JP2004052691A - Internal combustion engine with heat storage device - Google Patents

Abstract

The present invention relates to an internal combustion engine provided with a heat storage device capable of storing a heat medium such as cooling water in a heat-retaining state, without reducing the heat-retention performance of the heat storage device without reducing the heat-retention performance of the heat storage device. It is an object to provide a technology capable of accurately detecting a temperature.
An internal combustion engine includes a heat storage device that estimates a temperature of a heat medium stored in a heat storage tank according to a heat medium temperature detected by a heat medium temperature detection unit disposed outside the heat storage tank. By correcting the estimated temperature in consideration of the temperature element acting on the temperature of the heat medium in the heat storage tank, the temperature of the heat medium in the heat storage tank can be accurately determined regardless of the temperature environment of the heat storage tank. It is characterized by seeking.
[Selection] Fig. 10

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an internal combustion engine mounted on a vehicle or the like, and particularly to an internal combustion engine provided with a heat storage device.
[0002]
[Prior art]
In recent years, when the temperature of the internal combustion engine is low (cold state), the temperature of the internal combustion engine is quickly raised to improve startability, reduce the emission of unburned fuel components (improve exhaust emissions), For the purpose of improving the fuel consumption rate, etc., the development of an internal combustion engine equipped with a heat storage device is being promoted.
[0003]
The heat storage device includes a heat storage tank that stores cooling water (hot water) that has become hot during operation of the water-cooled internal combustion engine in a warm state, and uses the hot water in the heat storage tank when the internal combustion engine is in a cold state. To increase the temperature of the internal combustion engine quickly.
[0004]
In such a heat storage device, it is determined whether or not the heat retention performance of the heat storage tank has failed, whether or not hot water should be recovered to the heat storage tank, or whether or not hot water can be supplied from the heat storage tank to the internal combustion engine. It is also important to accurately detect the temperature of the cooling water in the heat storage tank in determining whether or not the cooling water is present.
[0005]
In response to such a demand, Japanese Patent Application Laid-Open No. H11-182307 discloses a method in which a temperature sensor for directly detecting the temperature of cooling water in a heat storage tank is attached to the heat storage tank, A method of estimating a water temperature in a heat storage tank using a water temperature and an elapsed time from when the operation of the internal combustion engine is stopped as a parameter is disclosed.
[0006]
[Problems to be solved by the invention]
By the way, in the above-mentioned conventional technique, in the method of directly detecting the water temperature in the heat storage tank by attaching the water temperature sensor to the heat storage tank, it is possible to accurately detect the water temperature in the heat storage tank. Heat easily leaks to the outside through the water temperature sensor, and the heat retention performance of the heat storage tank may be reduced.
[0007]
Further, in the method of estimating the water temperature in the heat storage tank using the water temperature in the internal combustion engine when the operation of the internal combustion engine is stopped and the elapsed time from the time when the operation of the internal combustion engine is stopped as a parameter, is the recovery of the hot water to the heat storage tank performed? No, because the environment in which the heat storage tank is placed (for example, the mounting position of the heat storage tank in the vehicle and the outside air temperature) is not taken into account, the estimation accuracy may be low.
[0008]
The present invention has been made in view of the various problems as described above, and in an internal combustion engine including a heat storage device capable of storing a heat medium such as cooling water in a heat-retained state, the heat storage performance of the heat storage device is reduced. It is an object of the present invention to provide a technique capable of accurately detecting the temperature of a heat medium stored in a heat storage device without causing the heat storage device to detect the temperature.
[0009]
[Means for Solving the Problems]
The present invention employs the following means in order to solve the above problems. That is, the internal combustion engine provided with the heat storage device according to the present invention,
A heat medium circulation path through which the heat medium circulates via the internal combustion engine;
A heat storage tank that stores a part of the heat medium circulating in the heat medium circulation path in a warm state,
Heat medium temperature detection means provided in the heat medium circulation path to detect the temperature of the heat medium,
Estimating means for estimating the heat medium temperature in the heat storage tank based on the heat medium temperature detected by the heat medium temperature detecting means when a heat medium is stored in the heat storage tank,
Correction means for correcting the heat medium temperature estimated by the estimation means according to a specific temperature element acting on the temperature of the heat medium stored in the heat storage tank,
Was provided.
[0010]
The present invention relates to an internal combustion engine provided with a heat storage device for estimating the temperature of a heat medium stored in a heat storage tank in accordance with a heat medium temperature detected by a heat medium temperature detection unit disposed outside the heat storage tank. The greatest feature is that the temperature of the heat medium is corrected in accordance with a temperature element acting on the temperature of the heat medium in the heat storage tank.
[0011]
In the internal combustion engine provided with such a heat storage device, the heat medium temperature detecting means detects the temperature of the heat medium when the heat medium is stored in the heat storage tank, that is, the temperature of the heat medium stored in the heat storage tank.
[0012]
The estimating means estimates the temperature of the heat medium stored in the heat storage tank based on the heat medium temperature detected by the heat medium temperature detecting means.
[0013]
By the way, since the heat retention performance of the heat storage tank, in other words, the temperature of the heat medium stored in the heat storage tank is affected by the environment in which the heat storage tank is placed, the temperature of the heat medium in the heat storage tank is accurately estimated. To do so, it is necessary to consider the environment in which the heat storage tank is placed.
[0014]
For example, when the heat storage tank is placed at a low temperature, the temperature of the heat medium stored in the heat storage tank tends to decrease. Conversely, when the heat storage tank is placed at a high temperature, it is stored in the heat storage tank. It is difficult for the temperature of the heating medium to decrease.
[0015]
Therefore, the internal combustion engine including the heat storage device according to the present invention includes a correction unit that corrects the heat medium temperature estimated by the estimation unit based on a temperature element acting on the temperature of the heat medium stored in the heat storage tank. I prepared for it.
[0016]
In this way, if the heat medium temperature in the heat storage tank is estimated in consideration of the specific temperature element acting on the temperature of the heat medium stored in the heat storage tank, if the heat storage tank is placed in any environment, Even so, the temperature of the heat medium in the heat storage tank can be easily estimated accurately.
[0017]
The specific temperature element that affects the temperature of the heat medium stored in the heat storage tank may be, for example, the outside air temperature. However, if the heat storage tank is placed in a place that is not directly affected by the outside air temperature, such as a vehicle engine room, a vehicle room, a vehicle trunk room, or a dedicated box having heat shielding properties, The temperature around the heat storage tank can also be used.
[0018]
Further, in the internal combustion engine including the heat storage device according to the present invention, when the storage process of the heat medium in the heat storage tank is interrupted, the amount of the heat medium flowing into the heat storage device during a period from the start of the storage process to the interruption is determined. The heat medium inflow amount calculating means for calculating the heat medium inflow amount calculated by the heat medium inflow amount calculating means, the specific temperature element acting on the temperature of the heat medium stored in the heat storage tank, and the heat medium inflow amount calculating means. The heat medium temperature estimated by the estimation means may be corrected according to the amount.
[0019]
This is because when the storage process of the heat medium in the heat storage tank is interrupted, the temperature of the heat medium in the heat storage tank changes according to the amount of the heat medium stored in the heat storage tank during the period from the start to the interruption of the storage process. Because you do.
[0020]
In the internal combustion engine provided with the heat storage device according to the present invention, the estimating means performs the storage processing of the heat medium in the heat storage tank in addition to the heat medium temperature detected by the heat medium temperature detecting means when the heat medium is stored in the heat storage tank. The temperature of the heat medium in the heat storage tank may be estimated using the elapsed time from the completion time as a parameter.
[0021]
In the internal combustion engine provided with the heat storage device according to the present invention, examples of the heat medium include cooling water and lubricating oil.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, a specific embodiment of an internal combustion engine provided with a heat storage device according to the present invention will be described with reference to the drawings.
