A low temperature cycle testing device and method

Abstract

The application discloses a low-temperature circulation testing device and method, which can quickly provide a low-temperature medium temperature. The low-temperature circulation testing device comprises a main circulation pipeline, a secondary circulation pipeline, a refrigerating unit, a high-position liquid tank, an interval oil tank, a pump, a pressure / temperature sensor, an adjusting valve and the like. When the low-temperature circulation testing device works, the target temperature, pressure and flow required by a test product are set on a testing software, and then the testing system compares real-time data collected by the temperature, pressure and flow sensors with the set parameters, adjusts the working stroke of each hydraulic element through a lower computer, so that the real-time data in the testing meet the set parameters, and then the functional performance indexes of the test product under the low-temperature medium state are detected. The high-position liquid tank and the interval liquid tank are adopted in the application, heat transfer between the low-temperature medium and the outside is reduced, condensed water in the air is prevented from entering the low-temperature medium, and the cooling rate and service life of the testing medium are improved.

Description

Technical Field

[0001] This invention relates to a low-temperature cycling test device and method, belonging to the field of fluid low-temperature test technology. Background Technology

[0002] With the continuous development of aviation technology, the technological updates and iterations of various aircraft are becoming increasingly rapid. Faced with the emergence of various new products, the evaluation of their technical parameters, quality, safety, economy, production cycle, and test results is becoming increasingly stringent. As one part of this process, test results are particularly important for the research and development of new products, as they can evaluate whether a new product has met the design requirements.

[0003] To simulate the resistance parameters of the test sample when flowing through a low-temperature medium and ensure that the flow performance of the test sample meets the system requirements in a low-temperature environment, the initial method was to place the hydraulic components such as the oil tank and oil pump in an ambient temperature chamber for overall cooling to simulate the working conditions of low-temperature medium flow. Although this test system completed the current test task, it had many problems, such as slow cooling rate, inability to maintain stable low temperature of the medium for a long time, and low test efficiency. Summary of the Invention

[0004] The present invention aims to provide a low-temperature cycling test device and method, which can quickly and stably simulate the low-temperature conditions of the test medium in the laboratory, conduct flow tests on the test sample, obtain accurate test data, and evaluate the flowability of the test sample. In particular, it can solve problems such as slow cooling rate, inability to maintain the low temperature of the medium for a long time, and low test efficiency.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A low-temperature cycling test apparatus, comprising: The main circulation pipeline is provided with, in sequence, a sample outlet, a third pressure sensor, a sixth temperature sensor, a third switching valve, a second electric regulating valve, a balance port, a second pressure sensor, a pump, a fifth temperature sensor, a fourth temperature sensor, a heat exchanger, a third temperature sensor, a second switching valve, a flow meter, a first switching valve, a first temperature sensor, a first pressure sensor, and a sample inlet. The hot-side inlet of the heat exchanger is connected to the fourth temperature sensor, and the hot-side outlet of the heat exchanger is connected to the third temperature sensor. A refrigeration unit, wherein the outlet of the refrigeration unit is connected to the cold side inlet of the heat exchanger, and the inlet of the refrigeration unit is connected to the cold side outlet of the heat exchanger; The secondary circulation bypass has its inlet connected to the main circulation pipeline and located between the inlet of the second switching valve and the third temperature sensor. The outlet of the secondary circulation bypass is connected to the main circulation pipeline and located between the outlet of the second electric regulating valve and the balance port. A first electric regulating valve is provided in the secondary circulation bypass. The inlet of the first electric regulating valve is connected to the inlet of the secondary circulation bypass, and the outlet of the first electric regulating valve is connected to the outlet of the secondary circulation bypass. The liquid tank includes an isolation tank and a high-level tank. Both the isolation tank and the high-level tank are filled with oil, and the inner cavities of the isolation tank and the high-level tank are in communication. The liquid level in the isolation tank is lower than that in the high-level tank. The isolation tank is a sealed oil tank. The isolation tank is connected to the balance port of the main circulation pipeline through a pipeline, and the lower end of the isolation tank is located above the balance port.

