Method for identifying internal leakage of high-temperature integrated four-way valve of hybrid vehicle

Abstract

The invention discloses an inner leakage identification method for a high-temperature integrated four-way valve of a hybrid vehicle, and the main conception is that whether the four-way valve has an inner leakage fault or not is judged by detecting the temperature of a battery loop and the refrigeration working condition of an air conditioner based on a heat management mode of high-temperature loop integration. The method specifically comprises the steps that after it is determined that a vehicle is in a pure electric working condition and enters a battery cooling state, the working states of a battery water pump, a compressor and an expansion valve before a chiller are detected and recorded, and the running state of an engine is monitored; calculating a difference value between the average temperature of the battery cell in unit time and the temperature of the cooling liquid at the water inlet of the battery in real time; and after it is monitored that the engine starts to be started, whether internal leakage happens to the high-temperature integrated four-way valve or not is comprehensively judged according to the recorded working state and the relation between the difference value and a preset reference value. According to the invention, the internal leakage inspection of the four-way valve can be realized in the normal running process of the vehicle without disassembling the parts of the whole vehicle, and the risk of thermal runaway of the battery is effectively avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of hybrid vehicle thermal management, and particularly to a method for identifying internal leakage of a high-temperature integrated four-way valve in a hybrid vehicle. Background Art

[0002] In a specific type of hybrid vehicle, the adopted thermal management system is a high-temperature loop integration and a three-in-three-out chiller is used for heat interaction with the battery. Among them, the heat source of the high-temperature loop is mainly composed of an engine and a PTC, the passenger compartment heater core and the chiller act as heat exchangers, and the low-temperature cooling loop is composed of a compressor, a condenser, an expansion valve, an evaporator, a chiller, etc. The above different functional units are interconnected by a four-way valve in a high-temperature integrated module (the high-temperature integrated module also includes a high-temperature water kettle and a heater water pump). For example, two inlets of the four-way valve are respectively connected to the passenger compartment heater core and the chiller, and two outlets of the four-way valve are respectively connected to the thermostat of the engine and the PTC connected via the heater water pump.

[0003] Currently, it is impossible to determine whether the four-way valve in the high-temperature integrated module leaks through fault diagnosis. Therefore, it is only possible to disassemble the whole vehicle, remove the four-way valve hardware, and then perform an air injection test to determine whether there is leakage.

[0004] However, the layout of the whole vehicle parts is relatively compact. Due to limited space, the difficulty of hardware disassembly is very high and it takes a long time. At the same time, it may also cause secondary damage to the surrounding parts. Summary of the Invention

[0005] In view of the above, the present invention aims to provide a method for identifying internal leakage of a high-temperature integrated four-way valve in a hybrid vehicle to solve the aforementioned technical problems.

[0006] The technical solution adopted by the present invention is as follows:

[0007] The present invention provides a method for identifying internal leakage of a high-temperature integrated four-way valve in a hybrid vehicle, which includes:

[0008] After determining that the vehicle is in pure electric working condition and entering the battery cooling state, detect and record the working states of the battery water pump, the compressor, and the expansion valve before the chiller, and monitor the running state of the engine;

[0009] Calculate in real time the difference between the average temperature of the battery cells and the coolant temperature at the battery water inlet within a unit time;

[0010] After monitoring the start of the engine, comprehensively determine whether the high-temperature integrated four-way valve has internal leakage according to the recorded working states and the relationship between the difference value and a preset reference value.

[0011] In at least one possible implementation, determining whether there is an internal leak in the integrated high-temperature four-way valve includes:

[0012] If the working state indicates that the battery water pump, the compressor, and the expansion valve before the chiller are all operating normally, and the relationship indicates a relatively low temperature difference, it is determined that there is an internal leak in the four-way valve.