[0023]
<Embodiment 1>
First, a first embodiment of an internal combustion engine provided with a heat storage device according to the present invention will be described with reference to FIGS.
FIG. 1 is a diagram showing a schematic configuration of a cooling water circulation system of a water-cooled internal combustion engine to which the present invention is applied.
[0024]
The internal combustion engine 1 shown in FIG. 1 is a water-cooled internal combustion engine mounted on a vehicle, and includes a cylinder head 1a and a cylinder block 1b. Each of the cylinder head 1a and the cylinder block 1b is provided with a head-side cooling water passage 2a and a block-side cooling water passage 2b for flowing cooling water, and the head-side cooling water passage 2a and the block-side cooling water passage 2b communicate with each other. are doing.
[0025]
The first cooling water passage 4 is connected to the head-side cooling water passage 2a. The first cooling water passage 4 is connected to a cooling water inlet of the radiator 5.
[0026]
The radiator 5 is a heat exchanger that exchanges heat between the cooling water flowing from the cooling water inlet and outside air, and is configured to discharge the cooling water after the heat exchange from the cooling water outlet.
[0027]
The cooling water outlet of the radiator 5 is connected to the second cooling water passage 6. The second cooling water passage 6 is connected to a thermostat valve 7. A third cooling water channel 8 and a bypass water channel 9 are connected to the thermostat valve 7 in addition to the second cooling water channel 6.
[0028]
When the temperature of the cooling water flowing through the thermostat valve 7 is lower than a predetermined valve opening temperature: T1, the thermostat valve 7 shuts off the second cooling water channel 6 and connects the third cooling water channel 8 with the bypass water channel 9. When the temperature of the cooling water flowing through the thermostat valve 7 becomes equal to or higher than the valve opening temperature: T1, the bypass water passage 9 is cut off to connect the second cooling water passage 6 and the third cooling water passage 8. Have been.
[0029]
Note that the above-described valve opening temperature: T1 is a temperature corresponding to the cooling water temperature when the internal combustion engine 1 is in the warm-up completed state, and is, for example, a temperature set to about 75 ° C to 90 ° C.
[0030]
The aforementioned third cooling water passage 8 is connected to a cooling water suction port of a mechanical water pump 10 attached to the internal combustion engine 1.
[0031]
The mechanical water pump 10 is a pump that generates a flow of cooling water by driving a rotation torque of an output shaft (crankshaft) of the internal combustion engine 1, and discharges the cooling water sucked from the cooling water suction port to the cooling water discharge port. It is configured to discharge from the outlet. The cooling water discharge port of the mechanical water pump 10 is connected to the block-side cooling water passage 2b.
[0032]
The bypass water passage 9 is a passage that bypasses the first cooling water passage 4, the radiator 5, and the second cooling water passage 6, and is connected to the head-side cooling water passage 2a.
[0033]
Next, a heater hose 11 is connected in the middle of the first cooling water passage 4. The heater hose 11 is connected in the middle of the third cooling water passage 8 described above.
[0034]
A heater core 12 for exchanging heat between room heating air and cooling water is provided in the middle of the heater hose 11.
[0035]
A first bypass passage 13a is connected in the middle of the heater hose 11 located between the heater core 12 and the third cooling water passage 8. The first bypass passage 13a is connected to a cooling water suction port of the electric water pump 14.
[0036]
The electric water pump 14 is a pump that generates a flow of cooling water using electric power output from a battery 25 as a drive source, and is configured to discharge cooling water sucked from the cooling water suction port from a cooling water discharge port. ing.
[0037]
The cooling water discharge port of the electric water pump 14 is connected to a second bypass passage 13b. The second bypass passage 13b is connected to a cooling water inlet 15a of the heat storage tank 15.
[0038]
The heat storage tank 15 is a container for storing the cooling water in a heat storage state. When the cooling water flows in from the cooling water inlet 15a, the cooling water is cooled instead of the cooling water originally stored in the heat storage tank 15. It is configured to discharge from the water outlet 15b.
[0039]
The cooling water outlet 15b of the heat storage tank 15 is connected to a third bypass passage 13c. The third bypass passage 13c is connected in the middle of a heater hose 11 located between the first cooling water passage 4 and the heater core 12.
[0040]
In the following, in the heater hose 11 located between the first cooling water passage 4 and the heater core 12, the portion on the first cooling water passage 4 side with respect to the connection portion with the third bypass passage 13c is set to the first position. The portion on the heater core 12 side is referred to as a heater hose 11a, and the second heater hose 11b. In the heater hose 11 located between the heater core 12 and the third cooling water passage 8, a portion on the side of the heater core 12 with respect to a connection portion with the first bypass passage 13a is referred to as a third heater hose 11c, and a third cooling hose 11c is provided. The portion on the water passage 8 side is referred to as a fourth heater hose 11d.
[0041]
Next, a flow path switching valve 16 is provided at a connection portion between the first heater hose 11a, the second heater hose 11b, and the third bypass passage 13c. The flow path switching valve 16 is driven by an electric motor or the like, and is configured to shut off any one of the first heater hose 11a, the second heater hose 11b, and the third bypass passage 13c.
[0042]
In the third bypass passage 13c, near the cooling water outlet 15b of the heat storage tank 15, a tank outlet for outputting an electric signal corresponding to the temperature of the cooling water discharged from the heat storage tank 15 (hereinafter, referred to as a tank outlet water temperature). A water temperature sensor 17 is provided. The tank outlet water temperature sensor 17 corresponds to a heat medium temperature detecting unit according to the present invention.
[0043]
An electric signal corresponding to the temperature of the cooling water flowing through the first cooling water passage 4 (hereinafter referred to as the engine-side water temperature) is provided near the connection portion between the first cooling water passage 4 and the head-side cooling water passage 2a. Is provided.
[0044]
An electronic control unit (ECU: Electronic Control Unit) 20 for controlling the flow of cooling water in the cooling water circulation system is provided in the cooling water circulation system of the internal combustion engine 1 configured as described above. The ECU 20 is an arithmetic and logic operation circuit including a CPU, a ROM, a RAM, a backup RAM, and the like, and is configured to operate using the power of the battery 25 as a drive source.
[0045]
The ECU 20 may be provided independently of the ECU for controlling the operating state of the internal combustion engine 1, or may be used also as the ECU for controlling the internal combustion engine 1.
[0046]
The ECU 20 is connected to an ignition switch 21, a starter switch 22, and a heater switch 23 provided in the interior of the vehicle equipped with the internal combustion engine 1, in addition to the tank outlet water temperature sensor 17 and the engine-side water temperature sensor 18 described above. A door switch 24 for detecting opening of a door for getting on and off the vehicle (preferably, a door for getting on and off the driver's seat) provided on a vehicle on which the internal combustion engine 1 is mounted, and an outside air temperature sensor mounted on the vehicle on which the internal combustion engine 1 is mounted 26 are connected.
[0047]
An electric water pump 14 and a flow path switching valve 16 are electrically connected to the ECU 20, so that the ECU 20 can control the electric water pump 14 and the flow path switching valve 16.
[0048]
For example, when the internal combustion engine 1 is in the operating state, the mechanical water pump 10 operates by receiving the rotational torque of the crankshaft. On the other hand, the ECU 25 controls the flow path switching valve 16 to shut off the first heater hose 11a, and cuts off the supply of the driving power from the battery 25 to the electric water pump 14 to stop the operation of the electric water pump 14. .
[0049]
In this case, the electric water pump 14 does not operate, and only the mechanical water pump 10 operates. If the temperature of the cooling water at this time is lower than the opening temperature of the thermostat valve 7: T1, the thermostat valve 7 does not operate. Cuts off the second cooling water passage 6 and connects the third cooling water passage 8 with the bypass water passage 9.
