Water-cooled intercooler system

Abstract

To provide a water-cooled intercooler system that can appropriately control the amount of cooling water circulated. [Solution] The cooling intercooler system is a water-cooled intercooler system mounted on a vehicle, comprising: an engine having a supercharger; a water-cooled intercooler that cools the intake air supercharged by the supercharger; a pump that adjusts the amount of coolant circulating through the water-cooled intercooler; and a control device that controls the rotational speed of the pump, wherein the control device switches between a first control that controls the rotational speed of the pump based on the intercooler efficiency of the water-cooled intercooler, and a second control that controls the rotational speed of the pump based on a predetermined map according to the load and rotational speed of the engine, according to the operating state of the vehicle.

Description

Technical Field

[0001] This disclosure relates to a water-cooled intercooler system.

Background Art

[0002] Conventionally, a water-cooled intercooler system that cools intake air supercharged by an engine supercharger with a water-cooled intercooler system is known (see, for example, Patent Document 1). The water-cooled intercooler system of Patent Document 1 includes a water-cooled intercooler and an electric pump that circulates cooling water flowing through the water-cooled intercooler. The water-cooled intercooler system of Patent Document 1 drives an electric pump to consume the power of a high-voltage battery mounted on a vehicle.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Such a water-cooled intercooler system generally determines the rotational speed of the pump based on a map stored in a control device. The map presets the rotational speed of the pump according to the engine rotational speed and the load of the engine. Thus, by using the map, the water-cooled intercooler system can determine the rotational speed of the pump without performing calculations. However, when determining the rotational speed of the electric pump by the map, depending on the operating conditions of the engine, the circulation volume of the cooling water may be insufficient.

[0005] An object of the present disclosure is to provide a water-cooled intercooler system capable of appropriately controlling the circulation volume of cooling water.

Means for Solving the Problems

[0006] The water-cooled intercooler system according to this disclosure is a water-cooled intercooler system mounted on a vehicle, comprising: an engine having a supercharger; a water-cooled intercooler for cooling intake air supercharged by the supercharger; a pump for adjusting the amount of coolant circulating through the water-cooled intercooler; and a control device for controlling the rotational speed of the pump, wherein the control device switches between a first control that controls the rotational speed of the pump based on the intercooler efficiency of the water-cooled intercooler, and a second control that controls the rotational speed of the pump based on a predetermined map according to the load and rotational speed of the engine, according to the operating state of the vehicle. [Effects of the Invention]

[0007] This water-cooled intercooler system allows switching between a first control and a second control depending on the engine operating conditions. This enables the water-cooled intercooler system to appropriately control the amount of coolant circulating using the first control, according to the vehicle's operating state. On the other hand, if the first control is not performed, the water-cooled intercooler system can determine the pump speed using the second control without calculating the pump speed. [Brief explanation of the drawing]

[0008] [Figure 1] A system diagram of a water-cooled intercooler system according to one embodiment of the present disclosure. [Figure 2] A flowchart illustrating a control procedure performed by a control device according to one embodiment of the present disclosure. [Modes for carrying out the invention]

[0009] Hereinafter, one embodiment of this disclosure will be described with reference to the drawings.

[0010] As shown in Figure 1, the water-cooled intercooler system 1 comprises an engine 2, a supercharger 4, a water-cooled intercooler 6, and a control unit (ECU) 10. In this embodiment, the water-cooled intercooler system 1 is mounted on a vehicle C.

[0011] Vehicle C in this embodiment is a plug-in hybrid electric vehicle (PHEV) comprising a motor (FrM) 20, a generator (GEN) 22, a drive battery (BT) 24, a transaxle 26, an inverter 28 that controls the motor 20 and generator 22, an accelerator pedal 30 operated by the user of vehicle C, a charger 32 that can be connected to an external power source, and an external power supply device 34 that can supply power to external devices such as home appliances. Each device is electrically connected to the control device 10.

