JP2014156801A - Engine system and cooling mechanism thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique that can continue operation even if a problem related to heat dissipation in an evaporative cooling type heat dissipation part 35 is caused by suspension of water supply, etc. while optimizing the performance of a whole engine system 1 by using an air cooling type in combination with an evaporative cooling type in a cooling mechanism 2 of the engine system 1.SOLUTION: The cooling mechanism 2 of the engine system 1 comprises: an air cooling type heat dissipation part 30; the evaporative cooling type heat dissipation part 35; a circuit 5 for causing cooling liquid C passing through a high-temperature cooling part 11 to circulate between the air cooling type heat dissipation part 30 and the high-temperature cooling part 11; an evaporative cooling type circuit 4A for allowing the cooling liquid C passing through a low-temperature cooling part 13 to circulate between the evaporative cooling type heat dissipation part 35 and the low-temperature cooling part 13; an air cooling type circuit 4B for allowing the cooling liquid C passing through the low-temperature cooling part 13 to circulate between the air cooling type heat dissipation part 30 and the low-temperature cooling part 13; and switching means 46 for alternatively switching a state of circulation of the cooling liquid C passing through the low-temperature cooling part 13 between a state where the cooling liquid B is circulated in the evaporative cooling type circuit 4A and a state where the cooling liquid B is circulated in the air cooling type circuit 4B.

Description

The present invention is provided in an engine system having an engine body that sucks fresh air from an intake passage into a combustion chamber and burns it to output rotational power.
The present invention relates to a cooling mechanism of an engine system that cools the coolant radiated by a heat radiating portion through a high-temperature cooling portion of the engine system and a low-temperature cooling portion that is lower in temperature than the high-temperature cooling portion, and an engine system including the same.

In an engine system, normally, it should be cooled in order to maintain the performance of the entire engine system, such as an engine body composed of a cylinder block, a cylinder head, etc., and fresh air sucked into a combustion chamber formed in the engine body. Multiple cooling objects exist.
The cooling mechanism for cooling the cooling target in such an engine system is a mode in which the coolant radiated by the heat radiating part is passed through the cooling part, and heat exchange between the cooling target and the cooling liquid is performed in the cooling part. The cooling object is cooled.
Specifically, with respect to the engine body, the piston is seized by passing the coolant radiated by the heat radiating section through a water jacket provided in the engine body and cooling the engine body to a relatively high temperature. Etc. are prevented.
In addition, for fresh air, the cooling air radiated by the heat radiating section is passed through an intercooler provided in the intake passage through which fresh air flows, and the fresh air is cooled to a relatively low temperature. The engine efficiency is improved as a whole by increasing the density of fresh air filled in the combustion chamber in the intake stroke, thereby increasing the average effective pressure in the combustion stroke.

As a heat radiating part provided in the cooling mechanism of such an engine system, there are an air cooling type heat radiating part and an evaporative cooling type heat radiating part classified according to a heat radiating method for the coolant.
The air-cooled heat radiating unit is typified by a so-called radiator or the like. For example, the cooling liquid is allowed to flow through the flow path in the finned copper tube, and the outside air blown by the fan to the outer surface of the copper tube. By flowing, the sensible heat of the coolant is taken as sensible heat of the outside air, and the coolant is cooled. Such an air-cooled heat radiating part has advantages such as a simple structure and low running cost because there is no consumption of water, but it also has a disadvantage that cooling capacity is low and cooling cannot be performed below the outside air temperature.
On the other hand, the evaporative cooling type heat radiating unit is typified by a so-called cooling tower. For example, the cooling liquid is passed through the flow path in the copper pipe and the fan is sprinkled on the outer surface of the copper pipe. By allowing the outside air blown by the air to flow, the sensible heat of the cooling liquid is taken away as the sensible heat of the water and the outside air and the heat of vaporization of the water, thereby cooling the cooling liquid. This evaporative cooling type heat radiation part has the advantage that it has a high cooling capacity and can be cooled below the outside air temperature, but since it consumes water by vaporization, it can not continue operation without water replenishment, and the running cost is also low. There are also disadvantages such as high.

Japanese Patent Laying-Open No. 2011-106302 (paragraph 0051, FIG. 2)

The conventional engine system cooling mechanism employs either the air cooling type or the evaporative cooling type as a heat radiation method of the heat radiating part for radiating the coolant, and does not use them in combination.
In addition, in order to optimize the performance of the entire engine system, when the air cooling type and the evaporative cooling type are used in combination, if the shortcomings of these heat dissipation methods are not properly compensated, the advantages of these heat dissipation methods are more effective. Can not enjoy.
In particular, the evaporative cooling type heat dissipation method has the disadvantage that operation cannot be continued without water replenishment. It becomes necessary to stop the operation.

  Therefore, the present invention has been made paying attention to this point, and its purpose is to optimize the performance of the entire engine system by using both the air cooling type and the vaporization cooling type in the cooling mechanism of the engine system. It is in the point which provides the technique which can continue an operation | movement, even if inconvenience arises in the heat radiation in a vaporization cooling type heat radiating part by water cutoff etc., aiming at.

