A thermal management system for a parallel hybrid vehicle

Abstract

The application discloses a kind of heat management systems of parallel hybrid electric vehicle, belong to automobile heat management technical field, solve the technical problem that existing parallel hybrid electric vehicle heat management system cannot be reasonably distributed according to the demand of cylinder preheating.The system includes engine, motor, cylinder preheating module, power distribution module, waste heat recovery module, rectifier module, high-voltage battery pack, control module;When user enables heat management system, the temperature of cylinder is detected by temperature sensor;If the temperature of current cylinder is in ideal working condition range, recommend user to start engine;If the temperature of current cylinder is lower than the lower limit of ideal working condition, control the heat transfer amount of cylinder preheating module to improve, until the temperature of cylinder is in ideal working condition range, recommend user to start engine;If the temperature of current cylinder is higher than the upper limit of ideal working condition, control cylinder preheating module to stop heating;When the temperature of cylinder reduces to ideal working condition range, recommend engine to start.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automobile thermal management, more specifically, it relates to a parallel hybrid vehicle thermal management system. BACKGROUND

[0002] With the large use of world energy resources and the increasing environmental pollution, the in-depth development of new energy vehicles has become a top priority in the field of automobiles. Today, automobiles have developed from traditional internal combustion engine vehicles to pure electric vehicles, and hybrid vehicles have become a good transition method. According to the power architecture, hybrid vehicles can be divided into series, parallel, series-parallel and power split, among which the parallel hybrid vehicle has the characteristics of high independence because the internal motor and engine can drive the transmission alone or together.

[0003] However, the parallel hybrid vehicle lacks close linkage between the motor and the engine, resulting in an immature thermal management method that cannot reasonably distribute the cylinder preheating requirements, especially in low temperature environments, the engine will start directly in a low temperature state, which not only causes a serious decline in engine efficiency, but also causes fuel waste. SUMMARY

[0004] The technical problem to be solved by the present application is to solve the above-mentioned deficiencies of the prior art, and the purpose of the present application is to provide a parallel hybrid vehicle thermal management system.

[0005] The technical solution of the present application is: a parallel hybrid vehicle thermal management system, comprising an engine and a motor, the engine and the motor form a parallel hybrid power system, further comprising a cylinder preheating module, a power distribution module, a waste heat recovery module, a rectifier module, a high-voltage battery pack and a control module.

[0006] The cylinder preheating module is installed in the cylinder of the engine, the cylinder of the engine is provided with a temperature sensor, the waste heat recovery module is installed in the exhaust pipe of the engine, the high-voltage battery pack is electrically connected to the rectifier module and the power distribution module in sequence, the power distribution module is electrically connected to the cylinder preheating module and the motor, and the control module is electrically connected to the high-voltage battery pack, the cylinder preheating module, the motor, the power distribution module and the temperature sensor.

[0007] The working process of the thermal management system includes the following steps:

[0008] Step 1. When the user enables the thermal management system, the control module detects the temperature of the cylinder through the temperature sensor.

[0009] Step 2. If the temperature of the current cylinder is in the ideal working condition range, the current working condition is stabilized and the user is recommended to start the engine; if the temperature of the current cylinder is not in the ideal working condition range, the current working condition needs to be further judged;

[0010] Step 3. If the temperature of the current cylinder is lower than the lower limit of the ideal working condition, the control module adjusts the distribution of power through the power distribution module to increase the heat transfer amount of the cylinder preheating module to increase the temperature of the cylinder; and through real-time detection, until the temperature of the cylinder is in the ideal working condition range, the user is recommended to start the engine;

[0011] Step 4. If the temperature of the current cylinder is higher than the upper limit of the ideal working condition, the control module adjusts the distribution of power through the power distribution module to stop heating of the cylinder preheating module; when the temperature of the cylinder decreases to the ideal working condition range, the current working condition is stabilized and the engine is recommended to start.

[0012] As a further improvement, the thermal management system runs an energy-saving scheme after the preheating is completed, including the following steps:

[0013] Step 21. Under the premise that the user enables the thermal management system, the control module calculates the power We required to heat the cylinder to the ideal working condition, and calculates the maximum limited power Wmax, Wmax = 1.2 * We;

[0014] Step 22. Real-time record the consumed power W during the heating process;

[0015] Step 23. If the consumed power W does not exceed the maximum limited power Wmax, maintain the short-time preheating function and continue to record the consumed power W; if the consumed power W exceeds the maximum limited power Wmax, the engine preheating function will be closed and a prompt will be sent to the user.

