Method for Thermal Diffusion Test of Complete Vehicles in New Energy Vehicles

Abstract

Provided is a method for heat diffusion test of a completed new energy vehicle. 【Solution means】 The method of the present invention includes the steps of: performing initial modification on the battery system, triggering the battery pack to generate thermal runaway, and monitoring the state change of the battery system; performing video capture on the vehicle after thermal runaway by a video capture device, and monitoring the presence or absence and corresponding time of smoke emission, ignition, and explosion inside and outside the vehicle passenger compartment and the battery; collecting the surface temperature data of the contact objects in the passenger compartment, the gas concentration data of the high-temperature exhaust smoke in the passenger compartment, and the temperature data of the high-temperature exhaust smoke, and comparing the surface temperature data, gas concentration data, and temperature data of the high-temperature exhaust smoke of the contact objects in the passenger compartment with the corresponding safety standards, and evaluating the heat diffusion ability of the completed vehicle of the vehicle from the comparison results. The present invention provides a basis and guidance for actual product testing, and improves the safety and reliability of the verified product.

Description

Technical Field

[0001] The present invention relates to the field of thermal runaway protection in new energy vehicles, and particularly to a method for thermal diffusion testing of a completed new energy vehicle.

Background Art

[0002] In recent years, as the integration level in completed new energy vehicles has increased, new structures in battery systems such as CTC (Cell to Chassis) and CTB (Cell to Body) have emerged one after another, and new energy vehicle manufacturing plants that establish their own battery factories have also increased. In the industry, the safety of the battery system has shifted from the safety of a single component to the system safety on the vehicle side. On the one hand, it is the structural safety that protects both sides of the battery system by the skeleton of the vehicle body, and on the other hand, it is the functional safety that strengthens the entire system by highly integrating the control strategy of the battery system with the completed vehicle strategy. As a result, there is a problem that the actual safety level of the vehicle cannot be fully reflected only by testing a single component. Among them, the strong correlation between the thermal safety of the battery system and the vehicle's ignition accident is the focus of attention in the industry and has become a hot spot.

[0003] With the promulgation and implementation of GB 38031-2020 "Safety Requirements for Electric Vehicle Drive Batteries", the thermal diffusion test of the battery system was first introduced into the product announcement management. As a result, the relevant requirements and test methods have greatly contributed to the improvement of product quality.

[0004] To improve the thermal safety of battery systems, new technologies and products are booming in the industry. These include CATL's Qilin Battery, Fengchao Energy's Dragon Scale Armor Battery, SAIC's Rubik's Cube-shaped Battery, SAIC's Magazine-shaped Battery, etc. These products mainly achieve a high level of thermal safety for battery systems from aspects such as passive protection, active thermal management, and early warning control. In passive protection, by adopting low thermal conductivity materials, the heat of a battery cell that has gone out of control is restricted within a predetermined spatial range without affecting the surrounding batteries. In the case of active thermal management, when thermal runaway of the battery occurs, the forced cooling system is activated to remove the heat caused by the battery's runaway. In the case of early warning control, early warnings are issued in advance about the battery's runaway through parameter recognition, and effective blocking measures are taken to reduce the probability of the battery's runaway. From the perspective of the application technologies for current products, passive protection and active thermal management are the main technologies, and the improvement of the maturity of the application of early warning control technology is an issue for the future.

[0005] Although many new technologies, new structures, and new methods have been developed and applied, there are still products in which active events such as runaway and ignition occur. Therefore, within the industry, it is necessary to promptly consider the influence of the actual layout structure and mounting method of the vehicle based on the test methods at the component level. For example, adding a body covering structure to enhance the overall strength of the battery system and reducing the deformation amount of the upper cover at the moment when the battery cell goes out of control. Currently, many companies have started to conduct thermal safety tests using completed new energy vehicles to verify the thermal safety protection technology level of the products. However, the thermal safety test of products using completed vehicles has brought about an undeniable problem that the standards and evaluation systems for the thermal safety test of products at the completed vehicle level lack the specifications of the prior art.

[0006] The 2020 version of the national standard GB 38031 does not clearly show the test conditions and test methods for completed vehicles, and similarly, there is no clear regulation regarding the judgment method of test results. Therefore, in the new stage of product development, it is necessary to complement the relevant technical details, which is also one of the main reasons for starting the revision of this standard.