In order to achieve this object, a cooling mechanism for an engine system according to the present invention comprises:
It is provided in an engine system having an engine body that draws fresh air from an intake passage into a combustion chamber and burns it to output rotational power,
A cooling mechanism for an engine system that performs cooling by passing a coolant radiated by a heat radiating section through a high temperature cooling section of the engine system and a low temperature cooling section having a temperature lower than that of the high temperature cooling section,
The first characteristic configuration is
As the heat dissipating part, an air-cooled heat dissipating part that dissipates heat by sensible heat exchange with the outside air, and a vaporized cooling heat dissipating part that dissipates heat by vaporizing heat exchange of the water sprayed with the coolant,
A high-temperature cooling unit air-cooling circuit for circulating the coolant flowing through the high-temperature cooling unit between the air-cooling heat dissipation unit and
A low-temperature cooling unit evaporative cooling circuit capable of circulating the coolant flowing through the low-temperature cooling unit between the evaporative cooling-type heat dissipation unit, and a cooling liquid flowing through the low-temperature cooling unit as the air-cooling heat dissipation unit A low-temperature cooling section air-cooled circuit that can circulate between
The low temperature cooling unit is disposed between a vaporization cooling type heat radiation state in which a cooling liquid is circulated through the low temperature cooling unit vaporization cooling type circuit and an air cooling type heat radiation state in which a cooling liquid is circulated through the low temperature cooling unit air cooling type circuit. It is in the point provided with the thermal radiation state switching means which can switch alternatively the circulating state of the flowing coolant.

An engine system according to the present invention for achieving this object is as follows:
An engine system having an engine main body that sucks fresh air from an intake passage into a combustion chamber and burns it to output rotational power,
Its feature configuration is
The cooling mechanism according to the present invention is provided as a cooling mechanism that cools the heat radiated from the heat radiating part by passing the cooling liquid radiated from the heat radiating part through the high temperature cooling part of the engine system and the low temperature cooling part having a temperature lower than the high temperature cooling part. It is in.

According to the first characteristic configuration of the engine system cooling mechanism and the characteristic configuration of the engine system, the high-temperature cooling unit is cooled by the air-cooling heat dissipation unit, while the low-temperature cooling unit is cooled by the vaporization cooling type heat-dissipating unit. The air cooling method and the vaporization cooling method are used in combination as the heat dissipation method of the heat dissipation part.
That is, there is no problem with the cooling of the relatively high temperature high temperature cooling section even if the temperature is maintained at a relatively high temperature. The high-temperature cooling unit can be cooled by adopting an air-cooling type heat dissipation method in such a manner that the coolant radiated by the air-cooled heat dissipation unit is passed through the unit. In addition, when the high temperature cooling unit is cooled, a simple and compact structure can be adopted to save the running cost.
On the other hand, since it is necessary to sufficiently cool the low-temperature cooling part having a temperature lower than that of the high-temperature cooling part, for example, during normal operation, the circulation state of the coolant is changed to the evaporative cooling type by the heat dissipation state switching means. By setting the heat dissipation state, the cooling liquid is circulated in the low temperature cooling part vaporization cooling type circuit, and the cooling liquid radiated by the vaporization cooling type heat dissipation part is passed through the low temperature cooling part, thereby evaporative cooling type heat dissipation. A low temperature cooling part can be cooled by adopting a method. In addition, when cooling the low temperature cooling part, it is necessary to replenish water to the evaporative cooling type heat radiating part, but the high temperature cooling part is omitted from the cooling target cooled by the evaporative cooling type heat radiating method. In addition, the replenishment of the water can be minimized, and the increase in running cost can be suppressed as much as possible.
In addition, when cooling the low temperature cooling unit, for example, when there is an inconvenience in heat dissipation in the vaporization cooling type heat dissipation unit, the circulation state of the coolant is changed from the vaporization cooling type heat dissipation state to the air cooling by the heat dissipation state switching means. By switching to the heat radiation state, the coolant is circulated through the low temperature cooling section air cooling circuit, and the cooling liquid radiated by the air cooling heat radiation section is passed through the low temperature cooling section. By adopting a heat dissipation method, the low temperature cooling part can be continuously cooled, and it is not necessary to supply water to the vaporization cooling type heat dissipation part.
Therefore, according to the present invention, the air cooling type and the vaporization cooling type are used together to optimize the performance of the entire engine system, and even if there is an inconvenience in the heat dissipation in the vaporization cooling type heat radiation part due to water breakage or the like, the operation can be performed. An engine system cooling mechanism that can be continued can be realized.

In addition to the first characteristic configuration, the second characteristic configuration of the cooling mechanism of the engine system according to the present invention is as follows.
The high temperature cooling part is a water jacket provided in the engine body, and the low temperature cooling part is an intercooler provided in the intake passage,
As the high-temperature cooling unit air-cooled circuit, a water jacket air-cooled circuit that circulates a coolant flowing through the water jacket between the air-cooled heat radiating unit,
As the low-temperature cooling unit evaporative cooling circuit, an intercooler evaporative cooling circuit that circulates a coolant flowing through the intercooler between the evaporative cooling heat dissipation unit,
The low-temperature cooling unit air-cooled circuit includes an intercooler air-cooled circuit that circulates the coolant flowing through the intercooler between the air-cooled heat radiating unit.

