A high-efficiency hybrid engine cooling system and thermal management method

Abstract

This application discloses a high-efficiency hybrid engine cooling system and thermal management method, relating to the field of engine thermal management. It includes an electric water pump, whose outlet is connected to a water jacket and the K2 port of a four-way valve. The water jacket outlet is connected to a check valve, the K4 port of the four-way valve, and a thermostat. The check valve outlet is connected to the K3 port of the four-way valve via an EGR cooler. The K1 port of the four-way valve is connected to the heater core via a PTC heater. The outlets of the heater core and the radiator both return to the electric water pump. The system uses only one electric water pump to provide circulation power. This invention uses temperature feedback control to switch the pipeline path of the four-way valve, isolating the engine's cold-end heat capacity, achieving pure electric independent heating, PTC bidirectional heating preheating of the engine body, and multi-branch exhaust waste heat recovery. The system has a simplified structure, effectively shortening the winter heating response and cold-start time, improving the overall vehicle waste heat utilization rate, and reducing overall energy consumption and hardware costs.

Description

Technical Field

[0001] This application relates to the field of engine thermal management, and more particularly to a high-efficiency hybrid engine cooling system and thermal management method. Background Technology

[0002] Currently, hybrid vehicles hold a certain market share due to their long driving range and low fuel consumption. To maintain the optimal operating temperature for all power components, the vehicle requires multiple cooling circuits. Hybrid vehicles combine an internal combustion engine with an electric drive system, resulting in a dense arrangement of components within the engine compartment. The branching and routing of the thermal management system piping are also quite complex.

[0003] To address the aforementioned thermal management requirements of the engine and cockpit, existing hybrid cooling systems typically employ a dual-pump, independently driven architecture. The engine coolant circuit houses the main water pump, which drives the coolant to circulate and dissipate heat through the engine water jacket and front radiator. A separate heater core pump is connected in series in the heater loop. When cabin heating is required, the heater core pump activates. The coolant is pumped into the PTC heater for heating and then flows into the heater core for heat exchange. Furthermore, the exhaust gas recirculation (EGR) system's cooling piping generally operates as a fixed branch in parallel with the main recirculation circuit.

[0004] However, the aforementioned architecture has shortcomings in actual operation. The dual-pump configuration increases the total number of system components and assembly costs. When heating is activated in pure electric mode, the PTC-heated coolant cannot completely bypass the engine water jacket. The cylinder block, when the engine is cold, has a large heat capacity. Some of the electric heating energy is transferred to the metal engine block. This makes it take longer for the cabin air to reach the target temperature. During the cold start phase, the engine can only rely on its own fuel combustion to heat up. The engine block is in the low-temperature range for a long time, and the low oil temperature leads to increased wear on mechanical parts. At the same time, the fixed piping connection method limits the flexible distribution of heat. Under normal driving conditions, most of the exhaust waste heat is dissipated through the radiator and cannot be switched to the heating circuit to provide heat according to the needs of the entire vehicle. The overall waste heat utilization rate of the system needs to be further improved.

[0005] Therefore, the present invention provides a high-efficiency hybrid engine cooling system and thermal management method to overcome the shortcomings of the prior art. Summary of the Invention

[0006] The purpose of this invention is to provide a high-efficiency hybrid engine cooling system and thermal management method, which aims to solve the problems of slow cabin heating, long cold start warm-up time, and low waste heat utilization caused by pipeline solidification in existing hybrid vehicle thermal management systems due to hardware redundancy, engine cold end heat capacity interference, etc.

[0007] This invention provides the following solution:

[0008] In a first aspect, the present invention provides a high-efficiency hybrid engine cooling system, which adopts the following technical solution:

[0009] A high-efficiency hybrid engine cooling system includes an electric water pump, the outlet of which is connected to a water jacket and the K2 port of a four-way valve; the outlet of the water jacket is connected to a one-way valve, the K4 port of the four-way valve, and a thermostat; the outlet of the one-way valve is connected to an EGR cooler, and the outlet of the EGR cooler is connected to the K3 port of the four-way valve; the outlet of the thermostat is connected to a radiator, and the outlet of the radiator is connected to the inlet of the electric water pump; the K1 port of the four-way valve is connected to a PTC heater, and the outlet of the PTC heater is connected to a heater core disposed inside the cabin; the outlet pipe of the heater core merges with the outlet pipe of the radiator and then connects to the inlet of the electric water pump; an engine cooler and a first coolant temperature sensor are connected to the water jacket; a second coolant temperature sensor is connected to the pipe between the K1 port of the four-way valve and the PTC heater.