[0050]
Therefore, when the internal combustion engine 1 is in the operating state and the temperature of the cooling water is lower than the temperature T1 at which the thermostat valve 7 is opened, as shown in FIG. 2, the mechanical water pump 10 → the block-side cooling water passage 2b A circulation circuit in which cooling water flows in the order of the head-side cooling water passage 2a, the bypass water passage 9, the thermostat valve 7, the third cooling water passage 8, and the mechanical water pump 10 is established.
[0051]
When the circulation circuit as shown in FIG. 2 is established, the relatively low-temperature cooling water flowing out of the internal combustion engine 1 flows around the radiator 5, so that the cooling water is not unnecessarily cooled by the radiator 5. become. As a result, the warm-up of the internal combustion engine 1 is not hindered.
[0052]
Thereafter, when the warming-up of the internal combustion engine 1 proceeds and the temperature of the cooling water becomes equal to or higher than the opening temperature T1 of the thermostat valve 7, the thermostat valve 7 opens the second cooling water channel 6 and simultaneously shuts off the bypass water channel 9. The second cooling water passage 6 and the third cooling water passage 8 are electrically connected.
[0053]
In this case, as shown in FIG. 3, the mechanical water pump 10 → block side cooling water passage 2b → head side cooling water passage 2a → first cooling water passage 4 → radiator 5 → second cooling water passage 6 → thermostat valve 7 → A circulation circuit in which the cooling water flows in the order of the third cooling water passage 8 → the mechanical water pump 10 is established.
[0054]
When the circulation circuit as shown in FIG. 3 is established, the relatively high-temperature cooling water that has absorbed the heat generated by the internal combustion engine 1 flows through the radiator 5, so that the heat of the cooling water And the heat absorption capacity of the cooling water is regenerated, thereby lowering the temperature of the cooling water. The cooling water whose heat absorbing ability has been regenerated in the radiator 5 re-flows into the head-side cooling water passage 2a and the block-side cooling water passage 2b of the internal combustion engine 1 to appropriately absorb the heat generated by the internal combustion engine 1. As a result, overheating of the internal combustion engine 1 is prevented.
[0055]
When the heater switch 23 is switched from off to on while the internal combustion engine 1 is in the normal operation state after the completion of warming-up, the ECU 20 sends a signal from the battery 25 to the electric water pump 14 to stop the electric water pump 14. While the power supply is cut off, the flow path switching valve 16 is controlled so as to cut off the third bypass passage 13c.
[0056]
In this case, the electric water pump 14 does not operate, only the mechanical water pump 10 operates, and the thermostat valve 7 shuts off the bypass passage 9 and connects the second cooling water passage 6 and the third cooling water passage 8 with each other. Further, since the flow path switching valve 16 conducts the first heater hose 11a and the second heater hose 11b, as shown in FIG. 4, a circulation circuit as described in the description of FIG. Water pump 10 → block side cooling water passage 2b → head side cooling water passage 2a → first cooling water passage 4 → first heater hose 11a → flow path switching valve 16 → second heater hose 11b → heater core 12 → third heater hose 11c A circulation circuit in which the cooling water flows in the order of → the fourth heater hose 11d → the third cooling water passage 8 → the mechanical water pump 10 is established.
[0057]
When the circulation circuit shown in FIG. 4 is established, the high-temperature cooling water that has absorbed the heat generated by the internal combustion engine 1 is supplied to the first cooling water passage 4 → the first heater hose 11a → the flow path switching valve 16 → the second heater. Since the coolant flows into the heater core 12 through the hose 11b, the heat of the cooling water in the heater core 12 is transmitted to the room heating air. As a result, the room heating air is warmed, so that the temperature inside the vehicle can be increased.
[0058]
Further, when the internal combustion engine 1 is started in a cold state, the temperature around the intake port and the vicinity of the combustion chamber (not shown) is low, so that the fuel injected from the fuel injection valve is difficult to atomize (or vaporize). Since it easily adheres to the wall of the port and the wall of the combustion chamber, it becomes difficult to form a highly flammable air-fuel mixture in the combustion chamber.As a result, the startability is deteriorated, and the unburned fuel components at the start and after the start are reduced. An increase in emissions (deterioration of exhaust emissions) may be induced.
[0059]
On the other hand, if a specific timing element related to the start of the internal combustion engine 1 is detected before the starter switch 22 is switched from off to on, the ECU 20 executes a pre-heat treatment for warming the internal combustion engine 1 prior to the start. I do.
[0060]
The specific timing elements related to the start of the internal combustion engine 1 include, for example, (1) when the door for getting on and off the vehicle equipped with the internal combustion engine 1 (the door for getting on and off the driver's seat) is opened; (3) when the seat belt provided on the driving seat of the vehicle equipped with the internal combustion engine 1 is worn, (4) when the seat mounted on the driving seat of the vehicle equipped with the engine 1 is worn, (5) When the operation of the clutch mechanism interposed between the internal combustion engine 1 and the transmission is performed, (6) the internal combustion engine 1 is mounted. (7) when the locking of the door for getting on and off the vehicle (at least the door for getting on and off the driver's seat) is released, (7) when the operation of the antitheft device attached to the vehicle on which the internal combustion engine 1 is mounted is released, (8) Key cylinder provided in a vehicle equipped with internal combustion engine 1 It can be exemplified such as when the ignition key is inserted.
[0061]
When the specific timing element as described above is detected, the ECU 20 determines whether or not the pre-heat treatment execution condition is satisfied. The condition for executing the pre-heat treatment is that the output signal value (engine-side water temperature) of the engine-side water temperature sensor 18 is lower than a predetermined temperature (for example, the cooling water temperature when the internal combustion engine 1 is in a warm-up completed state). The temperature of the cooling water inside the tank (hereinafter referred to as the tank water temperature) is higher than the engine-side water temperature, and the difference between the tank water temperature and the engine-side water temperature is a predetermined value or more ((tank water temperature-engine-side water temperature)> predetermined value ) Can be exemplified.
[0062]
The ECU 20 executes the following pre-heat treatment when the pre-heat treatment execution condition described above is satisfied.
[0063]
That is, the ECU 20 supplies the driving power from the battery 25 to the electric water pump 14 to operate the electric water pump 14, and controls the flow path switching valve 16 to shut off the second heater hose 11b.
[0064]
In this case, the mechanical water pump 10 does not operate, only the electric water pump 14 operates, and the first heater hose 11a and the third bypass passage 13c are electrically connected. Therefore, as shown in FIG. Pump 14 → second bypass passage 13b → heat storage tank 15 → third bypass passage 13c → flow passage switching valve 16 → first heater hose 11a → first cooling water passage 4 → head side cooling water passage 2a → block side cooling water passage 2b → machine A circulation circuit through which the cooling water flows in the order of the water pump 10 → the third cooling water passage 8 → the fourth heater hose 11d → the first bypass passage 13a → the electric water pump 14 is established.
[0065]
When the circulation circuit as shown in FIG. 5 is established, the cooling water discharged from the electric water pump 14 flows into the heat storage tank 15 via the second bypass passage 13b. When the cooling water flows into the heat storage tank 15, high-temperature hot water originally stored in the heat storage tank 15 (hereinafter, referred to as heat storage hot water) flows out from the cooling water outlet 15 b of the heat storage tank 15 instead of the cooling water.
[0066]
The heat storage hot water flowing out from the cooling water outlet 15b of the heat storage tank 15 flows into the head side cooling water passage 2a via the third bypass passage 13c → the flow passage switching valve 16 → the first heater hose 11a → the first cooling water passage 4; The cooling water flows from the head-side cooling water passage 2a to the block-side cooling water passage 2b.