According to the second characteristic configuration of the cooling mechanism of the engine system, since the high-temperature cooling part is a water jacket provided in the engine body, the cooling of the engine body is performed with an outside air temperature in order to prevent the piston from being seized. Since there is no problem even if the temperature is maintained at a higher temperature (for example, 90 ° C.), the coolant is circulated through the water jacket air-cooled circuit, and water serving as a high-temperature cooling unit provided in the engine body is provided. The engine main body can be cooled by adopting an air-cooling heat radiation method in a form in which the coolant radiated by the air-cooling heat radiation portion is passed through the jacket.
On the other hand, since the low-temperature cooling unit is an intercooler provided in the intake passage, the cooling of fresh air flowing through the intake passage is a temperature that can be lower than the outside air temperature (for example, 40) in order to improve engine efficiency. Therefore, during normal operation, the intercooler evaporative cooling circuit is cooled by changing the circulation state of the coolant to the evaporative cooling heat dissipation state by the heat dissipation state switching means. This is a form in which liquid is circulated and the cooling liquid radiated by the evaporative cooling type heat radiating part is passed through the intercooler as a low temperature cooling part provided in the intake passage. Can be cooled.
Also, in the case of abnormalities such as inconvenience in heat dissipation in the evaporative cooling type heat radiating section, the cooling liquid circulation state is changed from the evaporative cooling type heat dissipation state to the air cooling type heat dissipation state by the heat dissipation state switching means. By switching to the state, the cooling liquid is circulated through the intercooler air cooling circuit, and the cooling liquid radiated by the air cooling radiator is passed through the intercooler as the low-temperature cooling section. By adopting this heat dissipation method, fresh air can be continuously cooled.

In addition to any of the first to second feature configurations described above, the third feature configuration of the engine system cooling mechanism according to the present invention includes:
A water outage state detecting means for detecting a water outage state in which replenishment of spray water to the evaporative cooling type heat radiation unit is stopped;
In a normal operation before the water-stop state is detected by the water-stop state detection means, the cooling liquid circulation state is set to the evaporative cooling heat-release state by the heat-release state switching means, and the water-stop state is detected by the water-stop state detection means. At the time of the subsequent water-stop operation, the water-dissipating state switching means is provided with a water-cut control means for setting the circulating state of the coolant to the air-cooled heat-dissipating state.

According to the third characteristic configuration of the cooling mechanism of the engine system, in the normal operation before the water stop state is detected by the water stop state detecting unit, the circulation state of the coolant is changed to the vaporization cooling type heat dissipating state by the heat dissipating state switching unit. By operating and adopting a vaporization cooling type heat radiation method to cool the low temperature cooling part, while suppressing the increase in running cost as much as possible while minimizing the replenishment of water to the vaporization cooling type heat radiation part, Engine efficiency can be improved.
On the other hand, at the time of water shutoff after the water shutoff state is detected by the water shutoff state detecting means, the circulation state of the coolant is switched from the vaporization cooling heat dissipating state to the air cooling heat dissipating state by the heat dissipating state switching means. By adopting a heat dissipation method and cooling the low-temperature cooling part, it is possible to continue the operation by continuously cooling the fresh air without requiring replenishment of water to the evaporative cooling heat dissipation part.

The fourth characteristic configuration of the cooling mechanism of the engine system according to the present invention is in addition to the third characteristic configuration,
The water cutoff state detecting means is to detect the water cutoff state based on the temperature state of the coolant flowing through the low-temperature cooling unit evaporative cooling type circuit.

According to the fourth characteristic configuration of the cooling mechanism of the engine system, the water stop state is detected with an extremely simple configuration that only monitors the temperature state of the coolant flowing through the low temperature cooling unit vaporization cooling type circuit in the water stop state detecting means. It can be detected accurately.
That is, when the temperature of the coolant flowing through the low-temperature cooling unit evaporative cooling circuit is maintained at a normal temperature, the water supply to the evaporative cooling heat radiating unit is performed without stagnation, and the water supply to the evaporative cooling heat radiating unit is performed without delay. Therefore, it can be determined that the heat radiation from the coolant is normally performed.
Conversely, when the temperature of the coolant flowing through the low-temperature cooling section evaporative cooling circuit tends to rise with respect to the normal temperature, the water supply is stopped and water is supplied to the evaporative cooling heat dissipation section. It can be determined that there is an inconvenience in the heat dissipation of the coolant after stopping.

The fifth characteristic configuration of the cooling mechanism of the engine system according to the present invention is in addition to any of the first to fourth characteristic configurations described above,
The air-cooling heat radiating unit is connected to the high-temperature cooling unit side channel connected to the high-temperature cooling unit air-cooling circuit and the low-temperature cooling unit air-cooling circuit as a channel through which the coolant flows. The low-temperature cooling section side flow path is configured in a two-circuit type.

  According to the fifth characteristic configuration of the cooling mechanism of the engine system described above, if the air-cooled heat radiating portion is configured in a so-called two-circuit type in which two passages for allowing the coolant to flow are arranged, The high-temperature cooling unit air cooling circuit and the low-temperature cooling unit air-cooling circuit are connected to the road in a simple configuration. The coolant can be dissipated by a common air-cooled heat radiating part.

The figure which shows schematic structure of the engine system of embodiment of this invention, its cooling structure, and the flow of the cooling fluid of a vaporization cooling type thermal radiation state The figure which shows the schematic structure of the engine system of embodiment of this invention, its cooling structure, and the flow of the cooling fluid of an air cooling type thermal radiation state

Embodiments of the present invention will be described with reference to the drawings.
The engine system 1 shown in FIG. 1 includes an engine body 10 including a cylinder block and a cylinder head (not shown), a cooling mechanism 2 described later in detail, and a control unit 60 including a computer that controls operation.
The engine body 10 is configured as a normal four-cycle engine that outputs rotational power for driving the generator 20 by sucking the air-fuel mixture M as fresh air from the intake passage 12 into the combustion chamber 10a and burning it. . That is, although detailed description is omitted, in the intake stroke, intake of the air-fuel mixture M from the intake passage 12 to the combustion chamber 10a is performed as the volume of the combustion chamber 10a increases, and in the next compression stroke, the combustion chamber 10a As the volume is reduced, the mixture M is compressed, and the mixture M compressed in the combustion / expansion stroke is ignited and burned at an appropriate ignition timing to expand the volume of the combustion chamber 10a, and the exhaust stroke. The exhaust gas is exhausted from the combustion chamber 10a to the exhaust passage (not shown) as the volume of the combustion chamber 10a is reduced.