[0013] In at least one possible implementation, the relationship indicating a relatively low temperature difference includes:

[0014] Statistical average value of the difference within a single cycle to obtain the average temperature difference;

[0015] If in multiple consecutive cycles, the average temperature difference in each cycle is less than the reference value, it indicates a relatively low temperature difference.

[0016] In at least one possible implementation, determining that the battery water pump is operating normally includes:

[0017] The deviation between the actual speed feedback by the battery water pump and the requested speed of the battery water pump is within 1%, and the speed fluctuation does not exceed 10%; at the same time, the battery water pump does not at least feedback: battery water pump communication loss, battery water pump overcurrent, and battery water pump overvoltage.

[0018] In at least one possible implementation, determining that the compressor is operating normally includes:

[0019] The deviation between the actual speed feedback by the compressor and the requested speed of the compressor by the vehicle is within 1%, and the speed fluctuation does not exceed 10%; at the same time, the compressor does not at least feedback: compressor body failure, compressor body over-temperature, and exhaust gas temperature over-temperature.

[0020] In at least one possible implementation, determining that the expansion valve before the chiller is operating normally includes:

[0021] The deviation between the actual opening degree feedback by the expansion valve and the requested opening degree of the expansion valve is within 1%, and the opening degree fluctuation does not exceed 20%; at the same time, the expansion valve does not at least feedback: electronic expansion valve communication loss, electronic expansion valve overcurrent, and electronic expansion valve overvoltage.

[0022] Compared with the prior art, the main design concept of the present invention lies in a thermal management mode based on high-temperature loop integration. By detecting the temperature of the battery loop and the operating conditions of the air-conditioning refrigeration system, it is determined whether there is an internal leakage fault in the high-temperature integrated four-way valve. Specifically, after determining that the vehicle is in the pure electric working condition and enters the battery cooling state, the working states of the battery water pump, the compressor, and the expansion valve before the chiller are detected and recorded, and the operating state of the engine is monitored. The difference between the average temperature of the battery cells per unit time and the coolant temperature at the battery water inlet is calculated in real time. After monitoring the engine starts, based on the relationship between the recorded working states, the difference and the preset reference value, it is comprehensively determined whether the high-temperature integrated four-way valve has an internal leakage. The present invention can realize the internal leakage inspection of the four-way valve during the normal driving of the vehicle without disassembling the vehicle parts, effectively avoiding the risk of battery thermal runaway caused by the internal leakage of the four-way valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] To make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described below in conjunction with the drawings, where:

[0024] Figure 1 It is a schematic diagram of a method for identifying internal leakage of a high-temperature integrated four-way valve in a hybrid vehicle provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as limiting the present invention.

[0026] The present invention proposes an embodiment of a method for identifying internal leakage of a high-temperature integrated four-way valve in a hybrid vehicle. Specifically, as Figure 1 shown, which includes:

[0027] Step S1: After determining that the vehicle is in the pure electric working condition and enters the battery cooling state, detect and record the working states of the battery water pump, the compressor, and the expansion valve before the chiller, and monitor the operating state of the engine;

[0028] In actual operation, the controller of the hybrid vehicle can detect and determine the working states of the battery water pump, the compressor, and the expansion valve before the chiller in the thermal management system after determining that the vehicle is in a pure electric working condition such as charging or driving and enters the battery cooling state, and monitor the working state of the engine in real time.

[0029] Step S2: Calculate in real time the difference between the average temperature of the battery cells per unit time and the coolant temperature at the battery water inlet;

[0030] Step S3. After detecting that the engine starts to start, comprehensively determine whether there is an internal leakage in the high-temperature integrated four-way valve according to the relationship between the recorded working state, the difference value and a preset reference value.

[0031] In some preferred embodiments, the comprehensive determination of whether there is an internal leakage in the high-temperature integrated four-way valve includes:

[0032] If the working state indicates that through signal interaction, it is recognized that the battery water pump, the compressor, and the expansion valve before the chiller are all working normally, and the relationship indicates a lower temperature difference, then it is determined that there is an internal leakage in the four-way valve.