[0007] Therefore, based on the recognition that it is necessary to quickly establish a heat diffusion test method at the completed vehicle level in the present invention, from three perspectives of test conditions, test methods, evaluation systems, etc., it provides guidelines and bases for actual product tests, and proposes a heat safety test method at the completed vehicle level to improve the safety and reliability of verified products.

Summary of the Invention

[0008] An object of the present invention is to provide a heat diffusion test method for a completed new energy vehicle, which can provide bases and guidelines for actual product tests and improve the safety and reliability of the verified product.

[0009] To achieve the above object, the present invention provides the following solutions.

[0010] The heat diffusion test method for a completed new energy vehicle according to the present invention includes the following. Judging the charging method of the battery system of the test target vehicle, and correspondingly adjusting the charging state of the battery system according to the charging method. Performing an initial modification that meets a predetermined modification standard on the battery system. Triggering the battery pack in the battery system to generate a thermal runaway, recording the state information of the battery pack, and monitoring the state change situation of the battery system after the thermal runaway based on the state information of the battery pack, where the state information includes the instrument display SOC, the temperature inside the battery pack, and the voltage inside the battery pack. Performing video capture on the test target vehicle after the thermal runaway by a video capture device to obtain video data, and based on the video data, monitoring the presence or absence of smoke, fire, and explosion phenomena and the corresponding times in the passenger compartment, outside the vehicle, and the battery system of the test target vehicle, where the video capture device is arranged at the locations where the passenger compartment, outside the vehicle, and the battery system of the test target vehicle are located, and the video capture device arranged outside the vehicle meets a predetermined coverage range. A step of collecting temperature data of the surface of a contact object in the passenger compartment by a first temperature sensor arranged in the passenger compartment. A step of collecting gas concentration data of high-temperature exhaust gas in the passenger compartment by a group of gas concentration sensors and collecting temperature data of the high-temperature exhaust gas in the passenger compartment by a second temperature sensor, wherein the high-temperature exhaust gas contains CO, CO2, and O2, and both the group of gas concentration sensors and the second temperature sensor are provided at positions corresponding to the air outlet of the air conditioner and the human body's mouth and nose in the passenger compartment. A step of comparing the temperature data of the surface of the contact object in the passenger compartment, the gas concentration data, and the temperature data of the high-temperature exhaust gas with corresponding safety standards, and evaluating the heat diffusion ability of the completed vehicle of the test target vehicle from the corresponding comparison results.

[0011] Optionally, the predetermined modification standard is for maintaining the integrity of the normal connection of the high-voltage circuit and the low-voltage circuit in the completed vehicle, as well as the integrity of the existing heat protection structure.

[0012] Optionally, as the predetermined covering range, the distance from the vehicle head and the vehicle tail is both 1.2 m, and the distance from both sides of the vehicle body is 0.8 m.

[0013] Optionally, the safety standard for the surface temperature data of the contact object in the passenger compartment is 48 °C.

[0014] Optionally, the safety standard for the CO concentration data is that the CO concentration is 15 mg / m 3 or less in 15 min, or the CO concentration is 420 ppm or less in 10 min. The safety standard for the CO2 concentration data is that the CO2 concentration is 9839 ppm or less in 15 min. The safety standard for the O2 concentration data is that the O2 concentration is 12% or more.

[0015] Optionally, the safety standard for the temperature data of the high-temperature exhaust gas is 70 °C.

[0016] Optionally, the method further includes A step of obtaining temperature distribution conditions on the outer surface of the vehicle under test and the diffusion conditions of smoke and flames after thermal runaway by means of a thermograph arranged within the predetermined cover range, and obtaining temperature field data; A step of determining, based on the temperature field data, whether the vehicle under test will cause damage to facilities or personnel in the external environment after thermal runaway, is included.

[0017] Optionally, the method further includes: A step of obtaining the battery management system message and the complete vehicle message of the vehicle under test after thermal runaway; A step of monitoring, based on the battery management system message and the complete vehicle message, whether an abnormality occurs in the transmission of the first warning signal of the vehicle under test, where the first warning signal includes temperature abnormality, battery thermal runaway, turn signal lighting, horn sounding or door unlocking.

[0018] Optionally, the method further includes: A step of monitoring, based on the video data, whether the door handle in the passenger compartment can be unlocked after thermal runaway, and determining whether the vehicle is convenient for the escape or rescue of passengers after thermal runaway.

