Exhaust pipe icing test device, system, and method

Abstract

The application discloses an exhaust pipe icing test device, system and method, and belongs to the technical field of vehicles. The device comprises a first pressure sensor, a second pressure sensor and a data processor. The first pressure sensor is located at the air inlet end of the exhaust pipe of a test vehicle, and the probe of the first pressure sensor is located inside the exhaust pipe, for monitoring the air pressure at the air inlet end. The second pressure sensor is located at the air outlet end of the exhaust pipe, and the probe of the second pressure sensor is located inside the exhaust pipe, for monitoring the air pressure at the air outlet end. The data processor is connected with the first pressure sensor and the second pressure sensor, respectively, for determining whether icing phenomenon exists in the exhaust pipe based on the air pressure at the air inlet end and the air pressure at the air outlet end. The application determines the relationship between icing phenomenon and vehicle operating state through real-time monitoring of whether icing phenomenon exists in the exhaust pipe, so as to better solve the problem of icing of the exhaust pipe of the vehicle.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and in particular to an exhaust pipe icing test device, system and method. Background Technology

[0002] The exhaust pipe and exhaust system are important components of a vehicle and play a crucial role in its operation. Because vehicle exhaust contains a large amount of water vapor, this water vapor condenses into small water droplets when it cools. In low-temperature environments, these condensed water droplets freeze and adhere to the inside of the exhaust pipe, causing abnormalities in the exhaust system, affecting the normal operation of the engine, and even causing complete blockage of the exhaust pipe, leading to engine damage.

[0003] In related technologies, the control of vehicle exhaust is mainly achieved from the perspective of preventing water vapor condensation and icing. However, it is not possible to effectively determine the relationship between exhaust pipe icing in low-temperature environments and various operating states of the vehicle, so as to better solve the problem of vehicle exhaust pipe icing. Summary of the Invention

[0004] This application provides an exhaust pipe icing testing device, system, and method, which can better solve the problem of icing in vehicle exhaust pipes. The technical solution is as follows:

[0005] On the one hand, an exhaust pipe icing test device is provided, the device comprising: a first pressure sensor, a second pressure sensor and a data processor;

[0006] The first pressure sensor is located at the air intake end of the exhaust pipe of the test vehicle and the probe of the first pressure sensor is located inside the exhaust pipe, for monitoring the air pressure at the air intake end; the second pressure sensor is located at the air outlet end of the exhaust end and the probe of the second pressure sensor is located inside the exhaust pipe, for monitoring the air pressure at the air outlet end.

[0007] The data processor is connected to the first pressure sensor and the second pressure sensor respectively, and is used to determine whether there is icing in the exhaust pipe based on the air pressure at the intake end and the air pressure at the outlet end.

[0008] Optionally, the exhaust pipe has a bent portion that bends toward the chassis of the test vehicle, the bent portion being located between the first pressure sensor and the second pressure sensor; the device further includes: a first temperature sensor;

[0009] The first temperature sensor is located at the bend and the probe of the first temperature sensor is located inside the bend, for monitoring the temperature inside the bend;

[0010] The first temperature sensor is connected to the data processor, which is used to determine whether there is icing in the exhaust pipe based on the air pressure at the intake end, the air pressure at the outlet end, and the temperature monitored by the first temperature sensor.

[0011] Optionally, the device further includes: a second temperature sensor;

[0012] The second temperature sensor is located at the bend and its probe is located inside the bend, for monitoring the temperature inside the bend;

[0013] Wherein, the distance between the probe of the second temperature sensor and the chassis is greater than the distance between the first temperature sensor and the chassis;

[0014] The second temperature sensor is connected to the data processor, which is used to determine the icing height in the bend based on the temperature monitored by the first temperature sensor and the temperature monitored by the second temperature sensor.

[0015] Optionally, the device further includes: a third temperature sensor and a fourth temperature sensor;

[0016] The third temperature sensor is located at the air intake end of the exhaust pipe and the probe of the third temperature sensor is located inside the exhaust pipe, for monitoring the temperature at the air intake end of the exhaust pipe.

[0017] The fourth temperature sensor is located at the outlet end of the exhaust pipe and the probe of the fourth temperature sensor is located inside the exhaust pipe, for monitoring the temperature at the outlet end of the exhaust pipe.

[0018] Both the third and fourth temperature sensors are connected to the data processor, which is used to determine whether there is icing inside the exhaust pipe based on the air pressure at the intake end, the air pressure at the outlet end, the temperature at the intake end, and the temperature at the outlet end.

[0019] Optionally, the device further includes an image acquisition device;

[0020] The image acquisition device is located on the inner wall of the exhaust pipe and is connected to the data processor. The data processor is used to control the image acquisition device to acquire images of the inside of the exhaust pipe when it is determined that there is icing inside the exhaust pipe. The image acquisition device is used to send the acquired images to the data processor.

[0021] Optionally, the exhaust pipe has an observation hole on its wall, and a plug is installed on the observation hole.