[0006] As one option, the cryogenic cycling test apparatus also includes a second safety valve, which is connected to the pump.

[0007] As one option, the cryogenic cycling test device also includes a first safety valve, which is connected to the high-level liquid tank.

[0008] As one option, an oil filter is installed on the high-level liquid tank.

[0009] As one option, a second temperature sensor is installed on the high-level liquid tank.

[0010] As one option, a level gauge is installed on the high-level liquid tank.

[0011] As one solution: The isolation liquid tank is equipped with a first manual valve for draining liquid; The high-level liquid tank is equipped with a second manual valve for draining liquid.

[0012] As one embodiment, the inner cavities of the isolation liquid tank and the high-level liquid tank are connected by a drain pipe and an exhaust pipe, respectively. One end of the drain pipe is connected to the bottom of the inner cavity of the high-level liquid tank and the other end is connected to the inner cavity of the isolation liquid tank. One end of the exhaust pipe is connected to the top of the inner cavity of the isolation liquid tank and the other end is connected to the top of the inner cavity of the high-level liquid tank.

[0013] A low-temperature cycling test method, employing the aforementioned low-temperature cycling test apparatus, and comprising: The test sample is connected to the main circulation pipeline through the test sample outlet and the test sample inlet. A pump drives the medium to circulate in the main circulation pipeline, passing through the test sample. The medium flowing in the main circulation pipeline is cooled by a refrigeration unit and a heat exchanger; The flow rate of the medium in the main circulation pipeline is regulated by the first electric regulating valve in the secondary circulation bypass in conjunction with the pump and the second electric regulating valve in the main circulation pipeline (that is, the flow rate regulation is achieved by the combined regulation of the opening degree of the first electric regulating valve, the speed of the pump, and the opening degree of the second electric regulating valve, or in other words, the main circulation pipeline and the secondary circulation bypass pipeline are regulated in combination). The high-level liquid tank and the isolation liquid tank are kept at or near room temperature. The media in the high-level liquid tank and the isolation liquid tank do not actively participate in the circulation flow of the media in the main circulation pipeline and isolate the media in the main circulation pipeline from the ambient air. The high-level liquid tank and the isolation liquid tank collect excess gas in the main circulation pipeline through the balance port. At the same time, the high-level liquid tank and the isolation liquid tank replenish the media in the main circulation pipeline through the balance port.

[0014] The low-temperature cycling test apparatus and method of the present invention have the following characteristics: 1. Unlike existing testing devices that treat all media in the testing device at low temperatures, the low-temperature cycling testing device of this invention is a closed-loop system that only cools the liquid medium flowing through the test sample (i.e., the liquid medium in the main circulation pipeline), which greatly reduces the total amount of medium that needs to be cooled and improves the cooling rate.

[0015] 2. This invention incorporates a high-level liquid tank and an isolation liquid tank. The liquid medium participating in the pipeline circulation is primarily from the main circulation pipeline and the secondary circulation bypass. The medium in the isolation liquid tank and the high-level liquid tank essentially does not participate in the circulation. The isolation liquid tank is a sealed tank connected to the pump inlet at the balance port. When air or oil bubbles from the main circulation pipeline flow through the balance port, they enter the isolation liquid tank through the pipe between the balance port and the isolation liquid tank, and then enter the high-level liquid tank, thus removing excess air from the liquid.