[0019] Optionally, the method further includes: A step of monitoring, based on the video data, whether voice, optical warning signals and instrument warnings occur in the vehicle after thermal runaway.

[0020] According to the specific embodiments provided by the present invention, the present invention has the following technical effects.

[0021] The present invention provides a method for thermal diffusion testing of a completed new energy vehicle. By means of the method, through initial modification of the battery system, the safety of the existing battery system is guaranteed to a certain extent after thermal runaway, and the video capture devices arranged within a predetermined coverage range monitor the test phenomena of the vehicle after thermal runaway, so that video data from all angles can be comprehensively captured, enhancing the monitoring effect. By setting new safety standards corresponding to the surface temperature data of the contact objects in the passenger compartment, the gas concentration data, and the temperature data of the high-temperature exhaust smoke, the thermal diffusion protection ability of the completed vehicle can be evaluated more accurately and reliably.

Brief Description of the Drawings

[0022] To more clearly explain the technical solutions in the embodiments of the present invention or in the prior art, the drawings used in the embodiments will be briefly described below. Of course, the drawings described below are only a part of the embodiments of the present invention, and those skilled in the art can conceive of other drawings based on these drawings without creative effort.

[0023]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0024] Hereinafter, with reference to the drawings in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. However, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort shall fall within the protection scope of the present invention.

[0025] The present invention aims to provide a basis and guidance for actual product tests and to provide a heat diffusion test method for a completed new energy vehicle to improve the safety and reliability of the product to be verified.

[0026] To make the above objects, features, and advantages of the present invention more clear, the present invention will be further described in detail below in conjunction with the drawings and specific embodiments.

[0027] As the integration level in the completed new energy vehicle increases, within the industry, the safety of the battery system has shifted from the safety of a single component to the system safety on the vehicle side. There is a lack of test standards and evaluation systems corresponding to the product's thermal safety test for the completed vehicle in the prior art. Referring to the thermal diffusion test method and requirements of the battery system in the GB 38031-2020 version, the present invention proposes a heat diffusion test method at the completed vehicle level of new energy vehicles from three aspects: test conditions, test methods, and evaluation systems.

[0028] Example 1 Test conditions: Regarding the thermal safety test at the completed vehicle level of new energy vehicles, the test object is the completed new energy vehicle. As test conditions, referring to GB 38031-2020, they are set as follows.

[0029] Environmental conditions: The test is carried out at a temperature of 0°C or above, a relative humidity of 10% - 90%, and an atmospheric pressure of 86 kPa - 106 kPa, in an indoor environment or an environment with a wind speed of 2.5 km / h or less. Here, considering the influence of the test environment on the test results and the repeatability and reproducibility of the test results, it is recommended to carry out the test in an indoor environment.

[0030] Test method: As shown in Figure 1, the heat diffusion test method for the completed new energy vehicle in this embodiment includes the following steps S1 to S7.

[0031] Step S1: Determine the charging method of the battery system of the vehicle under test, and appropriately adjust the charging state of the battery system according to the charging method. Specifically, before the start of the test, set the state of charge (SOC) of the vehicle under test to a predetermined value.

[0032] 1) In the case of a vehicle designed for external charging, its SOC is adjusted to 95% or more of the normal SOC operating range specified by the manufacturer.

[0033] 2) In the case of a vehicle designed for charging by vehicle energy only, its SOC is adjusted to 90% or more of the operating range as well.

[0034] Step S2: Perform initial modification on the battery system to meet a predetermined modification standard. Specifically, the predetermined modification standard aims to maintain the integrity of the normal high-voltage circuit connection and low-voltage circuit connection of the completed vehicle, as well as the integrity of the existing thermal protection structure.

[0035] In order to trigger the battery to generate thermal runaway, it is necessary to perform certain modifications on the completed vehicle before the test. For example, arrange a heating device between cells or punch holes at specific positions on the housing of the battery system to achieve the purpose that the needle can pierce the target cell. During the test, the test samples should be changed as little as possible, and the manufacturer needs to submit a change list.

[0036] Currently, as an initial modification method that meets the conventional current standard requirements, it is common to replace some battery cells with planar heating sheets. In this modification method, since the actual battery cells are replaced with heating sheets, there is a risk of destroying the high-voltage connection of the entire pack. Also, in order to fix the heating sheet, it is usually necessary to destroy the original heat insulation material or add an additional protection structure, all of which destroy the actual state of the original battery system and there is a drawback that the severity of the test conditions of most of the modified battery systems is lower than the initial state. Therefore, in the present invention, the predetermined modification standard that the initial modification meets is limited.