[0022] On the other hand, an exhaust pipe icing test system is provided, the system comprising: a chassis dynamometer, an exhaust gas extraction device, and the aforementioned exhaust pipe icing test device;

[0023] The chassis dynamometer has a test vehicle fixed on it, and the chassis dynamometer is used to simulate the driving conditions of the test vehicle.

[0024] The exhaust gas extraction device is connected to the exhaust pipe of the test vehicle and is used to collect the gas discharged from the exhaust pipe.

[0025] Optionally, the system is located in a cryogenic rotating chamber, which is used to simulate ambient temperature.

[0026] On the other hand, a method for performing an exhaust pipe icing test on the aforementioned system is provided, the method comprising:

[0027] Set the ambient temperature of the test environment and the driving conditions of the test vehicle;

[0028] Turn on the exhaust gas extraction device and perform multiple cycles of testing on the engine start-up condition and engine shutdown condition of the test vehicle according to the driving conditions. The engine start-up condition includes: idling condition and / or low-speed operation condition.

[0029] The exhaust pipe icing test device records the test data for the engine start-up condition and the test data for the engine shutdown condition in each cycle.

[0030] If the test vehicle fails to start normally during the cyclic test or the number of cyclic tests reaches the threshold, the test ends, and the presence of ice in the exhaust pipe of the test vehicle is determined by the test data recorded by the exhaust pipe icing test device.

[0031] Optionally, the exhaust pipe icing test device further includes an image acquisition device; the method further includes:

[0032] If the test data recorded by the exhaust pipe icing test device is abnormal, an image of the inside of the exhaust pipe is acquired by the image acquisition device.

[0033] The technical solution provided in this application can bring at least the following beneficial effects:

[0034] The air pressure at the intake end of the exhaust pipe of the test vehicle is monitored by a first pressure sensor located at the intake end, and the air pressure at the outlet end of the exhaust pipe is monitored by a second pressure sensor located at the outlet end. Based on the air pressure at the intake and outlet ends of the exhaust pipe, it is determined whether there is icing in the exhaust pipe. This allows for real-time monitoring of the presence of icing in the exhaust pipe, and by determining the relationship between icing and the vehicle's operating status based on the real-time changes in icing, in order to better solve the problem of icing in the vehicle's exhaust pipe. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of the structure of an exhaust pipe icing test device provided in an embodiment of this application;

[0037] Figure 2 This is a schematic diagram of another exhaust pipe icing test device provided in an embodiment of this application;

[0038] Figure 3 This is a schematic diagram of another exhaust pipe icing test device provided in an embodiment of this application;

[0039] Figure 4 This is a schematic diagram of another exhaust pipe icing test device provided in an embodiment of this application;

[0040] Figure 5 This is a schematic diagram of another exhaust pipe icing test device provided in an embodiment of this application;

[0041] Figure 6 This is a schematic diagram of another exhaust pipe icing test device provided in an embodiment of this application;

[0042] Figure 7 This is a schematic diagram of another exhaust pipe icing test device provided in an embodiment of this application;

[0043] Figure 8 This is a schematic diagram of an exhaust pipe icing test system provided in an embodiment of this application;

[0044] Figure 9 This is a flowchart of an exhaust pipe icing test method provided in an embodiment of this application. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0046] Before providing a detailed explanation of the exhaust pipe icing test device provided in the embodiments of this application, the application scenarios involved in the embodiments of this application will be introduced first.

[0047] The embodiments of this application are mainly applied to scenarios where exhaust pipe icing is tested. These testing scenarios can be closed testing scenarios, such as in a vehicle performance testing laboratory; they can also be applied to everyday vehicle use scenarios, such as determining exhaust pipe icing during daily vehicle driving.

[0048] Please refer to Figure 1 , Figure 1 This is a schematic diagram of an exhaust pipe icing test device according to an exemplary embodiment. The exhaust pipe icing test device 100 includes a first pressure sensor 101, a second pressure sensor 102, and a data processor 103. The first pressure sensor 101 is located at the intake end of the exhaust pipe of the test vehicle, and its probe is located inside the exhaust pipe, for monitoring the air pressure at the intake end. The second pressure sensor 102 is located at the exhaust outlet end, and its probe is located inside the exhaust pipe, for monitoring the air pressure at the outlet end. The data processor 103 is connected to the first pressure sensor 101 and the second pressure sensor 102 respectively, for determining whether icing exists inside the exhaust pipe based on the air pressure at the intake end and the air pressure at the outlet end.

[0049] In some embodiments, the air pressure data detected by the first pressure sensor and the second pressure sensor can be transmitted to the data processor in real time. The data processor can determine whether there is icing in the exhaust pipe based on the changes in the air pressure data from the first pressure sensor and the second pressure sensor.

[0050] It should be noted that when ice forms in the exhaust pipe, the resulting ice can cause blockage, reducing the flow of gas within the pipe. Gas will accumulate in front of the ice, leading to increased pressure in front of the ice (intake end) and decreased pressure behind the ice (exit end). Therefore, the presence of ice in the exhaust pipe can be determined by observing the pressure changes at the intake and exhaust ends.

[0051] For example, if the air pressure detected by the first pressure sensor is greater than a first air pressure threshold and / or the air pressure detected by the second pressure sensor is less than a second air pressure threshold, it can be assumed that there is icing in the exhaust pipe.

