Turbocharger exhaust brake negative pressure resistance test device and test method

Abstract

The present invention relates to the technical field of turbocharger design, and discloses a turbocharger exhaust brake negative pressure resistance test device and test method. The turbine end of the turbocharger is connected to an exhaust gas discharge pipe, which is provided with an exhaust brake valve. The compressor end of the turbocharger is connected to an exhaust pipe, which is provided with an exhaust valve. A bypass line is provided on the exhaust pipe section between the exhaust valve and the compressor end of the turbocharger. The bypass line includes a shutoff valve, a vacuum pressure device, and a first pressure detector for monitoring the pressure of the vacuum pressure device. A second pressure detector is provided on the exhaust pipe section between the compressor end of the turbocharger and the bypass line. A speed detector is provided on the compressor end of the turbocharger. A third pressure detector and a temperature detector are provided on the exhaust gas discharge pipe. This test device simulates the exhaust brake operating conditions of a turbocharger vehicle. By monitoring the speed, turbine outlet pressure, temperature, and compressor outlet pressure, the braking operating conditions are monitored, and the compressor's negative pressure resistance capability is verified.

Description

Technical Field

[0001] The present invention relates to the technical field of turbocharger design, in particular to a turbocharger exhaust brake anti-negative pressure test device and a test method. Background Art

[0002] With the continuous upgrading of emission standards, OEMs are placing increasingly stringent demands on turbocharger development. Under vehicle exhaust braking conditions, the turbocharger's speed rapidly decreases, and the turbine outlet pressure and temperature rise. Simultaneously, the engine pistons continue to pump air at high speed, causing a rapid loss of pressure at the compressor outlet. These conditions can lead to oil leakage at the turbocharger compressor, abnormal shaft wear, and turbine failure due to thermal shock. Therefore, the structural reliability of the turbocharger under exhaust braking conditions, particularly the compressor's ability to withstand negative pressure, is crucial for successful turbocharger matching. Patent publication number CN104296996B discloses a turbocharger bench exhaust braking test method and apparatus. This apparatus and test method primarily simulates vehicle exhaust braking conditions on a turbocharger bench, detecting parameters such as turbocharger speed, temperature, and pressure to understand the turbocharger's operating conditions and provide a reliable basis for turbocharger design. However, this test device cannot provide a reference for the negative pressure resistance of the turbocharger. Therefore, it is impossible to evaluate the negative pressure resistance of the turbocharger in the early stage. Once the negative pressure resistance function is found to be insufficient during the road test, it will not only extend the development cycle of the turbocharger, but also increase the cost of the road test during the development process of the turbocharger.

[0003] In order to quickly and conveniently understand the reliability of turbochargers under exhaust brake operation during road tests, especially their ability to withstand negative pressure under these conditions, it is urgent to develop the most effective and direct test method and test device to simulate the exhaust brake operating conditions of the entire vehicle. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art and provide a turbocharger exhaust brake anti-negative pressure test device. The device simulates the exhaust brake working conditions of the whole vehicle, monitors relevant operating data, provides an evaluation reference for the anti-negative pressure capability of the turbocharger, and provides data support for the development of turbochargers.

[0005] The technical solution of the present invention is: a turbocharger exhaust brake anti-negative pressure test device, the turbine end of the turbocharger is connected to the exhaust gas exhaust pipe, the exhaust gas exhaust pipe is provided with an exhaust brake valve, the compressor end of the turbocharger is connected to the exhaust pipe, the exhaust pipe is provided with an exhaust valve;

[0006] A bypass line is provided on the section of the exhaust pipe between the exhaust valve and the compressor end of the turbocharger. The bypass line includes a stop valve and a vacuum pressure device arranged in sequence, and also includes a first pressure detector for monitoring the pressure of the vacuum pressure device; a second pressure detector is provided on the section of the exhaust pipe between the compressor end of the turbocharger and the bypass line; a speed detector is provided on the compressor end of the turbocharger; and a third pressure detector and a temperature detector are installed on the exhaust gas discharge pipe.