[0016] Further, the control module optimizes the optimal working temperature Tmax based on the temperature-time data information detected by the temperature sensor, with the optimization goal of high efficiency and low fuel consumption, and uses the Fuzzy-PID control algorithm. The ideal working condition range is [Tmax-5, Tmax+5].

[0017] Further, if the optimal working temperature Tmax is between 80℃ and 90℃, it is considered that the optimal working temperature Tmax is effective; otherwise, 85℃ is taken as the optimal working temperature Tmax.

[0018] Further, the waste heat recovery module comprises a water jacket sleeved on the periphery of the exhaust pipe of the engine, when the engine is started and the temperature of the cylinder body is lower than the lower limit of the ideal working condition, the control module controls the coolant of the cooling system of the engine to circulate through the water jacket until the temperature of the cylinder body is within the ideal working condition range, and the control module controls the coolant of the cooling system of the engine to stop circulating through the water jacket.

[0019] Further, the waste heat recovery module is an automobile waste heat power generation device, and the electric energy generated by the automobile waste heat power generation device is stored in the high-voltage battery pack.

[0020] Advantages

[0021] Compared with the prior art, the present application has the advantages that:

[0022] 1. The cylinder preheating module, waste heat recovery and control module of the present application can detect the change of engine temperature with time in real time, and adjust the power distribution system according to the demand. The Fuzzy-PID control algorithm adopted by the control module has strong adaptability, can be applied to the temperature detection system with large time lag, and can automatically optimize the parameters for control. The engine can be kept in the best working condition, the fuel consumption can be reduced, and the economic requirement can be better met.

[0023] 2. The present application systematically divides the power demand into the cylinder preheating module, the electric motor and the auxiliary user system, so as to achieve the effects of modularization and centralization. According to the residual heat required by the cylinder preheating module, the control module can adjust the distribution of the power distribution system in real time, realize tracking record, avoid waste of electric energy, achieve the purpose of saving electric energy and increasing endurance.

[0024] 3. The present application not only can reasonably distribute according to the demand of the cylinder preheating module, but also can ensure the sufficient demand of the user system and the electric motor driving system, and improve the driving experience of the user.

[0025] 4. The present application can also prevent preheating overload, recycle the waste heat generated during driving, has high environmental protection and economy, ensures the working power of the electric motor, and avoids the low power of the electric motor during driving. BRIEF DESCRIPTION OF DRAWINGS

[0026] Fig. 1 is the framework diagram of the system of the present application;

[0027] Fig. 2 is the working flowchart of the cylinder preheating module;

[0028] Fig. 3 is the working flowchart of the system of the present application;

[0029] Fig. 4The working flow chart of the energy saving scheme in the application.

[0030] Wherein: 1-engine, 2-motor, 3-cylinder preheating module, 4-power distribution module, 5-waste heat recovery module, 6-rectifier module, 7-high voltage battery pack, 8-control module, 9-oil tank, 10-user system, 11-gearbox. DETAILED DESCRIPTION

[0031] The application will be further described below with reference to the specific embodiments in the drawings.

[0032] Reference Figs. 1-4 A parallel hybrid vehicle thermal management system, comprising an engine 1 and a motor 2, the engine 1 and the motor 2 form a parallel hybrid system, and the vehicle is driven by the engine 1 or the motor 2 to realize vehicle driving. The thermal management system further comprises a cylinder preheating module 3, a power distribution module 4, a waste heat recovery module 5, a rectifier module 6, a high-voltage battery pack 7, and a control module 8.

[0033] The cylinder preheating module 3 is installed in the cylinder of the engine 1, the cylinder of the engine 1 is provided with a temperature sensor, the waste heat recovery module 5 is installed in the exhaust pipe of the engine 1, and the high-voltage battery pack 7 is electrically connected to the rectifier module 6 and the power distribution module in sequence. The power distribution module 4 is electrically connected to the cylinder preheating module 3 and the motor 2, and the control module 8 is electrically connected to the high-voltage battery pack 7, the cylinder preheating module 3, the motor 2, the power distribution module 4, and the temperature sensor.

[0034] The high-voltage battery pack 7 is used to store electric energy obtained from charging, brake energy recovery and the like, and is used to drive the motor 2 and the cylinder preheating module 3 and to supply power to other devices on the vehicle, such as the user system 10 (i.e. the car machine).

