JP4763641B2 - Cooling system for heat source - Google Patents

Description

  The present invention relates to a heat source cooling system for cooling a heat source.

  There is a heat source cooling system for cooling a heat source such as an internal combustion engine mounted on a vehicle. Such a heat source cooling system has a circulation path through which a cooling medium for cooling the heat source circulates via the heat source and the radiator, and branches from the branch portion of the circulation path, bypasses the radiator and circulates. A bypass path that merges at the merge section of the path, a thermostat that is provided at the branch or merge section and adjusts the flow rate of the cooling medium flowing through the radiator and the bypass path, and energizes the flow of the cooling medium And a pump. As the pump, a mechanical pump or an electric pump that operates using the driving force of the internal combustion engine is used.

  In such a heat source cooling system, the higher the outflow temperature of the cooling medium from the heat source, the greater the amount of heat dissipated in the radiator, that is, the greater the amount of cooling medium flowing through the radiator. It needs to be adjusted. Therefore, the thermostat is provided in the junction part or branch part of the flow path of the cooling medium connected to each of the outlet side of the heat source, the radiator side, and the inlet side of the heat source. The thermostat radiates a large amount of cooling medium flowing from the outlet side of the heat source to the radiator side to dissipate the cooling medium, or flows a large amount to the bypass path side to radiate most of the cooling medium. Whether or not to perform is automatically switched according to the temperature.

In other words, when the outflow temperature of the cooling medium from the heat source becomes high, the thermostat operates, and the amount of the cooling medium flowing through the radiator increases, and the cooling medium flows through the circulation path by the radiator. The temperature is lowered. Then, the cooling medium whose temperature has decreased falls back into the heat source.
In addition, when the temperature of the cooling medium flowing out from the heat source is low, such as when the heat source is started, the cooling medium hardly flows through the circulation path provided with the radiator, but flows through the bypass path. . As a result, the cooling medium re-enters the heat source while suppressing the heat radiation amount, so that the heat source can be reliably warmed up.

  In a conventional cooling system for a heat source, when a mechanical pump that operates using the driving force of an internal combustion engine (heat source) is used, the operating state of the mechanical pump depends on the operating state of the internal combustion engine. The flow rate of the cooling medium cannot be controlled. In other words, in the heat source cooling system, the cooling medium is always passed at a flow rate of a certain level or more according to the operating state of the internal combustion engine. In order to ensure the reliability of the internal combustion engine, more cooling medium than necessary is passed in most operating states of the internal combustion engine.

On the other hand, when an electric pump is used in a conventional heat source cooling system, the flow rate of the cooling medium in the circulation path can be freely controlled. As a result, there is an advantage that the electric power consumed by the electric pump can be reduced by making the output of the electric pump smaller than that of the mechanical pump.
However, if the output of the electric pump is reduced, the flow rate of the cooling medium flowing into the thermostat is also reduced, so that even if the temperature of the cooling medium rises, it becomes difficult for the thermostat to warm up. In other words, when an electric pump is used, if the flow rate of the cooling medium flowing through is reduced when the temperature of the cooling medium is low (that is, the amount of the cooling medium flowing through the thermostat is reduced). There is a problem that the operation of the thermostat is delayed with respect to the temperature rise of the cooling medium. This is because each part of the thermostat, such as the temperature sensing part, has a heat capacity, so if the flow rate of the cooling medium is low, it takes time to warm the temperature sensing part of the thermostat even if the temperature of the cooling medium rises. Because it takes.

For example, FIG. 1 shows that the thermostat 4 joins the flow path of the cooling medium connected to the outlet 13 side of the heat source 1, the radiator 5 side, and the inlet 14 side of the heat source 1. It is a figure at the time of being provided in the part 12. FIG. In this case, when the temperature of the cooling medium is low, the opening B on the side of the radiator 5 of the thermostat 4 is closed, and the thermostat 4 flows in from the opening A on the side of the outlet 13 of the heat source 1. The cooling medium is passed through the opening B on the inlet 14 side of the heat source 1. In such a state, when the temperature of the cooling medium flowing from the outlet 13 side of the heat source begins to rise, the cooling medium is flowing through the opening B on the radiator 5 side of the thermostat 4. Therefore, the temperature of the cooling medium existing in the opening B on the side of the radiator 5 of the thermostat 4 remains low.
Therefore, in consideration of the heat capacity of each component such as the temperature sensing part constituting the thermostat 4, even if the temperature on the opening A side of the thermostat 4 rises, the thermostat remains low at the opening B side of the thermostat 4. The temperature rise of the temperature sensing part 4 is not performed quickly. That is, conventionally, when the flow rate of the cooling medium is small, the operation of the thermostat is delayed, that is, the flow rate of the cooling medium flowing through the radiator 5 cannot be increased quickly. As a result, when the temperature of the heat source rises rapidly, the heat source cannot be sufficiently cooled.