[0052] In some embodiments, considering that the air pressure in the exhaust pipe is related to the gas flow rate and gas composition, the difference between the air pressure detected by the first pressure sensor and the air pressure detected by the second pressure sensor can be used to determine whether there is icing in the exhaust pipe, so as to reduce the air pressure changes caused by gas composition and other factors. If the difference between the air pressure detected by the first pressure sensor and the air pressure detected by the second pressure sensor is greater than the air pressure difference threshold, that is, the air pressure at the air inlet of the exhaust pipe is significantly greater than the air pressure at the air outlet, it is considered that there is icing in the exhaust pipe; if the difference is less than or equal to the air pressure difference threshold, it is considered that there is no icing in the exhaust pipe.

[0053] In some embodiments, considering that the air pressure at different horizontal positions in the same vertical direction of the exhaust pipe may differ, in order to further improve the accuracy of the judgment of icing phenomenon, the probe of the first pressure sensor and the probe of the second pressure sensor may be placed at the same horizontal position.

[0054] It's understandable that when a vehicle's engine is in a dormant state, meaning no more exhaust gases are entering the exhaust pipe, the gas flow within the exhaust pipe gradually slows down and eventually reaches a relatively still state. Therefore, even if icing occurs in the exhaust pipe, the air pressure at the intake and exhaust ends is essentially the same, making it impossible to determine the presence of icing using the first and second pressure sensors. In other words, when... Figure 1 When the first and second pressure sensors shown determine whether there is icing in the exhaust pipe, it is necessary to ensure that the gas in the exhaust pipe is in a normal flow state, that is, the vehicle engine is working normally.

[0055] In some embodiments, in order to better install and fix the first pressure sensor and the second pressure sensor, the exhaust pipe wall may have multiple mounting seats, so as to install and fix the first pressure sensor through the first mounting seat and install and fix the second pressure sensor through the second mounting seat.

[0056] In some embodiments, since the probe is usually located at the very top of the sensor (away from the sensor interface), in order to prevent other parts of the sensor from being damaged by ice or liquid, the mounting base can be set on the upper wall of the exhaust pipe, such as at the top of the vertical diameter of the exhaust pipe, so that the liquefied water can drip off in time due to gravity, and prevent the liquefied water and other substances from accumulating and condensing at the mounting base, thereby causing damage to the sensor.

[0057] The data processor 103 can be a general-purpose CPU (Central Processing Unit), NP (Network Processor), microprocessor, or one or more integrated circuits for implementing the scheme of this application, such as ASIC (Application-Specific Integrated Circuit), PLD (Programmable Logic Device), or a combination thereof. The aforementioned PLD can be CPLD (Complex Programmable Logic Device), FPGA (Field-Programmable Gate Array), GAL (Generic Array Logic), or any combination thereof.

[0058] In some embodiments, the connection between the data processor and the sensor can be a wired connection or a wireless connection, which can be determined according to actual usage requirements. This application does not limit this.

[0059] In some embodiments, such as Figure 2 As shown, the exhaust pipe has a bend that bends toward the chassis of the test vehicle, and the bend is located between the first pressure sensor 101 and the second pressure sensor 102. The device also includes a first temperature sensor 201. The first temperature sensor 201 is located in the bend and its probe is located inside the bend, for monitoring the temperature inside the bend. The first temperature sensor 201 is connected to the data processor 103, which is used to determine whether there is icing inside the exhaust pipe based on the air pressure at the intake end, the air pressure at the outlet end, and the temperature monitored by the first temperature sensor 201.

[0060] It should be noted that, due to considerations such as space layout, heat dissipation, and noise reduction, vehicle exhaust pipes typically have a downward-curving bend (e.g., Figure 2 (See the "U" shaped section shown). Icing typically occurs when water vapor condenses into droplets upon cooling, which then freeze into ice at low temperatures. These droplets, influenced by gravity and airflow, usually converge at the lower part of the exhaust pipe, specifically the bottom of the bend, where they condense into ice. Therefore, in some embodiments, temperature changes at the bend of the exhaust pipe can be monitored. This allows for a comprehensive assessment of the temperature changes at the bend, the air pressure at the intake end, and the air pressure at the outlet end to determine whether icing is present in the exhaust pipe, further improving the accuracy of icing detection.

[0061] If there is no icing in the bend, the temperature monitored by the first temperature sensor is the temperature of the exhaust gas flowing through the bend, and the temperature at this time is A1. If there is icing in the bend, the temperature at this time will be significantly reduced due to the influence of the ice, and the temperature at this time is A2. Then A2 is less than A1.

[0062] Therefore, in some embodiments, the presence of icing within the bend can be determined based on a temperature threshold. For example, if the temperature detected by the first temperature sensor is less than or equal to the first temperature threshold, it is considered that icing exists within the bend; if the temperature detected by the first temperature sensor is greater than the first temperature threshold, it is considered that icing does not exist within the bend.

