A range extended hybrid bus thermal management system, a control method thereof, a low-temperature environment waterway selection method, and a redundancy control method

Abstract

The application provides a range-extending hybrid bus thermal management system and a control method thereof, a low-temperature environment waterway selection method and a redundancy control method. The system comprises a cooling system, a PTC heating module, a battery liquid cooling plate, a water pump, a first three-way valve, a heat-insulating expansion water tank, a heat-insulating waterway, a second three-way valve, a non-heat-insulating expansion water tank, a semiconductor heat dissipation system and a non-heat-insulating waterway. The technical solution can realize low-energy-consumption thermal management control. Meanwhile, the redundancy control of the thermal management system can be realized, and the thermal management can still be realized when some parts fail, so that the vehicle cannot run.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heat management of extended-range hybrid buses, in particular to a heat management system of an extended-range hybrid bus, a control method thereof, a low-temperature environment water path selection method and a redundancy control method. BACKGROUND

[0002] With the continuous development of new energy technology, the application scenarios of power batteries are increasingly demanding due to the demand for vehicle service life and mileage of extended-range hybrid buses. Due to the particularity of the structure, the battery of the extended-range hybrid bus participates more in the charging and discharging process of the whole vehicle than other hybrid buses, and the performance requirement of the battery is also higher. In the case of configuring a small power battery, the extended-range hybrid bus needs to continuously charge and discharge the power battery at a high rate, which leads to a high temperature rise of the power battery, and therefore the heat management requirement of the power battery is higher. In order to ensure the normal use of the vehicle in various environments, the heat management mode of the power battery has gradually upgraded from the initial natural cooling to the liquid cooling and liquid heating mode. The principle diagram of the existing heat management system of the extended-range hybrid bus is shown in FIG. 1. The existing heat management system is composed of a cooling system, a PTC heating module, a water pump, an expansion tank, temperature detection, a battery water cooling plate and a water cooling pipe. The heat pipe system integrates liquid cooling and liquid heating into the same water path. When refrigeration is needed, the cooling system works and the PTC heating module does not work; when heating is needed, the PTC heating module works and the cooling system does not work. Although this heat management mode solves the problem of the use environment of the power battery and guarantees the use and safety of the battery, it will cause the waste of part of the energy in the whole refrigeration and heating process, and increase the energy consumption of the whole vehicle. Figure 1

[0003] The existing buses, such as public buses, highway passenger buses and the like, have fixed operation routes and operation times, and their typical operation mode is as follows: starting operation in the morning, continuing operation in the afternoon after a period of rest and power charging at noon, and charging the vehicle after work in the evening, and then parking the vehicle until the next morning.

[0004] ​Since the optimal working temperature range of the power battery applied in the existing passenger car is 20-30℃ (reference value), the battery manufacturer generally requires that the power battery needs to be heated when the temperature is lower than about 15℃ (reference value) and needs to be cooled when the temperature is higher than about 35℃ (reference value), and the temperature in the middle interval is only about 20℃. For most regions in China including the central and northern regions, the average temperature in winter is lower than 10℃. At the same time, the public bus and the large vehicle such as the operating highway passenger car are basically parked outdoors, which leads to that the power battery temperature is low when the vehicle starts in the morning, and the thermal management system needs to heat the power battery. When the vehicle runs to noon, the battery temperature reaches the cooling threshold to start cooling. The thermal management system heats first and then cools down in a day, which increases the energy consumption, especially for the extended-range hybrid passenger car, compared with the pure electric passenger car, the battery power is smaller, the charge-discharge rate is higher, and the temperature rise is more obvious.

[0005] As shown in the accompanying drawings Figure 2 The power battery temperature data curve of a certain line extended-range hybrid public bus in a day is shown in the accompanying drawings. When the vehicle starts in the morning, the power battery temperature is about 11℃. At this time, since the battery temperature is low, the thermal management system starts PTC heating to heat the battery, and the battery temperature rises to about 20℃. When the vehicle stops for rest at noon, the maximum temperature of the power battery is about 25℃. At this time, the driver rests to save the fuel consumption of the range extender to charge the power battery of the vehicle. After the charging is completed, the maximum temperature of the power battery rises to 37℃, and the thermal management system starts to cool the battery. Until about 23 o'clock in the evening, the thermal management system is working and cooling. As described above, the thermal management system heats first and then cools down in a day, which has high energy consumption. At the same time, in the water circuit, the water starts to heat when heating starts, and then the water needs to be cooled when the temperature of the water rises due to high temperature rise during charging at noon, which consumes part of the energy, thereby increasing the energy consumption again. SUMMARY

[0006] Therefore, the purpose of the present application is to provide an extended-range hybrid passenger car thermal management system and a control method thereof, a low-temperature environment water circuit selection method and a redundant control method, to realize low-energy thermal management control. At the same time, the redundant control of the thermal management system can be realized, and the thermal management can still be realized when some parts fail, so that the vehicle cannot run.