[0035] The rectifier module 6 is used to convert alternating current output by the high-voltage battery pack 7 into direct current suitable for the motor, and to record and transmit the converted power to the control module 8 in real time for visualized data (visualized data in the user system 10).

[0036] The waste heat recovery module 5 is used to recover the waste heat of exhaust gas and to preheat the engine.

[0037] In one embodiment, the waste heat recovery module 5 comprises a water jacket sleeved around the periphery of the exhaust pipe of the engine 1. When the engine 1 is started and the temperature of the current cylinder is lower than the lower limit of the ideal working condition, the control module 8 controls the coolant of the cooling system of the engine 1 to circulate through the water jacket until the temperature of the cylinder is within the ideal working condition range, and then the control module 8 controls the coolant of the cooling system of the engine 1 to stop circulating through the water jacket.

[0038] In one embodiment, the waste heat recovery module 5 is a car waste heat power generation device, which can be a mature car waste heat power generation device. The power generated by the car waste heat power generation device is stored in the high-voltage battery pack 7.

[0039] The power distribution module 4 is used to distribute the power released by the high-voltage battery pack 7 to the cylinder preheating module 3, the electric motor 2, and the user system 10. In the present application, the energy supply object of the cylinder preheating module 3 is designed as a main storage battery. The advantage is that the car does not need to be designed with a separate set of generators for engine preheating, which lightens the structure of the car and reduces complexity and tends to be integrated.

[0040] The cylinder preheating module 3 is an electric heating pipe installed in the cylinder of the engine 1, which is used for preheating the engine cylinder so that the engine cylinder is in an ideal working condition environment.

[0041] The working process of the thermal management system includes the following steps:

[0042] Step 1. When the user enables the thermal management system, the control module 8 detects the temperature of the cylinder through the temperature sensor.

[0043] Step 2. If the current temperature of the cylinder is within the ideal working condition range, the current working condition is stabilized, and the user is recommended to start the engine. If the current temperature of the cylinder is not within the ideal working condition range, the current working condition needs to be further judged.

[0044] Step 3. If the current temperature of the cylinder is lower than the lower limit of the ideal working condition, the control module 8 adjusts the distribution power through the power distribution module 4 to increase the heat transfer amount of the cylinder preheating module 3 to increase the temperature of the cylinder. Through real-time detection, until the temperature of the cylinder is within the ideal working condition range, the user is recommended to start the engine.

[0045] Step 4. If the current temperature of the cylinder is higher than the upper limit of the ideal working condition, the control module 8 adjusts the distribution power through the power distribution module 4 to stop heating the cylinder preheating module 3. When the temperature of the cylinder decreases to the ideal working condition range, the current working condition is stabilized, and the engine is recommended to start.

[0046] Since the ideal working condition is easily affected by many factors such as external temperature, pressure, and fuel viscosity, the ideal working temperature of the engine is usually between 80℃ and 90℃, and the difference between the upper and lower limits is relatively stable at 10℃. The control module first calculates the optimal working temperature Tmax, and then designs the limits as Tmax-5 and Tmax+5.

[0047] Preferably, the control module 8 optimizes the optimal working temperature Tmax according to the temperature-time data information detected by the temperature sensor, with the optimization goal of high efficiency and low oil consumption, using the Fuzzy-PID control algorithm, which can be well applied to nonlinear, time-varying and uncertain systems, has strong adaptability, is suitable for automatic parameter optimization control of large-lag systems, and the ideal working condition range is [Tmax-5, Tmax+5].

[0048] If the optimal working temperature Tmax is between 80℃ and 90℃, it is considered that the optimal working temperature Tmax is effective; otherwise, 85℃ is taken as the optimal working temperature Tmax.

[0049] To prevent the vehicle from using only the pure electric mode for a long time without starting the hybrid mode under the premise of starting the cylinder preheating module, which will cause continuous loss of electric energy and thermal energy. The heat management system of the present application runs the energy-saving scheme after the preheating is completed, including the following steps:

[0050] Step 21. Under the premise that the user starts the heat management system, the control module 8 calculates the power We required to heat the cylinder to the ideal working condition, calculates the maximum limited power Wmax, Wmax=1.2*We; Wmax is the main indicator to ensure that the engine preheating does not last for a long time;

[0051] Step 22. Real-time record the consumed power W of the cylinder during the heating process;

[0052] Step 23. If the consumed power W does not exceed the maximum limited power Wmax, maintain the short-time preheating function and continue to record the consumed power W; if the consumed power W exceeds the maximum limited power Wmax, the engine preheating function will be turned off, and a prompt will be sent to the user.