[0016] 3. During the low-temperature test, the liquid medium flows downwards and mainly collects at the balance port. A small amount of the low-temperature liquid medium rises from the balance port into the pipeline of the isolation tank. Convection with the higher-level isolation tank and high-level tank is minimal, resulting in less heat transfer between the high-level tank and the balance port. The medium in the main circulation pipeline and the secondary circulation bypass maintains a consistently low test temperature, while the high-level tank remains close to room temperature. The room-temperature liquid in the high-level tank seals the low-temperature liquid in the main circulation pipeline, preventing air from contacting the low-temperature liquid medium and causing condensation, thus maintaining the low temperature of the liquid medium for a longer period. As the temperature in the main circulation pipeline gradually decreases, the volume of the liquid medium shrinks. The reduced volume of liquid medium is replenished to the main circulation pipeline from the high-level tank through the isolation tank and the balance port. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the low-temperature cycling test device in this invention; Figure 2 This is a schematic diagram of the liquid tank in this invention; In the diagram: 1-First pressure sensor; 2-First temperature sensor; 3-First switching valve; 4-Flow meter; 5-Second switching valve; 6-First electric regulating valve; 7-First safety valve; 8-Oil filter; 9-Second temperature sensor; 10-Third temperature sensor; 11-Heat exchanger; 12-Fourth temperature sensor; 13-Fifth temperature sensor; 14-Refrigeration unit; 15-Second safety valve; 16-Second pressure sensor; 17-Pump; 18-Isolation tank; 19-First manual valve; 20-High-level tank; 21-Second electric regulating valve; 22-Third switching valve; 23-Sixth temperature sensor; 24-Third pressure sensor; 25-Test sample; 26-Level gauge; 27-Second manual valve; 28-Balance port. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, it should not be construed that the scope of the subject matter of the present invention is limited to the following embodiments. All modifications, substitutions and alterations made based on ordinary technical knowledge and conventional means in the art without departing from the above-described technical concept of the present invention are included within the scope of the present invention.

[0019] like Figure 1 As shown, the present invention provides a low-temperature cycling test device to quickly and stably meet existing low-temperature flow test requirements.

[0020] The low-temperature cycling test apparatus consists of four parts, namely: The lubricating oil system includes a liquid tank, pump, various switching valves, regulating valves, and various sensors.

[0021] The refrigeration system is equipped with an evaporator assembly, a condenser assembly, a valve body assembly, and a compressor.

[0022] The measurement and control system includes a PLC and measurement and control software.

[0023] Electrical systems include power generation and control systems.

[0024] Figure 1 neutralization Figure 2The corresponding low-temperature cycling test device includes a lubricating oil system and a refrigeration system, specifically comprising: a first pressure sensor 1, a first temperature sensor 2, a first switching valve 3, a flow meter 4, a second switching valve 5, a first electric regulating valve 6, a first safety valve 7, an oil filter 8, a second temperature sensor 9, a third temperature sensor 10, a heat exchanger 11, a fourth temperature sensor 12, a fifth temperature sensor 13, a refrigeration unit 14, a second safety valve 15, a second pressure sensor 16, a pump 17, an isolation liquid tank 18, a first manual valve 19, a high-level liquid tank 20, a second electric regulating valve 21, a third switching valve 22, a sixth temperature sensor 23, a third pressure sensor 24, a test sample 25, a level gauge 26, a second manual valve 27, and a balance port 28.

[0025] The isolation tank 18 is located above the balance port 28 and is used to allow air bubbles or excess air generated in the pipeline to rise through the isolation tank 18 to the high-level tank 20 for discharge. The high-level tank 20 is located above the isolation tank 18 and is mainly used to isolate the low-temperature test oil and reduce temperature loss. The first electric regulating valve 6 has two functions: first, to protect the test sample 25 by preventing the test medium from passing through the test sample 25 during the medium cooling process in the test preparation stage, i.e., opening the first electric regulating valve 6 and closing the second electric regulating valve 21; second, to coordinate the regulation of the medium flow rate in the main circulation pipeline.

[0026] The low-temperature cycling test device of this invention can easily control components such as pumps, electric regulating valves, and refrigeration units, including operations such as adjusting the temperature, pressure, and flow rate of the liquid medium, and adjusting the opening degree of electric valves. Test data from various electrical instruments can be stored and printed in real time, offering convenience and speed. The equipment layout is reasonable and aesthetically pleasing, with a user-friendly human-machine interface on the control panel and easy-to-operate function settings. During operation, the low-temperature cycling test device sets the target temperature, pressure, and flow rate required for the test sample on the testing software. The testing system then compares the real-time data collected by temperature, pressure, and flow sensors with the set parameters and adjusts the working stroke of each hydraulic component (electric regulating valve, pump, etc.) through the lower-level computer, thereby ensuring that the real-time data during the test meets the set parameters, and thus detecting the functional performance indicators of the test sample under low-temperature medium conditions.