[0037] Step S3: Trigger the battery pack in the battery system to generate thermal runaway, and record the status information of the battery pack. Based on the status information of the battery pack, monitor the state change situation of the battery system after the thermal runaway, and the status information includes an instrument display SOC, a temperature in the battery pack, and a voltage in the battery pack.

[0038] Specifically, in the thermal safety test method for new energy vehicles, the thermal runaway trigger method, trigger object, monitoring point scheme, etc. can all refer to the current GB 38031-2020 standard. Considering the need to avoid damaging the high and low voltage circuits and thermal protection structure of the battery system, the scheme of using a heating device instead of a battery in the original standard is deleted, and in terms of the trigger method, methods such as needle pricking, built-in heating or overcharging can be selected, or other trigger methods can be automatically selected. The method of selecting the trigger object is consistent with the original standard, and the cell close to the center position in the battery pack or the battery cell surrounded by other battery cells is selected.

[0039] Step S4: Using a video capture device, perform video capture of the test vehicle after thermal runaway to obtain video data, and based on the video data, monitor the presence or absence of smoke, ignition or explosion phenomena in the passenger compartment, outside the vehicle and battery system of the test vehicle and the corresponding time, and the video capture device is disposed at locations where the passenger compartment, outside the vehicle and battery system of the test vehicle are located, and the video capture device disposed outside the vehicle satisfies a predetermined coverage range.

[0040] Preferably, the predetermined coverage range is 1.2 m from both the front and rear of the vehicle, and 0.8 m from both sides of the vehicle body.

[0041] Specifically, the main difference between the present invention and the conventional battery system-level thermal diffusion test method is that requirements for video capture are added. In terms of the placement position of the video capture device, it should be ensured that the shooting area covers the entire vehicle including the vehicle body, the bottom of the vehicle, and the passenger compartment (seats, instruments, floor). The video capture device should cover at least a range of 1.2 m from the front and rear of the vehicle and 0.8 m from the side of the vehicle. As shown in FIG. 2, the video capture device is used to collect the presence or absence of phenomena such as smoke generation, ignition, explosion, etc. during the entire experimental process and the corresponding time.

[0042] The predetermined coverage range of the shooting area of the video capture device installed around the vehicle body is set with reference to the regulations on the dimensions related to parking spaces in two industry standards. First, GA / T 850-2009 "Urban Road Roadside Parking Space Installation Specification" defines three different installation methods for parking spaces: parallel, perpendicular, and inclined. In addition, JGJ100-2015 "Parking Lot Architectural Design Specification" defines the minimum clearances between motor vehicles and between motor vehicles and walls, columns, guardrails for different models in the case of three different installation forms of parking spaces. Considering currently commercially available passenger cars, SUVs (Sport Utility Vehicles) and MPVs (Multi-Purpose Vehicles) usually have a vehicle length of 5.5 m or less and a vehicle width of 2.2 m or less. Therefore, according to JGJ100-2015, it can be determined that a range of 1.2 m in the longitudinal direction and 0.8 m in the lateral direction of the motor vehicle basically covers the effective distance between the target vehicle and surrounding vehicles or buildings in an actual parking scenario.

[0043] Step S5: The first temperature sensor arranged in the passenger compartment acquires the temperature data of the surface of the contacted objects in the passenger compartment.

[0044] Specifically, for the surface temperature test of the contact objects in the passenger compartment, it is necessary to arrange corresponding temperature sensors on the test vehicle to obtain the temperature data of the surfaces of the contact objects. The corresponding positions mainly include the positions of each seat in the vehicle corresponding to the head, back, buttocks, and feet of the human body, the inner and outer door handles of each door, the steering wheel, the seat belt buckle release button, the hazard lamp button, the window lift button, the shift member, the center console box, the inner and outer openings of the front cabin, the inner and outer openings of the trunk, etc.

[0045] Step S6: The gas concentration sensor group collects the gas concentration data of the high-temperature exhaust smoke in the passenger compartment, and the second temperature sensor obtains the temperature data of the high-temperature exhaust smoke in the passenger compartment. The high-temperature exhaust smoke contains CO, CO2, and O2. Both the gas concentration sensor group and the second temperature sensor are provided at positions corresponding to the air outlet of the air conditioner and the human body's mouth and nose in the passenger compartment.