[0053] The above is only a preferred embodiment of the present application, and it should be pointed out that for those skilled in the art, without departing from the structure of the present application, a number of modifications and improvements can be made, which will not affect the effect and practicality of the patent.

Claims

1. A thermal management system for a parallel hybrid vehicle, comprising an engine (1) and an electric motor (2), wherein the engine (1) and the electric motor (2) form a parallel hybrid system, characterized in that: It also includes a cylinder preheating module (3), a power distribution module (4), a waste heat recovery module (5), a rectifier module (6), a high-voltage battery pack (7), and a control module (8); The cylinder preheating module (3) is installed in the cylinder of the engine (1), a temperature sensor is provided in the cylinder of the engine (1), the waste heat recovery module (5) is installed in the exhaust pipe of the engine (1), the high-voltage battery pack (7) is electrically connected to the rectifier module (6) and the power distribution module in sequence, the power distribution module (4) is electrically connected to the cylinder preheating module (3) and the electric motor (2), and the control module (8) is electrically connected to the high-voltage battery pack (7), the cylinder preheating module (3), the electric motor (2), the power distribution module (4), and the temperature sensor; The working process of the thermal management system includes the following steps: Step 1. When the user activates the thermal management system, the control module (8) detects the temperature of the cylinder through the temperature sensor; Step 2. If the current cylinder temperature is within the ideal operating range, stabilize the current operating condition and recommend starting the engine. If the current cylinder temperature is not within the ideal operating range, further evaluation of the current operating condition is required. Step 3. If the current cylinder temperature is lower than the lower limit of the ideal operating condition, the control module (8) adjusts the power distribution through the power distribution module (4) to increase the heat transfer of the cylinder preheating module (3) to increase the cylinder temperature; and then through real-time detection, until the cylinder temperature is within the ideal operating condition range, recommends the user to start the engine; Step 4. If the current cylinder temperature is higher than the upper limit of the ideal operating condition, the control module (8) adjusts the distributed power through the power distribution module (4) to stop the cylinder preheating module (3) from heating; when the cylinder temperature drops to within the ideal operating condition range, the current operating condition is stabilized and the engine start is recommended.

2. The thermal management system of a parallel hybrid vehicle according to claim 1, characterized in that: The thermal management system runs an energy-saving solution after preheating, including the following steps: Step 21. When the user activates the thermal management system, the control module (8) calculates the power We required to heat the cylinder to the ideal working condition and the maximum power limit Wmax, where Wmax=1.2*We; Step 22. Record in real time the power W consumed by the cylinder during the heating process; Step 23. If the consumed power W does not exceed the maximum power limit Wmax, the short-time preheating function is maintained and the consumed power W continues to be recorded; if the consumed power W exceeds the maximum power limit Wmax, the engine preheating function is turned off and a prompt is issued to the user.

3. The thermal management system of a parallel hybrid vehicle according to claim 1, characterized in that: The control module (8) selects the optimal operating temperature Tmax using a fuzzy-PID control algorithm based on the temperature-time data information detected by the temperature sensor, with high efficiency and low fuel consumption as optimization goals, and the ideal operating condition range is [Tmax-5, Tmax+5].

4. The thermal management system of a parallel hybrid vehicle according to claim 3, characterized in that: If the optimal operating temperature Tmax is between 80° C. and 90° C., the optimal operating temperature Tmax is considered to be valid; otherwise, 85° C. is used as the optimal operating temperature Tmax.

5. The thermal management system of a parallel hybrid vehicle according to claim 1, characterized in that: The waste heat recovery module (5) includes a water jacket sleeved on the outer periphery of the exhaust pipe of the engine (1). When the engine (1) is started and the temperature of the current cylinder body is lower than the lower limit of the ideal operating condition, the control module (8) controls the coolant of the cooling system of the engine (1) to circulate through the water jacket until the temperature of the cylinder body is within the ideal operating condition range. The control module (8) controls the coolant of the cooling system of the engine (1) to stop passing through the water jacket.

6. The thermal management system of a parallel hybrid vehicle according to claim 1, characterized in that: The waste heat recovery module (5) is an automobile waste heat power generation device, and the electric energy generated by the automobile waste heat power generation device is stored in the high-voltage battery pack (7).

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