Turbocharger variable altitude simulation test bench and test method

Abstract

A turbocharger variable altitude simulation test bench, an air compressor connected with an air inlet end of a combustion chamber, a fuel system providing fuel to the combustion chamber, an air outlet end of the combustion chamber connected with an inlet end of a turbine, an outlet end of the turbine connected with an inlet end of an exhaust pressure stabilizing tank, an outlet end of the exhaust pressure stabilizing tank connected with an inlet end of a vacuum pump, an outlet end of the vacuum pump connected with an atmospheric environment, a centrifugal compressor coaxially connected with the turbine and having an air inlet end connected with an outlet end of the inlet pressure stabilizing tank, an inlet pipe of the inlet pressure stabilizing tank connected with the atmospheric environment, an air outlet end of the centrifugal compressor connected with an air outlet pipe, the pipe being provided with a back pressure regulating valve and a quick de-surge valve in parallel, and the air outlet pipe of the centrifugal compressor being communicated with the air inlet pipe of the combustion chamber. The turbocharger variable altitude simulation test bench can simulate the atmospheric environment of the turbocharger in the actual work at variable altitudes, and respectively study the centrifugal compressor characteristics and the turbine efficiency characteristics of the turbocharger under the condition.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of engines, and particularly relates to a turbocharger variable-altitude simulation test bench and a test method. BACKGROUND

[0002] China's plateau region is vast, high in altitude and has a large range of altitude changes, and has not only plateau working requirements for internal combustion engines, but also variable-altitude working requirements. As an important means to meet the plateau working requirements of internal combustion engines, the matching design method of the key component of turbocharging, i.e., the turbocharger, has an important influence on improving the variable-altitude performance of the turbocharged internal combustion engine. With the increasing requirements for the power, economy and emission performance of internal combustion engines under variable-altitude conditions, the high-altitude design and matching method of the turbocharger has become a key to improving the variable-altitude performance of internal combustion engines.

[0003] Traditional vehicle engines generally use piston internal combustion engines. Due to the difference in motion characteristics between rotary impeller machines and reciprocating pistons, although better performance can be obtained at a certain matching design point of the turbocharger, when the internal combustion engine is actually working under variable-altitude conditions, once the working condition changes, especially the change of the intake and exhaust environment, the actual operation line of the internal combustion engine will deviate from the matching joint operation line of the turbocharger, resulting in matching disorders, and thus leading to a significant decrease in the performance indicators such as power and economy of the internal combustion engine.

[0004] Therefore, it is of great significance to simulate and study the characteristics of the turbocharger under the conditions of changes in intake and exhaust pressure and temperature through a test method for improving the variable-altitude performance of the internal combustion engine. SUMMARY

[0005] The present application aims to overcome the deficiencies in the prior art, and provides a turbocharger variable-altitude simulation test bench, which can simulate the atmospheric environment of the turbocharger during actual work under variable altitude, and respectively study the centrifugal compressor characteristics and turbine efficiency characteristics of the turbocharger under the conditions, so that the performance test results of the turbocharger are closer to the actual operating conditions, and the problem that the current turbocharger performance test bench can only study the performance of the turbocharger under fixed altitude is solved.

[0006] Another object of the present application is to provide a test method for the above-mentioned turbocharger variable-altitude simulation test bench.

[0007] To achieve the above object, the present application provides the following technical solutions:

[0008] A turbocharger altitude simulation test bench, comprising an air compressor connected with an air source, a combustion chamber, a turbine, an exhaust pressure stabilizing tank, a vacuum pump, a centrifugal compressor, and an intake pressure stabilizing tank; characterized in that: the air compressor connected with the air source is connected with the intake end of the combustion chamber through a combustion chamber intake pipe, a fuel system provides fuel to the combustion chamber through fuel injection holes in the combustion chamber, the exhaust end of the combustion chamber is connected with the intake end of the turbine through a turbine intake pipe, the outlet end of the turbine is connected with the intake end of the exhaust pressure stabilizing tank through a turbine exhaust pipe, and a heat exchanger is installed on the connecting pipe; the outlet end of the exhaust pressure stabilizing tank is connected with the intake end of the vacuum pump, and a back pressure regulating valve is installed on the connecting pipe; the outlet end of the vacuum pump is connected with the atmospheric environment; the turbine is driven by high-temperature gas from the combustion chamber to rotate at high speed; the centrifugal compressor is coaxially connected with the turbine, and the intake end of the centrifugal compressor is connected with the outlet end of the intake pressure stabilizing tank; the intake pipe of the intake pressure stabilizing tank is connected with the atmosphere, and an intake throttle valve and a temperature control device are installed on the pipe; the exhaust end of the centrifugal compressor is connected with an exhaust pipe connected with the atmosphere, and a back pressure regulating valve and a quick de-aeration valve are connected in parallel on the pipe; the exhaust pipe of the centrifugal compressor is connected with the combustion chamber intake pipe, and a two-position four-way valve is installed on the connecting pipe.

