricating oil tank 14 is monitored by thermal resistance, and the temperature change is recorded at intervals of 20s. T 3 and Δ T4. At least 4 data records can be completed during the rapid cooling time of 80s to 100s.

[0156] S11: Maintain the stable state of S10, that is, the lubricating oil circulation is smooth, Q 1=80L / min, ≤110K, P 1=115kPa (±1kPa), continue waiting time t 5, until the heat transfer between the inner and outer layers of the double-layer corrugated hose of the pipe test piece 19 is completed and the temperature is Δ T 1 = Stable state within 1K. According to the calculation method in S3, After reaching 110K for 11 minutes, the temperature change range does not exceed 1K. In order to ensure sufficient heat transfer and accurate and reliable test results, t 5=15min, at this time, the heat transfer between the inner and outer layers of the double-layer corrugated hose is considered to be completed.

[0157] S12: Maintain the stable state of S11, that is, the lubricating oil circulation is smooth, Q 1=80L / min, ≤110K, P 1=115kPa (±1kPa), Δ T 1=1K, interval time t 2 = 10min, monitor and confirm that there is no oil accumulation in the high-level oil tank 15, and record Q 1. , P 1. Oil outlet temperature of high oil tank 15 T 5 and lubricating oil tank 14 return oil port temperature T 6. Duration reaches t 3 = 2 hours to complete the test. Test state 3 can complete at least 16 data records.

[0158] S13: Adjust the speed of the oil pump 16 to n 2, the corresponding flow is Q 2=100L / min, a stable oil circulation is re-established in the closed lubricating oil circuit to make the flow reach a stable state. The stable state means that the oil flow from the high-level oil tank 15 is smooth, there is no oil accumulation at the bottom, and the oil level of the lubricating oil tank 14 is between the highest operating level and the lowest operating level.

[0159] S14: Maintain the stable state of S13 and S12, that is, the lubricating oil circulation is smooth, Q 2 = 100L / min, ≤110K, P 1=115kPa (±1kPa), Δ T 1=1K, interval time t2 = 10min, monitor and confirm that there is no oil accumulation in the high-level oil tank 15, and record Q 2. , P 1. Oil outlet temperature of high oil tank 15 T 7 and lubricating oil tank 14 return oil port temperature T 8, duration reaches t 3 = 2 hours to complete the test. Test state 4 completes 12 data records in total.

[0160] S15: Maintain the stable state of S13, that is, the lubricating oil circulation is smooth, Q 2=100L / min, the other steps and states are consistent with S5.

[0161] S16: Maintain the stable state of S15, that is, the lubricating oil circulation is smooth, Q 2 = 100L / min, P 2 = 225 kPa (± 2 kPa), at this time the average measured temperature in the cavity remains ≤110K, continue waiting t 6. Until the heat transfer between the inner and outer layers of the double-layer corrugated hose of the pipe test piece 19 is completed and the temperature is Δ T 1. According to the analysis in S6, t 6=10min, which means that Δ T 1 = Stable state within 1K range.

[0162] S17: Maintain the stable state of S16, that is, the lubricating oil circulation is smooth, Q 2 = 100L / min, ≤110K, P 2 = 225 kPa (± 2 kPa), Δ T 1=1K, interval time t 2 = 10min, monitor and confirm that there is no oil accumulation in the high-level oil tank 15, and record Q 2. , P 2. Oil outlet temperature of high oil tank 15 T 9 and lubricating oil tank 14 return oil port temperature T 10 , the duration reaches t 3 = 2 hours to complete the test. Test state 5 completes 12 data records in total.

[0163] S18: Maintain the stable state of S13, that is, the lubricating oil circulation is smooth, Q 2=100L / min, the other steps and states are consistent with S8.

[0164] S19: Maintain the stable state of S13, that is, the lubricating oil circulation is smooth,Q 2=100L / min, and the closing state of the control valve and exhaust valve in S8, and the remaining steps and states are consistent with S9.

[0165] S20: Maintain the stable state of S13, that is, the lubricating oil circulation is smooth, Q 2=100L / min, the rest of the steps and states are the same as S10, and the temperature changes of the oil outlet of the high oil tank 15 and the oil return port of the lubricating oil tank 14 are recorded respectively Δ T 5 and Δ T 6. At least 4 data records can be completed during the rapid cooling time of 80s to 100s.

[0166] S21: Maintain the stable state of S20, that is, the lubricating oil circulation is smooth, Q 2 = 100L / min, ≤110K, P 1=115kPa (±1kPa), continue waiting time t 7, until the heat transfer between the inner and outer layers of the double-layer corrugated hose of the pipeline test piece 19 is completed and the temperature is Δ T 1 = Stable state within 1K. According to the calculation method in S3, After reaching 110K for 14 minutes, the temperature change range does not exceed 1K. In order to ensure sufficient heat transfer and accurate and reliable test results, t 7=20min, at this time, the heat transfer between the inner and outer layers of the double-layer corrugated hose is considered to be completed.