[0046] Specifically, from the perspective that the high-temperature exhaust smoke in the passenger compartment may cause irreversible damage, poisoning, or asphyxiation to the human body, corresponding temperature sensors, CO gas sensors, CO2 gas sensors, and O2 gas sensors are arranged at the air outlets of the air conditioner (the air outlets corresponding to the face position, the air outlets corresponding to the foot position, and the air outlets corresponding to the window position) and the positions that simulate the human body's mouth and nose in the passenger compartment.

[0047] Step S7: Compare the temperature data of the surfaces of the contact objects in the passenger compartment, the gas concentration data, and the temperature data of the high-temperature exhaust smoke with their respective safety standards, and evaluate the heat diffusion ability of the completed vehicle of the test target vehicle from the corresponding comparison results.

[0048] Preferably, the safety standard for the surface temperature data of the contact objects in the passenger compartment is 48°C.

[0049] Preferably, the safety standard for the CO concentration data is that the CO concentration is 15 mg / m 3 or less within 15 minutes, or the CO concentration is 420 ppm or less within 10 minutes.

[0050] The safety standard for the concentration data of the CO2 is 9839 ppm or less within 15 minutes.

[0051] The safety standard for the concentration data of the O2 is that the O2 concentration is 12% or more.

[0052] Preferably, the safety standard for the temperature data of the high-temperature exhaust gas is 70 °C.

[0053] Furthermore, the method further includes step S8 of obtaining the temperature distribution status of the outer surface of the vehicle under test and the diffusion status of exhaust smoke and flames after thermal runaway by means of a thermography arranged within the predetermined coverage range, so as to obtain temperature field data. It should be noted that the installation position of the thermography shall coincide with that of the video capture device.

[0054] Based on the temperature field data, it is determined whether the vehicle under test will cause damage to facilities or personnel in the external environment after thermal runaway, that is, based on the temperature field data and the predetermined coverage range, it is possible to predict the damage and influence status of the target vehicle on the surrounding environment, facilities and personnel when the heat actually diffuses. For example, predict the potential risks that may occur to a vehicle with thermal runaway in a parking space of a parking lot.

[0055] Conduct a heat diffusion test at the completed vehicle level, start the video capture device and the thermography, and continuously monitor the test process for 2 hours after triggering thermal runaway for the target cell. In this test, it is necessary to record not only the relevant information of the battery system and the test phenomena, but also the information related to the entire vehicle and the test phenomena in the test process of the vehicle. Therefore, further, the method includes the step of obtaining the battery management system message and the completed vehicle message of the vehicle under test after thermal runaway.

[0056] Based on the battery management system message and the finished vehicle message, monitor whether an abnormality occurs in the transmission of the first warning signal of the vehicle under test. The first warning signal includes temperature abnormality, battery thermal runaway, turn signal lighting, horn sounding, door unlocking, etc.

[0057] Furthermore, the method further includes monitoring, based on the video data, whether the door handle in the passenger compartment can be unlocked after thermal runaway, and determining whether the vehicle is convenient for the escape or rescue of the passengers after thermal runaway.

[0058] Furthermore, the method further includes monitoring, based on the video data, whether voice, optical warning signals, and instrument warnings occur in the vehicle after thermal runaway.

[0059] Furthermore, the method includes a step of recording the time to trigger thermal runaway.

[0060] Furthermore, the method includes a step of recording the time when thermal runaway occurs in the battery system.

[0061] Evaluation system: Among the parameters recorded by the test, the instrument-displayed SOC (State of Charge) reflects the state of the test sample at the actual start time. From the temperature inside the battery pack, the voltage inside the battery pack, the temperature of the passenger compartment, and the smoke concentration data, it is possible to obtain the change process of the data related to all important feature points in the heat diffusion process of the completed vehicle. The Battery Management System (BMS) and the completed vehicle messages record the transmission status of the vehicle's first warning signal. For example, within a certain period of time after a thermal runaway occurs, whether the vehicle can further send warnings such as abnormal temperature, battery thermal runaway, turn signal lighting, horn sounding, or door unlocking. The actual external expression status of the warning signal can be evaluated by the voice, light, and instrument warnings of the completed vehicle. The time to trigger thermal runaway, the time when thermal runaway occurs in the battery system, the transmission of the warning signal, smoke emission (outside the vehicle), smoke emission (in the passenger compartment), and the time of ignition and explosion reflect the important test phenomena and corresponding time nodes in the complete test process. The door unlocking item is mainly used to evaluate whether the vehicle after runaway is convenient for the escape or rescue of passengers. On the one hand, whether personnel can easily open the door and escape from the vehicle, and on the other hand, whether firefighters can easily open the door to help the remaining personnel. When the battery runs away, the vehicle's power supply may be cut off, and it may not be possible to unlock the door or open the hidden door handle. Therefore, personnel may not be able to get out or easily open the door from the outside, which affects the rescue by firefighters. Therefore, future improvements are required for the event that the door cannot be opened after thermal runaway.