[0067]
When the heat storage hot water flows into the head-side cooling water passage 2a and the block-side cooling water passage 2b, the low-temperature cooling water that originally stayed in the head-side cooling water passage 2a and the block-side cooling water passage 2b becomes the head-side cooling water passage 2a and the block-side cooling water passage. 2b.
[0068]
In this way, when the low-temperature cooling water originally retained in the head-side cooling water passage 2a and the block-side cooling water passage 2b replaces the heat-storage hot water, the heat of the heat-storage water flows into the head-side cooling water passage 2a and the block-side cooling water passage 2b. The temperature is transmitted to the internal combustion engine 1 via the wall surface, and the temperature of the internal combustion engine 1 is suitably increased.
[0069]
As a result, the temperature around the combustion chamber of the internal combustion engine 1 is increased, so that atomization of the fuel is promoted and the amount of fuel deposited on the wall is reduced, so that the startability is improved and the emission of unburned fuel components is reduced. .
[0070]
When the engine-side water temperature at the time when the specific timing element is detected is equal to or higher than the predetermined temperature, the ECU 20 determines that the temperature of the internal combustion engine 1 is deteriorated such as startability, exhaust emission, and fuel consumption rate. It is determined that the temperature is high enough not to cause a problem, and the execution of the pre-heat treatment as described above is suspended.
[0071]
Here, in order for the ECU 20 to effectively perform the pre-heat treatment as described above, it is necessary that high-temperature cooling water be stored in the heat storage tank 15 when the pre-heat treatment is performed.
[0072]
On the other hand, when the condition for executing the hot water recovery process is satisfied when the internal combustion engine 1 is in the operating state, the ECU 20 recovers the high-temperature cooling water circulating in the head-side cooling water passage 2a and the block-side cooling water passage 2b into the heat storage tank 15. A hot water recovery process is performed as much as possible.
[0073]
Examples of the above-described hot water recovery processing execution conditions include conditions such as the engine-side water temperature being higher than the tank water temperature, and the difference between the engine-side water temperature and the tank water temperature being a predetermined value or more.
[0074]
When the above-described hot water recovery processing execution condition is satisfied, the ECU 20 executes the following hot water recovery processing.
[0075]
That is, the ECU 20 cuts off the supply of the driving power from the battery 25 to the electric water pump 14 to stop the operation of the electric water pump 14, and controls the flow path switching valve 16 to cut off the second heater hose 11b.
[0076]
In this case, the electric water pump 14 does not operate, only the mechanical water pump 10 operates, and the first heater hose 11a and the third bypass passage 13c are electrically connected. Therefore, as shown in FIG. Water pump 10 → block side cooling water path 2b → head side cooling water path 2a → first cooling water path 4 → first heater hose 11a → flow path switching valve 16 → third bypass passage 13c → heat storage tank 15 → second bypass passage 13b → A circulation circuit through which the cooling water flows in the order of the electric water pump 14 → the first bypass passage 13a → the fourth heater hose 11d → the third cooling water passage 8 → the mechanical water pump 10 is established. This circulation circuit corresponds to the heat medium circulation path according to the present invention.
[0077]
When the circulation circuit as shown in FIG. 6 is established, the high-temperature cooling water that has absorbed the heat of the internal combustion engine 1 in the head-side cooling water passage 2a and the block-side cooling water passage 2b becomes the first cooling water passage 4 → the first heater hose. 11a → flow path switching valve 16 → flow into the heat storage tank 15 via the third bypass passage 13c.
[0078]
When the high-temperature cooling water that has absorbed the heat of the internal combustion engine 1 flows into the heat storage tank 15 in this way, the low-temperature cooling water originally retained in the heat storage tank 15 flows out of the heat storage tank 15 instead of the high-temperature cooling water.
[0079]
Thereafter, when all of the cooling water in the heat storage tank 15 is replaced with high-temperature cooling water from the internal combustion engine 1, the ECU 20 controls the flow path switching valve 16 to shut off the first heater hose 11a or the third bypass passage 13c. Then, the execution of the hot water recovery processing is terminated.
[0080]
The method of determining whether or not all the cooling water in the heat storage tank 15 has been replaced by high-temperature cooling water from the internal combustion engine 1 includes (1) cooling that the mechanical water pump 10 discharges per unit time. Using the flow rate of water and the capacity of the heat storage tank 15 as parameters, the time required for all of the cooling water in the heat storage tank 15 to be replaced (hereinafter referred to as the required time of hot water recovery) is calculated. Or (2) mounting a water temperature sensor in the second bypass passage 13b, and outputting an output signal value of the water temperature sensor from the tank outlet water temperature sensor 17; A method of determining that all the cooling water in the heat storage tank 15 has been replaced by high-temperature cooling water from the internal combustion engine 1 when the output signal value becomes substantially the same as the output signal value of It is possible.
[0081]
In addition, as a method of performing the hot water recovery processing, the electric water pump 14 is configured such that the amount of cooling water discharged by the electric water pump 14 per unit time is larger than the amount of cooling water discharged by the mechanical water pump 10 per unit time. Is operated to reverse the flow of the cooling water, thereby establishing a circulation circuit as described in the description of FIG. 5 described above, or the method described above immediately after the operation of the internal combustion engine 1 is stopped. A method for establishing a circulation circuit as shown in FIG. 5 may be used.
[0082]
By the way, in order for the ECU 20 to effectively execute the pre-heat treatment and the hot water recovery process described above, it is necessary to accurately determine whether the pre-heat treatment execution condition or the hot water recovery process execution condition is satisfied. In order to accurately determine whether the execution condition or the hot water recovery process execution condition is satisfied, it is necessary to accurately detect the tank water temperature.
[0083]
As a method of detecting the water temperature in the tank, a method of attaching a water temperature sensor to the heat storage tank 15 and directly detecting the temperature of the cooling water in the heat storage tank 15 can be considered. However, when a water temperature sensor is attached to the heat storage tank 15, heat stored in the heat storage tank 15 leaks outside through the water temperature sensor, and there is a possibility that the heat storage performance of the heat storage tank 15 is reduced.
[0084]
On the other hand, the temperature of the cooling water flowing into the heat storage tank 15 during the hot water recovery process (the output signal of the tank outlet water temperature sensor 17) and the elapsed time from the end of the execution of the hot water recovery process to the current time (hereinafter referred to as the tank leaving time) ) May be used as a parameter to estimate the tank water temperature.
[0085]
This is based on the finding that although the rate of decrease in the water temperature in the tank is reduced by the heat retaining function of the heat storage tank 15, the water temperature in the tank gradually decreases as the elapsed time from the end of the execution of the hot water recovery processing increases. It is based on
[0086]
However, the above estimation method assumes that the heat storage tank 15 is placed at normal temperature (for example, about 25 ° C.) during the period from the end of the execution of the hot water recovery processing to the current time. When placed in a higher temperature environment or a lower temperature environment than normal temperature, the accuracy of estimating the water temperature in the tank may be reduced.
[0087]
For example, as shown in FIG. 7, in an environment where the outside air temperature is higher than room temperature, the rate of decrease of the water temperature in the tank with respect to the tank standing time becomes lower than at room temperature. , The rate of decrease of the water temperature in the tank becomes higher than at normal temperature. Therefore, when the heat storage tank 15 is left in a temperature environment higher than room temperature or in a temperature environment lower than room temperature, the error between the actual tank water temperature and the estimated value increases.
[0088]
Therefore, in the internal combustion engine provided with the heat storage device according to the present embodiment, ECU 20 determines the temperature of the cooling water flowing into heat storage tank 15 during the hot water recovery processing (hereinafter, referred to as the hot water recovery water temperature) and the tank leaving time. The current tank water temperature is estimated as a parameter, and the estimated tank water temperature is corrected according to the outside air temperature.