[0063] In some embodiments, the first temperature threshold can be determined based on actual usage requirements and experimental data. For example, considering that the temperature of the exhaust gas flowing through the bend varies depending on its position in the exhaust pipe—for instance, when the bend is located further forward (closer to the intake end), the exhaust gas temperature is typically higher because the cooling time is shorter; conversely, when the bend is located further back (closer to the exhaust outlet), the exhaust gas temperature is typically lower because it has undergone longer cooling. Therefore, to avoid misjudging icing phenomena, the first temperature threshold corresponding to the bend near the intake end and the bend near the exhaust end will differ. For example, since the temperature of the bend near the intake end is higher, the first temperature threshold corresponding to that bend will also be higher.

[0064] Furthermore, considering the presence of icing in the bend, the temperature monitored by the first temperature sensor will change depending on the relative position between the ice and the probe of the first temperature sensor. For example, if the probe of the first temperature sensor is not in contact with the ice, the temperature monitored by the first temperature sensor is the temperature of the exhaust gas after being cooled by the ice, and the temperature at this time is A3 (A3 is less than A1). If the probe of the first temperature sensor is in contact with the ice, the temperature monitored by the first temperature sensor is the temperature of the ice, and the temperature at this time is A4, then A4 is less than A3.

[0065] Therefore, in some embodiments, the positional relationship between the ice in the bend and the probe of the first temperature sensor can also be determined by a temperature threshold. If the temperature monitored by the first temperature sensor is less than or equal to the first temperature threshold and greater than the second temperature threshold, it is considered that there is icing in the bend and the ice is not in contact with the probe; if the temperature monitored by the first temperature sensor is less than or equal to the second temperature threshold, it is considered that there is icing in the bend and the ice is in contact with the probe.

[0066] To further improve the accuracy of judging icing in the exhaust pipe and avoid misjudgment of icing due to the failure of a single sensor, the presence of icing in the exhaust pipe can be determined by jointly considering the air pressure at the intake end, the air pressure at the exhaust end, and the temperature monitored by the first temperature sensor. For example, if the temperature monitored by the first temperature sensor is less than a first temperature threshold and the difference between the air pressure monitored by the first pressure sensor and the air pressure monitored by the second pressure sensor is greater than the air pressure difference threshold, it can be determined that there is icing in the exhaust pipe.

[0067] In some embodiments, if the exhaust pipe has a bend, since icing typically occurs within the bend, to more accurately determine whether icing exists within the bend, such as... Figure 2 As shown, the first pressure sensor can be located immediately before the bend (i.e., at the air inlet end of the bend) and adjacent to the bend, and the second pressure sensor can be located immediately after the bend (i.e., at the air outlet end of the bend) and adjacent to the bend.

[0068] In some embodiments, if the exhaust pipe has multiple bends that bend towards the chassis of the test vehicle, a first temperature sensor can be provided at each bend to improve the comprehensiveness of the judgment on icing at the bends.

[0069] It is understandable that when an exhaust pipe has multiple bends, if icing occurs at any bend, that is, if any temperature anomaly is detected by the first temperature sensor, it can be assumed that there is icing in the exhaust pipe.

[0070] In some embodiments, referring to the first and second mounting seats described above, the exhaust pipe wall may also have a third mounting seat to mount and fix the first temperature sensor. Other sensors described below can also be mounted and fixed using corresponding mounting seats, which will not be elaborated further.

[0071] It should be noted that the above example only takes the exhaust pipe being set above the chassis of the test vehicle. In some embodiments, the exhaust pipe can also be set below the chassis of the test vehicle, in which case the bend is usually bent in the opposite direction to the chassis of the test vehicle (i.e., the direction to the ground).

[0072] In some embodiments, such as Figure 3 As shown, the device further includes: a second temperature sensor 301; the second temperature sensor 301 is located in the bend and its probe is located inside the bend, for monitoring the temperature inside the bend; wherein the distance between the probe of the second temperature sensor 301 and the chassis is greater than the distance between the first temperature sensor 201 and the chassis; the second temperature sensor 301 is connected to the data processor 103, which is used to determine the icing height inside the bend based on the temperature monitored by the first temperature sensor 201 and the temperature monitored by the second temperature sensor 301.

[0073] It should be noted that, referring to the above principle of judging whether there is ice formation in the bend based on the first temperature sensor, multiple temperature sensors (i.e., the first temperature sensor and the second temperature sensor) with different probe positions can be set in the bend. Based on the temperature changes monitored by the temperature sensors at different probe positions, it can be determined whether the probes at different positions are in contact with the ice, so as to determine the height of ice formation in the bend.

[0074] For example, such as Figure 3 As shown, the probe of the first temperature sensor can be located inside the bend near the lower pipe wall of the bend (e.g., 3 / 4 of the diameter in the vertical direction of the exhaust pipe), and the probe of the second temperature sensor can be located inside the bend near the upper pipe wall of the bend (e.g., 1 / 4 of the diameter in the vertical direction of the exhaust pipe).

[0075] In some embodiments, in order to more accurately determine the icing height within the bend, there may be multiple second temperature sensors, with the probes of the multiple second temperature sensors positioned at different horizontal positions within the bend, thereby improving the accuracy of determining the icing height within the bend.