[0007] To achieve the above purpose, the present application adopts the following technical scheme: an extended-range hybrid passenger car thermal management system, comprising a cooling system, a PTC heating module, a battery liquid cooling plate, a water pump, a first three-way valve, a heat preservation expansion tank, a heat preservation water circuit, a second three-way valve, a non-heat preservation expansion tank, a semiconductor heat dissipation system and a non-heat preservation water circuit.

[0008] The inlet of the water pump is connected with the water outlet of the battery liquid cooling plate, the outlet of the water pump is connected with the first three-way valve, and the first three-way valve is further connected with a heat preservation water path and a non-heat preservation water path;

[0009] The heat preservation water path is provided with a heat preservation expansion water tank, and the non-heat preservation water path is provided with a non-heat preservation expansion water tank and a semiconductor heat dissipation system.

[0010] The three ports of the second three-way valve are respectively connected with the end of the heat preservation water path, the end of the non-heat preservation water path and a cooling system.

[0011] The cooling system is further connected with the PTC heating module, and the PTC heating module is further connected with the water inlet of the battery liquid cooling plate.

[0012] The cooling system and the PTC heating module are not operated at the same time.

[0013] In a preferred embodiment, an outlet temperature detection module and an inlet temperature detection module are further included, the outlet temperature detection module is connected between the water pump and the battery liquid cooling plate, and the inlet temperature detection module is connected between the PTC heating module and the battery liquid cooling plate.

[0014] In a preferred embodiment, a first one-way valve and a second one-way valve are further included, the first one-way valve is arranged between the heat preservation water path and the second three-way valve, and the second one-way valve is arranged between the non-heat preservation water path and the second three-way valve.

[0015] In a preferred embodiment, the semiconductor heat dissipation system mainly comprises a heat exchanger, a semiconductor refrigerator and a heat dissipation structure.

[0016] In a preferred embodiment, the path of the heat preservation water path is that water flow driven by the water pump is divided into the heat preservation water path through the first three-way valve, sequentially passes through the cooling system and the PTC heating module after flowing through the second three-way valve, enters the battery liquid cooling plate and flows back to the water pump again.

[0017] In a preferred embodiment, the path of the non-heat preservation water path is that water flow driven by the water pump is divided into the non-heat preservation water path through the first three-way valve, passes through the heat exchanger of the semiconductor heat dissipation system, sequentially passes through the cooling system and the PTC heating module after flowing through the second three-way valve, enters the battery liquid cooling plate and flows back to the water pump again.

[0018] The application also provides a control method of the range-extended hybrid power bus heat management system.

[0019] Step A1: in the morning, the vehicle is powered on for self-checking, the vehicle starts operation, and the temperature of the power battery is read.

[0020] Step A2: determine whether the temperature of the power battery is less than T1, if less than T1, determine that the temperature of the power battery is low, enter the heating process, start the water pump and the PTC heating module, control the first three-way valve and the second three-way valve to select the water path through the heat preservation water path, the power battery starts to heat, at this time the cooling system does not work, the water path does not flow through the non-heat preservation water path, and the semiconductor heat dissipation system also does not work; if the temperature of the power battery is greater than or equal to T1, determine that the temperature of the power battery is not low, enter the heat dissipation process;

[0021] Step A3: the temperature of the power battery is greater than T2, the heating is completed, the thermal management system stops working, and the vehicle continues to operate;

[0022] Step A4: when the vehicle is not working, the vehicle is powered, at this time, due to the demand for departure in the afternoon and the short power supply time, the vehicle uses high-power power supply, the battery temperature rises quickly, and the heat dissipation process is entered;

[0023] Step A5:

[0024] If the temperature of the power battery is greater than T3, it is determined that the temperature of the power battery is in the first high temperature level, the water path self-circulation heat dissipation process is entered, the water pump is started, the first three-way valve and the second three-way valve are controlled, and the water path is selected to flow through the non-heat preservation water path, at this time, the cooling system, the PTC heating module and the semiconductor heat dissipation system do not work, only the water pump is started, and the power battery is subjected to water path self-circulation heat dissipation;

[0025] If the temperature of the power battery is greater than T4, it is determined that the temperature of the power battery is in the second high temperature level, the semiconductor heat dissipation process is entered, the water pump is started, the first three-way valve and the second three-way valve are controlled, the water path is selected to flow through the non-heat preservation water path, and the semiconductor heat dissipation system is started, at this time, the cooling system and the PTC heating module do not work, the water pump and the semiconductor heat dissipation system are started, and the power battery is subjected to water path semiconductor heat dissipation system heat dissipation;