[0012] Engine 2 is connected to and drives the generator 22. Furthermore, in this embodiment, engine 2 can drive the wheels C1 via the transaxle 26. Engine 2 in this embodiment is an inline four-cylinder gasoline engine.

[0013] Motor 20 is connected to a wheel (an example of a drive wheel) C1 via a transaxle 26 and axle CW, and drives the wheel C1. Motor 20 in this embodiment is a three-phase AC motor having multiple coils and multiple permanent magnets. Motor 20 is also driven by the rotation of wheel C1 to generate electricity (regenerative power). Therefore, motor 20 is a motor-generator capable of both powering and generating electricity. Generator 22 is connected to engine 2 and can drive engine 2. Generator 22 motors engine 2 while powering from drive battery 24. On the other hand, generator 22 is driven by engine 2 to generate electricity while engine 2 is running. Therefore, generator 22 is a motor-generator capable of both powering and generating electricity.

[0014] The drive battery 24 outputs power to the motor 20 and the generator 22, and also receives power generated by the motor 20 and the generator 22. Furthermore, the drive battery 24 receives external power via the charger 32. In this embodiment, the drive battery 24 is composed of multiple lithium-ion batteries.

[0015] The transaxle 26 has multiple gears and a clutch 26a. The engine 2 is connected to the generator 22 and the axle CW via the transaxle 26. When the clutch 26a of the transaxle 26 is open, power transmission between the engine 2 and the axle CW is interrupted, and when the clutch 26a is engaged, power from the engine 2 is transmitted to the axle CW.

[0016] Vehicle C in this embodiment has driving modes such as EV mode, series mode, and parallel mode. In EV mode, with the engine 2 stopped, the motor 20 is driven by power from the drive battery 24. In series mode, the clutch 26a is disengaged, the engine 2 drives the generator 22, and the power generated by the generator 22 is used to drive the motor 20 and drive the wheels C1. In parallel mode, the clutch 26a is engaged, and the power from the engine 2 is used to drive the wheels C1 via the axle CW. Depending on the depression state of the accelerator pedal 30, the control device 10 switches between each driving mode and controls the motor 20 and generator 22 via the inverter 28, as well as the engine 2.

[0017] Furthermore, vehicle C of this embodiment has an external power supply mode. In the external power supply mode, when connector 34a is connected to an external device, the control device 10 performs external power supply control, which uses the external power supply device 34 to supply power from the drive battery 24 to the external device. When the State of Charge (SOC) of the drive battery 24 falls below a predetermined charge level SOCt during the external power supply mode, the control device 10 disengages the clutch 26a, starts the engine 2 to drive the generator 22, and performs an engine-generated external power supply mode, which stores the power generated by the generator 22 in the drive battery 24 and supplies it to the external device.

[0018] Furthermore, vehicle C has a charge mode. In charge mode, the control device 10 drives the generator 22 with the engine 2 and primarily stores the power generated by the generator 22 in the drive battery 24. Furthermore, vehicle C has a save mode. In save mode, the control device 10 limits the output of the drive battery 24 to maintain the state of charge (SOC) of the drive battery 24. In save mode, the power generated primarily by the generator 22 is supplied to the motor 20. In this embodiment, the save mode suppresses the power performance of vehicle C more than in series mode and prioritizes maintaining the output of the drive battery 24.

[0019] Engine 2 includes an intake manifold 2a and an exhaust purification device 2b. The intake manifold 2a is located downstream of the water-cooled intercooler 6 and distributes supercharged intake air to the cylinders of engine 2. The exhaust purification device 2b is located downstream of the supercharger 4 and purifies the exhaust gas.

[0020] The supercharger 4 is a device that pressurizes the intake air supplied to the engine 2. In this embodiment, the supercharger 4 is a turbocharger that uses the exhaust energy discharged from the engine 2 to supercharge the intake air. However, the supercharger 4 may also be a supercharger that supercharges using, for example, the driving force of the engine 2. The upstream side of the supercharger 4 is connected to an air cleaner 4a that draws in outside air. The downstream side of the supercharger 4 is connected to a water-cooled intercooler 6. An outside temperature sensor 4c that detects the temperature of the outside air is attached to the air cleaner 4a. The outside temperature sensor 4c is connected to a control device 10. The downstream side of the water-cooled intercooler 6 is connected to an intake manifold 2a.