[0007] A further technical solution of the present invention is: the vacuum pressure device includes a vacuum pressure tank, a vacuum pump and a vacuum pump control system, and the first pressure detector is signal-connected to the vacuum pump control system.

[0008] A further technical solution of the present invention is that the stop valve is installed on the bypass pipeline at a position where the bypass pipeline is 4 to 6 times the diameter of the bypass pipeline away from the exhaust pipe.

[0009] A further technical solution of the present invention is that the second pressure detector is installed on the exhaust pipe at a position 1 to 1.5 times the exhaust pipe diameter away from the turbocharger compressor end outlet.

[0010] A further technical solution of the present invention is that the third pressure detector is installed on the exhaust gas exhaust pipe at a distance of 1 to 1.5 times the diameter of the exhaust gas exhaust pipe from the outlet of the turbine end of the turbocharger.

[0011] A further technical solution of the present invention is that the temperature detector is arranged close to the third pressure detector and the distance between the temperature detector and the third pressure detector is 0.5 to 1 times the diameter of the exhaust gas exhaust pipe.

[0012] A further technical solution of the present invention is that the first pressure detector and / or the second pressure detector and / or the third pressure detector are pressure sensors.

[0013] A further technical solution of the present invention is that the temperature detector is a temperature sensor.

[0014] A further technical solution of the present invention is that the speed detector is a speed sensor.

[0015] The present invention also provides a technical solution: a method for performing a turbocharger exhaust brake negative pressure resistance test using the aforementioned test device, comprising the following steps:

[0016] 1) Run the exhaust brake test condition 1: Use high-temperature and high-pressure gas to adjust the turbocharger to the initial speed required by the test, adjust the exhaust brake valve opening, and adjust the turbocharger to the initial turbine outlet pressure P required by the test. t0At this time, the exhaust brake valve opening is a0; keep the flow rate and temperature of high-temperature and high-pressure gas unchanged, adjust the exhaust brake valve opening, and within t0 time, make the turbocharger turbine outlet pressure reach the test requirement value P t1 At this time, the exhaust brake valve opening is a1; close the exhaust valve, open the stop valve, and the air at the turbocharger compressor outlet is discharged through the stop valve and vacuum pressure device on the bypass line; monitor the pressure value of the second pressure detector. If the pressure value is higher than the test requirement, lower the working pressure value of the vacuum pressure device; if the pressure value is lower than the test requirement, increase the working pressure value of the vacuum pressure device; at the same time, monitor the pressure value change in the vacuum pressure device through the first pressure detector until the pressure value of the second pressure detector reaches the test requirement pressure P c1 ;

[0017] 2) Run exhaust brake test condition 2: When exhaust brake test condition 1 ends, continue running for time t2;

[0018] 3) Exhaust brake test condition 3: shut-off valve closed, exhaust valve open, turbocharger compressor outlet pressure rises to P c0 The exhaust brake valve opens from the opening a1 to a0 within the time t3. As the exhaust brake valve moves, the outlet pressure of the turbocharger turbine changes from P t1 to P t0 hour;

[0019] 4) Run exhaust brake test condition 4: At the end of exhaust brake test condition 3, continue running for time t4;

[0020] Repeat the operation in the order of working condition 1, working condition 2, working condition 3 and working condition 4, and monitor the changes of the turbocharger compressor end speed and the turbine end outlet temperature at the same time to test the turbocharger's ability to resist negative pressure under exhaust braking conditions.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The test device of the present invention can fully simulate the exhaust braking working condition of the whole vehicle of the turbocharger. By activating the exhaust brake valve to generate a rapid pressure loss condition at the compressor outlet, it can observe whether the compressor has oil leakage, abnormal shaft wear, and whether the turbine has malfunctioned due to thermal shock. At the same time, the turbocharger speed, turbine outlet pressure, temperature and compressor outlet pressure are monitored in real time, so as to grasp in advance the operating status of the turbocharger during the road test exhaust braking, verify the structural reliability of the turbocharger under this condition and the anti-negative pressure capability of the compressor under this working condition, and provide data support for the development of turbochargers.