[0026] If the temperature of the power battery is greater than T5, it is determined that the temperature of the power battery is in the third high temperature level, at this time, it is determined whether the external environment temperature is greater than T6, if the environment temperature is not greater than T6, it is determined that it is a low temperature environment, at this time, the semiconductor heat dissipation effect is obvious, the semiconductor heat dissipation process is entered, the water pump is started, the first three-way valve and the second three-way valve are controlled, the water path is selected to flow through the non-heat preservation water path, and the semiconductor heat dissipation system is started, at this time, the cooling system and the PTC heating module do not work, the water pump and the semiconductor heat dissipation system are started, and the power battery is subjected to water path semiconductor heat dissipation system heat dissipation; if the environment temperature is greater than T6, it is determined that it is a non-low temperature environment, at this time, the semiconductor heat dissipation is of little use, the water cooling heat dissipation process is entered, the water pump is started, the first three-way valve and the second three-way valve are controlled, the water path is selected to flow through the heat preservation water path, and the cooling system is started, at this time, the PTC heating module and the semiconductor heat dissipation system do not work, the water pump and the cooling system work, and the power battery is subjected to water cooling heat dissipation;

[0027] If the temperature of the power battery is greater than T7, it is judged that the temperature of the power battery is in the fourth high-temperature level, at this time it is judged that the heat dissipation effect of the semiconductor heat dissipation system is limited, the external environment is no longer judged, and the water cooling heat dissipation process is directly entered, the water pump is started, the first three-way valve and the second three-way valve are controlled, the water path flowing through the heat preservation water path is selected, and the cooling system is started, at this time the PTC heating module and the semiconductor heat dissipation system do not work, the water pump and the cooling system work, and the power battery is water-cooled and heat-dissipated;

[0028] Step A6: the temperature of the power battery is less than T8, the heat dissipation is completed, the thermal management system stops working, the vehicle continues to operate, and the process ends.

[0029] In a preferred embodiment, T1 < T2 < T3 < T4 < T5 < T7, and T2 < T6 < T8 < T3.

[0030] The application also provides a low-temperature environment water path selection method for a range-extended hybrid bus thermal management system, which adopts the range-extended hybrid bus thermal management system and comprises the following steps:

[0031] Step B1: in the morning, the vehicle is powered on for self-checking, the vehicle starts to operate, and the temperature of the power battery is read.

[0032] Step B2: it is judged that the temperature of the power battery is low, a heating process is entered, the heating water path flows through the heat preservation water path, and the heat preservation expansion tank water is heated.

[0033] Step B3: after heating is completed, the hot water is stored in the heat preservation expansion tank to slow down heat loss.

[0034] Step B4: the vehicle is recharged, the battery temperature is relatively high, a heat dissipation process is entered, the cooling water path flows through the non-heat preservation water path, the cold water in the non-heat preservation expansion tank is used, and the loss of the existing heat management scheme to refrigerate the hot water heated before is reduced.

[0035] Step B5: in the morning of the next day, the vehicle is started again, a heating process is entered, the heating water path flows through the heat preservation water path again, and the hot water of the heat preservation expansion tank is used for heating the battery again, since the hot water stored in the heat preservation expansion tank the day before has heat loss, but is still higher than the ambient temperature, the energy consumption can be reduced by heating again, and the vehicle energy consumption is reduced in this way every day.

[0036] The application also provides a redundancy control method for a range-extended hybrid bus thermal management system, which adopts the range-extended hybrid bus thermal management system and comprises the following steps:

[0037] Step C1: the vehicle is powered on for self-checking, the temperature of the power battery is read, and the vehicle starts to operate or is charged.

[0038] Step C2: when the power battery temperature is high, the water cooling system is entered, the cooling system fault information is read, whether the cooling system has a fault is judged, if the fault is reported, the semiconductor cooling system is entered, if there is no fault information, the water pump is started, the first three-way valve and the second three-way valve are controlled, the water path is selected to pass through the heat preservation water path, the cooling system is started, and the power battery starts water cooling.

[0039] Step C3: after working for Time1 in the water cooling system, the inlet and outlet temperature detection module data are read, the cooling system working condition is judged according to the inlet and outlet temperature, if the cooling system works normally, the water cooling is continued, if the cooling system is judged to be out of order, the water pump is started, the first three-way valve and the second three-way valve are controlled, the water path is selected to pass through the non-heat preservation water path, the semiconductor cooling system is started, and the power battery is cooled by the semiconductor cooling system.