[0009] An air heater, an air source intake regulating valve, a pressure gauge, and a flow meter are installed on the combustion chamber intake pipe.

[0010] A pressure transmitter, a temperature transmitter, an inlet temperature sensor, an inlet total pressure sensor, and an inlet static pressure sensor are installed on the combustion chamber exhaust pipe.

[0011] The shaft between the coaxially connected centrifugal compressor and turbine is lubricated by a lubricating system.

[0012] A pressure transmitter, a temperature transmitter, an outlet temperature sensor, an outlet total pressure sensor, and an outlet static pressure sensor are installed on the exhaust pipe connected with the exhaust end of the centrifugal compressor.

[0013] A rotation speed sensor is installed in the centrifugal compressor to measure the rotation speed of the turbocharger.

[0014] A variable altitude simulation test method using the above-mentioned turbocharger altitude simulation test bench, comprising the following steps:

[0015] Firstly, the turbocharger is adjusted to a stable test working condition on the plain: firstly, the turbocharger is installed on the turbocharger altitude simulation test bench and prepared to be in a normal working state; then, the centrifugal compressor end intake system and the turbine end air source are started, adjusted to standard atmospheric environment conditions, the combustion chamber is ignited to drive the turbine to work, the centrifugal compressor is driven to compress air, and the working state of the turbocharger is confirmed.

[0016] Secondly, the centrifugal compressor variable altitude characteristic test is performed:

[0017] First, open the intake pressure regulating box connection valve, adjust the intake pressure through the intake throttle valve at the centrifugal compressor end, and adjust the intake temperature through the pressure regulating box temperature control system. Based on the compressor inlet total temperature and the required equivalent speed, the compressor characteristic test is carried out at the equivalent speed. Change the turbine end intake valve opening or adjust the combustion chamber fuel quantity to adjust the turbocharger speed. Adjust the compressor outlet pressure through the centrifugal compressor end back pressure regulating valve to adjust the compressor working flow. During the test, each equivalent speed line is measured point by point from surge flow to blockage flow, and the relevant test data are recorded.

[0018] Then, adjust the intake pressure and temperature to the calibration values ​​corresponding to the simulated target altitude, and record the relevant test data according to the above steps;

[0019] Finally, adjust the intake pressure and temperature to a stable working state under standard atmospheric conditions before shutting down the machine, check and record the condition of the test bench, and provide the measured results for data processing and evaluation after optimization.

[0020] The third step is to conduct turbine variable altitude efficiency characteristic tests:

[0021] First, the air compressor of the external air source at the turbine end is turned on to compress air. After heating, it drives the turbine to rotate stably. At the same time, the vacuum pump is turned on. The pressure of the exhaust pressure box, i.e. the exhaust back pressure, is controlled by adjusting the back pressure regulating valve. The temperature of the simulated atmospheric environment is adjusted by the pressure box temperature control system. The turbine efficiency characteristic test is performed in stages according to the turbine circumference Mach number or similar speed, and the relevant test data is recorded.

[0022] Then, adjust the exhaust back pressure and temperature to the calibration values ​​corresponding to the simulated target altitude, and record the relevant test data according to the above steps;

[0023] Finally, adjust the exhaust back pressure and temperature to a stable operating state under standard atmospheric conditions before shutting down the machine. Check and record the condition of the test bench, optimize it, and provide the measured results for data processing and evaluation.

[0024] The test bench of this invention can simulate the atmospheric environment of a turbocharger when it is working at varying altitudes (0 to 5500m), and study the centrifugal compressor characteristics and turbine efficiency characteristics of the turbocharger under these conditions. This makes the turbocharger performance test results closer to the actual operating conditions and solves the problem that current turbocharger performance test benches can only study the performance of turbochargers when they are working at a fixed altitude. Attached Figure Description

[0025] Figure 1 This is a schematic diagram showing the connection and operation of the test bench of the present invention;

[0026] Figure 2 This is a schematic diagram of the test point arrangement for the turbine variable altitude efficiency characteristic test on the test bench of this invention.