  With regard to the above problem in the case of using an electric pump, a technique for quickly operating a thermostat with respect to a temperature change of a cooling medium is disclosed. For example, Patent Document 1 describes a technique for promoting the operation of the thermostat by forming individual flow paths for applying a cooling medium to the temperature sensing portion of the thermostat. Also, in Patent Document 2, the temperature sensing part of the thermostat is configured so that it can be heated by a heater, and when the temperature of the cooling medium is expected to rise, the heater is energized to promote the operation of the thermostat. The technology to do is described.

JP 2002-129959 A Japanese Utility Model Publication No. 6-25682

  As in the techniques described in Patent Document 1 and Patent Document 2, providing special mechanisms such as individual flow paths and heaters to promote the operation of the thermostat increases the cost and weight, and the device This is not preferable because the configuration is complicated.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to quickly increase the flow rate of the cooling medium flowing through the radiator with respect to the temperature rise of the cooling medium with a simple apparatus configuration. It is the point which provides the cooling system for the heat source performed.

The cooling system for a heat source according to the present invention for achieving the above object includes a circulation path through which a cooling medium for cooling the heat source can be circulated via the heat source and a radiator,
A bypass path that branches off from the branch section of the circulation path, bypasses the radiator, and merges at the junction section of the circulation path;
A thermostat that is provided in the branching section or the merging section and operates to increase the flow rate of the cooling medium flowing through the radiator of the radiator and the bypass when the temperature is high;
An electric pump for passing the cooling medium;
Temperature detecting means for detecting the temperature of the cooling medium flowing therethrough;
Control means for controlling the operation of the electric pump so as to increase the flow rate of the cooling medium flowing into the thermostat when the temperature of the cooling medium detected by the temperature detecting means satisfies a rapid heating condition; In the point provided with.

According to the above characteristic configuration, when the temperature of the cooling medium satisfies the rapid heating condition, the flow rate of the cooling medium flowing into the thermostat is increased. Therefore, the temperature of the thermostat is lower than the temperature of the cooling medium compared to the case where the flow rate is small. To get closer to. That is, the operation of the thermostat is promoted, and the flow rate of the cooling medium flowing through the radiator is increased. As a result, the cooling medium after having been radiated in the radiator again flows into the heat source, so that the heat source is sufficiently cooled.
As described above, the operation of the thermostat is promoted with respect to the temperature rise of the cooling medium so that the flow rate of the cooling medium flowing through the radiator can be increased quickly. When the rapid heating condition is not satisfied, the flow rate of the cooling medium can be reduced.
Further, it is not necessary to provide a special mechanism such as an individual flow path or a heater in order to promote the operation of the thermostat.
Therefore, it is possible to provide a heat source cooling system in which the flow rate of the cooling medium flowing through the radiator is rapidly increased with a simple apparatus configuration as the temperature of the cooling medium rises.

  Another characteristic configuration of the cooling system for a heat source according to the present invention is that the control unit determines that the rapid heating condition is satisfied when a temperature of the cooling medium is equal to or higher than a set temperature.

  According to the above characteristic configuration, before the temperature of the cooling medium becomes too high, that is, before the temperature of the heat source becomes too high, the operation of the thermostat is promoted so that the flow rate of the cooling medium flowing through the radiator is increased. Can be increased.

  Another feature of the heat source cooling system according to the present invention is that the thermostat operates to maximize the flow rate of the cooling medium flowing through the radiator when the temperature is equal to or higher than the set temperature. .

  According to the above characteristic configuration, when the temperature of the cooling medium becomes equal to or higher than the set temperature, the thermostat can be quickly operated to an operation state in which the flow rate of the cooling medium flowing through the radiator is maximized.