[0089]
Specifically, the ECU 20 reads the output signal value of the tank outlet water temperature sensor 17 during the execution of the hot water recovery process, and stores the output signal value in the backup RAM as the hot water recovery water temperature. When the execution of the hot water recovery process is completed, the ECU 20 activates a soak timer built in the ECU 20 in advance. The soak timer is a timer that measures the tank leaving time, and is configured to be operable using the power of the battery 25 as a drive source even after the operation of the internal combustion engine 1 is stopped.
[0090]
Subsequently, the ECU 20 reads the measurement time of the soak timer (tank leaving time) when determining whether the pre-heat treatment execution condition or the hot water recovery process execution condition is satisfied, and reads the hot water recovery water temperature stored in the backup RAM. Further, the output signal value (outside air temperature) of the outside air temperature sensor 26 is read.
[0091]
The ECU 20 estimates the reference tank water temperature using the tank leaving time and the hot water recovery water temperature as parameters. The reference tank water temperature is a temperature corresponding to the tank water temperature when the heat storage tank 15 is left at normal temperature during the period from the end of the execution of the hot water recovery process to the current time.
[0092]
At this time, the relationship between the hot water recovery water temperature, the tank leaving time, and the reference tank water temperature may be experimentally obtained in advance, and the relationship may be mapped and stored in the ROM of the ECU 20. Hereinafter, a map indicating the relationship between the water temperature at the time of collecting the hot water, the tank leaving time, and the water temperature in the reference tank will be referred to as a reference tank water temperature control map.
[0093]
The ECU 20 calculates a correction coefficient corresponding to the above-described outside air temperature (hereinafter, referred to as an outside air temperature correction coefficient). For example, as shown in FIG. 8, the outside air temperature correction coefficient is set to be “1.0” when the outside air temperature is normal temperature, and has a larger value as the outside air temperature becomes higher and the lower the outside air temperature becomes. The value is set to be as small as possible.
[0094]
This is because, as described in the description of FIG. 7 described above, the rate of decrease in the water temperature in the tank is lower than that at normal temperature when the outside air temperature is higher than normal temperature, and is lower when the outside air temperature is lower than normal temperature. This is because the temperature becomes higher than that at normal temperature.
[0095]
The relationship between the outside air temperature and the outside air temperature correction coefficient as shown in FIG. 8 may be mapped in advance and stored in the ROM.
[0096]
The ECU 20 estimates the current tank water temperature by multiplying the reference tank water temperature by the outside air temperature correction coefficient.
[0097]
By estimating the water temperature in the tank in consideration of the temperature environment in which the heat storage tank 15 is placed (in this case, the outside air temperature), the case where the heat storage tank 15 is left in a temperature environment other than the normal temperature is considered. This also makes it possible to accurately estimate the water temperature in the tank.
[0098]
As a result, the ECU 20 can determine whether the pre-heat treatment execution condition or the hot water recovery condition is satisfied based on the accurate tank water temperature.
[0099]
Hereinafter, the operation of the internal combustion engine including the heat storage device according to the present embodiment will be described with reference to FIGS. 9 and 10. Here, an example will be described in which the water temperature in the tank is estimated in order to determine whether or not the pre-heat treatment execution condition is satisfied.
[0100]
FIG. 9 is a flowchart showing a first tank water temperature estimation control routine, and FIG. 10 is a flowchart showing a second tank water temperature estimation control routine.
These first and second tank water temperature estimation control routines are routines stored in the ROM of the ECU 20 in advance.
[0101]
The above-described first tank water temperature estimation control routine is a routine executed by the ECU 20 triggered by the start of execution of the hot water recovery process. In the first tank water temperature estimation control routine, the ECU 20 first determines in S901 whether or not the hot water recovery process is being executed.
[0102]
If it is determined in S901 that the hot water collection process is not being executed, the ECU 20 ends the execution of this routine.
[0103]
On the other hand, if it is determined in S901 that the hot water recovery process is being executed, the ECU 20 proceeds to S902 and reads the output signal value of the tank outlet water temperature sensor 17.
[0104]
In S903, the ECU 20 stores the output signal value of the tank outlet water temperature sensor 17 read in S902 in the backup RAM as the hot water recovery water temperature: Temp.
[0105]
In S904, the ECU 20 determines whether the execution of the hot water recovery process has been completed.
[0106]
If it is determined in S904 that the execution of the hot water recovery processing has not been completed, the ECU 20 repeatedly executes the processing of S904 until the execution of the hot water recovery processing ends.
[0107]
If it is determined in S904 that the execution of the hot water recovery process has been completed, the ECU 20 activates the soak timer in S905, and then ends the execution of this routine.
[0108]
Next, the above-described second tank water temperature estimation control routine is a routine executed by the ECU 20 triggered by occurrence of a specific timing element related to the start of the internal combustion engine 1. Here, as a specific timing element related to the start of the internal combustion engine 1, a time when the door for getting on and off the vehicle equipped with the internal combustion engine 1 is opened, that is, a time when the door switch 24 is switched from off to on. This will be described using an example.
[0109]
In the second tank water temperature estimation control routine, the ECU 20 first determines in S1001 whether the door switch 24 has been switched from off to on.
[0110]
If it is determined in step S1001 that the door switch 24 has not been switched from off to on, the ECU 20 ends the execution of this routine.
[0111]
On the other hand, if it is determined in S1001 that the door switch 24 has been switched from off to on, the ECU 20 proceeds to S1002, and reads the measurement time of the soak timer, that is, the tank leaving time: Time.
[0112]
In S1003, the ECU 20 reads out the hot water recovery temperature: Temp stored in the backup RAM in the first tank water temperature estimation control routine described above.
[0113]
In step S1004, the reference tank water temperature: Tunkbase is determined using the tank leaving time: Time and the hot water recovery water temperature: Temp as parameters.
[0114]
In S1005, the ECU 20 reads an output signal value (outside air temperature): Airtemp of the outside air temperature sensor 26.
[0115]
In S1006, the ECU 20 accesses the map as described in the above description of FIG. 8 using the outside air temperature: Airtemp read in S1005 as a parameter, and calculates an outside air temperature correction coefficient: C corresponding to the outside air temperature: Airtemp. I do.
[0116]
In S1007, the ECU 20 calculates the tank water temperature (= Tunkbase * C) by multiplying the reference tank water temperature: Tunkbase obtained in S1004 by the outside air temperature correction coefficient: C calculated in S1006.
[0117]
The water temperature in the tank in this case is a temperature that reflects the temperature environment in which the heat storage tank 15 is placed, in addition to the temperature of the cooling water collected in the heat storage tank 15 and the standing time of the heat storage tank 15. As a result, even when the heat storage tank 15 is placed under any temperature environment, it is possible to accurately estimate the tank water temperature.
[0118]
As described above, when it is determined whether the pre-heat treatment execution condition is satisfied or not, it is possible to accurately determine the water temperature in the tank. Pre-heat treatment can be realized.
[0119]
In the present embodiment, the method of estimating the water temperature in the tank when judging whether the pre-heat treatment execution condition or the hot water recovery process execution condition is satisfied has been described, but whether or not the heat storage performance of the heat storage tank 15 is normal is determined. It is possible to accurately estimate the water temperature in the tank also when determining, for example, by the estimation method similar to the present embodiment.
[0120]
<Embodiment 2>
Next, a second embodiment of the internal combustion engine provided with the heat storage device according to the present invention will be described with reference to FIGS. Here, a configuration different from that of the above-described first embodiment will be described, and a description of a similar configuration will be omitted.
[0121]
The difference between the above-described first embodiment and the present embodiment is that in the above-described first embodiment, the water temperature in the tank is estimated in consideration of the outside air temperature, whereas in the present embodiment, the heat storage tank 15 is that the water temperature in the tank is estimated in consideration of the ambient temperature.