[0062] Specifically, the safety standards are considered from two perspectives: the escape and rescue of the driver and passengers in the passenger compartment. Tests and judgments can be made based on whether the surface of the contact objects in the passenger compartment burns the passengers and whether the high-temperature smoke in the compartment causes asphyxiation or poisoning of the passengers.

[0063] Regarding the surface temperature protection safety threshold of the contact objects in the passenger compartment, reference can be made to the national standard GB / T 18153-2000 "Safety of machinery - Surface temperature of touchable parts - Ergonomic data for the determination of temperature limits for hot surfaces". In this standard, when the human body continuously contacts different materials for different times, the safety boundaries for whether the human body is burned are defined. In the case of a 1-minute continuous contact time, depending on different materials, the safety boundary values for burning the human body range from 51°C to 60°C. When the human body continuously contacts for 10 minutes, the safety boundary for burning is unified to 48°C. Considering that there are many materials that the human body in the passenger compartment can contact, and at the same time considering the definition of the 5-minute personnel evacuation time in the current standard, if 48°C corresponding to the 10-minute condition is selected, it not only has a certain safety redundancy but also fully meets the 5-minute evacuation time. Above all, passengers will not be burned by the surface of any contact object in the passenger compartment.

[0064] Regarding whether the high-temperature smoke exhaust in the passenger compartment causes irreversible damage to the human body or causes poisoning or asphyxiation of passengers, from the perspective of temperature, refer to the descriptions in medical literature and science popularization literature. When the temperature of the gas inhaled by the human body exceeds 70°C, it will cause mucosal congestion, bleeding, blisters or tissue necrosis in the trachea and bronchi, leading to death from pulmonary edema. Therefore, it is appropriate to set the temperature safety threshold of the high-temperature smoke exhaust at 70°C.

[0065] In addition, for the three typical gases of CO, CO2, and O2 that may affect personnel evacuation and thus cause poisoning of passengers, the corresponding safety boundaries are defined simultaneously. Among them, for the safety boundary of O2, reference can be made to the definition in the "Safety Guidelines Manual for Confined Space Work" of the Emergency Management Department. When the oxygen content is less than 12%, it may cause a serious decline in personnel's judgment and movement coordination, as well as permanent damage to the heart due to respiratory function decline, nausea and vomiting. Therefore, it is appropriate to set the O2 concentration at 12% or more.

[0066] Regarding the safety limits of CO and CO2, reference can be made to the relevant definitions in GBZ 2.1-2019 "Occupational Exposure Limits for Hazardous Agents in the Workplace - Part 1: Chemical Hazardous Agents" and the Material Safety Data Sheet (MSDS). In the above standard, three grades of different injuries to the human body caused by related gases within different time ranges are defined. Among them, PC-TWA (Permissible Concentration-Time Weighted Average) is the average permissible exposure concentration during 8 hours a day and 40 hours a week of working hours. Considering the short-term nature of heat diffusion, the PC-TWA value has little significance as a reference. PC-STEL (Permissible Concentration-Short Term Exposure Limit) is the weighted average permissible concentration for 15 minutes of exposure, and MAC (Maximum Allowable Concentration) is the concentration that must not be exceeded at any time or workplace. Regarding CO2, since the PC-STEL value in the standard is defined as 18000 mg / m 3 , the safety limit of CO2 can be defined as not exceeding 18000 mg / m 3 within 15 minutes. Converted by the formula in the standard, it corresponds to approximately 9839 ppm.

[0067] Regarding CO, the PC-STEL value and MAC value corresponding to different altitudes are defined in the standard. Considering the wide range of automobile use, the MAC value corresponding to altitudes over 3000 m is selected as the strictest safety limit, that is, it can be required that CO does not exceed 15 mg / m 3 within 15 minutes.