[0076] In some embodiments, such as Figure 4 As shown, the device further includes: a third temperature sensor 401 and a fourth temperature sensor 402; the third temperature sensor 401 is located at the air inlet end of the exhaust pipe and its probe is located inside the exhaust pipe, used to monitor the temperature at the air inlet end of the exhaust pipe; the fourth temperature sensor 402 is located at the air outlet end of the exhaust pipe and its probe is located inside the exhaust pipe, used to monitor the temperature at the air outlet end of the exhaust pipe; both the third temperature sensor 401 and the fourth temperature sensor 402 are connected to the data processor 103, which is used to determine whether there is icing inside the exhaust pipe based on the air pressure at the air inlet end, the air pressure at the air outlet end, the temperature at the air inlet end, and the temperature at the air outlet end.

[0077] It should be noted that during the process of exhaust gas entering from the intake end of the exhaust pipe and exiting from the exhaust end, the exhaust gas will naturally cool down due to the influence of the ambient temperature. That is, the temperature at the exhaust end (the temperature monitored by the fourth temperature sensor) will be significantly lower than the temperature at the intake end (the temperature monitored by the third temperature sensor). If the temperature difference between the intake end and the exhaust end before ice forms inside the exhaust pipe is B1; when ice forms inside the exhaust pipe, the exhaust gas will be further cooled as it flows through the ice. Due to the blocking effect of the ice, less exhaust gas will flow through the ice, and the gas density will decrease, causing the cooling rate of the gas after the ice to further increase. Therefore, the temperature difference between the intake end and the exhaust end will be further widened. If the difference at this time is B2, then B2 is greater than B1.

[0078] Therefore, in some embodiments, the presence of icing in the exhaust pipe can be determined by a temperature difference threshold. For example, if the difference between the temperature at the intake end (i.e., the temperature monitored by the third sensor) and the temperature at the exhaust end (i.e., the temperature monitored by the fourth temperature sensor) is less than or equal to a first temperature difference threshold, it is considered that there is no icing in the exhaust pipe; if the difference is greater than the first temperature difference threshold, it is considered that there is icing in the exhaust pipe.

[0079] In addition, considering that when the exhaust pipe is completely blocked by ice, the exhaust gas entering the exhaust pipe cannot flow to the exhaust outlet and be discharged from there. Therefore, the temperature at the exhaust outlet will be basically the same as the ambient temperature. Since the ambient temperature is low (e.g., minus 20 degrees Celsius), the temperature difference between the intake and exhaust outlet will be further increased. If the difference is B3, then B3 is greater than B2 mentioned above.

[0080] Therefore, in some embodiments, the temperature difference threshold can also be used to determine whether the exhaust pipe is completely blocked. For example, if the difference between the temperature at the intake end (i.e., the temperature monitored by the third sensor) and the temperature at the exhaust end (i.e., the temperature monitored by the fourth temperature sensor) is greater than the first temperature difference threshold and less than or equal to the second temperature difference threshold (which is greater than the first temperature difference threshold), it is considered that there is icing in the exhaust pipe, but it is not completely blocked; if the difference is greater than the second temperature difference threshold, it is considered that there is icing in the exhaust pipe and it is completely blocked.

[0081] In some embodiments, if the exhaust pipe has a bend, since icing typically occurs within the bend, to more accurately determine whether icing exists within the bend, such as... Figure 5 As shown, the third temperature sensor can be located before the bend (i.e., the air inlet end of the bend), and the fourth temperature sensor can be located after the bend (i.e., the air outlet end of the bend).

[0082] In some embodiments, such as Figure 6 As shown, the device also includes an image acquisition device 601; the image acquisition device 601 is located on the pipe wall inside the exhaust pipe and is connected to the data processor 103. The data processor 103 is used to control the image acquisition device 601 to acquire images of the inside of the exhaust pipe when it is determined that there is icing inside the exhaust pipe. The image acquisition device 601 is used to send the acquired images to the data processor 103.

[0083] In some embodiments, the image acquisition device can be installed on the upper pipe wall at the air inlet end of the exhaust pipe, or on the side wall of the exhaust pipe. If the exhaust pipe has a bend, the image acquisition device can also be installed on the upper pipe wall of the bend in the exhaust pipe. The specific installation location can be determined based on actual usage requirements.

[0084] The image acquisition device can be selected based on actual usage requirements. For example, considering that the temperature of the ice body is significantly different from the surrounding temperature, the image acquisition device can be an infrared imaging device to acquire thermal infrared images of the inside of the exhaust pipe and send the acquired thermal infrared images to the data processor.

[0085] In some embodiments, the image acquisition device can be configured to actively acquire images of the inside of the exhaust pipe, such as controlling the image acquisition device to acquire images of the inside of the exhaust pipe in real time, so as to realize real-time monitoring of icing phenomena inside the exhaust pipe.

[0086] In some embodiments, such as Figure 7 As shown, the exhaust pipe has an observation hole 701 on its wall, and a plug 702 is installed on the observation hole 701.