[0027] Figure 3 This is a schematic diagram of the test point layout for testing the variable altitude characteristics of a centrifugal compressor on the test bench of this invention.

[0028] Figure 4 This is a schematic diagram showing the simulated intake pressure and temperature corresponding to different simulated altitudes in the experiment of this invention. Detailed Implementation

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0031] See Figure 1 A variable altitude simulation test bench for a turbocharger includes an air compressor 1 with an external air source, a combustion chamber 5, a turbine 6, an exhaust pressure regulating box 8, a vacuum pump 10, a centrifugal compressor, and an intake pressure regulating box. The air compressor 1 is connected to the intake end of the combustion chamber via an intake pipe. The fuel system supplies fuel to the combustion chamber through injection holes within the combustion chamber. The exhaust end of the combustion chamber is connected to the inlet end of the turbine via an intake pipe. The outlet end of the turbine is connected to the inlet end of the exhaust pressure regulating box 8 via an exhaust pipe, and a heat exchanger 7 is installed on the connecting pipe. The outlet end of the exhaust pressure regulating box 8 is connected to the inlet end of the vacuum pump 10, and a back pressure regulating valve 9 is installed on the connecting pipe. The outlet end of the vacuum pump is open to the atmospheric environment. The turbine is driven to rotate at high speed by high-temperature combustion gases from the combustion chamber. An air heater, a pressure gauge 2, a flow meter 3, and an air source intake regulating valve 4 are installed on the combustion chamber intake pipe. The combustion chamber exhaust pipe is equipped with a pressure transmitter 11, a temperature transmitter 12, an inlet temperature sensor 13, an inlet total pressure sensor 14, and an inlet static pressure sensor 15.

[0032] Centrifugal compressor 16 is coaxially connected to turbine 6, and the inlet end of the centrifugal compressor is connected to the outlet end of inlet pressure regulating box 17. The inlet pipe of the inlet pressure regulating box is connected to the atmosphere, and an inlet throttle valve 18 and a temperature control device 19 are installed on the pipe. The outlet end of the centrifugal compressor is connected to an outlet pipe leading to the atmosphere, and a back pressure regulating valve 20 and a quick-release valve 21 are connected in parallel on the pipe. The outlet pipe of the centrifugal compressor is connected to the combustion chamber inlet pipe, and a two-position four-way valve 22 is installed on the connecting pipe. A pressure transmitter 23, a temperature transmitter 24, an outlet temperature sensor 25, an outlet total pressure sensor 26, and an outlet static pressure sensor 27 are installed on the outlet pipe connected to the outlet end of the centrifugal compressor. The shaft between the centrifugal compressor and the turbine is lubricated by a lubrication system, and a speed sensor is installed inside the centrifugal compressor to measure the turbocharger speed.

[0033] The specific steps of the test method for performing variable altitude simulation based on the aforementioned turbocharger variable altitude simulation test bench are as follows:

[0034] The first step is to adjust the turbocharger to a stable test condition on a flat surface:

[0035] First, install the turbocharger onto the turbocharger altitude simulation test bench, add fuel, lubricant and coolant, connect the test bench and the turbocharger wiring harness, and prepare it for normal operation.

[0036] Then, the compressor-side intake system and turbine-side air source are turned on and adjusted to standard atmospheric conditions. The combustion chamber is ignited to simulate the engine combustion heating process (the mass flow rate of the high-temperature gas generated by the combustion chamber heating covers 0.12 to 1.20 kg / s, and the outlet heating temperature is 300 to 900°C), which drives the turbine to do work, drives the compressor to compress air, and confirms the working status of the turbocharger.