[0021] The water-cooled intercooler 6 is a device that cools the intake air supercharged by the supercharger 4. The water-cooled intercooler 6 includes a heat exchanger 6a, a radiator 6b, and a pump 6c. The heat exchanger 6a has a passage through which cooling water passes and a passage through which intake air passes. The cooling water passage is connected to the radiator 6b via an outlet passage 6d. The radiator 6b performs heat exchange between the cooling water and the intake air and cools the cooling water. The radiator 6b is connected to the pump 6c via a pump inlet passage 6e. The pump 6c circulates the cooling water. The pump 6c is connected to the heat exchanger 6a via a pump outlet passage 6f. In this embodiment, the pump 6c is an electric pump. The higher the rotational speed of the pump 6c, the greater the circulation volume of the cooling water. As a result, the amount of cooling water passing through the heat exchanger 6a per unit time increases.

[0022] An upstream temperature sensor 6g for detecting the intake air temperature is arranged on the intake air passage upstream of the water-cooled intercooler 6. A downstream temperature sensor 6h for detecting the intake air temperature is arranged on the intake air passage downstream of the water-cooled intercooler 6. The pump 6c, the upstream temperature sensor 6g, and the downstream temperature sensor 6h are electrically connected to the control device 10.

[0023] The control device 10 is actually an ECU (Electronic Control Unit) composed of a microcomputer including an arithmetic unit, a memory, an input / output buffer, etc. The control device 10 controls the vehicle C based on maps and programs stored in the memory.

[0024] The control device 10 obtains the upstream intake air temperature Tu from the upstream temperature sensor 6g. The control device 10 obtains the downstream intake air temperature Td from the downstream temperature sensor 6h. The control device 10 obtains the intercooler efficiency Ie from the upstream intake air temperature Tu and the downstream intake air temperature Td. In this configuration, the intercooler efficiency Ie is the value obtained by dividing the difference between the upstream intake air temperature Tu and the downstream intake air temperature Td by the difference between the upstream intake air temperature Tu and the ambient air temperature. The intercooler efficiency Ie is poor when the difference between the upstream intake air temperature Tu and the downstream intake air temperature Td is small relative to the difference between the upstream intake air temperature Tu and the ambient air temperature, and good when the difference between the upstream intake air temperature Tu and the downstream intake air temperature Td is large relative to the difference between the upstream intake air temperature Tu and the ambient air temperature.

[0025] The control device 10 controls the pump speed Pr of the pump 6c. The control device 10 performs a first control that controls the pump speed Pr based on the intercooler efficiency Ie of the water-cooled intercooler. The control device 10 also performs a second control that controls the pump speed Pr based on a predetermined map according to the load Q and engine speed Er of the engine 2. The control device 10 switches between the first control and the second control depending on the operating state of the engine 2.

[0026] Next, the control procedure executed by the control device 10 will be explained using the flowchart in Figure 2.

[0027] In step S1, the control device 10 determines whether or not it is in series mode. If the control device 10 determines that it is in series mode (step S1 YES), it proceeds to step S2.

[0028] In step S2, the control device 10 performs the first control. After performing the first control, the control device 10 proceeds to step S3. In step S3, the control device 10 feedback-controls the pump rotation speed Pr so that the intercooler efficiency Ie becomes a first target value TPr1. That is, if the intercooler efficiency Ie is worse than the first target value TPr1, the pump rotation speed Pr is lowered, and if the intercooler efficiency Ie is better than the first target value TPr1, the pump rotation speed Pr is increased. During series mode, even if the load Q of engine 2 or the engine rotation speed Er increases, the speed of vehicle C does not necessarily increase. Therefore, the airflow hitting the heat exchanger 6a of the water-cooled intercooler 6 does not necessarily increase. As a result, it is preferable to perform the first control rather than the second control by map. After performing the processing in step S3, the control device 10 returns.