[0087] It should be noted that, under normal engine conditions, the inspection port must be kept closed (or sealed) for exhaust pipe sealing to prevent leakage of high-temperature exhaust gases. Therefore, during normal engine operation, the plug can be installed on the inspection port to prevent exhaust gas leakage; when the engine is idle and it is necessary to determine whether there is icing inside the exhaust pipe, the plug can be removed from the inspection port to determine the icing situation inside the exhaust pipe.

[0088] For example, when the engine is in sleep mode and it is necessary to determine the icing phenomenon inside the exhaust pipe, the plug installed on the inspection port can be removed, and the icing phenomenon inside the exhaust pipe can be observed and determined by using a device such as an endoscope.

[0089] The installation method of the plug can be determined according to the actual usage requirements. For example, the plug can be a bolt plug, which is screwed onto the observation hole.

[0090] In this embodiment, a first pressure sensor located at the intake end of the exhaust pipe and a second pressure sensor located at the exhaust end of the exhaust pipe determine whether icing exists inside the exhaust pipe based on pressure changes at different locations within the exhaust pipe, thereby achieving real-time monitoring of icing inside the exhaust pipe. However, considering the poor stability of judging icing solely through pressure sensors—such as malfunctions of a single sensor or pressure fluctuations—a first, third, and fourth temperature sensor are installed at the bend of the exhaust pipe. These sensors jointly determine the presence of icing based on changes in intake pressure, exhaust pressure, intake temperature, exhaust temperature, and the temperature at the bend, thus improving the accuracy of determining whether icing exists inside the exhaust pipe. To further improve the accuracy of judging icing phenomena, a second temperature sensor is installed at the bend of the exhaust pipe, in a different position than the first temperature sensor probe. By using probes located at different positions, the icing situation at different locations within the bend can be determined, enabling the judgment of the icing height within the bend. This allows for real-time monitoring of exhaust pipe icing during vehicle operation, and based on experiments, the correlation between different operating states of the vehicle and exhaust pipe icing can be determined, thus better solving the problem of vehicle exhaust pipe icing.

[0091] To further improve the accuracy of judging icing phenomena and avoid sensor misjudgments, when it is determined that there is icing in the exhaust pipe, an image acquisition device automatically acquires images of the inside of the exhaust pipe to intuitively determine the icing situation inside the exhaust pipe. The icing situation inside the exhaust pipe can also be observed more intuitively through the observation hole.

[0092] Those skilled in the art should understand that the above-described sensors, data processors, and image acquisition devices are merely examples. Other existing or future sensors, data processors, and image acquisition devices that are applicable to the embodiments of this application should also be included within the scope of protection of the embodiments of this application, and are hereby incorporated by reference.

[0093] Figure 8 This is a schematic diagram of the structure of an exhaust pipe icing test system provided in an embodiment of this application, as shown below. Figure 8 As shown, the system includes: a chassis dynamometer 801, an exhaust gas extraction device 802, and the aforementioned exhaust pipe icing test device 100; the chassis dynamometer 801 is fixed with a test vehicle, and the chassis dynamometer 801 is used to simulate the driving conditions of the test vehicle; the exhaust gas extraction device 802 is connected to the exhaust pipe of the test vehicle and is used to collect the gas discharged from the exhaust pipe.

[0094] This chassis dynamometer can simulate different driving conditions of the test vehicle by simulating parameters such as road resistance (e.g., different road surfaces, slopes, etc.), wind resistance, load changes, and driving speed.

[0095] In some embodiments, such as Figure 8 As shown, the system is located in a cryogenic rotating chamber, which is used to simulate ambient temperature.

[0096] It should be noted that, since the embodiments of this application mainly involve icing tests on exhaust pipes, the ambient temperature simulated in the low-temperature rotating drum laboratory is usually a low-temperature environment (such as minus 20 degrees Celsius).

[0097] This application provides an exhaust pipe icing test system. It uses a chassis dynamometer to simulate different driving conditions of the test vehicle and a low-temperature rotating drum laboratory to simulate ambient temperature, thereby simulating the driving conditions of the vehicle (i.e., the test vehicle) in a low-temperature environment. Based on the exhaust pipe icing test device, it monitors the icing phenomenon inside the exhaust pipe during driving, thus testing the exhaust pipe icing during vehicle operation to determine the correlation between different operating states of the vehicle and exhaust pipe icing, and better solve the problem of vehicle exhaust pipe icing.

[0098] Figure 9 This is a flowchart illustrating an exhaust pipe icing test method provided in an embodiment of this application. This method is applied to the aforementioned exhaust pipe icing test system. Please refer to... Figure 9 The method includes the following steps.

[0099] Step 901: Set the ambient temperature of the test environment and the driving conditions of the test vehicle.

[0100] In some embodiments, the ambient temperature of the test environment can be set through the aforementioned low-temperature rotating wheel laboratory based on testing requirements, and the driving conditions of the test vehicle can be set through the chassis dynamometer.

[0101] To fully simulate real-world driving scenarios, after setting the ambient temperature, you can wait a certain period of time before starting the test. For example, after the ambient temperature reaches the set target temperature, let it stand for 8 hours before conducting the test.