[0167] S22: Maintain the stable state of S21, that is, the lubricating oil circulation is smooth, Q 2 = 100L / min, ≤110K, P 1=115kPa (±1kPa), Δ T 1=1K, interval time t 2 = 10min, monitor and confirm that there is no oil accumulation in the high-level oil tank 15, and record Q 2. , P 1. Oil outlet temperature of high oil tank 15 T 11 and lubricating oil tank 14 return oil port temperature T 12 , the duration reaches t 3 = 2 hours to complete the test. Test state 6 can complete at least 16 data records.

[0168] In the insulation test method, the cylinder of the low-temperature test component 17 adopts a solid insulation structure, and its test process and steps are consistent with the process and steps of the non-insulation test method.

[0169] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A low temperature test method for lubricating oil pipeline of deep low temperature axial flow compressor, characterized in that: The method is implemented by using a cryogenic test device for lubricating oil pipelines of a deep cryogenic axial flow compressor, which includes a lubricating oil tank, an oil pump, a high-position oil tank, cryogenic test components, a Dewar flask, and connecting pipes; The oil outlet of the lubricating oil tank is connected to the oil pump, the oil pump is connected to the oil inlet of the high-position oil tank, the arrangement height of the high-position oil tank is higher than the arrangement height of the lubricating oil tank, and the arrangement height of the low-temperature test component is located between the high-position oil tank and the lubricating oil tank; The low temperature test component has a cavity inside, and the cavity is used to place the pipeline test piece; The oil outlet of the high-position oil tank is connected to the inlet end of the pipeline test piece, and the outlet end of the pipeline test piece is connected to the oil return port of the lubricating oil tank; Liquid nitrogen is stored in the Dewar flask, a control valve is installed on the Dewar flask, the Dewar flask is connected to the low-temperature test component, and the Dewar flask is used to inject liquid nitrogen into the cavity to achieve cooling; A heater is also provided in the cavity; The low temperature test component comprises three sections of cylinders connected in sequence, the three sections of the cylinders are cylinder I, cylinder II and cylinder III, and two adjacent sections of the cylinders are detachably connected; the cylinder I is connected to the lubricating oil tank, and the cylinder III is connected to the high-position oil tank; The low temperature test components are arranged obliquely, the pipeline test piece is located inside the cavity and is concentric with the central axis of the cavity, and the installation heights of the cylinder I, the cylinder II and the cylinder III increase in sequence; The cylinder I is provided with a liquid nitrogen filling port, a first thermal resistor and a safety valve, the cylinder II is provided with a pressure gauge and a second thermal resistor, and the cylinder III is provided with a third thermal resistor and a nitrogen discharge port; The liquid nitrogen filling port is connected to the Dewar flask, and the nitrogen discharge port is connected to the exhaust valve; The deep low temperature axial flow compressor lubricating oil pipeline low temperature test method comprises the following steps: S1A: Select the structure of the low temperature test component and determine the working parameters; The working parameters include the lubricating oil flow rate, the cooling rate in the cavity of the low temperature test component, and the pressure in the cavity of the low temperature test component; The cooling rate is calculated as follows: In the formula, t (n) Indicates n a moment, T (n) Indicates n The temperature inside the low-temperature test component cavity at a certain moment; t (n-1) Indicates n -1 moment, T (n-1) Indicates n -The temperature inside the low temperature test component cavity at one moment; S2A: Test according to the operating parameters determined in S1A; S2A specifically includes: S201: record the initial state; The initial state includes: ambient temperature, temperature of the three-section cylinder of the low-temperature test component, temperature of the lubricating oil tank, ambient pressure, and pressure in the cavity of the low-temperature test component; S202: starting the oil pump and adjusting its speed so that the corresponding lubricating oil flow reaches the stable state of the flow value determined by S1A, and establishing a stable oil circulation in the closed loop; S203: Open the control valve of the Dewar flask, and continuously inject liquid nitrogen into the cavity of the low-temperature test component through the Dewar flask. Monitor the cooling state of the cavity through the thermal resistor in the low-temperature test component, calculate the cooling rate according to the cooling temperature and cooling time, and adjust the opening of the control valve on the Dewar flask accordingly. When the cooling rate reaches the cooling rate value determined by S1A, keep the opening of the control valve of the Dewar flask unchanged so that the average measured temperature in the cavity The temperature is stable at no more than 110K. The pressure in the cavity is detected by a pressure gauge. The low-temperature nitrogen gas vaporized from the liquid nitrogen is dynamically discharged by adjusting the exhaust valve to establish a stable pressure inside the cavity and make the pressure reach the stable state of the pressure value determined by S1A. S204: maintaining the stable state in S202 and S203, and waiting for a period of time to complete the heat transfer between the inner and outer layers of the double-layer corrugated hose of the pipeline test piece; S205: Conducting a test, and recording test process parameters multiple times within the test duration; The test process parameters recorded include the lubricating oil flow rate, the cooling rate in the low temperature test component cavity, the pressure in the low temperature test component cavity, the oil outlet temperature of the high-level oil tank, and the oil return port temperature of the lubricating oil tank; S206: Change one of the working parameters in S1A, perform multiple tests in sequence and record the test process parameters accordingly.