[0122]
When the heat storage tank 15 is disposed in the engine room of the vehicle, the interior of the vehicle, the trunk room of the vehicle, or a dedicated box having heat shielding properties, the heat storage performance of the heat storage tank 15 may not be directly affected by the outside air temperature. is there.
[0123]
In particular, since the heat released from the internal combustion engine 1, the transmission, and the like easily accumulates in the engine room, the temperature in the engine room tends to be significantly higher than the outside air temperature.
[0124]
Here, the relationship between the temperature in the engine room and the outside air temperature is shown in FIG.
[0125]
When the internal combustion engine 1 is in the operating state, the internal combustion engine 1 and the transmission continuously generate heat, so that the temperature in the engine room is maintained at a temperature significantly higher than the atmospheric temperature.
[0126]
Even after the operation of the internal combustion engine 1 is stopped, the heat absorbed in the cylinder head 1a, the cylinder block 1b, the transmission case, and the like during the operation of the internal combustion engine 1 is released into the engine room. In a period until the temperature of the cylinder block 1b, the transmission case, and the like decreases to a temperature equivalent to the outside air temperature (hereinafter, referred to as a heat radiation period): t, the temperature in the engine room becomes higher than the outside air temperature.
[0127]
After the elapse of the heat radiation period t from the stop of the operation of the internal combustion engine 1, the temperature in the engine room becomes equal to the outside air temperature.
[0128]
Therefore, when the heat storage tank 15 is disposed in the engine room, the heat storage tank 15 is placed in a temperature environment higher than the outside air temperature. Need to be considered.
[0129]
Therefore, in the tank water temperature estimation control according to the present embodiment, the ECU 20 determines whether the temperature in the engine room when the operation of the internal combustion engine 1 is stopped and whether the preheat treatment execution condition or the hot water recovery process execution condition is satisfied or not. The reference tank water temperature is corrected based on the room temperature.
[0130]
In the tank water temperature estimation control in the first embodiment described above, the elapsed time from the end of execution of the hot water recovery process to the present time is used as the tank leaving time when obtaining the reference tank water temperature. In the tank water temperature estimation control in the embodiment, the elapsed time from the time when the operation of the internal combustion engine 1 is stopped to the current time is used as the tank leaving time.
[0131]
As described in the description of FIG. 11, when the heat storage tank 15 is disposed in the engine room, the heat storage tank 15 is stored during the period from the end of the execution of the hot water recovery process to the stop of the operation of the internal combustion engine 1. This is because the tank 15 is placed at a high temperature, so that the water temperature in the tank hardly decreases.
[0132]
Hereinafter, the tank water temperature estimation control according to the present embodiment will be described with reference to FIGS.
[0133]
FIG. 12 is a flowchart showing a first tank water temperature estimation control routine, FIG. 13 is a flowchart showing a second tank water temperature estimation control routine, and FIG. 14 is a third tank water temperature estimation control routine. It is a flowchart figure which shows. These first to third tank internal water temperature estimation control routines are routines stored in the ROM of the ECU 20 in advance.
[0134]
The above-described first tank water temperature estimation control routine is a routine executed by the ECU 20 triggered by the start of execution of the hot water recovery process. In the first tank water temperature estimation control routine, the ECU 20 first determines in S1201 whether or not the hot water recovery process is being executed.
[0135]
If it is determined in S1201 that the hot water recovery process is not being executed, the ECU 20 ends the execution of this routine.
[0136]
On the other hand, if it is determined in S1201 that the hot water recovery process is being executed, the ECU 20 proceeds to S1202 and reads the output signal value of the tank outlet water temperature sensor 17.
[0137]
In S1203, the ECU 20 stores the output signal value of the tank outlet water temperature sensor 17 read in S1202 in the backup RAM as the hot water recovery water temperature: Temp, and ends the execution of this routine.
[0138]
The above-described second tank water temperature estimation control routine is a routine executed by the ECU 20 when the operation of the internal combustion engine 1 is stopped. In the second tank water temperature estimation control routine, the ECU 20 first determines in S1301 whether or not the operation of the internal combustion engine 1 has been stopped.
[0139]
If it is determined in S1301 that the operation of the internal combustion engine 1 has not been stopped, the ECU 20 ends the execution of this routine.
[0140]
On the other hand, if it is determined in S1301 that the operation of the internal combustion engine 1 has been stopped, the ECU 20 proceeds to S1302 and detects the temperature in the engine room.
[0141]
As a method of detecting the temperature in the engine room, a method of providing a temperature sensor in the engine room can be exemplified. However, when the internal combustion engine 1 is provided with an intake air temperature sensor in advance, the method of using the intake air temperature sensor is used. The temperature in the engine room may be detected.
[0142]
In S1303, the temperature in the engine room detected in S1302 is stored in the backup RAM as the first tank ambient temperature: Temp1.
[0143]
Subsequently, the ECU 20 activates the soak timer in S1304, and ends the execution of this routine.
[0144]
The third tank water temperature estimation control routine described above is executed by the ECU 20 triggered by a specific timing element related to the start of the internal combustion engine 1, that is, the switching of the door switch 24 from off to on. It is a routine. In the third tank water temperature estimation control routine, the ECU 20 first determines in step S1401 whether the door switch 24 has been switched from off to on.
[0145]
If it is determined in step S1401 that the door switch 24 has not been switched from off to on, the ECU 20 ends the execution of this routine.
[0146]
On the other hand, if it is determined in S1401 that the door switch 24 has been switched from off to on, the ECU 20 proceeds to S1402, and reads the measurement time of the soak timer, that is, the tank leaving time: Time.
[0147]
In step S1403, the ECU 20 reads the hot water recovery-time water temperature Temp stored in the backup RAM in the first tank water temperature estimation control routine described above.
[0148]
In S1404, the reference tank water temperature: Tunkbase is calculated using the tank leaving time: Time and the hot water recovery water temperature: Temp as parameters.
[0149]
In S1405, the ECU 20 detects the current temperature in the engine room.
[0150]
In S1406, the ECU 20 stores the engine room temperature detected in S1405 in the backup RAM as the second tank ambient temperature: Temp2.
[0151]
In S1407, the ECU 20 reads the first tank ambient temperature: Temp1 and the second tank ambient temperature: Temp2 from the backup RAM.
[0152]
In S1408, based on the first and second tank ambient temperatures: Temp1 and Temp2, the temperature at which the heat storage tank 15 is placed during the period from the time when the operation of the internal combustion engine 1 is stopped to the present time (hereinafter, the tank ambient temperature when left unattended). Temperature :) Estimate Temp3.
[0153]
As a method for estimating the tank ambient temperature at the time of leaving: Temp3, an average value of the first tank ambient temperature: Temp1 and the second tank ambient temperature: Temp2 (= (Temp1 + Temp2) / 2) is taken as the tank ambient temperature at leaving. The method can be illustrated.
[0154]
Note that the temperature in the engine room after the operation of the internal combustion engine 1 is stopped is equal to the first tank ambient temperature: Temp1 within the heat radiation period: t after the operation of the internal combustion engine 1 is stopped, as described above with reference to FIG. , Gradually converges to a temperature equivalent to the outside air temperature when the heat radiation period: t elapses, and thereafter, maintains a temperature equivalent to the outside air temperature.
[0155]
Therefore, if the tank storage time does not exceed the heat radiation period: t, the heat retention performance of the heat storage tank 15 is more affected by the first tank ambient temperature: Temp1 than the second tank ambient temperature: Temp2. However, if the heat radiation period exceeds t, the longer the tank leaving time is, the less the influence from the first tank ambient temperature: Temp1 is and the more the influence from the second tank ambient temperature: Temp2 is.