[0040] Step C4: when the power battery temperature decreases, the cooling is completed, the thermal management system stops working, and the process is ended.

[0041] Compared with the prior art, the present application has the following beneficial effects:

[0042] 1. A range-extending hybrid power bus power battery thermal management system architecture, the thermal management system is composed of two sets of water paths, one set is composed of a heat preservation expansion tank, a heat preservation water path and the like, and the other set is composed of a non-heat preservation expansion tank, a semiconductor cooling system and a non-heat preservation water path and the like. Compared with the existing thermal management system scheme, the present application scheme can realize the combination of multiple thermal management modes, and reduce the energy consumption of the vehicle.

[0043] 2. The semiconductor cooling system is used to provide higher cooling efficiency than the air cooling system, the semiconductor cooling system is powered by the low-voltage 24V battery of the vehicle, and the heat-conducting glue is used between the semiconductor cooler and the heat exchanger to realize the adhesion. The system uses a small power product, and realizes small power and faster cooling through the thermoelectric effect.

[0044] 3. The control strategy flow of the thermal management system, when the power battery temperature is low and needs to be heated, the PTC heating is used to pass through the heat preservation water path, when the temperature is high and needs to be cooled, the power battery temperature and the external environment temperature are combined to judge the situation, the self-circulation cooling mode, the semiconductor cooling mode and the water cooling mode are used respectively, through the combination of multiple thermal management modes, different water paths or parts are selected to work, and the low-energy consumption thermal management control is realized.

[0045] 4. The water path selection control strategy in low temperature environment, the water in the water path is heated and stored in the heat preservation expansion water tank in the morning, when the battery temperature is high and refrigeration is needed at noon, cold water in the non-heat preservation expansion water tank is used to reduce refrigeration consumption, and the water in the heat preservation expansion water tank is used for heating again in the morning of the next day, so that the daily cycle is reduced, and the energy consumption of the vehicle is reduced.

[0046] 5. The redundancy control strategy of the thermal management system, when some parts such as the water cooling unit are faulty, other thermal management methods can be used to replace, the redundancy control of the thermal management strategy is realized, the problem that the whole thermal management system cannot work due to the damage of some parts and the vehicle cannot run is prevented. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 It is the schematic diagram of the existing thermal management system architecture;

[0048] Figure 2 It is the temperature change curve diagram of the power battery of a certain bus on a certain day;

[0049] Figure 3 It is the schematic diagram of the thermal management system architecture of the preferred embodiment of the application;

[0050] Figure 4 It is the semiconductor heat dissipation system structure diagram of the preferred embodiment of the application;

[0051] Figure 5 It is the thermal management system control strategy flow chart of the preferred embodiment of the application;

[0052] Figure 6 It is the water path selection strategy flow chart of the preferred embodiment of the application in low temperature environment;

[0053] Figure 7 It is the redundancy control strategy flow chart of the thermal management system of the preferred embodiment of the application. DETAILED DESCRIPTION

[0054] The application will be further described below in combination with the drawings and embodiments.

[0055] It should be pointed out that the following detailed description is exemplary and is intended to provide further description of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as generally understood by those skilled in the art to which the present application belongs.

[0056] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting; as used herein, the singular form "a", "an" and "the" is intended to include the plural forms as well, unless the context clearly indicates otherwise; moreover, it is understood that, when terms such as "comprising", "including", "containing" and / or "having" are used in this specification, they are meant to encompass the items listed thereafter, as well as any equivalents thereof.

[0057] A range-extended hybrid bus thermal management system, referring to Figures 3-7 , comprising a cooling system, a PTC heating module, a battery liquid cooling plate, a water pump, a first three-way valve, a thermal insulation expansion tank, a thermal insulation water path, a second three-way valve, a non-thermal insulation expansion tank, a semiconductor heat dissipation system and a non-thermal insulation water path.

[0058] The inlet of the water pump is connected to the outlet of the battery liquid cooling plate, and the outlet of the water pump is connected to the first three-way valve, which is further connected to the thermal insulation water path and the non-thermal insulation water path.

[0059] The thermal insulation expansion tank is arranged on the thermal insulation water path, and the non-thermal insulation expansion tank and the semiconductor heat dissipation system are arranged on the non-thermal insulation water path.

[0060] The three ports of the second three-way valve are respectively connected to the end of the thermal insulation water path, the end of the non-thermal insulation water path and the cooling system.

[0061] The cooling system is further connected to the PTC heating module, and the PTC heating module is further connected to the water inlet of the battery liquid cooling plate.

[0062] The cooling system and the PTC heating module do not work at the same time.