  Another characteristic configuration of the cooling system for a heat source according to the present invention is that the control unit determines that the rapid heating condition is satisfied when a temperature change per unit time of the cooling medium is equal to or higher than a set increase rate. is there.

  According to the above characteristic configuration, before the temperature of the cooling medium rapidly rises, that is, before the temperature of the heat source becomes too high, the operation of the thermostat is promoted to increase the flow rate of the cooling medium flowing through the radiator. Can be made.

  Another characteristic configuration of the heat source cooling system according to the present invention is that the temperature of the cooling medium is equal to or higher than a set temperature, and the temperature change per unit time of the cooling medium is a set increase rate. If it becomes above, it exists in the point determined with the said rapid heating conditions having been satisfy | filled.

  According to the above-described characteristic configuration, the operation of the thermostat is promoted before the temperature of the cooling medium does not become too high and the temperature of the cooling medium rises rapidly, that is, before the temperature of the heat source becomes too high, The flow rate of the cooling medium flowing through the radiator can be increased.

<First Embodiment>
The configuration of the heat source cooling system of the present embodiment will be described below with reference to the drawings.
FIG. 1 is a block diagram illustrating a configuration of a heat source cooling system according to the first embodiment. In the heat source cooling system illustrated in FIG. 1, an internal combustion engine, a fuel cell, or the like installed in a vehicle or a building is used as the heat source 1. The heat source 1 has a temperature suitable for normal operation. Therefore, in order to maintain an appropriate temperature of the heat source 1, a cooling medium such as cooling water or cooling oil can recover the exhaust heat from the heat source 1. In the following description, an example in which cooling water as a cooling medium recovers exhaust heat from the heat source 1 will be described.

Cooling water for cooling the heat source 1 flows through the circulation path 10 via the heat source 1 and the radiator 5. The cooling water flows through the electric pump 3 provided in the middle of the circulation path 10. The radiator 5 has a large surface area in contact with the outside air, and can reduce the temperature of the cooling water by heat exchange with the outside air having a lower temperature than the cooling water flowing through the circulation path 10. A heat radiating fan 6 that blows outside air to the heat radiator 5 is also provided. Therefore, when the heat radiating fan 6 is operated, heat exchange between the heat radiator 5 (cooling water) and the outside air is promoted, so that the heat radiation effect of the cooling water in the heat radiator 5 can be further enhanced.
The operation of the electric pump 3 and the heat radiating fan 6 described above is controlled by the control means 30.

  The heat source cooling system includes a bypass path 20 that branches from the branch section 11 of the circulation path 10, bypasses the radiator 5, and merges at the merge section 12 of the circulation path 10. The junction 12 is provided with a thermostat 4 that operates so that the flow rate of cooling water flowing through the radiator 5 out of the radiator 5 and the bypass path 20 increases as the temperature rises. A temperature sensor 2 is provided at the outlet 13 of the heat source 1 as temperature detecting means for detecting the temperature of the flowing coolant. The detection result of the temperature sensor 2 is transmitted to the control means 30 and stored.

  In the present embodiment, the thermostat 4 is connected to the opening A connected to the outlet 13 of the heat source 1, the opening B connected to the radiator 5, and the inlet 14 of the heat source 1. The opening C is provided. Moreover, the thermostat 4 equips an inside with the temperature sensing part which has the thermowax expand | swelled and shrink | contracted according to the temperature of the cooling water which flowed in. The thermostat 4 operates so that the flow rate of the cooling water flowing through the radiator 5 increases when the temperature increases (that is, when the temperature of the temperature sensing unit increases).

  FIG. 2 is a diagram illustrating temperature characteristics of the thermostat 4 used in the present embodiment. As shown in the drawing, in the thermostat 4, the opening B on the side of the radiator 5 is fully closed at about 82 ° C. or less. At this time, the opening A of the thermostat 4 is fully open. Therefore, as shown by a broken line in FIG. 1, the cooling water flowing out from the heat source 1 does not flow into the radiator 5 but flows through the bypass path 20. That is, the cooling water exits from the outlet 13 of the heat source 1 and flows through the circulation path 10, the branching section 11, the bypass path 20, the junction section 12 (thermostat 4), and the circulation path 10 in order to the inlet of the heat source 1. Circulate the route leading to 14.