[0010] By adopting the above technical solution, the functions of the engine water pump and the heater water pump are combined by using a four-way valve and multiple branch pipelines. By controlling the connection status of the internal valve ports, the system achieves the effects of dynamically switching between parallel and series coolant pipelines, integrating exhaust gas waste heat and electric heating heat, reducing system hardware complexity, and improving thermal management efficiency.

[0011] Preferably, the high-efficiency hybrid engine cooling system includes only one electric water pump, and the inlet of the water jacket and the outlet pipe of the heater core are both connected to the electric water pump.

[0012] By adopting the above technical solutions, the number of system water pumps can be reduced, thereby lowering the cost of component procurement and the system layout volume.

[0013] Preferably, the water jacket is provided with a water inlet and a water outlet, the inlet of the mechanical cooler is connected to the water inlet, and the outlet of the mechanical cooler is connected to the water outlet.

[0014] By adopting the above technical solutions, heat exchange between engine oil and coolant is ensured, and the operating temperature of the engine lubrication system is kept stable.

[0015] Preferably, the first coolant temperature sensor is installed on the outlet pipe of the water jacket, and the second coolant temperature sensor is installed on the pipe between the K1 port of the four-way valve and the PTC heater.

[0016] By adopting the above technical solutions, actual temperature data before and after the heat exchange node is provided, supporting the precise switching of multi-mode thermal management strategies.

[0017] Preferably, the pipeline connecting the electric water pump and the K2 port of the four-way valve is a bypass pipeline, and the pipeline channel where the bypass pipeline is located is in parallel with the fluid channel inside the water jacket.

[0018] By adopting the above technical solution, the heat capacity of the engine cold end is isolated, avoiding ineffective heat loss during heating in pure electric mode, and accelerating the cabin heating rate.

[0019] Preferably, the unidirectional flow direction inside the one-way valve is defined as flowing from the water jacket to the EGR cooler.

[0020] By adopting the above technical solution, backflow of coolant inside the pipeline is prevented, ensuring the flow stability of the waste heat recovery branch.

[0021] Preferably, the outlet of the water jacket branches into three independent outlet pipes, which are respectively connected to the one-way valve, the K4 port of the four-way valve, and the thermostat.

[0022] By adopting the above technical solution, physical isolation of the heat exchange branch sources is achieved, avoiding hydraulic interference caused by different return paths.

[0023] Preferably, the pipeline containing the four-way valve is independent of the pipeline containing the thermostat, and the pipeline containing the four-way valve and the pipeline containing the thermostat are arranged in a non-series configuration.

[0024] By adopting the above technical solutions, the engine's large-circulation cooling pipes are not affected by the cabin heating flow distribution, ensuring the engine's safe cooling requirements during operation.

[0025] Preferably, the electric water pump is a multi-speed adjustable water pump.

[0026] By adopting the above technical solution, the circulation flow rate of the coolant can be adjusted according to the real-time temperature and operating load requirements, thereby reducing the energy consumption of the water pump.

[0027] Secondly, this invention provides a high-efficiency hybrid engine thermal management method, employing the following technical solution:

[0028] A high-efficiency hybrid engine thermal management method, applied to the high-efficiency hybrid engine cooling system described in the first aspect above, includes the following steps:

[0029] When the engine is off and the cabin needs heating, the control valve’s K3 and K4 ports are closed, the control valve’s K2 port is opened, the control valve’s thermostat is closed, and the control valve’s electric water pump and PTC heater are operated, so that the coolant flows through the K2 and K1 ports of the four-way valve, the PTC heater, the heater core and then back to the electric water pump.

[0030] When the engine is in a cold preheating state and the cabin temperature reaches the preset cabin heating temperature, the opening of port K2 of the four-way valve is reduced and port K4 is opened, keeping the thermostat closed and the PTC heater running, so that the coolant is diverted to flow through port K2 and the water jacket and merges in the four-way valve, flowing from port K1 to the PTC heater.