[0063] The thermal management system further comprises an outlet temperature detection module and an inlet temperature detection module; the outlet temperature detection module is connected between the water pump and the battery liquid cooling plate, and the inlet temperature detection module is connected between the PTC heating module and the battery liquid cooling plate. Further comprising a first one-way valve and a second one-way valve, the first one-way valve is arranged between the thermal insulation water path and the second three-way valve, and the second one-way valve is arranged between the non-thermal insulation water path and the second three-way valve.

[0064] Specifically, the first and second three-way valves are electronic three-way valves, which can control the selection of the heat preservation water path or the non-heat preservation water path through a hard-wire; the heat preservation effect of the heat preservation expansion water tank is realized by adopting a vacuum insulation layer and heat preservation cotton wrapping the heat preservation water path; the non-heat preservation expansion water tank and the non-heat preservation water path are made of conventional materials and have no heat preservation effect; the semiconductor heat dissipation system mainly comprises a heat exchanger, a semiconductor refrigerator, a heat dissipation structure and a heat dissipation fan, the heat exchanger is tightly attached to the semiconductor refrigerator, the heat of the water flowing through the heat exchanger is taken away by the semiconductor refrigerator, is converted to the heat dissipation structure, and then is taken away by the heat dissipation fan, so that a stronger effect than that of the ordinary air cooling heat dissipation is realized; the inlet water temperature detection and outlet water temperature detection modules mainly detect the water temperature, and judge the refrigeration / heating effect of the thermal management system; the water pump mainly realizes the circulation of the water path, and the one-way valve controls the water flow direction to prevent backflow. Figure 3

[0065] The semiconductor heat dissipation system mainly comprises a heat exchanger, a semiconductor refrigerator and a heat dissipation structure, and the heat dissipation structure is a fan, and the semiconductor refrigerator is the core. The semiconductor refrigerator is also called a thermoelectric refrigerator, which uses the thermoelectric effect of a semiconductor to refrigerate. It mainly uses a conductor to connect two different N-type semiconductors and P-type semiconductors, and when a direct current is connected, the temperature at one junction is reduced and the temperature at the other junction is increased. The semiconductor heat dissipation system adopted in the application is powered by a whole vehicle low-voltage 24V storage battery, the cold end is tightly attached to the heat exchanger, the hot end is tightly attached to the heat dissipation structure, and then the fan takes away the heat. The semiconductor heat dissipation system has a small power, but can realize a stronger refrigeration capacity than that of the air cooling heat dissipation system. The structure and physical diagram are shown in Figure 4

[0066] The whole water path circulation is divided into two paths, one is a heat preservation water path, and the other is a non-heat preservation water path. The water flow driven by the water pump is divided into the heat preservation water path through the first three-way valve, flows through the second three-way valve, then passes through the cooling system and the PTC heating module, enters the battery liquid cooling plate, and then flows back to the water pump again. The water flow driven by the water pump is divided into the non-heat preservation water path through the first three-way valve, flows through the heat exchanger of the semiconductor heat dissipation system, then passes through the second three-way valve, then passes through the cooling system and the PTC heating module, enters the battery liquid cooling plate, and then flows back to the water pump again.

[0067] 1. Thermal management system control strategy (flow chart see Figure 5 )

[0068] Step one: in the morning, the vehicle is powered on for self-checking, the vehicle starts to operate, and the power battery temperature is read.

[0069] ​​Step two: judge whether the temperature of the power battery is less than T1, if less than T1, judge that the temperature of the power battery is low, enter the heating process, start the water pump and the PTC heating module, control the first three-way valve and the second three-way valve to select the water path through the heat preservation water path, the power battery starts to heat, at this time the cooling system does not work, the water path does not flow through the non-heat preservation water path, and the semiconductor heat dissipation system also does not work; if the temperature of the power battery is greater than or equal to T1, judge that the temperature of the power battery is not low, enter the heat dissipation process.

[0070] Step three: the temperature of the power battery is greater than T2, the heating is completed, the thermal management system stops working, and the vehicle continues to operate.

[0071] Step four: the driver starts to rest at noon, and the vehicle is powered, at this time, due to the demand for departure in the afternoon and the short power supply time, the driver uses high-power power supply, the battery temperature rises quickly, and enters the heat dissipation process.