2. The method for testing the lubricating oil pipeline of a deep cryogenic axial flow compressor according to claim 1 is characterized in that: In S1A, the structures of low-temperature test components include hollow non-insulated structures and solid insulated structures. The test methods corresponding to the two structures are non-insulated test methods and insulated test methods. For each test method, the working parameters include: lubricating oil flow rate is Q 1 and Q 2. The cooling rate in the low temperature test component cavity is v T1 and v T2 , the pressure inside the low temperature test component cavity is P 1 and P 2, and Q 1< Q 2. v T1 < v T2 and P 1< P 2; The non-insulation test method includes the following steps: S0: Record the initial state: the ambient temperature, the temperature of the three-section cylinder of the low-temperature test component and the temperature of the lubricating oil tank are all at room temperature 288.7K, and the ambient pressure and the pressure in the cavity of the low-temperature test component are both at normal pressure 101.3kPa; S1: Start the oil pump and adjust the speed to n 1, the corresponding flow is Q 1. Establish a stable oil circulation in the closed lubricating oil circuit so that the lubricating oil flow reaches Q 1 is a stable state, during which the high-level oil tank is required to have no oil accumulation; S2: Open the control valve on the Dewar flask and set the temperature at the cooling rate. v T1 Liquid nitrogen is continuously injected into the cavity of the cryogenic test component from the Dewar flask, and the temperature drop in the cavity is monitored by the thermal resistor in the cryogenic test component, so that the average measured temperature in the cavity is The temperature is stable at no more than 110K. The pressure in the cavity of the low-temperature test component is monitored by a pressure gauge, and the low-temperature nitrogen is discharged by adjusting the exhaust valve to establish a stable pressure inside the cavity. P 1; S3: Keep S1 and S2 stable and continue to wait for the time t 1. Until the heat transfer between the inner and outer layers of the double-layer corrugated hose of the pipeline test piece is completed and the temperature is Δ T 1 stable state within the range; S4: Maintain the stable state of S3, interval time t 2. Monitor and confirm that there is no oil accumulation in the high-level oil tank, and record Q 1. , P 1、 High oil tank outlet temperature T 1 and lubricating oil tank return port temperature T 2. Duration reaches t The test was completed at 3 o'clock; S5: Keep the stable state of S1, close the exhaust valve, and continue to cool down at the rate of the Dewar flask. v T1 Inject liquid nitrogen into the cavity until the pressure gauge detects that the pressure in the cavity reaches P 2. Keep the control valve opening on the Dewar flask unchanged, gradually open the exhaust valve to a certain opening, and keep the pressure inside the chamber at P 2 stable state; S6: Maintain the stable state of S5 and continue to wait for the time t 4. Until the heat transfer between the inner and outer layers of the double-layer corrugated hose of the pipeline test piece is completed and the temperature is Δ T 1 stable state within the range; S7: Maintain the stable state of S6, interval time t 2. Monitor and confirm that there is no oil accumulation in the high-level oil tank, and record Q 1. , P 2. High oil tank outlet temperature T 3. Temperature of oil return port of lubricating oil tank T 4. Duration Arrival t The test was completed at 3 o'clock; S8: Keep the stable state of S1, close the control valve on the Dewar flask, keep the opening of the exhaust valve unchanged, and release the pressure in the chamber until the pressure returns to P 1. Close the exhaust valve; S9: Keep the stable state of S1 and the closed state of the control valve and exhaust valve in S8, turn on the heater, and heat the inside of the low-temperature test component cavity until the average measured temperature in the low-temperature test component cavity reaches At 155K±Δ T 2 temperature range; S10: Keep S1 stable, open the control valve on the Dewar flask, and follow the cooling rate. v T2 Liquid nitrogen is injected into the cavity, and the temperature drop in the cavity is monitored by the thermal resistor in the low-temperature test component, so that the average measured temperature in the cavity The temperature is stable at no more than 110K. The pressure in the cavity is monitored by a pressure gauge, and low-temperature nitrogen is discharged through the exhaust valve to establish a stable pressure inside the cavity. P 1. Use thermal resistors to monitor the temperature of the oil outlet of the high-position oil tank and the oil return port of the lubricating oil tank, and record the temperature changes Δ T 3 and Δ T 4; S11: Keep S10 stable and continue to wait t 5. Until the heat transfer between the inner and outer layers of the double-layer corrugated hose of the pipeline test piece is completed and the temperature is Δ T 1 stable state within the range; S12: Maintain the stable state of S11, interval time t 2. Monitor and confirm that there is no oil accumulation in the high-level oil tank, and record Q 1. , P 1. High oil tank outlet temperature T 5. Temperature of oil return port of lubricating oil tank T 6. Duration reaches t The test was completed at 3 o'clock; S13: Adjust the oil pump speed to n 2, the corresponding flow is Q 2. Re-establish a stable oil circulation in the closed lubricating oil circuit so that the lubricating oil flow reaches Q 2. The stable state requires that there is no oil accumulation in the high-level oil tank during the process; S14: Keep S13 and S12 stable, interval time t 2. Monitor and confirm that there is no oil accumulation in the high-level oil tank, and record Q 2. , P 1. High oil tank outlet temperature T 7 and lubricating oil tank return port temperature T 8, duration reaches t The test was completed at 3 o'clock; S15: Keep the stable state of S13, and the remaining steps and states are consistent with S5; S16: Maintain the stable state of S15 and continue to wait for the time t 6. Until the heat transfer between the inner and outer layers of the double-layer corrugated hose of the pipeline test piece is completed and the temperature is Δ T 1 stable state within the range; S17: Maintain the stable state of S16, interval time t 2. Monitor and confirm that there is no oil accumulation in the high-level oil tank, and record Q 2. , P 2. High oil tank outlet temperature T 9 and lubricating oil tank return port temperature T 10 , duration reached t The test was completed at 3 o'clock; S18: Keep the stable state of S13, and the remaining steps and states are consistent with S8; S19: Keep the stable state of S13 and the closed state of the control valve and the exhaust valve in S8, and the remaining steps and states are consistent with S9; S20: Keep the stable state of S13, and keep the other steps and states consistent with S10, and record the temperature changes of the oil outlet of the high-level oil tank and the oil return port of the lubricating oil tank Δ T 5 and Δ T 6; S21: Keep S20 stable and continue to wait t 7. Until the heat transfer between the inner and outer layers of the double-layer corrugated hose of the pipeline test piece is completed and the temperature is Δ T 1 stable state within the range; S22: maintain the stable state of S21, interval time t 2. Monitor and confirm that there is no oil accumulation in the high-level oil tank, and record Q 2. , P 1. High oil tank outlet temperature T 11 and lubricating oil tank return port temperature T 12 , the duration reaches t The test was completed at 3 o'clock; The steps of the adiabatic test method are the same as those of the non-insulated test method described above.