A water jacket 11 is provided in the engine main body 10, and cooling of the engine main body 10 is performed by flowing a coolant C radiated by a heat radiating portion Y described later through the water jacket 11. Accordingly, the temperature of the engine body 10 is maintained at a temperature (for example, 90 ° C.) higher than the outside air temperature, for example, and the seizure of the piston is prevented.
The water jacket 11 may be referred to as a high temperature cooling part Xh because the cooling target temperature is high.

In the intake passage 12, a fuel 15 such as natural gas is mixed with the air A through a fuel supply valve 16 to form an air-fuel mixture M, and the formed air-fuel mixture M is subjected to kinetic energy of exhaust gas. A supercharger 14 that compresses by using the compressor, an intercooler 13 that cools the compressed air-fuel mixture M, and a throttle valve 18 that can adjust the engine output by adjusting the intake amount of the air-fuel mixture M to the combustion chamber 10a. The air-fuel mixture M after passing through the intercooler 13 is sucked into the combustion chamber 10a.
The opening of the fuel supply valve 16 is controlled by the control unit 60 based on the output of an oxygen sensor provided in an exhaust passage (not shown), so that the air-fuel ratio of the air-fuel mixture M formed in the intake passage 12 is reduced. The desired target air / fuel ratio is adjusted.
Further, the opening degree of the throttle valve 18 is also controlled by the control unit 60, whereby the intake amount of the air-fuel mixture M to the combustion chamber 10a is adjusted, and the engine output is adjusted to a desired target output.

Cooling of the air-fuel mixture M flowing through the intercooler 13 is performed by flowing through the intercooler 13 a coolant C radiated by a heat radiating portion Y described later. Thus, the temperature of the air-fuel mixture M sucked into the combustion chamber 10a is maintained at a temperature (for example, 40 ° C.) that can be lower than the outside air temperature, for example, and the air-fuel mixture M filled in the combustion chamber 10a in the intake stroke. Increases the average effective pressure in the combustion stroke and improves engine efficiency.
The intercooler 13 may be referred to as a low temperature cooling part Xl because the cooling target temperature is lower than that of the water jacket 11.
Further, in addition to the water jacket 11 and the intercooler 13, the engine body 10 is provided with an oil cooler 17 as a cooling part X. The oil cooler 17 is cooled by the heat radiating part Y described later. As the liquid C flows, the engine oil is cooled.

  The engine system 1 configured as described above is provided with a cooling mechanism 2 that performs cooling by flowing the coolant C radiated by the heat radiating portion Y through the water jacket 11 and the intercooler 13. The basic configuration of the cooling mechanism 2 will be described below.

The cooling mechanism 2 of the engine system 1 is provided with a radiator 30 as an air-cooled heat radiating portion and a cooling tower 35 as a vaporization-cooling heat radiating portion as the heat radiating portion Y.
The radiator 30 allows the coolant C to flow through the pipe lines 30a and 30b in the finned copper pipe and allows the outside air A blown by the fan 30c to flow through the outer surfaces of the pipe lines 30a and 30b. The sensible heat of the coolant C is taken as sensible heat of the outside air A, and the coolant C is cooled.
Further, the radiator 30 has a configuration in which pipes 30a and 30b formed of two copper pipes with fins are arranged in parallel in a passage through which the outside air A flows, and is a first pipe as a pipe through which the coolant C flows. It is configured in a two-circuit system in which two flow paths, a pipe line 30a (an example of a high temperature cooling section side flow path) and a second pipe line 30b (an example of a low temperature cooling section side flow path), are arranged separately. . That is, two types of coolant C, that is, coolant C flowing through the first conduit 30 a and coolant C flowing through the second conduit 30 b can be radiated by the common radiator 30.
Such a radiator 30 has advantages such as a simple structure and low running cost because there is no consumption of clean water W. However, since it has a configuration that only performs sensible heat exchange, the cooling capacity is low and the outside air temperature is low. There are other disadvantages, such as the inability to cool down.

The cooling tower 35 allows the coolant C to flow through a pipe line 35a formed of a copper pipe, and also supplies water W from the water sprinkling part 35b provided at the upper part of the pipe line 35a to the outer surface of the pipe line 35a. The sensible heat of the coolant C is taken away as the sensible heat of the fresh water W and the fresh air A and the heat of vaporization of the fresh water W. C is configured to cool.
Further, the clean water W that has passed through the outer surface of the pipe 35a and dropped downward is temporarily stored in a water tank part 35d provided at the bottom of the casing, and is sent again to the watering part 35b by the pump 35e. Further, in order to supplement consumption of the water W due to vaporization, a water supply valve 35f for replenishing the water W is provided in the water tank part 35d, and this water supply valve 35f is predetermined when the water level of the water tank part 35d decreases. It automatically opens and closes in the form of supplying clean water W up to the water level.
Such a cooling tower 35 has a merit that it has a cooling capacity and can be cooled below the outside air temperature because it uses the heat of vaporization. However, since the water W is consumed by vaporization, There is a disadvantage that driving cannot be continued without replenishment and running costs are high.