[0072] Step five:

[0073] If the temperature of the power battery is greater than T3, it is judged that the temperature of the power battery is high, the water path self-circulation heat dissipation process is entered, the water pump is started, the first three-way valve and the second three-way valve are controlled, and the water path is selected to flow through the non-heat preservation water path, at this time, the cooling system, the PTC heating module and the semiconductor heat dissipation system do not work, only the water pump is started, and the power battery is water path self-circulation heat dissipation;

[0074] If the temperature of the power battery is greater than T4, it is judged that the temperature of the power battery is high, the semiconductor heat dissipation process is entered, the water pump is started, the first three-way valve and the second three-way valve are controlled, the water path is selected to flow through the non-heat preservation water path, and the semiconductor heat dissipation system is started, at this time, the cooling system and the PTC heating module do not work, the water pump and the semiconductor heat dissipation system are started, and the power battery is water path semiconductor heat dissipation system heat dissipation;

[0075] If the temperature of the power battery is greater than T5, it is judged that the temperature of the power battery is high, at this time, it is judged whether the external environment temperature is greater than T6, if the environment temperature is not greater than T6, it is judged that it is a low temperature environment, at this time, the semiconductor heat dissipation effect is obvious, the semiconductor heat dissipation process is entered, the water pump is started, the first three-way valve and the second three-way valve are controlled, the water path is selected to flow through the non-heat preservation water path, and the semiconductor heat dissipation system is started, at this time, the cooling system and the PTC heating module do not work, the water pump and the semiconductor heat dissipation system are started, and the power battery is water path semiconductor heat dissipation system heat dissipation; if the environment temperature is greater than T6, it is judged that it is not a low temperature environment, at this time, the semiconductor heat dissipation is less useful, the water cooling heat dissipation process is entered, the water pump is started, the first three-way valve and the second three-way valve are controlled, the water path is selected to flow through the heat preservation water path, and the cooling system is started, at this time, the PTC heating module and the semiconductor heat dissipation system do not work, the water pump and the cooling system work, and the power battery is water cooling heat dissipation;

[0076] If the temperature of the power battery is greater than T7, it is determined that the temperature of the power battery is too high, at this time it is determined that the heat dissipation effect of the semiconductor heat dissipation system is limited, the external environment is no longer judged, and the water cooling heat dissipation process is directly entered, the water pump is started, the first three-way valve and the second three-way valve are controlled, the water path flowing through the heat preservation water path is selected, the cooling system is started, at this time the PTC heating module and the semiconductor heat dissipation system do not work, the water pump and the cooling system work, and the power battery is water-cooled and heat-dissipated.

[0077] Step six: the temperature of the power battery is less than T8, the heat dissipation is completed, the thermal management system stops working, the vehicle continues to operate, and the process ends.

[0078] In the above process, the example reference values of T1-T8 are respectively: T1=10℃, T2=20℃, T3=35℃, T4=40℃, T5=45℃, T6=25℃, T7=50℃, and T8=30℃.

[0079] 2. Water path selection strategy in low temperature environment (flow chart see Figure 6 )

[0080] Step one: the vehicle starts in the morning, the whole vehicle is powered on for self-checking, the vehicle starts to operate, and the temperature of the power battery is read.

[0081] Step two: it is determined that the temperature of the power battery is low, the heating process is entered, the heating water path flows through the heat preservation water path, and the heat preservation expansion tank water is heated.

[0082] Step three: the heating is completed, the hot water is stored in the heat preservation expansion tank, and the heat loss is slowed down.

[0083] Step four: the vehicle is recharged, the battery temperature is high, the heat dissipation process is entered, the cooling water path flows through the non-heat preservation water path, and the cold water in the non-heat preservation expansion tank is used to reduce the loss of the existing heat management scheme to recool the hot water that has been heated before.

[0084] Step five: the vehicle starts again in the morning of the next day, enters the heating process, the heating water path flows through the heat preservation water path again, and the hot water in the heat preservation expansion tank is used to heat the battery again. Since the hot water stored in the heat preservation expansion tank the day before has heat loss, it is still higher than the ambient temperature, and the re-heating can reduce energy consumption. In this way, the energy consumption of the vehicle is reduced every day.

[0085] 3. Redundant control strategy of the thermal management system (flow chart see Figure 7 )

[0086] Step one: the whole vehicle is powered on for self-checking, the temperature of the power battery is read, and the vehicle starts to operate / charge.

[0087] Step two: the temperature of the power battery is high, enters the water cooling process, reads the cooling system fault information, judges whether the cooling system has reported a fault, if there is a fault, enters the semiconductor cooling process; if there is no fault information, opens the water pump, controls the first and second three-way valves, selects the water path through the heat preservation water path, opens the cooling system, and the power battery starts water cooling.

[0088] Step three: after working for Time1 in the water cooling process, read the inlet and outlet water temperature detection module data, judge the cooling system working condition according to the inlet and outlet water temperature, if the cooling system works normally, continue to cool by water; if it is judged that the cooling system fails, open the water pump, control the first and second three-way valves, select the water path through the non-heat preservation water path, open the semiconductor cooling system, and the power battery is cooled by the semiconductor cooling system.