[0029] If the control device 10 determines in step S1 that it is not in series mode (step S1 NO), the control device 10 proceeds to step S4.

[0030] In step S4, the control device 10 determines whether or not it is in parallel mode. If the control device 10 determines that it is in parallel mode (step S4 YES), it proceeds to step S5.

[0031] In step S5, the control device 10 performs a second control. That is, it increases the pump speed Pr as the load Q or engine speed Er of engine 2 increases. During parallel mode, the speed of vehicle C increases in accordance with the increase in the load Q or engine speed Er of engine 2. As a result, the amount of airflow hitting the heat exchanger 6a of the water-cooled intercooler 6 increases. Consequently, it is preferable to perform the second control by map during parallel mode. After performing step S5, the control device 10 returns.

[0032] If the control device 10 determines in step S4 that it is not in parallel mode (step S4 NO), the process proceeds to step S6.

[0033] In step S6, the control device 10 determines whether or not it is in charge mode. If the control device 10 determines that it is in charge mode (step S6 YES), it proceeds to step S7.

[0034] In step S7, the control device 10 performs the first control. After performing the first control, the control device 10 proceeds to step S8. In step S8, the control device 10 feedback-controls the pump rotation speed Pr so that the intercooler efficiency Ie becomes the second target value TPr2. The second target value TPr2 is an intercooler efficiency Ie that is higher than the first target value TPr1. An intercooler efficiency Ie higher than the first target value TPr1 means that, when the target value TPr is the difference between the upstream intake air temperature Tu and the downstream intake air temperature Td, the difference between the upstream intake air temperature Tu and the downstream intake air temperature Td is greater for the second target value TPr2 than for the first target value TPr1. Also, when the target value TPr is the ratio of the upstream intake air temperature Tu and the downstream intake air temperature Td, the ratio between the upstream intake air temperature Tu and the downstream intake air temperature Td is smaller for the second target value TPr2 than for the first target value TPr1. In charge mode, engine 2 operates even when vehicle C is stopped. Therefore, it receives less airflow than in series mode. As a result, a higher intercooler efficiency Ie is required than in series mode. For this reason, control device 10 feedback-controls the pump rotation speed Pr, aiming for a second target value TPr2 that is higher than the first target value TPr1. Control device 10 returns after executing the process in step S8.

[0035] If the control device 10 determines in step S6 that it is not in charge mode (step S6 NO), the process proceeds to step S9.

[0036] In step S9, the control device 10 determines whether or not it is in save mode. If the control device 10 determines that it is in save mode (step S9 YES), it proceeds to step S10.

[0037] In step S10, the control device 10 performs a first control. After performing the first control, the control device 10 proceeds to step S11. In step S11, the control device 10 feedback-controls the pump rotation speed Pr so that the intercooler efficiency Ie becomes the third target value TPr3. The third target value TPr3 is an intercooler efficiency Ie that is lower than the first target value TPr1. An intercooler efficiency Ie lower than the first target value TPr1 means that, when the target value TPr is the difference between the upstream intake air temperature Tu and the downstream intake air temperature Td, the difference between the upstream intake air temperature Tu and the downstream intake air temperature Td is smaller for the third target value TPr3 than for the first target value TPr1. Also, when the target value TPr is the ratio of the upstream intake air temperature Tu and the downstream intake air temperature Td, the ratio between the upstream intake air temperature Tu and the downstream intake air temperature Td is larger for the third target value TPr3 than for the first target value TPr1. In save mode, the output of vehicle C is suppressed, so there are fewer opportunities for the output of engine 2 to increase compared to series mode. As a result, there are also fewer opportunities for the boost pressure to be low compared to series mode. On the other hand, in save mode, as in series mode, the speed of vehicle C and the load Q and engine speed Er of engine 2 are not linked. As a result, a lower intercooler efficiency Ie than in series mode is sufficient. For this reason, the control device 10 feedback-controls the pump speed Pr with a target of a third target value TPr3, which is lower than the first target value TPr1. This suppresses energy consumption due to high-output driving of pump 6c and suppresses deterioration of fuel efficiency (electricity efficiency). The control device 10 returns after executing the process in step S11.