[0031] When driving in hybrid mode and requiring exhaust gas recirculation, the control valve opens port K3 to keep the thermostat closed. Based on temperature feedback, the opening of ports K2, K3 and K4 is adjusted so that the coolant is split and flows through the water jacket, EGR cooler and port K2, and then converges in the four-way valve to flow to the heater core.

[0032] When the coolant temperature is between 80℃ and 110℃, the PTC heater, the K2 and K4 ports of the four-way valve are closed, and the K3 port and the thermostat are opened, so that the coolant circulates between the water jacket, the thermostat and the radiator. At the same time, some of the coolant flows through the check valve, the EGR cooler, the K3 port, the K1 port and the heater core in sequence.

[0033] By adopting the above technical solutions, the valve opening and flow direction are adjusted according to different vehicle operating conditions and temperature feedback to achieve a pure electric heating independent small cycle, a bidirectional heating parallel cycle between the engine and the cabin, and a passive heating cycle based on engine waste heat and exhaust waste heat; the warm-up time for cold starts is shortened, the overall power consumption of the PTC heater is reduced, and the energy utilization rate of the whole vehicle is improved.

[0034] The above solution achieves the following beneficial technical effects:

[0035] This invention incorporates a four-way valve in the water jacket outlet pipe, merging the functions of the engine water pump and heater water pump in a traditional cooling system into a single electric water pump. By controlling the opening and closing states of different ports within the four-way valve, the system can dynamically switch the coolant return path, flexibly selecting whether to use a PTC heater to heat the heater core or the engine water jacket. This improves the hardware utilization rate of the vehicle's thermal management piping and the utilization rate of waste heat from exhaust gases under normal driving conditions.

[0036] This invention's system retains only one electric water pump to provide coolant circulation power for the heater core and PTC heater, reducing the number of vehicle parts and lowering manufacturing and maintenance costs. Combined with a bypass piping structure, the system allows the coolant to bypass the engine water jacket and circulate independently during engine-off heating conditions, cutting off thermal interference from the engine itself. This shortens the response time for cabin heating in winter and reduces temperature fluctuations.

[0037] This invention enables the opening of a corresponding port on a four-way valve during the cold start preheating phase, allowing the high-temperature coolant, heated by the PTC heater, to be introduced into the engine's water jacket. This control mode utilizes electric heating energy to preheat the engine block, shortening the cold start period and reducing wear on moving mechanical parts. This allows the engine to quickly enter its high thermal efficiency range after startup, reducing fuel consumption and exhaust emissions during cold starts. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the structure of the high-efficiency hybrid engine cooling system of the present invention;

[0039] Figure 2 This is a flowchart of the high-efficiency hybrid engine thermal management method of the present invention.

[0040] Among them, 1. Water jacket; 2. Engine cooler; 3. Thermostat; 4. Electric water pump; 5. Radiator; 6. Check valve; 7. EGR cooler; 8. Four-way valve; 9. PTC heater; 10. Heater core; 11. Cabin; 12. Coolant temperature sensor one; 13. Coolant temperature sensor two. Detailed Implementation

[0041] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] See attached document Figure 1 The present invention provides a high-efficiency hybrid engine cooling system, which may include:

[0043] The system comprises: water jacket 1, engine cooler 2, thermostat 3, electric water pump 4, radiator 5, one-way valve 6, EGR cooler 7, four-way valve 8, PTC heater 9, heater core 10, cabin 11, coolant temperature sensor 12, and coolant temperature sensor 2 13. This high-efficiency hybrid engine cooling system combines the functions of the engine water pump and the heater water pump into a single electric water pump 4. A four-way valve 8 is installed in the outlet pipe of water jacket 1. By controlling the connection status of the various internal interfaces of the four-way valve 8, the parallel or series structure of the coolant piping can be changed.

[0044] Two water inlet branches branch off from the outlet of the electric water pump 4. The first inlet branch connects to the inlet of the water jacket 1 and is used to pump coolant into the water jacket 1. The second inlet branch serves as a bypass pipe and connects directly to port K2 of the four-way valve 8.

[0045] The outlet of water jacket 1 branches into three independent outlet pipes. The first outlet pipe connects sequentially to one-way valve 6 and EGR cooler 7. The inlet of one-way valve 6 connects to the outlet of water jacket 1, the outlet of one-way valve 6 connects to the inlet of EGR cooler 7, and the outlet of EGR cooler 7 connects to port K3 of four-way valve 8. The second outlet pipe connects directly to port K4 of four-way valve 8 via a pipe. The third outlet pipe connects to the inlet of thermostat 3, and the outlet of thermostat 3 connects to the inlet of radiator 5.