[0089] Step four: the temperature of the power battery decreases, the heat management system stops working, and the process ends.

[0090] The example reference value of Time1 is 5 minutes.

Claims

1. A thermal management system for a range-extended hybrid electric bus, characterized in that, It includes a cooling system, a PTC heating module, a battery liquid cooling plate, a water pump, a first three-way valve, an insulated expansion tank, an insulated water circuit, a second three-way valve, a non-insulated expansion tank, a semiconductor heat dissipation system, and a non-insulated water circuit; The inlet of the water pump is connected to the outlet of the battery liquid cooling plate, and the outlet of the water pump is connected to the first three-way valve. The first three-way valve is also connected to an insulated water circuit and a non-insulated water circuit. An insulated expansion tank is provided on the insulated water line, and a non-insulated expansion tank and a semiconductor heat dissipation system are provided on the non-insulated water line. The three ports of the second three-way valve are respectively connected to the end of the insulated water circuit, the end of the non-insulated water circuit, and the cooling system; The cooling system is also connected to the PTC heating module, and the PTC heating module is also connected to the water inlet of the battery liquid cooling plate; The cooling system and the PTC heating module do not operate simultaneously.

2. The thermal management system for a range-extended hybrid electric bus according to claim 1, characterized in that, It also includes an outlet temperature detection module and an inlet temperature detection module; the outlet temperature detection module is connected between the water pump and the battery liquid cooling plate, and the inlet temperature detection module is connected between the PTC heating module and the battery liquid cooling plate.

3. The thermal management system for a range-extended hybrid electric bus according to claim 1, characterized in that, It also includes a first check valve and a second check valve. The first check valve is located between the insulated water circuit and the second three-way valve, and the second check valve is located between the non-insulated water circuit and the second three-way valve.

4. The thermal management system for a range-extended hybrid electric bus according to claim 1, characterized in that, Semiconductor heat dissipation systems mainly consist of heat exchangers, semiconductor coolers, and heat dissipation structures.

5. The thermal management system for a range-extended hybrid electric bus according to claim 1, characterized in that, The heat preservation water path is as follows: the water pump drives the water flow through the first three-way valve to the heat preservation water path, and after flowing through the second three-way valve, it passes through the cooling system and the PTC heating module in sequence, and then enters the battery liquid cooling plate and flows back to the water pump.

6. The thermal management system for a range-extended hybrid electric bus according to claim 1, characterized in that, The non-insulated water path is as follows: the water pump drives the water flow through the first three-way valve to the non-insulated water path, flows through the heat exchanger of the semiconductor heat dissipation system, then through the second three-way valve and successively through the cooling system and the PTC heating module, enters the battery liquid cooling plate and then flows back to the water pump.