In the cooling mechanism 2 of the engine system 1 of the present embodiment, it is appropriate for the various cooling units X, Xh, and Xl such as the water jacket 11 that is the high temperature cooling unit Xh and the intercooler 13 that is the low temperature cooling unit Xl. By adopting the heat dissipation part Y of the heat dissipation method, the performance of the entire engine system is optimized, and it is configured to achieve energy saving, low cost, and compactness. The detailed configuration will be described below. To do.
In the cooling mechanism 2 of the engine system 1, the coolant C flowing through the water jacket 11 is used as a circuit for circulating the coolant C between the various cooling units X, Xh, Xl and the various heat radiation units Y. A water jacket air cooling circuit 5 that circulates between the radiator 30 and an intercooler evaporative cooling circuit 4A that circulates the coolant C flowing through the intercooler 13 with the cooling tower 35 is provided. .

The water jacket air-cooled circuit 5 includes an outgoing pipe 50 connecting the outlet side of the first pipe 30 a of the radiator 30 and the inlet side of the water jacket 11, the outlet side of the water jacket 11, and the first of the radiator 30. A return pipe 51 connecting the outlet side of the pipe 30a and a coolant C provided in the return pipe 51 from the outlet side of the water jacket 11 toward the inlet side of the first pipe 30a of the radiator 30 And a circulating pump 52.
As shown in FIGS. 1 and 2, the circulating pump 52 is operated to circulate the coolant C in the water jacket air-cooled circuit 5 so that the first conduit 30a of the radiator 30 flows. Coolant C, which has become relatively low in temperature (for example, 87 ° C.) by radiating heat to the outside air A, is supplied to the water jacket 11 via the forward conduit 50, and simultaneously flows through the water jacket 11 from the engine body 10. The cooling liquid C, which has become relatively high temperature (for example, 92 ° C.) by absorbing heat, is supplied to the first pipe 30 a of the radiator 30 via the return pipe 51, and the cooling liquid C is a water jacket air cooling type. The circuit 5 is circulated.
Then, by circulating the coolant C through the water jacket air cooling circuit 5, the air cooling heat dissipation method in the radiator 30 is adopted to cool the cylinder block and cylinder head of the engine body 10, and the piston Burn-in etc. are prevented.
The water jacket air-cooled circuit 5 is referred to as a high-temperature cooling unit air-cooled circuit 5 because the coolant C flowing through the water jacket 11 serving as the high-temperature cooling unit Xh is circulated with the radiator 30. There is a case.

On the downstream side of the circulation pump 52 of the return pipe 51 of the water jacket air-cooled circuit 5, the water W is heated by heat exchange with the coolant C heated to a high temperature by flowing the water jacket 11. An exhaust heat recovery heat exchanger 55 is disposed, and the heated clean water W is used for hot water supply or heating.
Further, a bypass pipe 53 that connects the downstream side of the heat exchanger 55 for exhaust heat recovery in the return pipe 51 and the forward pipe 50 is provided, and a connection portion between the bypass pipe 53 and the forward pipe 50 is provided. Is provided with a three-way valve 54. This three-way valve 54 cools the circulation state of the coolant C in the water jacket air-cooled circuit 5 to the state in which the coolant C flows through the first conduit 30 a of the radiator 30 to dissipate heat and to the bypass conduit 53. It is configured to be switchable between a state in which the liquid C is allowed to flow and heat is not released. And the control part 60 controls the action | operation of the said three-way valve 54, and the temperature of the cooling fluid C supplied to the water jacket 11 is changed by switching the circulation state of the cooling fluid C in the water jacket air cooling type circuit 5. It is configured to maintain a desired temperature.

The intercooler evaporative cooling type circuit 4A includes forward pipes 44 and 40 that connect the outlet side of the pipe 35a of the cooling tower 35 and the inlet side of the intercooler 13, the outlet side of the intercooler 13, and the cooling tower 35. Return pipes 41 and 45 connecting the outlet side of the pipe line 35a and the coolant C provided in the return pipe line 41 from the outlet side of the intercooler 13 toward the inlet side of the pipe line 35a of the cooling tower 35. It comprises a circulating pump 43 to be sent out.
Then, as shown in FIG. 1, the circulation pump 43 is operated to circulate the coolant C in the intercooler evaporative cooling circuit 4A, thereby flowing through the pipe line 35a of the cooling tower 35 to the outside air A. The coolant C having a relatively low temperature (for example, 34 ° C.) due to heat dissipation is supplied to the intercooler 13 via the outgoing pipes 44 and 40, and at the same time, the mixture M compressed through the intercooler 13 is compressed. Then, the coolant C having a relatively high temperature (for example, 41 ° C.) by absorbing heat from the engine cooler 17 and absorbing heat from the engine oil passes through the return pipes 41 and 45 to the pipe 35a of the cooling tower 35. The coolant C circulates in the intercooler evaporative cooling circuit 4A.
Then, by circulating the coolant C in the intercooler evaporative cooling circuit 4A, the air-fuel mixture M flowing through the intake passage 12 is sufficiently cooled by employing the evaporative cooling heat dissipation method in the cooling tower 35. As a result, the engine efficiency is improved.
The intercooler evaporative cooling circuit 4A circulates the coolant C flowing through the intercooler 13, which is the low-temperature cooling unit Xl, between the cooling tower 35 and the low-temperature cooling unit evaporative cooling circuit 4A. Sometimes called.