[0156]
Therefore, when estimating the tank ambient temperature at the time of leaving: Temp3, as the tank leaving time becomes shorter, the tank ambient temperature at the time of leaving: Temp3 becomes a value closer to the first tank ambient temperature: Temp1, and the tank leaving time becomes Temp1. It is preferable that the longer the tank ambient temperature is, the longer the tank ambient temperature during standing: Temp3 becomes a value closer to the second tank ambient temperature: Temp2.
[0157]
In this case, as shown in FIG. 15, the correction coefficient becomes larger as the tank leaving time becomes shorter and becomes smaller as the tank leaving time becomes longer, and correction becomes smaller as the tank leaving time becomes shorter and becomes larger as the tank leaving time becomes longer. The sum of the coefficient and F is always set to “1.0”, and the first tank ambient temperature: Temp1 multiplied by the correction coefficient: E (= Temp1 * E) and the second tank ambient temperature: The sum (= Temp1 * E + Temp2 * F) of the value (= Temp1 * E + Temp2 * F) obtained by multiplying Temp2 by the correction coefficient: F may be used as the ambient tank temperature at standing: Temp3.
[0158]
Referring back to FIG. 14, in S1409, the ECU 20 calculates a temperature correction coefficient: D corresponding to the tank ambient temperature during standing: Temp3. As shown in FIG. 16, the temperature correction coefficient D is set to “1.0” when the tank ambient temperature during standing: Temp3 is at room temperature, and the higher the ambient tank temperature during standing: Temp3, the higher the temperature. This is a coefficient that is set to be a large value and to be a smaller value as the tank ambient temperature during standing: Temp3 is lower.
[0159]
In S1410, the ECU 20 multiplies the reference tank water temperature: Tunkbase obtained in S1404 by the temperature correction coefficient: D calculated in S1409 to calculate the tank water temperature (= Tunkbase * D).
[0160]
The water temperature in the tank in this case is a temperature that reflects the temperature in the engine room in which the heat storage tank 15 is arranged, in addition to the temperature of the cooling water collected in the heat storage tank 15 and the standing time of the heat storage tank 15. As a result, even when the heat storage tank 15 is placed under any temperature environment, it is possible to accurately estimate the tank water temperature.
[0161]
As described above, when it is determined whether the pre-heat treatment execution condition is satisfied or not, it is possible to accurately determine the water temperature in the tank. Pre-heat treatment can be realized.
[0162]
<Embodiment 3>
Next, a third embodiment of the internal combustion engine provided with the heat storage device according to the present invention will be described with reference to FIGS. Here, a configuration different from the above-described first and second embodiments will be described, and a description of a similar configuration will be omitted.
[0163]
The difference between the first and second embodiments and the present embodiment is that the first and second embodiments estimate the water temperature in the tank when the execution of the hot water recovery process is completed. On the other hand, in the present embodiment, the point is to estimate the water temperature in the tank when the execution of the hot water recovery processing is interrupted halfway.
[0164]
When the hot water recovery processing is interrupted halfway, such as when the operation of the internal combustion engine 1 is stopped during the execution of the hot water recovery processing, one of the low-temperature cooling water originally stored in the heat storage tank 15 is removed. Since the portion remains in the heat storage tank 15, one of the high-temperature cooling water (hot water) supplied from the internal combustion engine 1 to the heat storage tank 15 and the low-temperature cooling water (cold water) originally stored in the heat storage tank 15 is removed. Parts are mixed in the heat storage tank 15.
[0165]
In such a case, if the tank water temperature is estimated based on the hot water recovery water temperature, the estimated value of the tank water temperature may be higher than the actual tank water temperature.
[0166]
Therefore, in the tank water temperature estimation control in the present embodiment, the ECU 20 determines the amount and temperature of the hot water flowing into the heat storage tank 15 during the period from the start of the execution of the hot water recovery process to the suspension of the execution of the hot water recovery process. By using the amount and temperature of the cold water remaining in the heat storage tank 15 at the time when the execution of the hot water recovery process is interrupted as a parameter, the water temperature in the tank at the time when the execution of the hot water recovery process is interrupted is determined, and the tank The internal water temperature was estimated.
[0167]
As a method for determining the amount of hot water flowing into the heat storage tank 15 during the period from the start of the hot water recovery process to the suspension of the hot water recovery process (hereinafter referred to as the hot water recovery process execution period) (hereinafter referred to as the hot water recovery amount), A method of obtaining the amount of recovered hot water using the integrated value of the engine speed during the recovery processing execution period as a parameter can be exemplified.
[0168]
This means that the hot water recovery amount varies according to the total amount of cooling water discharged by the mechanical water pump 10 during the hot water recovery processing execution period, and the total amount of cooling water discharged by the mechanical water pump 10 during the hot water recovery processing execution period is This is because it changes according to the integrated value of the engine speed during the hot water recovery processing execution period.
[0169]
As the temperature of the hot water flowing into the heat storage tank 15 during the hot water recovery processing execution period (hereinafter, referred to as the recovered hot water temperature), an output signal value of the tank outlet water temperature sensor 17 during the execution of the hot water recovery processing can be used.
[0170]
The amount of cold water remaining in the heat storage tank 15 when the execution of the hot water recovery processing is interrupted (hereinafter, referred to as the amount of residual cold water in the tank) is calculated from the amount of cooling water that can be stored in the heat storage tank 15 (hereinafter, referred to as the tank storage water amount). It can be obtained by subtracting the collected hot water amount.
[0171]
As a method for obtaining the temperature of the cold water remaining in the heat storage tank 15 when the execution of the hot water recovery processing is interrupted (hereinafter referred to as the remaining cold water temperature in the tank), as shown in FIG. A tank inlet water temperature sensor 28 that outputs an electric signal corresponding to the temperature of the cooling water in the second bypass passage 13b is attached to a portion near 15a, and detects the temperature of the cold water flowing out of the heat storage tank 15 during the hot water recovery process. An example of a method for performing this is as follows.
[0172]
When the hot water recovery amount, the recovered hot water temperature, the residual cold water amount in the tank, and the residual cold water temperature in the tank are determined in this way, the ECU 20 determines the amount of the hot water in the heat storage tank 15 using the hot water recovery amount and the recovered hot water temperature as parameters. In addition to calculating the amount of heat possessed, the amount of heat of the cold water remaining in the heat storage tank 15 is calculated using the amount of residual cold water in the tank and the temperature of the residual cold water in the tank as parameters, and the amounts of heat are added and stored in the heat storage tank 15. Obtain the total calorific value.
[0173]
Subsequently, the ECU 20 calculates the water temperature in the tank when the execution of the hot water recovery process is interrupted (hereinafter, referred to as the water temperature when the hot water recovery is interrupted), using the total amount of heat stored in the heat storage tank 15 and the amount of water stored in the tank as parameters. .
[0174]
When the water temperature at the time of suspension of hot water recovery is obtained in this way, the ECU 20 determines the water temperature in the tank using the water temperature at the time of suspension of hot water recovery instead of the water temperature at the time of hot water recovery in the first and second embodiments described above. presume.
[0175]
In this case, even if the execution of the hot water recovery process is interrupted on the way, it is possible to accurately estimate the tank water temperature.
[0176]
Hereinafter, the tank water temperature estimation control in the present embodiment will be described with reference to FIG. Here, a case where the reference tank internal water temperature is corrected in accordance with the outside air temperature will be described as an example.
[0177]
FIG. 18 is a flowchart illustrating a first tank water temperature estimation control routine. The first tank water temperature estimation control routine is a routine executed by the ECU 20 with the execution start of the hot water recovery process as a trigger.
[0178]
In the first tank water temperature estimation control routine, the ECU 20 first determines in S1801 whether or not the execution of the hot water recovery process has been started.
[0179]
If it is determined in S1801 that the execution of the hot water recovery process has not been started, the ECU 20 ends the execution of this routine.