[0046] The four-way valve 8 has a K1 port for coolant outflow. The K1 port of the four-way valve 8 is connected to the inlet of the PTC heater 9. The outlet of the PTC heater 9 is connected to a heater core 10 arranged inside the cabin 11 for heat exchange with the air inside the cabin 11. The outlet pipe of the heater core 10 and the outlet pipe of the radiator 5 merge and are connected to the inlet of the electric water pump 4 to form a complete coolant return circulation loop.

[0047] The water jacket 1 is equipped with an inlet and an outlet. The inlet of the mechanical cooler 2 is connected to the inlet, and the outlet of the mechanical cooler 2 is connected to the outlet, for guiding a portion of the coolant through the mechanical cooler 2. A coolant temperature sensor 12 is installed on the outlet pipe of the water jacket 1 to monitor the temperature of the coolant flowing out of the water jacket 1 in real time. A coolant temperature sensor 13 is installed on the pipe between the K1 port of the four-way valve 8 and the PTC heater 9 to monitor the temperature of the coolant flowing towards the PTC heater 9 in real time.

[0048] The four-way valve 8 is installed in the outlet pipe of the water jacket 1, and the pipe containing the four-way valve 8 is independent of the pipe containing the thermostat 3. The pipes containing the four-way valve 8 and the thermostat 3 are arranged without series connection. The four-way valve 8 changes the flow direction of the coolant by controlling the opening and closing of its internal ports K2, K3 and K4, so as to keep the heat dissipation circulation pipe from the water jacket 1 to the thermostat 3 and the radiator 5 unaffected, and ensure the cooling requirements of the engine.

[0049] The pipeline connecting the electric water pump 4 and the K2 port of the four-way valve 8 is a bypass pipeline. The pipeline channel of this bypass pipeline is in parallel with the fluid channel inside the water jacket 1, allowing some coolant to bypass the water jacket 1. When the pure electric heating mode is activated, the coolant directly enters the four-way valve 8 through this bypass pipeline and flows to the PTC heater 9, thereby cutting off the pipeline flowing through the water jacket 1, preventing the heat generated by the PTC heater 9 from being transferred to the engine body, shortening the response time of the cabin heating 11 and reducing temperature fluctuations.

[0050] The inlet of the water jacket 1 and the outlet pipe of the heater core 10 are both connected to the electric water pump 4. The high-efficiency hybrid engine cooling system contains only one electric water pump 4 for coolant delivery, reducing the overall number of components in the system. This electric water pump 4 is a multi-speed adjustable water pump. It operates at different speeds to adjust the circulation speed and flow rate of the coolant in the system based on the temperature values ​​monitored by the coolant temperature sensor 12 and the coolant temperature sensor 13, as well as the heating requirements of the cabin 11.

[0051] See attached document Figure 2 The present invention provides a method for efficient thermal management of a hybrid engine, which may include:

[0052] This efficient hybrid engine thermal management method is implemented based on the hardware structure of the efficient hybrid engine cooling system in the aforementioned embodiments. The vehicle's electronic control unit acquires real-time information on the vehicle's current operating conditions and heating demand signals within the cabin 11. The electronic control unit acquires real-time coolant temperature data on the outlet pipe of the water jacket 1 through coolant temperature sensor 12, and acquires real-time coolant temperature data on the pipe between the K1 port of the four-way valve 8 and the PTC heater 9 through coolant temperature sensor 13.

[0053] Based on the acquired operating condition information, heating demand signal, and coolant temperature data from two locations, the electronic control unit sends control commands to various actuators within the cooling system. These control commands dynamically adjust the speed of the electric water pump 4, the opening degree of the internal flow channel of the four-way valve 8, the opening and closing status of the thermostat 3, and the operating status of the PTC heater 9, thereby achieving coolant flow distribution and heat transfer in different pipeline branches. The control flow of the thermal management method consists of the following specific steps.

[0054] In step S100, when it is determined that the vehicle is in pure electric drive mode, the engine is in a stopped state, the cabin 11 has a heating demand and the coolant temperature is lower than the preset cabin heating temperature, the electronic control unit controls the system to execute the pure electric shutdown heating mode.