Further, when the temperature of the thermostat 4 becomes about 82 ° C. or higher, the opening B on the side of the radiator 5 starts to open, and the flow rate of the cooling water flowing through the radiator 5 increases. Along with this, the opening A of the thermostat 4 starts to close, and the flow rate of the cooling water flowing through the bypass path 20 decreases.
And when the temperature of the thermostat 4 will be about 94 degreeC or more, the opening part B by the side of the heat radiator 5 will be in a full open state. Further, the opening A of the thermostat 4 is fully closed. Therefore, as shown by the solid line in FIG. 1, the cooling water flowing out from the heat source 1 does not flow into the bypass path 20, but flows through the radiator 5. In other words, the cooling water circulates through a path from the outlet 13 of the heat source 1 through the circulation path 10, the radiator 5, and the circulation path 10 to the inlet 14 of the heat source 1.
However, the valve opening temperature of the thermostat 4 described above: about 82 ° C. and the radiator side full open temperature: about 94 ° C. are examples for explaining the present embodiment. Depending on the type of the thermostat 4, the valve opening temperature and the radiator side full open temperature can be set as appropriate.

  As described above, the thermostat 4 flows a large amount of cooling water flowing out from the heat source 1 to the radiator 5 to dissipate the cooling water, or flows a large amount to the bypass path 20 to hardly dissipate the cooling water. Is automatically adjusted according to the temperature.

  The heat source cooling system of the present embodiment has a configuration in which cooling water is passed by an electric pump, so that the output of the electric pump is smaller than that of a mechanical pump, and electric power consumed by the electric pump is reduced. There is an advantage that the amount can be reduced. Furthermore, even if the temperature of the heat source 1 rises rapidly, the thermostat 4 operates quickly, and sudden heating of the cooling water is prevented. Specifically, in the present embodiment, by increasing the flow rate of the cooling water flowing into the thermostat 4, the temperature of each component such as the temperature sensing portion constituting the thermostat 4 is quickly brought close to the cooling water temperature. 4 is promoted, and the flow rate of the cooling water flowing through the radiator is increased.

  Below, with reference to FIG.3 and FIG.4, control of the electric pump 3 by the control means 30 is demonstrated. FIG. 3 is a diagram for explaining a temporal change in the outflow temperature of the cooling water from the heat source 1. FIG. 4 is a flowchart of the rapid heating prevention control using the electric pump 3 in the first embodiment.

  In step # 100, the control means 30 determines whether or not the temperature of the cooling water detected by the temperature sensor 2 satisfies the rapid heating condition. Specifically, when the temperature of the cooling water becomes equal to or higher than the set temperature (or exceeds the set temperature), that is, the temperature of the cooling water is equal to or higher than the radiator side full open temperature (about 94 ° C.) of the thermostat 4. If there is, it is determined that the rapid heating condition is satisfied. In the present embodiment, the set temperature is a temperature at which the thermostat 4 operates so as to maximize the flow rate of the cooling water flowing through the radiator 5 (that is, fully open). Moreover, the control means 30 will operate the thermal radiation fan 6 when it becomes more than this preset temperature.

When the cooling water temperature is equal to or higher than the radiator side full open temperature (about 94 ° C.) of the thermostat 4 (ie, “Yes” in step # 100 of FIG. 4), the output level of the electric pump 3 is increased to increase the thermostat. It is necessary to increase the flow rate of the cooling water flowing into 4. Therefore, control shifts to process # 102. On the other hand, when the cooling water temperature is lower than the radiator side fully open temperature of thermostat 4 (when “No” in step # 100 of FIG. 4), it is not necessary to increase the output level of electric pump 3. Therefore, control proceeds to step # 106.
Here, the output level of the electric pump 3 controlled by the control means 30 is preferably set in a plurality of stages of three or more. This is because the output level of the electric pump 3 can be finely controlled in accordance with the temperature rise of the cooling water.

In step # 102, the control means 30 determines whether or not the output level of the electric pump 3 is the maximum. When it is not the maximum, the control means 30 proceeds to step # 104 and increases the output level of the electric pump 3. That is, the control means 30 determines that the heat dissipation of the cooling water is insufficient, and increases the flow rate of the cooling water flowing into the thermostat 4. As a result, since the temperature of the thermostat 4 approaches the temperature of the cooling water faster than when the flow rate of the cooling water flowing into the thermostat 4 is small, the operation of the thermostat 4 is promoted and the radiator 5 flows. The flow rate of cooling water to be increased.
On the other hand, the control means 30 maintains the output level when the output level of the electric pump 3 is maximum, and returns to the beginning of the control.