[0027] The method for using a low-temperature cycling test device to perform low-temperature cycling tests is as follows. Figure 1 The middle arrow indicates the direction of medium flow: Step 1: Connect the inlet and outlet of the test sample 25 to the inlet and outlet of the test system. Open the first switch valve 3, the second switch valve 5 and the third switch valve 22 in the test system pipeline. Connect the temperature / pressure sensors, including the first pressure sensor 1 and the first temperature sensor 2 connected to the inlet of the test sample 25, and the sixth temperature sensor 23 and the third pressure sensor 24 connected to the outlet of the test sample 25. Step 2: Turn on the power to the electrical control console, open the human-machine interface, and check that all instruments are displaying normally. Step 3: Set the test medium temperature parameters and adjust the opening of the second electric regulating valve 21 in the main circulation pipeline and the first electric regulating valve 6 in the secondary circulation bypass to 100%; Step 4: Enable communication for pump 17, set a 5Hz input frequency to start pump 17 normally, and observe that there is no oil leakage at any pipeline interface in the low temperature cycle test device and that the instrument sensors display normally. Step 5: Start the refrigeration unit 14. The low-temperature cycle test device will automatically start cooling the medium according to the temperature parameters set in Step 3. Step 6: After the medium temperature approaches the set temperature, adjust the frequency of the first electric regulating valve 6 and the pump 17 so that the medium flow rate (through the flow meter 4) and temperature (first temperature sensor 2 and sixth temperature sensor 23) through the test sample 25 reach the set requirements. Test the flow resistance value of the test sample 25 under the required conditions and record the flow rate, temperature and pressure values ​​in the main circulation pipeline. Step 7: After the test is completed, turn off the refrigeration unit 14, adjust the opening of the first electric regulating valve 6 to 100%, and raise the temperature of the liquid medium in the low temperature cycle test device to about 0°C. Then, turn off the pump 17 and the first electric regulating valve 6. Step 8: Close the first switch valve 3, the second switch valve 5, the third switch valve 22, and the second electric regulating valve 21; disassemble the test sample 25; and turn off the power to the electrical control console.

[0028] In the low-temperature cycling test device, the liquid medium flowing in the main circulation pipeline is cooled by the heat exchanger 11, and the refrigeration unit 14 provides the cold side medium for the heat exchanger 11. The first safety valve 7 ensures the pressure safety of the high-level liquid tank 20, and the second safety valve 15 ensures the safety of the pump 17. The oil filter 8 is used to filter the oil when adding oil to the high-level liquid tank 20 to prevent oil contamination. The level gauge 26 is used to observe the oil level in the high-level liquid tank 20. The first manual valve 19 and the second manual valve 27 are used to drain the oil from the isolation tank 18 and the high-level liquid tank 20, respectively.

[0029] The low-temperature cycling test device of this invention can achieve rapid cooling and low-temperature holding time of liquid media. The sensors arranged in the low-temperature cycling test device have the function of real-time acquisition of liquid flow rate, temperature, and pressure. The device of this invention has the advantages of high automation, stable test parameters, high test measurement accuracy, simple test operation, and strong safety.

[0030] Those skilled in the art can make various adjustments to this application based on the actual circumstances. The general principles defined in this application can be implemented in other embodiments without departing from their connotations. Therefore, this application is not limited to the structure shown in the specific embodiments, but is to be accorded the widest scope consistent with the principles and features set forth in the claims of this application.