[0023] The detailed structure of the present invention is further described below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic structural diagram of the turbocharger exhaust brake anti-negative pressure test device described in Example 1. DETAILED DESCRIPTION

[0025] Example 1

[0026] This embodiment provides a method for testing the negative pressure resistance of a turbocharger under exhaust braking conditions. This test method monitors relevant operating data by designing a test device that can simulate the exhaust braking conditions of a complete vehicle, providing a reference for evaluating the negative pressure resistance of the turbocharger, and further providing data support for the development of turbochargers.

[0027] Specifically, if Figure 1 As shown, the test device includes a turbocharger 1 for receiving high-temperature and high-pressure fuel gas for testing. The turbine end 11 of the turbocharger is connected to the exhaust gas exhaust pipe 2, on which an exhaust brake valve 21 is provided. The compressor end 12 of the turbocharger is connected to the exhaust pipe 3, on which an exhaust valve 31 is provided. When the exhaust brake valve 21 is working, the turbocharger speed, turbine end outlet temperature and pressure will change with the opening degree of the exhaust brake valve 21. In order to monitor the turbocharger speed and turbine end outlet pressure and temperature, a speed detector 4 can be set at the compressor end 12. At the same time, a third pressure detector 51 and a temperature detector 52 are installed in sequence on the exhaust gas exhaust pipe 2. The speed detector 4 is preferably a speed sensor, the third pressure detector 51 is a pressure sensor, and the temperature detector 52 is a temperature sensor. Among them, the installation position of the third pressure detector 51 on the exhaust gas exhaust pipe 2 is 1 to 1.5 times the exhaust gas exhaust pipe diameter away from the outlet of the turbocharger turbine end 11; the temperature detector 52 is arranged close to the third pressure detector 51 and the distance between it and the third pressure detector 51 is 0.5 to 1 times the exhaust gas exhaust pipe diameter.

[0028] In order to further simulate the exhaust braking conditions of the entire vehicle, especially the impact of the exhaust braking conditions on the compressor's ability to resist negative pressure, a bypass line is provided on the exhaust pipe 3 between the exhaust valve 31 and the turbocharger compressor end 12. The bypass line includes a stop valve 6 and a vacuum pressure device arranged in sequence. The stop valve 6 is installed on the bypass line at a distance of 4 to 6 times the bypass line diameter from the exhaust pipe. The bypass line also includes a first pressure detector 7 for monitoring the pressure of the vacuum pressure device.

[0029] The vacuum pressure device includes a vacuum pressure tank 81, a vacuum pump 82 and a vacuum pump control system (not shown in the figure). The vacuum pressure tank 81 is connected to the vacuum pump 82 through a pipeline to maintain a constant pressure in the vacuum pressure tank. The first pressure detector 7 is connected to the vacuum pump control system signal to automatically control the operating load of the vacuum pump 82 according to the set vacuum pump operating pressure.

[0030] In addition, a second pressure sensor 9 is installed on the exhaust pipe 3 between the turbocharger compressor end 12 and the bypass line to monitor the compressor outlet pressure. This pressure can be adjusted via a vacuum pump 82 and a shutoff valve 6 on the bypass line. The second pressure sensor 9 is installed on the exhaust pipe at a distance of 1 to 1.5 exhaust pipe diameters from the turbocharger compressor end 12 outlet.

[0031] The first pressure detector 7 and the second pressure detector 9 are both selected as pressure sensors.