In step # 106, the control means 30 determines whether or not the output level of the electric pump 3 is minimum. Then, when the output level of the electric pump 3 is not minimum, the control means 30 proceeds to step # 108 and decreases the output level of the electric pump 3. That is, the control unit 30 determines that the cooling water is sufficiently dissipated and reduces the flow rate of the cooling water flowing into the thermostat 4. As a result, the amount of power consumed by the electric pump 3 can be reduced without cooling the heat source 1 more than necessary.
On the other hand, when the output level of the electric pump 3 is minimum, the control means 30 maintains the output level and returns to the beginning of the control.

  In FIG. 3, a solid line B is an example in which the operation of the thermostat 4 can follow the temperature rise of the cooling water, although the heat source 1 is rapidly heated. In this case, the flow rate of the cooling water that initially flows is small. Therefore, when the temperature of the cooling water at the outlet 13 of the heat source 1 rises and becomes equal to or higher than the valve opening temperature (about 82 ° C.) of the thermostat 4, the operation of the thermostat 4 cannot follow the temperature rise, and the radiator The flow rate of the cooling water flowing through 5 is not increased quickly. Then, the cooling water flows into the heat source 1 again with insufficient heat dissipation. As a result, the cooling of the heat source 1 becomes insufficient, and the temperature of the cooling water flowing out from the heat source 1 further increases. And the rapid heating conditions shown to process # 100 of FIG. 4 are satisfy | filled because the temperature of a cooling water becomes more than the radiator side full open temperature (about 94 degreeC) of the thermostat 4. FIG. For example, when a vehicle equipped with a heat source 1 such as an internal combustion engine or a fuel cell is operated on a traffic jam or on an uphill, if the cooling water flowing through the radiator 5 is insufficient, the cooling in the radiator 5 Water tends to be insufficiently dissipated.

  Therefore, the control means 30 raises the output level of the electric pump 3 as shown in step # 102 and step # 104 of FIG. As a result, the flow rate of the cooling water flowing into the thermostat 4 increases, and the temperature of the thermostat 4 is brought closer to the temperature of the cooling water. And the action | operation of the thermostat 4 is accelerated | stimulated and the flow volume of the cooling water which flows the heat radiator 5 increases. Therefore, the cooling water that has been radiated in the radiator 5 reflows into the heat source 1, so that the heat source 1 is sufficiently cooled, and the temperature of the cooling water is gradually increased over time on the radiator side of the thermostat 4 (about 94 ° C.) or lower.

In FIG. 3, a broken line A and a broken line C are comparative examples of the present invention.
The broken line A is an example in which the operation of the thermostat 4 can follow the temperature rise of the cooling water because the heat source 1 is not rapidly heated. In this case, when the temperature of the cooling water at the outlet 13 of the heat source 1 rises and becomes equal to or higher than the valve opening temperature of the thermostat 4 (about 82 ° C.), the operation of the thermostat 4 is performed following the temperature rise. The flow rate of the cooling water flowing through the radiator 5 increases. And the heat dissipation of the cooling water in the radiator 5 is promoted, and the cooling water having a relatively low temperature flows again into the heat source 1. As a result, the cooling of the heat source 1 is appropriately performed, and the temperature of the cooling water flowing out from the heat source 1 is stabilized without rapidly increasing.

  On the other hand, the broken line C is an example in the case where the temperature of the cooling water continues to rise rapidly because the operation of the thermostat 4 was not performed quickly when the heat source 1 was rapidly heated in the conventional heat source cooling system. . In this case, when the temperature of the cooling water at the outlet 13 of the heat source 1 rises and becomes equal to or higher than the valve opening temperature of the thermostat 4 (about 82 ° C.), the operation of the thermostat 4 cannot follow the temperature rise, and heat is dissipated. The flow rate of the cooling water flowing through the vessel 5 is not increased quickly. Therefore, even if the heat radiating fan 6 is activated, the heat radiation of the cooling water in the radiator 5 is insufficient. Then, the cooling water flows into the heat source 1 again with insufficient heat dissipation. As a result, the cooling of the heat source 1 becomes insufficient, and the temperature of the cooling water flowing out from the heat source 1 further increases. And even if the temperature of a cooling water becomes more than the radiator side full open temperature (about 94 degreeC) of the thermostat 4, it will continue rising.