7. A control method for a thermal management system of a range-extended hybrid electric bus, characterized in that, The thermal management system for a range-extended hybrid electric bus, as described in any one of claims 1-6, comprises the following steps: Step A1: Depart in the morning, the vehicle performs a power-on self-test, the vehicle begins operation, and the power battery temperature is read; Step A2: Determine if the power battery temperature is less than T1. If it is less than T1, the power battery temperature is considered low, and the heating process begins. The water pump and PTC heating module are turned on, and the first three-way valve and the second three-way valve are controlled to select the water path to flow through the heat preservation water path. The power battery begins to heat up. At this time, the cooling system does not work, the water path does not flow through the non-heat preservation water path, and the semiconductor heat dissipation system does not work. If the power battery temperature is greater than or equal to T1, the power battery temperature is considered not low, and the heat dissipation process begins. Step A3: When the power battery temperature exceeds T2, heating is complete, the thermal management system stops working, and the vehicle continues to operate; Step A4: When the vehicle is not working, recharge the vehicle. At this time, due to the need to depart in the afternoon and the short recharging time, the vehicle uses high-power recharging, and the battery temperature rises quickly, so the heat dissipation process is initiated. Step A5: If the power battery temperature is greater than T3, it is determined that the power battery temperature is at the first high temperature level, and the water circuit self-circulation heat dissipation process is entered. The water pump is turned on, and the first three-way valve and the second three-way valve are controlled to select the water circuit to flow through the non-insulated water circuit. At this time, the cooling system, PTC heating module and semiconductor heat dissipation system are not working, only the water pump is turned on, and the power battery performs water circuit self-circulation heat dissipation. If the power battery temperature is greater than T4, it is determined that the power battery temperature is at the second high temperature level, and the semiconductor heat dissipation process is entered. The water pump is turned on, the first three-way valve and the second three-way valve are controlled, the water flows through the non-insulated water path, and the semiconductor heat dissipation system is turned on. At this time, the cooling system and PTC heating module are not working, the water pump and the semiconductor heat dissipation system are turned on, and the power battery is cooled by the water-semiconductor heat dissipation system. If the power battery temperature is greater than T5, it is determined that the power battery temperature is at the third high temperature level. At this time, it is determined whether the ambient temperature is greater than T6. If the ambient temperature is not greater than T6, it is determined to be a low temperature environment. At this time, the semiconductor heat dissipation effect is obvious, and the semiconductor heat dissipation process is entered. The water pump is turned on, the first three-way valve and the second three-way valve are controlled, and the water flows through the non-insulated water path. The semiconductor heat dissipation system is turned on. At this time, the cooling system and PTC heating module are not working. The water pump and the semiconductor heat dissipation system are turned on, and the power battery is cooled by the water-circuit semiconductor heat dissipation system. If the ambient temperature is greater than T6, it is determined to be a non-low temperature environment. At this time, the semiconductor heat dissipation effect is small, and the water cooling process is entered. The water pump is turned on, the first three-way valve and the second three-way valve are controlled, and the water flows through the insulated water path. The cooling system is turned on. At this time, the PTC heating module and the semiconductor heat dissipation system are not working. The water pump and the cooling system are working, and the power battery is cooled by water cooling. If the power battery temperature is greater than T7, it is determined that the power battery temperature is at the fourth high temperature level. At this time, it is determined that the heat dissipation effect of the semiconductor heat dissipation system is limited. Without further consideration of the external environment, the water cooling process is directly entered. The water pump is turned on, the first three-way valve and the second three-way valve are controlled, the water flows through the heat preservation water circuit, and the cooling system is turned on. At this time, the PTC heating module and the semiconductor heat dissipation system are not working, the water pump and the cooling system are working, and the power battery is subjected to water cooling. Step A6: When the power battery temperature is below T8, heat dissipation is complete, the thermal management system stops working, the vehicle continues to operate, and the process ends.

8. The control method for a thermal management system of a range-extended hybrid electric bus according to claim 7, characterized in that, The values ​​are T1 < T2 < T3 < T4 < T5 < T7, and T2 < T6 < T8 < T3.

9. A method for selecting a low-temperature environment water circuit in the thermal management system of a range-extended hybrid electric bus, characterized in that, The thermal management system for a range-extended hybrid electric bus, as described in any one of claims 1-6, comprises the following steps: Step B1: Depart in the morning, power on the vehicle for self-test, start the vehicle operation, and read the power battery temperature; Step B2: If the power battery temperature is low, the heating process begins. The heating water flows through the insulation water circuit, and the water in the insulation expansion tank is heated. Step B3: Heating is complete, and the hot water is stored in the insulated expansion tank to reduce heat loss; Step B4: When the vehicle is recharged, the battery temperature is high, and the cooling process begins. The cooling water flows through the non-insulated water circuit and uses the cold water in the non-insulated expansion tank to reduce the loss of the existing thermal management solution by cooling the hot water that has already been heated. Step B5: The vehicle starts again on the morning of the second day and enters the heating process. The heating water flows through the insulation water circuit again, and the hot water in the insulation expansion tank is used to heat the battery. Although the hot water stored in the insulation expansion tank the previous day has lost some heat, it will still be higher than the ambient temperature. Reheating can reduce energy consumption. This cycle continues every day to reduce vehicle energy consumption.

10. A redundancy control method for a thermal management system of a range-extended hybrid electric bus, characterized in that, The thermal management system for a range-extended hybrid electric bus, as described in any one of claims 1-6, comprises the following steps: Step C1: The vehicle performs a power-on self-test, reads the power battery temperature, and then begins operation or charging; Step C2: When the power battery temperature is high, the water cooling process is initiated. The cooling system fault information is read to determine if the cooling system reports a fault. If a fault is reported, the semiconductor cooling process is initiated. If no fault information is reported, the water pump is turned on, the first three-way valve and the second three-way valve are controlled, the water flows through the insulation water circuit, the cooling system is turned on, and the power battery begins water cooling. Step C3: After the water cooling process has been running for Time1, read the data from the inlet and outlet temperature detection modules. Determine the working status of the cooling system based on the inlet and outlet temperatures. If the cooling system is working normally, continue water cooling. If the cooling system is determined to be malfunctioning, turn on the water pump, control the first three-way valve and the second three-way valve, select the non-insulated water path to flow through, and turn on the semiconductor cooling system. The power battery will then be cooled by the semiconductor cooling system. Step C4: The power battery temperature drops, heat dissipation is complete, the thermal management system stops working, and the process ends.

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