[0102] In some embodiments, considering that temperature may fluctuate, a target temperature range can be set. When the ambient temperature is within the target range, it can be considered that the ambient temperature has reached the set target temperature.

[0103] For example, the target temperature range is set to [-19℃, -21℃]. When the ambient temperature is within this range, such as the current ambient temperature being -19.6℃, the ambient temperature can be considered to have reached the set target temperature.

[0104] Step 902: Turn on the exhaust gas extraction device and perform multiple cycles of testing on the engine start-up and engine shutdown conditions of the test vehicle under the driving conditions. The engine start-up conditions include: idling conditions and / or low-speed operation conditions.

[0105] The test order and test content of a single cycle can be determined based on actual test requirements. For example, in order to better simulate normal driving scenarios, the test content in a single cycle can include the following in sequence: idling condition test (simulating engine starting condition before driving), low speed condition test (simulating engine condition during driving), idling condition test (simulating engine condition after driving and before turning off), and engine shutdown condition (simulating parking scenario after driving ends).

[0106] The test time for each cycle can also be determined based on actual test requirements. For example, considering the higher probability of icing in the exhaust pipe during short-distance, low-speed driving, the idle test time can be set to 3 minutes, and the low-speed test time can be set to 2km at a speed of 30km / h. In other words, for a single cycle, the test can be performed as follows: turn on the exhaust gas extraction device; start the engine and run it at idle for 3 minutes; turn on the chassis dynamometer and drive the vehicle at 30km / h for 2km; run the engine at idle for 3 minutes; turn off the engine to end the test.

[0107] The test time for engine shutdown conditions can still be determined based on actual test requirements. For example, in order to improve test efficiency and considering the time required for water vapor in the exhaust pipe to turn into ice in a low-temperature environment, the test time for engine shutdown conditions can be 2 hours.

[0108] Step 903: Record the test data of the engine start-up condition and the test data of the engine shutdown condition in each cycle using the exhaust pipe icing test device.

[0109] In some embodiments, in conjunction with the exhaust pipe icing test device described above, the monitoring data of each sensor during the cycle can be recorded by a data processor.

[0110] In some embodiments, exhaust gas components emitted by the vehicle during cyclic testing can be analyzed and recorded using an exhaust gas extraction device, such as the water vapor content in the exhaust gas, to further determine the correlation between engine operation and exhaust pipe icing based on the exhaust gas components emitted by engine combustion under low-temperature conditions.

[0111] Step 904: If the test vehicle fails to start normally during the cyclic test or the number of cyclic tests reaches the threshold, the test ends, and the test data recorded by the exhaust pipe icing test device is used to determine whether there is icing in the exhaust pipe of the test vehicle.

[0112] It should be noted that when the test vehicle can start normally, even if the test data recorded by the exhaust pipe icing test device is abnormal, that is, if there is icing in the exhaust pipe, the test vehicle can still drive normally at this time. Therefore, it can be considered that the icing phenomenon is within a controllable range and does not affect the normal driving of the vehicle. The cyclic test can continue.

[0113] In some embodiments, after the test is completed, the changes in the icing phenomenon inside the exhaust pipe during the test can be determined based on the monitoring data recorded by the exhaust pipe icing test device during the cycle, and adjustments can be made to the exhaust pipe layout design, engine operating parameters, etc., based on the analysis results.

[0114] In some embodiments, when the number of cyclic tests reaches a threshold, the ambient temperature of the test environment and / or the driving conditions of the test vehicle can be reset to determine whether there is icing in the exhaust pipe under different ambient temperatures and driving conditions, and the degree of icing, so as to make corresponding adjustments for different ambient temperatures and driving conditions, such as adjusting the relevant operating parameters of the engine under different ambient temperatures and driving conditions.

[0115] In some embodiments, the exhaust pipe icing test apparatus further includes an image acquisition device; the method further includes: in the event that the test data recorded by the exhaust pipe icing test apparatus is abnormal, acquiring an image of the exhaust pipe through the image acquisition device.

[0116] In some embodiments, the principles for judging icing phenomena based on different sensors at different locations are different. Therefore, the criteria for judging whether the test data of different sensors are abnormal are also different. For details, please refer to the corresponding description of the exhaust pipe icing test device mentioned above, which will not be repeated here.

[0117] In some embodiments, if there are abnormalities in the test data recorded by the exhaust pipe icing test device, the test can be temporarily stopped if there is an observation hole on the exhaust pipe. The icing phenomenon inside the exhaust pipe can be confirmed through the observation hole to avoid misjudgment of the icing phenomenon due to sensor failure, signal fluctuation, or other problems. The test can then continue when the observation ends.

[0118] In some embodiments, if the test data of a certain sensor is abnormal, but no icing is found inside the exhaust pipe, the sensor can be considered to be faulty and needs to be replaced.

[0119] This application provides a method for testing exhaust pipe icing. By conducting multiple cycles of testing on the test vehicle under engine start-up and engine shutdown conditions, the method simulates the vehicle's usage scenarios in low-temperature environments. The method uses an exhaust pipe icing test device to determine whether icing occurs in the exhaust pipe and the degree of icing during the cyclic testing process. This helps to establish the correlation between different operating states of the vehicle during driving and exhaust pipe icing, thereby better addressing the problem of vehicle exhaust pipe icing.