[0033] For this concept, two aspects can also be expanded:

[0034] First aspect, in order to ensure the detection accuracy, the fact that the relationship indicates a lower temperature difference can be further expanded as follows:

[0035] Statistically calculate the average value of the difference values within a single cycle (a cycle can be set to one minute, or can be adjusted according to the actual vehicle situation) to obtain the average temperature difference;

[0036] If in multiple consecutive cycles, the average temperature difference in each cycle is less than the reference value, it indicates a lower temperature difference.

[0037] Through actual verification, if there is a leakage in the four-way valve, then the aforementioned difference value, more precisely, the aforementioned average temperature difference, will drop below the reference value K relatively quickly and remain below the K value. Therefore, the above embodiment can be preferably designed such that if in five consecutive cycles, the average temperature difference statistically calculated in each cycle is less than the K value, it is determined that there is a leakage in the four-way valve at this time.

[0038] Second aspect, regarding the judgment of the normal operation of the electronic expansion valve before the battery water pump, the compressor, and the chiller through signal interaction, it can be elaborated as follows:

[0039] 1. Reference for the determination of the normal working state of the battery water pump:

[0040] (1) The actual rotation speed feedback by the battery water pump and the requested rotation speed of the battery water pump are within a 1% deviation range, and the fluctuation range does not exceed 10%;

[0041] (2) The actual working state feedback by the battery water pump is normal, and the following several faults are not feedback: battery water pump communication loss, battery water pump overcurrent, battery water pump overvoltage and other faults.

[0042] 2. Reference for the determination of the normal working state of the compressor:

[0043] (1)The actual rotational speed feedback from the compressor and the vehicle's requested compressor rotational speed are within a 1% deviation range, and the fluctuation range does not exceed 10%.

[0044] (2)The actual working state feedback from the compressor is normal, without feedback of the following several faults: compressor body fault, compressor body over-temperature, exhaust gas temperature over-temperature, etc.

[0045] III. Reference for determining the normal working state of the expansion valve before the chiller:

[0046] (1)The actual opening degree feedback from the expansion valve and the requested opening degree of the expansion valve are within a 1% deviation range, and the fluctuation range does not exceed 20%.

[0047] (2)The actual working state feedback from the expansion valve is normal, without feedback of the following several faults: electronic expansion valve communication loss, electronic expansion valve over-current, electronic expansion valve over-voltage, etc.

[0048] Finally, what can be supplemented to the foregoing first aspect is that before comprehensively determining whether there is an internal leakage in the high-temperature integrated four-way valve, if the cumulative cycle of the pure electric working condition reaches five (such as five minutes) or more, then increase the calculated average temperature difference of the current cycle, such as refreshing it to 1.2K. The coefficient 1.2 is to exclude the influence of the engine start on the front-end heat dissipation; further, from this concept, if the average temperature difference within a certain week in the previous several cycles (such as three) except the current cycle is less than 0.9K, it is determined that no refresh adjustment is required.

[0049] In summary, the main design concept of the present invention lies in, based on the thermal management mode integrated with the high-temperature circuit, detecting the battery circuit temperature and the working conditions of the air-conditioning refrigeration system to determine whether there is an internal leakage fault in the high-temperature integrated four-way valve. Specifically, after determining that the vehicle is in the pure electric working condition and enters the battery cooling state, detect and record the working states of the battery water pump, the compressor, and the expansion valve before the chiller, and monitor the operating state of the engine; calculate in real time the difference between the average temperature of the battery cells per unit time and the coolant temperature at the battery water inlet; after monitoring the engine start, comprehensively determine whether there is an internal leakage in the high-temperature integrated four-way valve according to the relationship between the recorded working states, the difference value and the preset reference value. The present invention can realize the internal leakage inspection of the four-way valve without disassembling the vehicle parts, effectively avoiding the risk of battery thermal runaway caused by the internal leakage of the four-way valve.