  As described above, in the heat source cooling system of the present embodiment, when the temperature of the cooling water satisfies the rapid heating condition, the flow rate of the cooling water flowing into the thermostat 4 is increased. Therefore, the flow rate of the cooling water flowing into the thermostat 4 The temperature of the thermostat 4 can be brought closer to the temperature of the cooling water compared to the case where the temperature is small. That is, the operation of the thermostat 4 is promoted, and the flow rate of the cooling water flowing through the radiator 5 is increased. As a result, the cooling water that has been radiated in the radiator 5 flows into the heat source 1 again, so that the heat source 1 is sufficiently cooled.

  As described above, the operation of the thermostat 4 is promoted with respect to the temperature rise of the cooling water so that the flow rate of the cooling water flowing through the radiator 5 can be quickly increased. When the heating condition is not satisfied, the flow rate of the cooling water can be reduced. Further, it is not necessary to provide a special mechanism such as an individual flow path or a heater in order to promote the operation of the thermostat 4. Therefore, the flow rate of the cooling water flowing through the radiator 5 can be quickly increased with a simple apparatus configuration as the temperature of the cooling water rises.

Second Embodiment
In the heat source cooling system of the second embodiment, the contents of the rapid heating conditions in the rapid heating prevention control are different from those described in the first embodiment. Although the rapid heating prevention control performed by the heat source cooling system of the second embodiment will be described below, the description of the same configuration as that of the first embodiment will be omitted.

FIG. 5 is a flowchart of the rapid heating prevention control in the second embodiment. However, the contents of the rapid heating conditions shown in the process # 200 are only different from those in the first embodiment, and the other processes # 202 to # 208 are the same as the processes # 102 to # 108 shown in FIG. It is the same.
As shown in FIG. 5, in step # 200, the control means 30 determines whether or not the temperature of the cooling water detected by the temperature sensor 2 satisfies the rapid heating condition. Specifically, in this embodiment, the control unit 30 determines that the rapid heating condition is satisfied when the temperature change per unit time of the cooling water is equal to or higher than the set increase rate.

  And in the rapid heating prevention control of this embodiment, the control means 30 is an electric pump in process # 202 and process # 204 which follow, if the temperature change per unit time of cooling water is rising above a setting increase rate. Increase the output level of 3. As a result, the flow rate of the cooling water flowing into the thermostat 4 increases, and the temperature of the thermostat 4 is brought closer to the temperature of the cooling water. And the action | operation of the thermostat 4 is accelerated | stimulated and the flow volume of the cooling water which flows the heat radiator 5 increases. Therefore, the cooling water after being radiated in the radiator 5 is re-flowed into the heat source 1 so that the heat source 1 is sufficiently cooled, and the temperature of the cooling water becomes lower than the full open temperature on the radiator side of the thermostat 4 over time. To fall. Here, the specific value of the set increase rate as the rapid heating condition can be set as appropriate.

<Third Embodiment>
In the heat source cooling system of the third embodiment, the contents of the rapid heating condition in the rapid heating prevention control are different from those described in the first embodiment and the second embodiment. Although the rapid heating prevention control performed in the heat source cooling system of the third embodiment will be described below, the description of the same configuration as that of the first embodiment and the second embodiment will be omitted.

FIG. 6 is a flowchart of the rapid heating prevention control in the third embodiment. However, the contents of the rapid heating conditions consisting of the steps # 300 and # 302 are only different from those of the first embodiment and the second embodiment, and the other steps # 304 to # 310 are shown in FIG. This is the same as step # 102 to step # 108 and step # 202 to step # 208 shown in FIG.
The rapid heating condition in the present embodiment is that the temperature of the cooling water is equal to or higher than the set temperature (or exceeds the set temperature), and the temperature change per unit time of the cooling water is equal to or higher than the set increase rate.

  As shown in FIG. 6, the control means 30 is configured so that the temperature of the cooling water detected by the temperature sensor 2 in step # 300 is equal to or higher than the set temperature, and the cooling water detected by the temperature sensor 2 in step # 302. When the temperature change per unit time is increasing at a set increase rate or more, it is determined that the rapid heating condition is satisfied. Then, when the temperature of the cooling water becomes equal to or higher than the set temperature and the temperature change per unit time of the cooling water becomes equal to or higher than the set increase rate, the control unit 30 determines that the rapid heating condition is satisfied and continues to step # 304. And in process # 306, it controls so that the output level of the electric pump 3 may be raised. On the other hand, if the rapid heating condition is not satisfied, the control means 30 performs control so as to lower the output level of the electric pump 3 in the subsequent step # 308 and step # 310.