Claims

1. A low-temperature cycling test device, characterized in that, include: The main circulation pipeline is provided with the following components in sequence: sample outlet, third pressure sensor (24), sixth temperature sensor (23), third switch valve (22), second electric regulating valve (21), balance port (28), second pressure sensor (16), pump (17), fifth temperature sensor (13), fourth temperature sensor (12), heat exchanger (11), third temperature sensor (10), second switch valve (5), flow meter (4), first switch valve (3), first temperature sensor (2), first pressure sensor (1) and sample inlet. The hot side inlet of the heat exchanger (11) is connected to the fourth temperature sensor (12), and the hot side outlet of the heat exchanger (11) is connected to the third temperature sensor (10). The outlet of the refrigeration unit (14) is connected to the cold side inlet of the heat exchanger (11), and the inlet of the refrigeration unit (14) is connected to the cold side outlet of the heat exchanger (11). The secondary circulation bypass has its inlet connected to the main circulation pipeline and located between the inlet of the second switching valve (5) and the third temperature sensor (10). The outlet of the secondary circulation bypass is connected to the main circulation pipeline and located between the outlet of the second electric regulating valve (21) and the balance port (28). The secondary circulation bypass is equipped with a first electric regulating valve (6). The inlet of the first electric regulating valve (6) is connected to the inlet of the secondary circulation bypass, and the outlet of the first electric regulating valve (6) is connected to the outlet of the secondary circulation bypass. The liquid tank includes an isolation liquid tank (18) and a high-level liquid tank (20). Both the isolation liquid tank (18) and the high-level liquid tank (20) are filled with oil, and the inner cavities of the isolation liquid tank (18) and the high-level liquid tank (20) are in communication. The liquid level of the isolation liquid tank (18) is lower than that of the high-level liquid tank (20). The isolation liquid tank (18) is a sealed oil tank. The isolation liquid tank (18) is connected to the balance port (28) of the main circulation pipeline through a pipeline. The lower end of the isolation liquid tank (18) is located above the balance port (28).

2. The low-temperature cycling test device according to claim 1, characterized in that: It also includes a second safety valve (15), which is connected to the pump (17).

3. The low-temperature cycling test device according to claim 1, characterized in that: It also includes a first safety valve (7), which is connected to the high-level liquid tank (20).

4. The low-temperature cycling test device according to claim 1, characterized in that: An oil filter (8) is installed on the high-level liquid tank (20).

5. The low-temperature cycling test device according to claim 1, characterized in that: A second temperature sensor (9) is installed on the high-level liquid tank (20).

6. The low-temperature cycling test device according to claim 1, characterized in that: A level gauge (26) is installed on the high-level liquid tank (20).

7. The low-temperature cycling test device according to claim 1, characterized in that: The isolation liquid tank (18) is equipped with a first manual valve (19) for draining liquid. The high-level liquid tank (20) is equipped with a second manual valve (27) for draining liquid.

8. The low-temperature cycling test device according to claim 1, characterized in that: The inner cavities of the isolation liquid tank (18) and the high-level liquid tank (20) are connected by a drain pipe and an exhaust pipe, respectively. One end of the drain pipe is connected to the bottom of the inner cavity of the high-level liquid tank (20), and the other end is connected to the inner cavity of the isolation liquid tank (18). One end of the exhaust pipe is connected to the top of the inner cavity of the isolation liquid tank (18), and the other end is connected to the top of the inner cavity of the high-level liquid tank (20).

9. A method for low-temperature cycling testing, characterized in that: The low-temperature cycling test apparatus according to claim 1 is used, and includes: The test sample (25) is connected to the main circulation pipeline through the test sample outlet and the test sample inlet. The medium is driven by the pump (17) to circulate in the main circulation pipeline and pass through the test sample (25), wherein: The medium flowing in the main circulation pipeline is cooled by the refrigeration unit (14) and the heat exchanger (11); The flow rate of the medium in the main circulation pipeline is adjusted by the first electric regulating valve (6) in the secondary circulation bypass in conjunction with the pump (17) and the second electric regulating valve (21) in the main circulation pipeline. The high-level liquid tank (20) and the isolation liquid tank (18) are kept at room temperature or close to room temperature. The media in the high-level liquid tank (20) and the isolation liquid tank (18) do not actively participate in the circulation flow of the media in the main circulation pipeline and isolate the media in the main circulation pipeline from the ambient air. The high-level liquid tank (20) and the isolation liquid tank (18) collect excess gas in the main circulation pipeline through the balance port (28). At the same time, the high-level liquid tank (20) and the isolation liquid tank (18) replenish the media in the main circulation pipeline through the balance port (28).

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