[0038] If the control device 10 determines in step S9 that it is not in save mode (step S9 NO), the process proceeds to step S12.

[0039] In step S12, the control device 10 determines whether or not it is in external power supply mode. If the control device 10 determines that it is in external power supply mode (step S12 YES), it proceeds to step S13.

[0040] In step S13, the control device 10 performs a second control. During external power supply mode, the vehicle C is often stopped. Therefore, the control device 10 controls the pump speed Pr using a map in which the pump speed Pr is higher than in parallel mode, corresponding to the load Q of the engine 2 and the engine speed Er. This allows the control device 10 to cool the water-cooled intercooler 6 more effectively.

[0041] If the control device 10 determines in step S12 that it is not in external power supply mode (step S13 NO), the control device 10 returns.

[0042] As described above, this disclosure provides a water-cooled intercooler system 1 capable of appropriately controlling the amount of cooling water circulated.

[0043] <Other Embodiments> Although embodiments of the present disclosure have been described above, the present disclosure is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention. In particular, the various modifications described herein can be combined as needed.

[0044] In the embodiments described above, engine 2 was described as a gasoline engine, but this disclosure is not limited thereto. Engine 2 may be a diesel engine. [Explanation of Symbols]

[0045] 1: Water-cooled intercooler system, 2: Engine 4: Supercharger, 6: Water-cooled intercooler, 6c: Pump 10: Control device 20: Motor, 22: Generator, 24: Drive battery C: Vehicle, C1: Wheel, Er: Engine RPM Ie: Intercooler efficiency, Pr: Pump rotation speed Q: Load, SOC: Charging rate TPr1: First target value, TPr2: Second target value, TPr3: Third target value

Claims

1. A water-cooled intercooler system installed in a vehicle, An engine with a supercharger, A water-cooled intercooler that cools the intake air supercharged by the supercharger, A pump that adjusts the amount of coolant circulating through the water-cooled intercooler, A control device for controlling the pump rotation speed of the aforementioned pump, Equipped with, The control device switches between a first control that controls the pump rotation speed based on the intercooler efficiency of the water-cooled intercooler and a second control that controls the pump rotation speed based on a predetermined map according to the engine load and engine speed, depending on the operating state of the vehicle. Water-cooled intercooler system.

2. The vehicle has a series mode that supplies electricity generated by the engine to the motor. In the case of the series mode, the control device performs the first control and provides feedback control of the pump rotation speed in the first control so that the intercooler efficiency becomes a first target value. The water-cooled intercooler system according to claim 1.

3. The vehicle has a charge mode that primarily stores electricity generated by the engine in a battery. In the charge mode, the control device performs the first control, and in the first control, it provides feedback control of the pump rotation speed so that the intercooler efficiency becomes a second target value that is higher than the first target value. The water-cooled intercooler system according to claim 2.

4. The vehicle has a save mode that limits the output of the battery in order to maintain the battery's charge level. In the save mode, the control device performs the first control and provides feedback control of the pump rotation speed in the first control so that the intercooler efficiency becomes a third target value that is lower than the first target value. The water-cooled intercooler system according to claim 2.

5. The vehicle has a parallel mode that outputs the output of the engine to the drive wheels of the vehicle, In the case of the parallel mode, the control device executes the second control. The water-cooled intercooler system according to claim 1.

6. The vehicle further comprises a drive battery capable of supplying power to external equipment, The vehicle has an external power supply mode that supplies at least one of the power generated by the engine and the power from the drive battery to external equipment. The control device, in the case of the external power supply mode, executes the second control. The water-cooled intercooler system according to claim 1.

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