[0037] The second step is to conduct a variable altitude performance test on the centrifugal compressor:

[0038] First, open the intake pressure regulating chamber (its volume should allow the airflow velocity to reach a Mach number less than 0.05) and the intake pressure regulating chamber connection valve. Adjust the intake pressure using the centrifugal compressor intake throttle valve and the intake temperature using the intake pressure regulating chamber temperature control device. Adjust the centrifugal compressor intake pressure (101.33 kPa) and temperature (15°C), simulating an altitude of 0 m. Based on the centrifugal compressor inlet total temperature and the required equivalent speed, conduct the compressor characteristic test at the equivalent speed. Change the turbine end intake valve opening or adjust the combustion chamber fuel quantity to adjust the turbocharger speed. The measurement sequence can be from the highest permissible speed to the lowest operating speed, with constant speed lines spaced at appropriate intervals, but no fewer than five. The compressor outlet pressure is adjusted by regulating the back pressure valve at the centrifugal compressor end to regulate the compressor operating flow rate. During the test, each isotropic speed line is measured point by point from surge flow rate to blockage flow rate (at least 5 points are measured), and the supercharger speed, compressor flow rate, compressor inlet total gas pressure, compressor outlet total gas pressure, compressor inlet total gas temperature, and compressor outlet total gas temperature are recorded. Specifically, when the compressor is operating close to the surge zone, the compressor air flow rate should be slowly reduced to determine the compressor surge point; when the compressor is operating close to the blockage zone, the compressor air flow rate should be slowly increased to determine the compressor blockage point.

[0039] Then, adjust the intake pressure and temperature to the calibration values ​​corresponding to the simulated target altitude (the simulated intake pressure and temperature for different simulated altitudes are as follows). Figure 4 As shown in the figure, following the steps above, record the turbocharger speed, compressor flow rate, compressor inlet gas total pressure, compressor outlet gas total pressure, compressor inlet gas total temperature, and compressor outlet gas total temperature.

[0040] Finally, adjust the intake pressure (101.33 kPa) and temperature (15°C), and once the environment stabilizes to standard atmospheric conditions, reconfirm the test bench status. After the booster has stabilized, stop the machine, check and record the test bench status, optimize it, and provide the measured results for data processing and evaluation.

[0041] The third step is to conduct turbine variable altitude efficiency characteristic tests:

[0042] First, open the external compressed air source at the turbine end, heat it, and drive the turbine to rotate stably. Simultaneously, turn on the vacuum pump, and control the exhaust back pressure (exhaust back pressure) by adjusting the back pressure regulating valve. Adjust the simulated atmospheric temperature through the pressure stabilization box temperature control system to adjust the turbine end exhaust back pressure (101.33 kPa) and temperature (15℃). The simulated atmospheric conditions should remain consistent throughout the test to avoid measurement errors. The turbocharger lubricating oil inlet pressure is (3±0.5)×100 kPa; the inlet oil temperature is 50~75℃, and the outlet oil temperature should not exceed 120℃. The turbocharger test speed deviation should be controlled within ±0.5% of the speed range. The turbine efficiency characteristic test is performed in stages according to the turbine circumference Mach number or similar speeds, recording the turbine speed, inlet gas flow rate, inlet gas static pressure, inlet gas total pressure, inlet gas total temperature, outlet gas static pressure, outlet gas total pressure, and outlet gas total temperature.

[0043] Then, adjust the exhaust back pressure and temperature to the calibration values ​​corresponding to the simulated target altitude. Following the steps above, record the turbine speed, inlet gas flow rate, inlet gas static pressure, inlet gas total pressure, inlet gas total temperature, outlet gas static pressure, outlet gas total pressure, and outlet gas total temperature.

[0044] Finally, adjust the exhaust back pressure (101.33 kPa) and temperature (15°C), and once the environment stabilizes to standard atmospheric conditions, reconfirm the test bench status. Stop the machine only after the booster has stabilized, check and record the test bench status, and provide the measured results for data processing and evaluation after optimization.