[0032] The following describes the simulated exhaust brake operation of the test device: After the turbine outlet of the turbocharger is connected to the exhaust brake valve, the compressor outlet is connected to the exhaust valve, and the bypass line stop valve, vacuum pressure tank, and vacuum pump are in place, the turbocharger is adjusted to the initial turbocharger speed n0 and initial turbine outlet temperature T0 required by the test through high-temperature and high-pressure fuel gas, and the compressor outlet pressure P is monitored. c0 By adjusting the exhaust brake valve opening, the turbocharger is adjusted to the initial turbine outlet pressure P required by the test. t0 , record the exhaust brake valve opening a0.

[0033] Keep the flow rate and temperature of high-temperature and high-pressure gas constant, adjust the opening of the exhaust brake valve, and make the turbine outlet pressure reach the test requirement value P t1 , record the opening position a1 of the exhaust brake valve at this time. Close the exhaust valve, open the stop valve, and the air at the compressor outlet is discharged through the stop valve on the bypass line, the vacuum pressure tank, and the vacuum pump. Monitor the pressure value fed back by the second pressure detector at the compressor outlet. If the pressure value is higher than the test requirement, lower the working pressure value of the vacuum pump; if the pressure value is lower than the test requirement, increase the working pressure value of the vacuum pump; at the same time, monitor the pressure value change in the vacuum pressure tank until the pressure value fed back by the second pressure detector reaches the test requirement pressure P c1 .

[0034] The test device experienced four working conditions when simulating exhaust braking, namely:

[0035] 1) Exhaust brake test condition 1: The exhaust brake valve makes the turbocharger turbine outlet pressure reach the test requirement value P within the time t0. t1At this time, the exhaust brake valve opening is a1; close the exhaust valve, open the stop valve, and the air at the turbocharger compressor outlet is discharged through the stop valve and vacuum pressure device on the bypass line; monitor the pressure value of the second pressure detector. If the pressure value is higher than the test requirement, lower the working pressure value of the vacuum pressure device; if the pressure value is lower than the test requirement, increase the working pressure value of the vacuum pressure device; at the same time, monitor the pressure value change in the vacuum pressure device through the first pressure detector until the pressure value of the second pressure detector reaches the test requirement pressure P c1 ;

[0036] 2) Exhaust brake test condition 2: At the end of exhaust brake test condition 1, continue running for time t2;

[0037] 3) Exhaust brake test condition 3: shut-off valve closed, exhaust valve open, turbocharger compressor outlet pressure rises to P c0 The exhaust brake valve opens from the opening a1 to a0 within the time t3. As the exhaust brake valve moves, the outlet pressure of the turbocharger turbine changes from P t1 to P t0 hour;

[0038] 4) Exhaust brake test condition 4: At the end of exhaust brake test condition 3, continue running for time t4;

[0039] The test method of the present application is to cycle through the above-mentioned operating conditions 1, 2, 3, and 4 in sequence, while simultaneously monitoring the changes in the turbocharger compressor end speed and the turbine end outlet temperature, so as to verify the turbocharger's ability to resist negative pressure under exhaust braking conditions and its structural reliability under such conditions.

[0040] The present invention is not limited to the above-mentioned specific structure or connection method. Any test device with the same or similar concept as the technical solution falls within the protection scope of the present invention.