[0055] In step S200, when it is determined that the vehicle is in a cold start preheating state before starting, the coolant temperature is below 50°C, and the current temperature of the cabin 11 is below the preset cabin heating temperature, the electronic control unit controls the system to execute the cold start dual-effect preheating mode.

[0056] In step S300, when it is determined that the vehicle starts to enter the low-temperature hybrid driving state, the coolant temperature rises to the range of 50°C to 80°C, and the vehicle generates exhaust gas recirculation demand, the electronic control unit controls the system to execute the low-temperature hybrid transition mode.

[0057] In step S400, when it is determined that the vehicle is in normal driving condition and the coolant temperature reaches the range of 80°C to 110°C, the electronic control unit controls the system to execute the normal driving waste heat heating mode.

[0058] In step S100, the electronic control unit acquires the vehicle's status information in real time. When it detects that the vehicle is in pure electric driving mode or parked mode, and the engine is off, the electronic control unit further acquires the heating demand signal and temperature data of the cabin 11. When it receives the heating demand signal of the cabin 11, and the current coolant temperature monitored by coolant temperature sensor 12 or coolant temperature sensor 13 is lower than the preset cabin heating temperature, the electronic control unit determines that the triggering condition is met and begins to execute the pure electric shutdown heating mode operation.

[0059] The electronic control unit sends a valve adjustment command to the four-way valve 8, controlling the K3 and K4 ports inside the four-way valve 8 to enter and remain closed, while simultaneously controlling the K2 port inside the four-way valve 8 to enter and remain open. The electronic control unit sends a control command to the thermostat 3, controlling it to enter the closed state, cutting off the coolant flow to the radiator 5. Subsequently, the electronic control unit sends operation commands to the electric water pump 4 and the PTC heater 9, controlling the electric water pump 4 to perform pumping operations, and simultaneously controlling the PTC heater 9 to perform electric heating operations.

[0060] With the components in the above-described state, an independent small circulation path for warm air is formed inside the system, bypassing the water jacket 1. Driven by the electric water pump 4, the coolant flows out of the outlet of the electric water pump 4. Because the outlet pipe of the water jacket 1 is blocked by ports K3 and K4 of the four-way valve 8, the coolant flows directly into port K2 of the four-way valve 8 along the bypass pipe. The coolant entering the four-way valve 8 then flows out from port K1 of the four-way valve 8 and flows through the pipe into the inlet of the PTC heater 9.

[0061] The coolant flowing into the PTC heater 9 absorbs heat generated by the electric heating, raising its temperature. The heated coolant then flows out of the PTC heater 9 and enters the heater core 10. At the heater core 10, the hot coolant exchanges heat with the air inside the cabin 11, releasing heat into the cabin. After releasing heat, the cooled coolant flows out of the heater core 10 and back along the return pipe to the inlet of the electric water pump 4, where it is pumped out again to participate in the next cycle.

[0062] Through the aforementioned control logic, the coolant circulates only between the electric water pump 4, the four-way valve 8, the PTC heater 9, and the heater core 10. This circulation pipeline cuts off the path into the water jacket 1, preventing the high-temperature coolant heated by the PTC heater 9 from flowing into the engine block for ineffective heat transfer. This control method reduces the total volume of coolant participating in the heat exchange cycle and the heat loss in the pipeline, allowing all the heat generated by the PTC heater 9 to be concentrated on the heat exchange of the heater core 10. This shortens the time required for the air temperature inside the cabin 11 to reach the set value and reduces temperature fluctuations within the cabin 11.

[0063] In step S200, the electronic control unit acquires real-time vehicle operating status data. When the vehicle is detected to be in a cold start preheating state, the electronic control unit obtains the current coolant temperature through coolant temperature sensor 12 and coolant temperature sensor 13, and also obtains the current temperature of the cabin 11. If it is determined that the coolant temperature is below 50°C and the current temperature of the cabin 11 is below the preset cabin heating temperature, the electronic control unit controls the engine to remain off and controls the system to initially operate in the aforementioned pure electric shutdown heating mode, prioritizing the heating needs of the cabin 11.

[0064] During system operation, the electronic control unit continuously monitors the temperature changes in cabin 11. When the received sensor signal indicates that the temperature of cabin 11 has reached the preset cabin heating temperature, the electronic control unit sends a dynamic adjustment command to the four-way valve 8. The electronic control unit controls the opening of port K2 of the four-way valve 8 to decrease and port K4 to open, while keeping the thermostat 3 closed and the PTC heater 9 running. At this time, the system enters the bidirectional heating stage.