[0068] In addition, regarding the definition of the CO safety limit, there is another international reference, the Acute Exposure Guideline Levels (AEGLs) issued by the US Environmental Protection Agency (EPA). Similarly, this guideline defines three levels of different injuries to the human body. Level 1 causes obvious discomfort, irritation, and clear asymptomatic and insensible effects to the human body. These effects do not cause disorders, are temporary, and become reversible when contact ceases. Level 2 is irreversible, or seriously affects health, is harmful in the long term, or has other effects that impair the ability to escape. Level 3 endangers life and health or leads to death. Therefore, referring to the safety limit defined by Level 2, for CO, the CO concentration during contact within 10 minutes can be made not to exceed 420 ppm, and this value can be used with reference to the safety limit of the CO within 15 minutes at the same time.

[0069] The present invention has the following technical effects.

[0070] 1) In the present invention, by presetting the transformation standard for the initial transformation of the battery system so as not to destroy the existing high and low voltage circuit connections and the existing thermal protection structure of the battery system, it is possible to maintain a certain safety situation after the thermal runaway of the existing battery system.

[0071] 2) By using a video capture device that meets a predetermined coverage range to monitor the test phenomena of the vehicle after thermal runaway, video data from all angles can be comprehensively captured, and the monitoring accuracy can be improved.

[0072] 3) By setting new safety standards corresponding to the surface temperature data, gas concentration data, and temperature data of high-temperature smoke exhaust of the contact objects in the passenger compartment and using more reliable evaluation indicators, the thermal diffusion protection ability of the complete vehicle of the vehicle can be evaluated more accurately and reliably. In addition, it can provide a direction for improving the performance of the vehicle.

[0073] 4) The present invention adopts a heat diffusion test for a complete vehicle, which is closer to the actual scenario and more oriented towards the actual use of consumers. Considering the complex working conditions and variable scenarios in actual applications, it is necessary to formulate a more systematic plan for the heat diffusion test method and requirements of the complete vehicle. On the one hand, it includes the requirement at the component level that no ignition or explosion occurs within 5 minutes after the warning signal is sent. On the other hand, when combined with vehicle products, the determination of the temperature inside the vehicle, smoke exhaust, etc. is added.

[0074] 5) In the present invention, the test methods and limit value conditions for temperature, smoke exhaust, etc. are systematically presented, and deeply analyzed in combination with actual cases. On the one hand, it provides a basis and guidance for actual product tests. On the other hand, it can effectively support the creation and revision work of international laws and national standards, and also contribute to the improvement of the safety and reliability of verified products.

[0075] Example 2 A computer device that can be a database, an example of whose internal structure is shown in FIG. 3. The computer device includes a processor, a memory, an input / output interface (abbreviated as Input / Output, I / O), and a communication interface. Here, the processor, the memory, and the input / output interface are connected via a system bus, and the communication interface is connected to the system bus via the input / output interface. Here, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the execution of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store transactions to be processed. The input / output interface of the computer device is for information exchange between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal via a network connection. When the computer program is executed by the processor, the heat diffusion test method for the completed vehicle of the new energy vehicle shown in Example 1 is realized.

[0076] A person skilled in the art can realize all or part of the methods in the above embodiments by issuing instructions to related hardware through a computer program. The computer program may be stored in a non-volatile computer-readable storage medium and may include the flow of the embodiments of the above methods when executed. Here, any reference to memory, database, or other media used in each embodiment provided by the present invention may include at least one of non-volatile and volatile memory. Non-volatile memory may include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory may include random access memory (RAM) or external cache memory, etc. Although it has been exemplified that RAM may be in various forms such as static random access memory (SRAM) or dynamic random access memory (DRAM), it is not limited thereto. The database according to each embodiment provided by the present invention may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on blockchain, etc., but is not limited thereto. The processor according to each embodiment provided by the present invention may be a general-purpose processor, a central processor, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but is not limited thereto.

[0077] In the embodiments described above, each of the technical features can be arbitrarily combined. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments have been described. However, as long as these combinations of technical features do not conflict, they should be regarded as being included within the scope described in this specification.

[0078] In this specification, the principles and embodiments of the present invention have been described using specific individual examples. However, the description of the above embodiments is only for the purpose of helping to understand the method and the gist of the present invention. Also, those skilled in the art can make changes to the specific embodiments and the scope of application based on the idea of the present invention. Therefore, the content of this specification should not be understood as limiting the present invention.