In such an intercooler 13, the coolant C absorbs heat from the air-fuel mixture M, which is not so hot, so the temperature of the coolant C discharged from the intercooler 13 to the return pipe 41 is discharged from the water jacket 11. Compared with the cooling liquid C, the temperature is maintained at a low temperature. In view of this, an oil cooler 17 is disposed on the downstream side of the intercooler 13 in the return pipe 41. In the oil cooler 17, the coolant C maintained at a relatively low temperature flows therethrough. Engine oil is cooled.
Further, the temperature of the coolant C supplied to the intercooler 13 is detected as the temperature state of the coolant C flowing through the intercooler evaporative cooling type circuit 4 </ b> A and is output to the control unit 60. A temperature sensor 19 is provided.

  Since the water jacket air cooling circuit 5 and the intercooler evaporative cooling circuit 4A are provided as described above, the air cooling type heat radiation method in the radiator 30 is adopted to cool the engine body 10 and the cooling. As the mixture M is cooled by adopting the vaporization cooling type heat radiation method in the tower 35, the heat radiation part Y of the appropriate heat radiation method is adopted, and the performance of the entire engine system 1 is optimized, Energy saving, low cost, and compactness are achieved.

Furthermore, in the cooling mechanism 2 of the engine system 1 of the present embodiment, the disadvantages of the respective heat radiation methods can be achieved while optimizing the performance of the entire engine system 1 by using the radiator 30 and the cooling tower 35 in combination as described above. In order to enjoy the maximum effect due to the advantages, it is configured so that operation can be continued even if there is inconvenience in heat dissipation in the evaporative cooling type heat dissipation part due to water shutoff etc. explain.
The cooling mechanism 2 of the engine system 1 includes an intercooler 13 as a circuit for circulating the coolant C between the intercooler 13 and the heat radiating portion Y in addition to the intercooler evaporative cooling circuit 4A as described above. An intercooler air-cooled circuit 4 </ b> B that circulates the flowing coolant C to and from the radiator 30 is provided.

The intercooler air-cooled circuit 4B includes forward pipes 47 and 40 that connect the outlet side of the second pipe 30b of the radiator 30 and the inlet side of the intercooler 13, the outlet side of the intercooler 13, and the radiator 30. Return pipes 41, 48 connecting the outlet side of the second pipe line 30b, and the coolant C provided in the return pipe line 41 from the outlet side of the intercooler 13 to the inlet side of the second pipe line 30b of the radiator 30 And a circulation pump 43 that feeds toward the center.
Then, as shown in FIG. 2, the circulation pump 43 is operated to circulate the coolant C in the intercooler air cooling circuit 4B, thereby flowing into the outside air A through the second pipe 30b of the radiator 30. On the other hand, the coolant C, which has become relatively low temperature (for example, 55 ° C.) by radiating heat, is supplied to the intercooler 13 via the forward pipes 47 and 40, and at the same time, the mixture is compressed by flowing through the intercooler 13. The coolant C, which has absorbed heat from M and then passed through the oil cooler 17 and absorbed heat from the engine oil, has reached a relatively high temperature (for example, 61 ° C.), and is returned to the second pipe of the radiator 30 via the return pipes 41 and 48. The coolant C circulates through the intercooler air-cooled circuit 4B in the form supplied to the passage 30b.
Then, by circulating the coolant C through the intercooler air-cooled circuit 4B, the mixture M flowing through the intake passage 12 via the intercooler 13 is heated to the coolant C cooled to some extent by the radiator 30. It will be cooled by replacement.
The intercooler air-cooled circuit 4B circulates the coolant C flowing through the intercooler 13, which is the low-temperature cooling part Xl, between the radiator 30 and the intercooler air-cooled circuit 4B. There is a case.

Further, the intercooler air cooling circuit 4B shares the forward conduit 40, the return conduit 41, and the circulation pump 43 with the intercooler vaporization cooling circuit 4A, and the intercooler vaporization cooling circuit 4A. The circulation state of the coolant C in each of the circuits 4A and 4B can be switched by a three-way valve 46 arranged at a connection portion of the forward conduit 47 to the return conduit 41. It has become.
That is, the three-way valve 46 is an evaporative cooling heat radiation state (the state shown in FIG. 1) in which the coolant C is circulated through the intercooler evaporative cooling circuit 4A, and an air in which the coolant C is circulated in the intercooler evaporative cooling circuit 4A. It functions as a heat radiation state switching means that can selectively switch the circulation state of the coolant C flowing through the intercooler 13 between the cooling heat radiation state (the state shown in FIG. 2).

Further, the control unit 60 functions as a water stop state detection unit 61 that detects a water stop state in which the replenishment of the clean water W to the cooling tower 35 is stopped, and the normal state before the water stop state detection unit 61 detects the water stop state. During operation, the three-way valve 46 is switched to change the circulation state of the coolant C to the evaporative cooling heat radiation state (the state shown in FIG. 1), while the water-stop operation after the water-stop state detection means 61 detects the water-stop state. In some cases, the three-way valve 46 is switched to function as the water cutoff control means 62 that changes the circulating state of the coolant C to the air-cooled heat radiation state (the state shown in FIG. 2).
That is, in the normal operation other than the water shutoff operation, as shown in FIG. 1, the evaporative cooling type heat dissipation state in which the coolant C circulates in the intercooler evaporative cooling type circuit 4A is provided. The mixture M is cooled by adopting a vaporization cooling type heat radiation method in a form in which the cooling tower 35 dissipates heat to the intercooler 13 and allows a sufficiently low temperature coolant C to flow, thereby improving the engine efficiency. Is planned.
On the other hand, at the time of a water shut-off operation that causes inconvenience in heat dissipation in the cooling tower 35 due to a water shut-off state, as shown in FIG. 2, an air-cooled heat dissipating state in which the coolant C circulates in the intercooler air-cooled circuit 4B Therefore, the air-cooled mixture M is continuously cooled by adopting an air-cooling type heat dissipation method in such a manner that the coolant C radiated by the radiator 30 is passed through the intercooler 13 provided in the intake passage 12. Thus, the operation can be continued without the need to supply water to the cooling tower 35.