[0065] With the opening setting of the four-way valve 8 as described above, two parallel coolant circulation paths are formed inside the system. The first path is the heater circulation. After some coolant flows out of the electric water pump 4, it flows directly into port K2 of the four-way valve 8 along the bypass pipe, and then flows out through port K1 of the four-way valve 8 and into the PTC heater 9. After absorbing heat in the PTC heater 9, the coolant flows into the heater core 10, releases heat, and then flows back to the inlet of the electric water pump 4.

[0066] The second path is a heat engine cycle. The remaining coolant flowing out of the electric water pump 4 is pumped into the inlet of the engine water jacket 1. This portion of coolant flows through the internal channels of the engine water jacket 1, then flows out from the outlet of the engine water jacket 1 and enters the K4 port of the four-way valve 8. The coolant entering the K4 port flows out through the K1 port of the four-way valve 8, merges with the coolant from the first path, and flows together from the K1 port into the PTC heater 9 to absorb heat. The heated high-temperature coolant then flows through the heater core 10 again, and finally merges into the electric water pump 4.

[0067] Through the aforementioned parallel water flow distribution structure, the coolant, driven by the electric water pump 4 and heated in the PTC heater 9, is divided into two parts and supplied to the heater core 10 and the engine water jacket 1 respectively. The high-temperature coolant entering the engine water jacket 1 transfers heat to the engine block, raising its temperature. This heat distribution method allows the engine block temperature to rise to the set warm-up temperature range before the engine is officially started, thereby reducing the frictional resistance and mechanical wear of internal components during the cold start phase of the engine.

[0068] In step S300, the electronic control unit continuously acquires and analyzes the vehicle's operating parameters. When the vehicle is detected to be in a cold start or low-temperature hybrid driving state, the electronic control unit acquires the coolant temperature data on the engine water jacket 1 outlet pipe in real time through the coolant temperature sensor 12. When it is determined that the coolant temperature is within the range of 50°C to 80°C, and the electronic control unit determines that the engine has an exhaust gas recirculation requirement based on the overall vehicle operating status, the trigger condition is met, and the electronic control unit controls the system to enter the low-temperature hybrid transition mode.

[0069] Upon meeting the trigger conditions, the electronic control unit opens port K3 of the four-way valve 8 while keeping the thermostat 3 closed, thereby cutting off the main circulation path of coolant to the radiator 5. Simultaneously, the electronic control unit continuously receives real-time temperature data from coolant temperature sensor 12 and coolant temperature sensor 13 installed on the pipeline between port K1 of the four-way valve 8 and the PTC heater 9. Based on the temperature feedback, the electronic control unit adjusts the opening degrees of ports K2, K3, and K4 inside the four-way valve 8. The electric water pump 4 and the PTC heater 9 remain operational.

[0070] With the aforementioned component configuration, the coolant system forms a complex circulation path with multiple parallel branches. The first portion of coolant flows out from the electric water pump 4 and directly into port K2 of the four-way valve 8 via a bypass pipe. The second portion of coolant flows out from the electric water pump 4 and is pumped into the engine water jacket 1. The coolant entering the engine water jacket 1 absorbs the heat generated by the engine's operation. The high-temperature coolant exiting the engine water jacket 1 then splits into two paths. One path flows directly into port K4 of the four-way valve 8. The other high-temperature coolant flows sequentially through the one-way valve 6 and the EGR cooler 7. Inside the EGR cooler 7, the coolant absorbs heat from the exhaust gas in the exhaust gas recirculation system, further increasing its own temperature, before flowing into port K3 of the four-way valve 8.

[0071] Coolant flowing into port K2 from the bypass pipe, high-temperature coolant flowing directly into port K4 from engine water jacket 1, and coolant absorbing exhaust heat flowing into port K3 from EGR cooler 7 all converge inside four-way valve 8. The combined coolant flows out from port K1 of four-way valve 8 and then enters PTC heater 9. Inside PTC heater 9, the coolant absorbs heat generated by electric heating, further increasing its temperature. Finally, the high-temperature coolant flows into heater core 10, transferring heat to the cabin 11, and then flows back to the inlet of electric water pump 4 to complete the circulation.