3. The method for testing the lubricating oil pipeline of a deep cryogenic axial flow compressor according to claim 1 is characterized in that: The heater is an electric heater, and each section of the cylinder is equipped with the electric heater.

4. The method for low temperature testing of lubricating oil pipelines of deep low temperature axial flow compressors according to claim 1, characterized in that: The structure of the cylinder adopts a hollow non-insulated structure or a solid insulated structure; When the cylinder adopts a hollow non-insulated structure, the cavity inside the cylinder is hollow and has no filler. After the pipeline test piece is placed in the cavity, a cavity exists between the pipeline test piece and the cylinder in the radial direction. When the cylinder adopts a solid insulation structure, an insulation layer and an elastic compensation layer are provided in the cavity inside the cylinder, the pipeline test piece is located on the central axis of the cavity and between the insulation layer and the elastic compensation layer, and there is a gap between the pipeline test piece and the insulation layer and the elastic compensation layer.

5. The method for low temperature testing of lubricating oil pipeline of deep low temperature axial flow compressor according to claim 1, characterized in that: The liquid nitrogen filling port is connected to the Dewar flask through a stainless steel hose, and the nitrogen discharge port is connected to the exhaust valve through a stainless steel hose.

6. The method for low temperature testing of lubricating oil pipeline of deep low temperature axial flow compressor according to claim 1, characterized in that: The pipeline test piece includes a stainless steel pipe and a double-layer corrugated hose, which are detachably connected; The stainless steel pipe and the oil outlet of the high-position oil tank, as well as the double-layer corrugated hose and the oil return port of the lubricating oil tank are both connected by pipelines and flanges.

7. The method for low temperature testing of lubricating oil pipelines of deep low temperature axial flow compressors according to claim 1, characterized in that: The oil outlet of the high-position oil tank and the oil return port of the lubricating oil tank are both equipped with thermal resistors, and there is a height difference Δ between the oil outlet of the high-position oil tank and the oil return port of the lubricating oil tank. h ; The lubricating oil tank is equipped with a flap type liquid level gauge and a thermal resistor; The oil pump adopts a variable frequency speed regulating quantitative pump.

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