[0045] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A test method based on a turbocharger variable altitude simulation test bench, characterized in that: This method is applicable to a variable altitude simulation test bench for turbochargers. The test bench includes an air compressor with an external air source, a combustion chamber, a turbine, an exhaust pressure regulator, a vacuum pump, a centrifugal compressor, and an intake pressure regulator. The air compressor is connected to the intake end of the combustion chamber via an intake pipe. The fuel system supplies fuel to the combustion chamber through injection holes within the combustion chamber. The exhaust end of the combustion chamber is connected to the inlet end of the turbine via an intake pipe. The outlet end of the turbine is connected to the inlet end of the exhaust pressure regulator via an exhaust pipe, and a heat exchanger is installed on the connecting pipe. The outlet end of the exhaust pressure regulator is connected to the inlet end of the vacuum pump, and a heat exchanger is installed on the connecting pipe. A back pressure regulating valve is installed, and the outlet of the vacuum pump is connected to the atmospheric environment. The turbine is driven to rotate at high speed by high-temperature combustion gas from the combustion chamber. A centrifugal compressor is coaxially connected to the turbine, and the inlet of the centrifugal compressor is connected to the outlet of the intake pressure stabilizing box. The inlet pipe of the intake pressure stabilizing box is connected to the atmosphere, and an intake throttle valve and a temperature control device are installed on the pipe. The outlet of the centrifugal compressor is connected to the outlet pipe leading to the atmosphere, and a back pressure regulating valve and a quick-release valve are connected in parallel on the pipe. The outlet pipe of the centrifugal compressor is connected to the combustion chamber intake pipe, and a two-position four-way valve is installed on the connecting pipe. The test method based on this test bench includes the following steps: The first step is to adjust the turbocharger to a stable test condition on a flat plain: First, install the turbocharger on the turbocharger variable altitude simulation test bench and prepare it to normal working condition; then, turn on the centrifugal compressor end intake system and turbine end air source, adjust to standard atmospheric environment conditions, ignite the combustion chamber to drive the turbine to do work, drive the compressor to compress air, and confirm the working condition of the turbocharger. The second step is to conduct a variable altitude performance test on the centrifugal compressor: First, open the intake pressure regulating box connection valve, adjust the intake pressure through the intake throttle valve at the centrifugal compressor end, and adjust the intake temperature through the pressure regulating box temperature control system. Based on the compressor inlet total temperature and the required equivalent speed, the compressor characteristic test is carried out at the equivalent speed. Change the turbine end intake valve opening or adjust the combustion chamber fuel quantity to adjust the turbocharger speed. Adjust the compressor outlet pressure through the centrifugal compressor end back pressure regulating valve to adjust the compressor working flow. During the test, each equivalent speed line is measured point by point from surge flow to blockage flow, and the relevant test data are recorded. Then, adjust the intake pressure and temperature to the calibration values ​​corresponding to the simulated target altitude, and record the relevant test data according to the above steps; Finally, adjust the intake pressure and temperature to a stable working state under standard atmospheric conditions before shutting down the machine, check and record the condition of the test bench, and provide the measured results for data processing and evaluation after optimization. The third step is to conduct turbine variable altitude efficiency characteristic tests: First, the air compressor of the external air source at the turbine end is turned on to compress air. After heating, it drives the turbine to rotate stably. At the same time, the vacuum pump is turned on. The pressure of the exhaust pressure box, i.e. the exhaust back pressure, is controlled by adjusting the back pressure regulating valve. The temperature of the simulated atmospheric environment is adjusted by the pressure box temperature control system. The turbine efficiency characteristic test is performed in stages according to the turbine circumference Mach number or similar speed, and the relevant test data is recorded. Then, adjust the exhaust back pressure and temperature to the calibration values ​​corresponding to the simulated target altitude, and record the relevant test data according to the above steps; Finally, adjust the exhaust back pressure and temperature to a stable operating state under standard atmospheric conditions before shutting down the machine. Check and record the condition of the test bench, optimize it, and provide the measured results for data processing and evaluation.

2. The test method based on a turbocharger variable altitude simulation test bench according to claim 1, characterized in that: An air heater, an air source intake regulating valve, a pressure gauge, and a flow meter are installed on the combustion chamber intake pipe.

3. The test method based on a turbocharger variable altitude simulation test bench according to claim 1, characterized in that: The combustion chamber exhaust pipe is equipped with a pressure transmitter, a temperature transmitter, an inlet temperature sensor, an inlet total pressure sensor, and an inlet static pressure sensor.

4. The test method based on a turbocharger variable altitude simulation test bench according to claim 1, characterized in that: The centrifugal compressor and the turbine are coaxially connected and lubricated by a lubrication system.

5. The test method based on a turbocharger variable altitude simulation test bench according to claim 1, characterized in that: The centrifugal compressor is equipped with a pressure transmitter, a temperature transmitter, an outlet temperature sensor, an outlet total pressure sensor, and an outlet static pressure sensor on the outlet pipe connected to the outlet end.

6. The test method based on a turbocharger variable altitude simulation test bench according to claim 1, characterized in that: A speed sensor is installed inside the centrifugal compressor to measure the speed of the booster.

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