The water cutoff state detecting means 61 detects the water cutoff state based on the temperature state of the coolant C flowing through the intercooler evaporative cooling circuit 4A, specifically, the temperature of the coolant C detected by the temperature sensor 19. Is configured to do.
In other words, the water cutoff state detection means 61 detects the temperature of the coolant C supplied to the intercooler 13 by the temperature sensor 19 and maintains the temperature of the coolant C detected by the temperature sensor 19 at a normal temperature. If it is, it is determined that the water supply to the cooling tower 35 is not replenished without stagnation, and the heat radiation of the coolant is normally performed.
On the contrary, when the temperature of the coolant C detected by the temperature sensor 19 tends to increase with respect to the normal temperature, the water-stop state detection means 61 enters the water-stop state and causes water to enter the cooling tower 35. It is determined that replenishment has stopped and inconvenience has occurred in the heat dissipation of the coolant C.

  Furthermore, in the cooling mechanism 2 of the engine system 1 according to the present embodiment, as described above, the radiator 30 and the cooling tower 35 are used together to optimize the performance of the engine system 1 as a whole. Therefore, even if the heat radiation method is inconvenient to the cooling tower 35 and the heat radiation method is switched to the air cooling method with inferior cooling capacity, the stable operation state can be maintained. Is described below.

That is, when the circulation state of the coolant C is switched from the vaporization cooling type heat radiation state to the air cooling type heat radiation state in which the cooling capacity is inferior to that by the three-way valve 46, the intercooler 13 as the low temperature cooling part Xl. Inconvenience may occur as the temperature rises. Specifically, there is a concern about the occurrence of knocking or the increase in NOx accompanying the temperature rise of the mixture M.
Therefore, when the three-way valve 46 switches the heat dissipation state of the coolant C from the vaporization-cooling heat dissipation state to the air-cooling heat dissipation state in which the cooling capacity is inferior, the control unit 60 is generated as the temperature of the intercooler 13 increases. It functions as the optimum operation control means 63 for avoiding abnormal operation states such as occurrence of abnormal combustion such as knocking and increase of NOx emission amount.
Specifically, the optimum operation control means 63 adjusts the opening of the fuel supply valve 16 to increase the air-fuel ratio of the air-fuel mixture M sucked into the combustion chamber 10a, in other words, the air-fuel mixture M is fueled. By setting it as a lean state, it is comprised so that generation | occurrence | production of knocking by the early ignition accompanying the temperature rise of the intercooler 13 may be avoided.
Then, occurrence of knocking is avoided by the optimum operation control means 63, and a stable operation state is maintained.

[Another embodiment]
Finally, another embodiment will be described. Note that the configuration of each embodiment described below is not limited to being applied independently, and can be applied in combination with the configuration of other embodiments as long as no contradiction arises.

(1) In the above embodiment, the exhaust heat recovery heat exchanger 55 that heats the clean water W by heat exchange with the coolant C before flowing out of the water jacket 11 and flowing into the radiator 30 is provided. May be omitted, and all the radiators 30 of the heat held by the coolant C may be dissipated.

(2) In the above embodiment, the oil cooler 17 that cools the engine oil by heat exchange with the cooling liquid C is provided in the return pipe 41, but another pipe that allows the cooling liquid C to flow through the oil cooler 17. You may arrange in.

(3) In the above embodiment, the optimum operation control means 63 is configured to avoid the occurrence of knocking by increasing the air-fuel ratio of the air-fuel mixture M sucked into the combustion chamber 10a. The control means 63 limits the increase in engine output or retards the ignition timing in the combustion chamber 10a, thereby causing the occurrence of knocking in the combustion chamber 10a due to the temperature rise of the intercooler 13 and the increase in NOx emissions. You may comprise so that abnormal operation states, such as, may be avoided.
For example, when the optimum operation control means 63 is configured to limit the increase in engine output, it is limited to the maximum adjustment range of the opening of the throttle valve 18 so that the engine output does not increase beyond a predetermined upper limit output. It can comprise so that it may provide.
Further, when the optimum operation control means 63 is configured to retard the ignition timing in the combustion chamber 10a, the ignition timing in the combustion chamber 10a is set to the optimum ignition timing (MBT) that generates the maximum torque. It can be configured to retard.

(4) In the above embodiment, when the three-way valve 46 switches the heat release state of the coolant C from the vaporization-type heat release state to the air-cooled heat release state with inferior cooling capacity, the occurrence of knocking or an increase in NOx emissions The optimum operation control means 63 for avoiding the abnormal operation state is provided. However, when the occurrence of knocking or the increase in NOx due to this state switching does not become a problem, the optimum operation control means 63 may be omitted. Absent.