[0072] Through the aforementioned multi-branch coordinated water supply structure and the dynamic adjustment of the multi-port opening of the four-way valve 8, the system integrates and utilizes the waste heat from the engine body, the exhaust heat recovered by the EGR cooler 7, and the electrical heating provided by the PTC heater 9. This coordinated heat supply method increases the coolant temperature entering the heater core 10, thereby improving the heating efficiency of the cabin 11. Simultaneously, by dynamically distributing the coolant flow into the engine water jacket 1, the engine can maintain a suitable warm-up rate while providing waste heat, thus improving the engine warm-up speed.

[0073] In step S400, the electronic control unit monitors the coolant temperature on the engine water jacket 1 outlet pipe in real time through the coolant temperature sensor 12. When the vehicle is detected to be in normal driving condition and the current coolant temperature fed back by the coolant temperature sensor 12 reaches the range of 80°C to 110°C, the trigger condition is determined to be met, and the electronic control unit controls the system to execute the normal driving waste heat heating mode.

[0074] Once the triggering conditions are met, the electronic control unit closes ports K2 and K4 of the PTC heater 9 and the four-way valve 8, and opens port K3 and the thermostat 3. In this state, the engine is running, and the electric water pump 4 continues normal pumping operation under the drive of the electronic control unit.

[0075] Under the control of the aforementioned actuators, the system synchronously operates the engine cooling large circulation path and the heating small circulation path with exhaust gas recirculation and waste heat recovery. For the engine cooling large circulation path, coolant is pumped into the engine water jacket 1 by the electric water pump 4. After absorbing heat from the engine, the coolant flows out of the outlet of the engine water jacket 1, then flows through the thermostat 3 and into the radiator 5. Inside the radiator 5, the coolant releases heat to the external environment, thus lowering its own temperature. The cooled coolant then flows out of the radiator 5 and back to the inlet of the electric water pump 4, where it is pumped back into the engine water jacket 1 to achieve engine cooling, thus circulating the coolant between the water jacket 1, the thermostat 3, and the radiator 5.

[0076] For the heating loop path with exhaust gas recirculation (EGR) waste heat recovery, a portion of the coolant is simultaneously discharged from the outlet of the engine water jacket 1, flowing sequentially through the one-way valve 6 and the EGR cooler 7. Inside the EGR cooler 7, this portion of coolant exchanges heat with the high-temperature exhaust gas in the EGR system, absorbing the waste heat of the high-temperature exhaust gas to further increase its own temperature. The cooled coolant, now at a higher temperature, flows out of the EGR cooler 7 and into the four-way valve 8 through port K3, then flows out through port K1 and into the heater core 10.

[0077] The high-temperature coolant entering the heater core 10 exchanges heat with the air inside the cabin 11, releasing the absorbed engine waste heat and exhaust waste heat into the cabin 11 to provide heating. After the heat exchange is completed, the cooled coolant flows out of the heater core 10, flows back to the inlet of the electric water pump 4 along the return water pipe, and merges with the coolant returning from the radiator 5. Together, they are pumped out of the engine water jacket 1 by the electric water pump 4 to participate in the next cycle.

[0078] Through the aforementioned control method, the system completely cuts off the electric heating energy consumption of the PTC heater 9 when the coolant temperature reaches the range of 80℃ to 110℃. It relies entirely on the waste heat from the engine water jacket 1 and the exhaust heat recovered by the EGR cooler 7 to meet the heating needs of the cabin 11, thus reducing the overall vehicle's energy consumption. By allowing the coolant in the heating circuit to flow through the EGR cooler 7, exhaust heat from the exhaust system is recovered, and the temperature of the coolant flowing into the heater core 10 is increased. This ensures a stable heating temperature in the cabin 11 even when external energy heating is stopped, improving the overall vehicle's energy utilization efficiency.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-efficiency hybrid engine cooling system, characterized in that, Includes an electric water pump (4), the outlet of which is connected to a water jacket (1) and the K2 port of a four-way valve (8); The outlet of the water jacket (1) is connected to a one-way valve (6), the K4 port of the four-way valve (8), and a thermostat (3). The outlet of the one-way valve (6) is connected to an EGR cooler (7), and the outlet of the EGR cooler (7) is connected to the K3 port of the four-way valve (8). The outlet of the thermostat (3) is connected to a radiator (5), and the outlet of the radiator (5) is connected to the inlet of the electric water pump (4). The K1 port of the four-way valve (8) is connected to a PTC heater (9), and the outlet of the PTC heater (9) is connected to a warm air core (10) arranged inside the cabin (11). The outlet pipe of the heating core (10) merges with the outlet pipe of the radiator (5) and is then connected to the inlet of the electric water pump (4). The water jacket (1) is connected to an organic cooler (2) and a coolant temperature sensor (12). A coolant temperature sensor 2 (13) is connected to the pipeline between the K1 port of the four-way valve (8) and the PTC heater (9).