Claims

1. A process of determining a charging method of a battery system of a vehicle under test and adjusting the state of charge of the battery system according to the charging method, when the charging method is external charging, adjusting the corresponding SOC to 95% or more of the normal SOC operating range specified by the manufacturer, when the charging method is charging by vehicle energy, adjusting the corresponding SOC to 90% or more of the normal operating range specified by the manufacturer, performing an initial modification on the battery system to meet a predetermined modification standard, where the predetermined modification standard aims to maintain the integrity of the normal connection of the high-voltage and low-voltage circuits of the completed vehicle and the integrity of the existing thermal protection structure, triggering the battery pack in the battery system to generate thermal runaway, recording the state information of the battery pack, and monitoring the state change situation of the battery system after thermal runaway based on the state information, where the state information includes the instrument display SOC, the temperature inside the battery pack, and the voltage inside the battery pack, performing video capture on the vehicle under test after thermal runaway by a video capture device, acquiring video data, and monitoring the presence or absence of smoke, fire, and explosion phenomena and their occurrence times in the passenger compartment, outside the vehicle, and the battery system based on the video data, where the video capture devices are respectively arranged at the positions of the passenger compartment, outside the vehicle, and the battery system of the vehicle under test, and the video capture device arranged outside the vehicle meets a predetermined coverage range, and the predetermined coverage range is such that the distances from the vehicle head and the vehicle tail are each 1.2 m, and the distances from both sides of the vehicle body are 0.8 m, collecting temperature data of the surface of the contacted objects in the passenger compartment by a first temperature sensor arranged in the passenger compartment, Collecting gas concentration data of high-temperature smoke in the passenger compartment by the gas concentration sensor group and collecting temperature data of the high-temperature smoke in the passenger compartment by the second temperature sensor, wherein CO, CO ２ and O ２ are included, and the step of arranging both the gas concentration sensor group and the second temperature sensor at positions corresponding to the air outlet of the air conditioner and the mouth and nose of the occupant comparing the temperature data of the surface of the contacted objects in the passenger compartment, the gas concentration data, and the temperature data of the high-temperature exhaust smoke with the corresponding safety standards, and evaluating the heat dissipation ability of the completed vehicle of the vehicle under test based on the comparison result, including, the safety standard for the temperature data of the surface of the contacted objects in the passenger compartment is 48 °C, The safety standard for the concentration data of the CO is that the CO concentration is 15 mg / m ３ or less within 15 minutes, or the CO concentration is 420 ppm or less within 10 minutes, The aforementioned CO ２ The safety standard for the concentration data is 9839 ppm or less within 15 minutes, The safety standard for the concentration data of the above-mentioned O ２ is that the concentration of O ２ is 12% or more, the safety standard for the temperature data of the high-temperature exhaust smoke is 70 °C, and the process is executed by a processor. A method for a heat dissipation test of a completed new energy vehicle.

2. Collecting the temperature distribution status, smoke diffusion status, and flame diffusion status outside the test vehicle after thermal runaway by a thermograph arranged within the predetermined cover range to obtain temperature field data; Further including a step of determining whether the test vehicle after thermal runaway causes damage to facilities or personnel in the external environment based on the temperature field data, characterized in that the method for testing heat diffusion of a completed vehicle of a new energy vehicle according to claim 1.

3. Obtaining the battery management system message and the completed vehicle message of the test vehicle after thermal runaway; Further including a step of monitoring whether an abnormality occurs in the transmission of the first warning signal of the test vehicle based on the battery management system message and the completed vehicle message; The method for testing heat diffusion of a completed vehicle of a new energy vehicle according to claim 1, characterized in that the first warning signal includes temperature abnormality, battery thermal runaway, turn signal lighting, horn sounding, or door unlocking.

4. Further including a step of monitoring whether the door handle in the passenger compartment can be unlocked based on the video data after thermal runaway, and determining whether the vehicle after thermal runaway is suitable for the escape or rescue of passengers, characterized in that the method for testing heat diffusion of a completed vehicle of a new energy vehicle according to claim 1.

5. Further including a step of monitoring whether a sound warning signal, a light warning signal, or an instrument warning occurs in the vehicle after thermal runaway based on the video data, characterized in that the method for testing heat diffusion of a completed vehicle of a new energy vehicle according to claim 1.

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