[0180]
On the other hand, if it is determined in S1801 that the execution of the hot water recovery process has been started, the ECU 20 proceeds to S1802 and activates the engine speed integration counter. This engine speed integration counter is a counter that integrates the engine speed during execution of the hot water recovery process.
[0181]
In S1803, the ECU 20 reads the output signal of the tank inlet water temperature sensor 28.
[0182]
In S1804, the ECU 20 reads the output signal of the tank outlet water temperature sensor 17.
[0183]
In S1805, the ECU 20 determines whether the operation of the internal combustion engine 1 has been stopped.
[0184]
If it is determined in S1805 that the operation of the internal combustion engine 1 has not been stopped, the ECU 20 proceeds to S1806, and determines whether the execution of the hot water recovery process has been completed.
[0185]
If it is determined in S1806 that the execution of the hot water recovery processing has not been completed, the ECU 20 executes the above-described processing from S1805 again.
[0186]
If it is determined in step S1806 that the execution of the hot water recovery process has been completed, the ECU 20 proceeds to step S1807 and sets the output signal value of the tank outlet water temperature sensor 17 read in step S1804 as the hot water recovery water temperature: Temp in the backup RAM. To memorize.
[0187]
In S1808, after activating the soak timer, the ECU 20 ends the execution of this routine.
[0188]
If it is determined in step S1805 that the operation of the internal combustion engine 1 has been stopped, the ECU 20 determines that the execution of the hot water recovery process has been interrupted, and proceeds to step S1809.
[0189]
In S1809, the ECU 20 obtains the hot water recovery amount using the counter value of the engine speed integration counter as a parameter, and calculates the hot water recovery amount and the output signal value (recovered hot water temperature) of the tank inlet water temperature sensor 28 read in S1803. Using the output signal value of the tank outlet water temperature sensor 17 (remaining chilled water temperature in the tank) read in S1804 and the tank storage water amount of the heat storage tank 15, the water temperature at the time of hot water recovery interruption is calculated.
[0190]
In S1810, the ECU 20 causes the backup RAM to store the hot water recovery interruption water temperature calculated in S1809 as the hot water recovery water temperature: Temp.
[0191]
After completing the process of S1810, the ECU 20 proceeds to S1808, activates a soak timer, and ends the execution of this routine.
[0192]
When a specific timing element related to the start of the internal combustion engine 1 occurs after the operation of the internal combustion engine 1 is stopped, the ECU 20 executes the second tank water temperature estimation control routine in the first embodiment described above. It is assumed that a similar routine is executed.
[0193]
Therefore, according to the internal combustion engine provided with the heat storage device in the present embodiment, even when the execution of the hot water recovery process is interrupted on the way, the water temperature in the tank at the time of determining whether the pre-heat treatment execution condition is satisfied or not is determined. It is possible to obtain the exact value.
[0194]
【The invention's effect】
The present invention relates to an internal combustion engine equipped with a heat storage device for estimating a heat medium temperature in a heat storage tank according to a heat medium temperature detected by a heat medium temperature detection unit arranged outside a heat storage tank. Since the temperature of the heat medium in the heat storage tank is estimated in consideration of the temperature element that acts, it is possible to accurately estimate the temperature of the heat medium in the heat storage tank regardless of the environment in which the heat storage tank is placed. It becomes.
[0195]
In this case, since it is not necessary to attach a temperature sensor for directly detecting the temperature of the heat medium in the heat storage tank to the heat storage tank, the heat in the heat storage tank does not leak through the temperature sensor.
[0196]
Therefore, according to the internal combustion engine provided with the heat storage device according to the present invention, it is possible to accurately determine the temperature of the heat medium in the heat storage tank without lowering the heat retaining performance of the heat storage tank.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of a cooling water circulation system of an internal combustion engine according to a first embodiment.
FIG. 2 is a diagram showing a flow of cooling water when the internal combustion engine is in a warm-up operation state.
FIG. 3 is a diagram showing a flow of cooling water when the internal combustion engine is in a warm-up completed state.
FIG. 4 is a diagram showing a flow of cooling water when a heater switch is turned on.
FIG. 5 is a diagram showing a flow of cooling water when a pre-heat treatment is performed.
FIG. 6 is a diagram showing a flow of cooling water when a hot water recovery process is performed.
FIG. 7 is a diagram showing the relationship among the water temperature in the tank, the tank leaving time, and the outside air temperature.
FIG. 8 is a diagram showing a relationship between an outside air temperature correction coefficient and outside air temperature.
FIG. 9 is a flowchart showing a first tank water temperature estimation control routine according to the first embodiment;
FIG. 10 is a flowchart illustrating a second tank water temperature estimation control routine according to the first embodiment;
FIG. 11 is a diagram showing how the temperature in the engine room changes.
FIG. 12 is a flowchart showing a first tank water temperature estimation control routine according to the second embodiment;
FIG. 13 is a flowchart showing a second tank water temperature estimation control routine according to the second embodiment;
FIG. 14 is a flowchart illustrating a third tank water temperature estimation control routine according to the second embodiment;
FIG. 15 is a diagram showing a relationship between a correction coefficient: E, a correction coefficient: F, and a tank leaving time.
FIG. 16 is a diagram showing a relationship between a temperature correction coefficient and a tank ambient temperature when left unused
FIG. 17 is a diagram showing a schematic configuration of a cooling water circulation system of an internal combustion engine according to a third embodiment.
FIG. 18 is a flowchart showing a first tank water temperature estimation control routine according to the third embodiment;
[Explanation of symbols]
1 ... Internal combustion engine
1a: Head-side cooling water channel
1b: Block side cooling water channel
2a: Head side cooling water channel
2b: Block side cooling water channel
4. First cooling water channel
11 ... heater hose
13a-1st bypass passage
13b ··· Second bypass passage
13c ··· Third bypass passage
15 ・ ・ ・ Heat storage tank
16 ... Channel switching valve
17 ・ ・ ・ Tank outlet water temperature sensor
20 ECU
26 ・ ・ ・ Outside air temperature sensor
28 ・ ・ ・ Tank inlet water temperature sensor

Claims (4)

A heat medium circulation path through which the heat medium circulates via the internal combustion engine;
A heat storage tank that stores a part of the heat medium circulating in the heat medium circulation path in a warm state,
Heat medium temperature detection means provided in the heat medium circulation path to detect the temperature of the heat medium,
Estimating means for estimating the heat medium temperature in the heat storage tank based on the heat medium temperature detected by the heat medium temperature detecting means when a heat medium is stored in the heat storage tank,
Correction means for correcting the heat medium temperature estimated by the estimation means according to a specific temperature element acting on the temperature of the heat medium stored in the heat storage tank,
An internal combustion engine equipped with a heat storage device, comprising: When the storage process of the heat medium in the heat storage tank is interrupted, the storage device further includes a heat medium inflow amount calculation unit that calculates an amount of the heat medium flowing into the heat storage device during a period from a start of the storage process to an interruption.
The estimating unit estimates the correction unit according to a specific temperature element acting on the temperature of the heat medium stored in the heat storage tank and the heat medium inflow amount calculated by the heat medium inflow amount calculation unit. The internal combustion engine provided with the heat storage device according to claim 1, wherein the heat medium temperature is corrected. The said correction | amendment means uses the outside air temperature and / or the temperature of the said heat storage tank as a specific temperature element which acts on the temperature of the heat carrier stored in the said heat storage tank, The Claim 1 or Claim 2 characterized by the above-mentioned. An internal combustion engine comprising the heat storage device according to 2. The estimating means is a parameter for the heat medium temperature detected by the heat medium temperature detecting means when the heat medium is stored in the heat storage tank, and the elapsed time from the completion of the heat medium storage processing for the heat storage tank. An internal combustion engine provided with the heat storage device according to any one of claims 1 to 3, wherein the temperature of the heat medium in the heat storage tank is estimated.

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