2. The high-efficiency hybrid engine cooling system according to claim 1, characterized in that, The high-efficiency hybrid engine cooling system contains only one electric water pump (4), and the inlet of the water jacket (1) and the outlet pipe of the heater core (10) are both connected to the electric water pump (4).

3. The high-efficiency hybrid engine cooling system according to claim 1, characterized in that, The water jacket (1) is provided with a water intake port and a water return port. The inlet of the mechanical cooler (2) is connected to the water intake port, and the outlet of the mechanical cooler (2) is connected to the water return port.

4. The high-efficiency hybrid engine cooling system according to claim 1, characterized in that, The first coolant temperature sensor (12) is installed on the outlet pipe of the water jacket (1), and the second coolant temperature sensor (13) is installed on the pipe between the K1 port of the four-way valve (8) and the PTC heater (9).

5. The high-efficiency hybrid engine cooling system according to claim 1, characterized in that, The pipeline connecting the electric water pump (4) and the K2 port of the four-way valve (8) is a bypass pipeline. The pipeline channel where the bypass pipeline is located is in parallel with the fluid channel inside the water jacket (1).

6. The high-efficiency hybrid engine cooling system according to claim 1, characterized in that, The one-way valve (6) has a unidirectional flow direction that is limited to flow from the water jacket (1) to the EGR cooler (7).

7. The high-efficiency hybrid engine cooling system according to claim 1, characterized in that, The water jacket (1) has three independent outlet pipes branching off from its outlet. The three outlet pipes are respectively connected to the one-way valve (6), the K4 port of the four-way valve (8), and the thermostat (3).

8. The high-efficiency hybrid engine cooling system according to claim 1, characterized in that, The pipeline where the four-way valve (8) is located is independent of the pipeline where the thermostat (3) is located, and the pipeline where the four-way valve (8) is located and the pipeline where the thermostat (3) is located are arranged without series connection.

9. The high-efficiency hybrid engine cooling system according to claim 1, characterized in that, The electric water pump (4) is a multi-speed adjustable water pump.

10. A high-efficiency hybrid engine thermal management method, characterized in that, The system is applied to a high-efficiency hybrid engine cooling system according to any one of claims 1 to 9, comprising the following steps: When the engine is off and the cabin (11) requires heating, the K3 and K4 ports of the four-way valve (8) are closed, the K2 port is opened, the thermostat (3) is closed, and the electric water pump (4) and PTC heater (9) are operated, so that the coolant flows through the K2 and K1 ports of the four-way valve (8), the PTC heater (9), the heater core (10) and flows back to the electric water pump (4). When the engine is in a cold preheating state and the cabin (11) temperature reaches the preset cabin heating temperature, the opening of port K2 of the four-way valve (8) is reduced and port K4 is opened, keeping the thermostat (3) closed and the PTC heater (9) running, so that the coolant flows through port K2 and merges with the water jacket (1) in the four-way valve (8), and flows from port K1 to the PTC heater (9). When driving in hybrid mode and there is a need for exhaust gas recirculation, the K3 port of the four-way valve (8) is opened, the thermostat (3) is kept closed, and the opening of the K2, K3 and K4 ports is adjusted based on temperature feedback, so that the coolant flows through the water jacket (1), EGR cooler (7) and K2 port, and then converges in the four-way valve (8) and flows to the heater core (10). When the coolant temperature is between 80°C and 110°C, control the PTC heater (9), the K2 port and K4 port of the four-way valve (8) to close, and control the K3 port and the thermostat (3) to open, so that the coolant circulates between the water jacket (1), the thermostat (3) and the radiator (5), and simultaneously allow some of the coolant to flow through the one-way valve (6), the EGR cooler (7), the K3 port, the K1 port and the heater core (10) in sequence.

Images