(5) In the above embodiment, the high temperature cooling part Xh is the water jacket 11 provided in the engine body, and the low temperature cooling part Xl is the intercooler 13 provided in the intake passage 12. The example in which the present invention is applied to the configuration in which the circuit for circulating the coolant C is arranged has been described. However, another high-temperature cooling unit Xh that maintains a relatively high temperature and another that maintains a relatively low temperature. The present invention can also be applied to a configuration in which a circuit that circulates the coolant C is disposed in the low-temperature cooling section Xl.

  The present invention includes an engine system having an engine body that sucks fresh air from an intake passage into a combustion chamber and burns it to output rotational power, and the cooling fluid that is provided in the engine system and dissipates heat in a heat dissipation portion. The engine system can be suitably used as a cooling mechanism for an engine system that performs cooling by flowing through a high-temperature cooling unit included in the engine system and a low-temperature cooling unit that is lower in temperature than the high-temperature cooling unit.

1: Engine system 2: Cooling mechanism 4A: Intercooler evaporative cooling circuit (low-temperature cooling section evaporative cooling circuit)
4B: Intercooler air-cooled circuit (low-temperature cooling section air-cooled circuit)
5: Water jacket air-cooled circuit (high-temperature cooling section air-cooled circuit)
10: Engine main body 10a: Combustion chamber 11: Water jacket 12: Intake passage 13: Intercooler 30: Radiator (air-cooling heat radiation part)
30a: 1st pipe line (high temperature cooling part side flow path)
30b: 2nd pipe line (low temperature cooling part side flow path)
35: Cooling tower (vaporization cooling type heat radiation part)
46: Three-way valve (heat dissipation state switching means)
61: Water outage detection means 62: Water outage control means A: Air, outside air C: Coolant M: Air-fuel mixture (fresh air)
W: Clean water Xh: High temperature cooling part Xl: Low temperature cooling part Y: Heat radiation part

Claims (6)

It is provided in an engine system having an engine body that draws fresh air from an intake passage into a combustion chamber and burns it to output rotational power,
A cooling mechanism for an engine system that performs cooling by passing a coolant radiated by a heat radiating section through a high temperature cooling section of the engine system and a low temperature cooling section having a temperature lower than that of the high temperature cooling section,
As the heat dissipating part, an air-cooled heat dissipating part that dissipates heat by sensible heat exchange with the outside air, and a vaporized cooling heat dissipating part that dissipates heat by vaporizing heat exchange of the water sprayed with the coolant,
A high-temperature cooling unit air-cooling circuit for circulating the coolant flowing through the high-temperature cooling unit between the air-cooling heat dissipation unit and
A low-temperature cooling unit evaporative cooling circuit capable of circulating the coolant flowing through the low-temperature cooling unit between the evaporative cooling-type heat dissipation unit, and a cooling liquid flowing through the low-temperature cooling unit as the air-cooling heat dissipation unit A low-temperature cooling section air-cooled circuit that can circulate between
The low temperature cooling unit is disposed between a vaporization cooling type heat radiation state in which a cooling liquid is circulated through the low temperature cooling unit vaporization cooling type circuit and an air cooling type heat radiation state in which a cooling liquid is circulated through the low temperature cooling unit air cooling type circuit. A cooling mechanism for an engine system, comprising a heat radiation state switching means capable of selectively switching a circulating state of a flowing coolant. The high temperature cooling part is a water jacket provided in the engine body, and the low temperature cooling part is an intercooler provided in the intake passage,
As the high-temperature cooling unit air-cooled circuit, a water jacket air-cooled circuit that circulates a coolant flowing through the water jacket between the air-cooled heat radiating unit,
As the low-temperature cooling unit evaporative cooling circuit, an intercooler evaporative cooling circuit that circulates a coolant flowing through the intercooler between the evaporative cooling heat dissipation unit,
2. The engine system according to claim 1, further comprising an intercooler air-cooled circuit that circulates a coolant flowing through the intercooler between the low-temperature cooling unit and the air-cooling heat radiating unit. Cooling mechanism. A water outage state detecting means for detecting a water outage state in which replenishment of spray water to the evaporative cooling type heat radiation unit is stopped;
In a normal operation before the water-stop state is detected by the water-stop state detection means, the cooling liquid circulation state is set to the evaporative cooling heat-release state by the heat-release state switching means, and the water-stop state is detected by the water-stop state detection means. 3. The engine system cooling mechanism according to claim 1, further comprising: a water cutoff control unit configured to change the circulation state of the coolant to the air-cooled heat radiation state by the heat radiation state switching unit during the subsequent water cutoff operation.   4. The cooling mechanism for an engine system according to claim 3, wherein the water cutoff state detection means detects the water cutoff state based on a temperature state of a coolant flowing through the low temperature cooling unit evaporative cooling type circuit.   The air-cooling heat radiating unit is connected to the high-temperature cooling unit side channel connected to the high-temperature cooling unit air-cooling circuit and the low-temperature cooling unit air-cooling circuit as a channel through which the coolant flows. The engine system cooling mechanism according to any one of claims 1 to 4, wherein the engine system cooling mechanism is configured in a two-circuit configuration in which the low-temperature cooling section side flow paths are separately arranged. An engine system having an engine main body that sucks fresh air from an intake passage into a combustion chamber and burns it to output rotational power,
6. The cooling mechanism for performing cooling by passing the coolant radiated by the heat radiating section through a high temperature cooling section of the engine system and a low temperature cooling section having a temperature lower than that of the high temperature cooling section. 6. Engine system equipped with a cooling mechanism.

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