Claims

1. A method for a turbocharger exhaust brake negative pressure resistance test, using a turbocharger exhaust brake negative pressure resistance test device, characterized by: The turbocharger exhaust brake negative pressure resistance test device includes: an exhaust gas exhaust pipe connected to the turbine end of the turbocharger, the exhaust gas exhaust pipe being provided with an exhaust brake valve; an exhaust pipe connected to the compressor end of the turbocharger, the exhaust pipe being provided with an exhaust valve; a bypass line provided on the exhaust pipe section between the exhaust valve and the compressor end of the turbocharger, the bypass line including a shut-off valve and a vacuum pressure device arranged in sequence, and a first pressure detector for monitoring the pressure of the vacuum pressure device; a second pressure detector provided on the exhaust pipe section between the compressor end of the turbocharger and the bypass line; a speed detector provided on the compressor end of the turbocharger; and a third pressure detector and a temperature detector installed on the exhaust gas exhaust pipe. The turbocharger exhaust brake negative pressure test method includes the following steps: 1) Run the exhaust brake test condition 1: Use high-temperature and high-pressure gas to adjust the turbocharger to the initial speed required by the test, adjust the exhaust brake valve opening, and adjust the turbocharger to the initial turbine outlet pressure P required by the test. t0 At this time, the exhaust brake valve opening is a0; keep the flow rate and temperature of high-temperature and high-pressure gas unchanged, adjust the exhaust brake valve opening, and within t0 time, make the turbocharger turbine end outlet pressure reach the test requirement value P t1 At this time, the exhaust brake valve opening is a1; close the exhaust valve, open the stop valve, and the air at the turbocharger compressor outlet is discharged through the stop valve and vacuum pressure device on the bypass line; monitor the pressure value of the second pressure detector. If the pressure value is higher than the test requirement, lower the working pressure value of the vacuum pressure device; if the pressure value is lower than the test requirement, increase the working pressure value of the vacuum pressure device; at the same time, monitor the pressure value change in the vacuum pressure device through the first pressure detector until the pressure value of the second pressure detector reaches the test requirement pressure P c1 ; 2) Run exhaust brake test condition 2: When exhaust brake test condition 1 ends, continue running for time t2; 3) Exhaust brake test condition 3: shut-off valve closed, exhaust valve open, turbocharger compressor outlet pressure rises to P c0 The exhaust brake valve opens from the opening a1 to a0 within the time t3. As the exhaust brake valve moves, the outlet pressure of the turbocharger turbine changes from P t1 to P t0 hour; 4) Run exhaust brake test condition 4: At the end of exhaust brake test condition 3, continue running for time t4; Repeat the operation in the order of working condition 1, working condition 2, working condition 3 and working condition 4, and monitor the changes of the turbocharger compressor end speed and the turbine end outlet temperature at the same time to test the turbocharger's ability to resist negative pressure under exhaust braking conditions.

2. The method for the turbocharger exhaust brake negative pressure resistance test according to claim 1, characterized in that: The vacuum pressure device includes a vacuum pressure tank, a vacuum pump and a vacuum pump control system, and the first pressure detector is connected to the vacuum pump control system signal.

3. The method for the turbocharger exhaust brake negative pressure resistance test according to claim 1, characterized in that: The installation position of the stop valve on the bypass pipeline is 4 to 6 times the bypass pipeline diameter away from the exhaust pipe.

4. The method for the turbocharger exhaust brake negative pressure resistance test according to claim 1, characterized in that: The second pressure detector is installed on the exhaust pipe at a position 1 to 1.5 times the diameter of the exhaust pipe away from the turbocharger compressor end outlet.

5. The method for the turbocharger exhaust brake negative pressure resistance test according to claim 1, characterized in that: The installation position of the third pressure detector on the exhaust gas exhaust pipe is 1 to 1.5 times the diameter of the exhaust gas exhaust pipe away from the turbine end outlet of the turbocharger.

6. The method for the turbocharger exhaust brake negative pressure resistance test according to claim 5, characterized in that: The temperature detector is arranged close to the third pressure detector and the distance between the temperature detector and the third pressure detector is 0.5 to 1 times the diameter of the exhaust gas discharge pipe.

7. The method for the turbocharger exhaust brake negative pressure resistance test according to claim 1, characterized in that: The first pressure detector and / or the second pressure detector and / or the third pressure detector are pressure sensors.

8. The method for the turbocharger exhaust brake negative pressure resistance test according to claim 1, characterized in that: The temperature detector is a temperature sensor.

9. The method for the turbocharger exhaust brake negative pressure resistance test according to claim 1, characterized in that: The speed detector is a speed sensor.

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