[0050] In the embodiments of the present invention, if there are any expressions referring to directions, they are relative concepts based on the embodiments. In addition, "at least one" means one or more, and "a plurality of" means two or more. "And / or" describes the relationship between related objects and indicates that there can be three relationships. For example, A and / or B can represent the cases of A existing alone, A and B existing simultaneously, and B existing alone. Here, A and B can be singular or plural. The character " / " generally represents an "or" relationship between the related objects before and after. "At least one of the following" and its similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, and c can represent: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, and c can be single or multiple.

[0051] The structure, features, and effects of the present invention have been described in detail based on the embodiments shown in the drawings above. However, the above are only the preferred embodiments of the present invention. It should be noted that for the technical features involved in the above embodiments and their preferred modes, those skilled in the art can, without departing from or changing the design concept and technical effects of the present invention, reasonably combine and match them into multiple equivalent solutions. Therefore, the scope of the present invention is not limited by the drawings shown. Any changes made in accordance with the concept of the present invention or modified into equivalent embodiments with equivalent changes still fall within the spirit covered by the specification and the drawings, and should be within the protection scope of the present invention.

Claims

1. A method for identifying internal leakage of a high-temperature integrated four-way valve in a hybrid vehicle, characterized in that Including: After determining that the vehicle is in the pure electric working condition and entering the battery cooling state, detect and record the working states of the battery water pump, the compressor, and the expansion valve before the chiller, and monitor the operating state of the engine; Calculate in real time the difference between the average temperature of the battery cells per unit time and the coolant temperature at the battery water inlet; After monitoring the start of the engine, comprehensively determine whether there is an internal leakage in the high-temperature integrated four-way valve according to the recorded working states and the relationship between the difference value and a preset reference value.

2. The method for identifying internal leakage of the high-temperature integrated four-way valve of a hybrid vehicle according to claim 1, wherein The comprehensive determination of whether there is an internal leakage in the high-temperature integrated four-way valve includes: If the working states indicate that the battery water pump, the compressor, and the expansion valve before the chiller are all working normally, and the relationship indicates a low temperature difference, it is determined that there is an internal leakage in the four-way valve.

3. The method for identifying internal leakage of the high-temperature integrated four-way valve of a hybrid vehicle according to claim 2, wherein The relationship indicating a low temperature difference includes: Statistically calculate the average value of the difference values within a single cycle to obtain the average temperature difference; If in multiple consecutive cycles, the average temperature difference in each cycle is less than the reference value, it indicates a low temperature difference.

4. The method for identifying internal leakage of the high-temperature integrated four-way valve of a hybrid vehicle according to claim 2, wherein Determining that the battery water pump is working normally includes: The deviation between the actual speed feedback by the battery water pump and the requested speed of the battery water pump is within 1%, and the speed fluctuation does not exceed 10%; at the same time, the battery water pump does not at least feedback: battery water pump communication loss, battery water pump overcurrent, and battery water pump overvoltage.

5. The method for identifying internal leakage of the high-temperature integrated four-way valve of a hybrid vehicle according to claim 2, wherein Determining that the compressor is working normally includes: The deviation between the actual speed feedback by the compressor and the requested speed of the compressor by the whole vehicle is within 1%, and the speed fluctuation does not exceed 10%; at the same time, the compressor does not at least feedback: compressor body failure, compressor body over-temperature, and exhaust gas temperature over-temperature.

6. The method for identifying internal leakage of the high-temperature integrated four-way valve of a hybrid vehicle according to claim 2, wherein Determining that the expansion valve before the Chiller is working normally includes: The deviation between the actual opening degree feedback by the expansion valve and the requested opening degree of the expansion valve is within 1%, and the opening degree fluctuation does not exceed 20%; at the same time, the expansion valve does not at least feedback: electronic expansion valve communication loss, electronic expansion valve overcurrent, and electronic expansion valve overvoltage.

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