[0120] It should be understood that "at least one" as mentioned herein refers to one or more, and "multiple" refers to two or more. In the description of the embodiments of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B; "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. In addition, in order to clearly describe the technical solutions of the embodiments of this application, the terms "first," "second," etc., are used in the embodiments of this application to distinguish identical or similar items with substantially the same function and effect. Those skilled in the art will understand that the terms "first," "second," etc., do not limit the quantity or execution order, and the terms "first," "second," etc., are not necessarily different.

[0121] It should be noted that the information (including but not limited to user device information, user personal information, etc.), data (including but not limited to data used for analysis, data stored, data displayed, etc.) and signals involved in the embodiments of this application are all authorized by the user or fully authorized by all parties, and the collection, use and processing of related data must comply with the relevant laws, regulations and standards of the relevant countries and regions.

[0122] The above descriptions are embodiments provided in this application and are not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An exhaust pipe icing test apparatus characterized by, The device includes: a first pressure sensor, a second pressure sensor, a data processor, a first temperature sensor, and a second temperature sensor; The first pressure sensor is located at the air intake end of the exhaust pipe of the test vehicle and the probe of the first pressure sensor is located inside the exhaust pipe, for monitoring the air pressure at the air intake end; the second pressure sensor is located at the air outlet end of the exhaust pipe and the probe of the second pressure sensor is located inside the exhaust pipe, for monitoring the air pressure at the air outlet end. The exhaust pipe has a bend that bends toward the chassis of the test vehicle, and the bend is located between the first pressure sensor and the second pressure sensor; the first temperature sensor and the second temperature sensor are located at the bend, and the probes of both temperature sensors are located inside the bend, for monitoring the temperature inside the bend; the distance between the probe of the second temperature sensor and the chassis is greater than the distance between the first temperature sensor and the chassis; The data processor is connected to the first pressure sensor, the second pressure sensor, the first temperature sensor, and the second temperature sensor respectively, and is used to determine whether there is icing in the exhaust pipe based on the air pressure at the intake end, the air pressure at the outlet end, and the temperature monitored by the first temperature sensor, and to determine the icing height in the bend based on the temperature monitored by the first temperature sensor and the temperature monitored by the second temperature sensor.

2. The apparatus of claim 1, wherein, The device further includes: a third temperature sensor and a fourth temperature sensor; The third temperature sensor is located at the air intake end of the exhaust pipe and the probe of the third temperature sensor is located inside the exhaust pipe, for monitoring the temperature at the air intake end of the exhaust pipe. The fourth temperature sensor is located at the outlet end of the exhaust pipe and the probe of the fourth temperature sensor is located inside the exhaust pipe, for monitoring the temperature at the outlet end of the exhaust pipe. Both the third and fourth temperature sensors are connected to the data processor, which is used to determine whether there is icing inside the exhaust pipe based on the air pressure at the intake end, the air pressure at the outlet end, the temperature at the intake end, and the temperature at the outlet end.

3. The apparatus of claim 1, wherein, The device also includes an image acquisition device; The image acquisition device is located on the inner wall of the exhaust pipe and is connected to the data processor. The data processor is used to control the image acquisition device to acquire images of the inside of the exhaust pipe when it is determined that there is icing inside the exhaust pipe. The image acquisition device is used to send the acquired images to the data processor.

4. The apparatus of claim 1, wherein, The exhaust pipe has an observation hole on its wall, and a plug is installed on the observation hole.

5. An exhaust pipe icing test system characterized by, The system includes: a chassis dynamometer, an exhaust gas extraction device, and an exhaust pipe icing test device as described in any one of claims 1-4; The chassis dynamometer has a test vehicle fixed on it, and the chassis dynamometer is used to simulate the driving conditions of the test vehicle. The exhaust gas extraction device is connected to the exhaust pipe of the test vehicle and is used to collect the gas discharged from the exhaust pipe.

6. The system of claim 5, wherein, The system is located in a cryogenic rotating hub laboratory, which is used to simulate ambient temperature.

7. A method of conducting an exhaust pipe icing test using the system of claim 5 or 6, wherein, The method includes: Set the ambient temperature of the test environment and the driving conditions of the test vehicle; Turn on the exhaust gas extraction device and perform multiple cycles of testing on the engine start-up condition and engine shutdown condition of the test vehicle according to the driving conditions. The engine start-up condition includes: idling condition and / or low-speed operation condition. The exhaust pipe icing test device records the test data for the engine start-up condition and the test data for the engine shutdown condition in each cycle. If the test vehicle fails to start normally during the cyclic test or the number of cyclic tests reaches the threshold, the test ends, and the presence of ice in the exhaust pipe of the test vehicle is determined by the test data recorded by the exhaust pipe icing test device.

8. The method of claim 7, wherein, The exhaust pipe icing test device further includes an image acquisition device; the method further includes: If the test data recorded by the exhaust pipe icing test device is abnormal, an image of the inside of the exhaust pipe is acquired by the image acquisition device.

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