In the present embodiment, the set temperature may be a value different from the set temperature described in the first embodiment. For example, in the first embodiment, the radiator side fully open temperature (about 94 ° C.) of the thermostat 4 is set as the set temperature, but a temperature lower than or equal to it may be set as the set temperature for the rapid heating prevention control in the present embodiment. . Further, the set rate of increase in temperature change per unit time may be a value different from that described in the second embodiment.
For example, in the rapid heating prevention control in the present embodiment, the control means 30 has a temperature change per unit time equal to or higher than the set increase rate even if the temperature of the cooling water is a set temperature lower than the full open temperature on the radiator side of the thermostat 4. If so, the operation of the thermostat 4 is promoted and the flow rate of the cooling water flowing through the radiator 5 is increased. As a result, the flow rate of the cooling water flowing through the radiator 5 can be quickly increased with respect to the temperature rise of the cooling water.

<Another embodiment>
<1>
In the said embodiment, the control means 30 can also be comprised so that the failure determination of the thermostat 4 may be performed. For example, when the control means 30 maximizes the output level of the electric pump 3 and the rapid heating condition continues to be satisfied, the cooling water is not flowing through the radiator 5 or the flow rate is insufficient. The thermostat 4 can be determined to be out of order. Specifically, after maximizing the output level of the electric pump 3, the control means 30 measures the time during which the rapid heating condition is satisfied, and if the time reaches a predetermined time, the thermostat 4 breaks down. It is determined that

<2>
In the above embodiment, the thermostat 4 may be provided at the branching portion 11 of the circulation path 10. Even in that case, the thermostat 4 operates so that the flow rate of the cooling water flowing through the radiator 5 of the radiator 5 and the bypass path 20 increases as the temperature increases.

In the above embodiment, the temperature sensor 2 may be provided at another position such as the inlet 14 of the heat source 1. Further, the temperature sensor 2 may be provided at a plurality of positions such as the outlet 13 and the inlet 14.
The electric pump 3 may be provided at another position such as the outlet 13 of the heat source 1.

<3>
In the above embodiment, the output level of the electric pump 3 controlled by the control means 30 may be set in two stages (for example, a normal output level with a small output and an output level for preventing sudden heating with a large output). In this case, the output control of the electric pump in the above-described rapid heating prevention control is simplified.

Block diagram explaining the configuration of the heat source cooling system Diagram explaining temperature characteristics of thermostat The figure explaining the time change of the outflow temperature of the cooling water from the heat source Flowchart of sudden heating prevention control in the first embodiment Flow chart of sudden heating prevention control in the second embodiment Flowchart of sudden heating prevention control in the third embodiment

Explanation of symbols

1 Heat source 2 Temperature sensor (temperature detection means)
DESCRIPTION OF SYMBOLS 3 Electric pump 4 Thermostat 5 Radiator 10 Circulation path 11 Branch part 12 Merge part 20 Bypass path 30 Control means

Claims (5)

A circulation path through which a cooling medium for cooling the heat source can circulate via the heat source and the radiator;
A bypass path that branches off from the branch section of the circulation path, bypasses the radiator, and merges at the junction section of the circulation path;
A thermostat that is provided in the branching section or the merging section and operates to increase the flow rate of the cooling medium flowing through the radiator of the radiator and the bypass when the temperature is high;
An electric pump for passing the cooling medium;
Temperature detecting means for detecting the temperature of the cooling medium flowing therethrough;
Control means for controlling the operation of the electric pump so as to increase the flow rate of the cooling medium flowing into the thermostat when the temperature of the cooling medium detected by the temperature detecting means satisfies a rapid heating condition; , Comprising a heat source cooling system.   2. The heat source cooling system according to claim 1, wherein the control unit determines that the rapid heating condition is satisfied when a temperature of the cooling medium is equal to or higher than a preset temperature.   The heat source cooling system according to claim 2, wherein the thermostat operates to maximize the flow rate of the cooling medium flowing through the radiator when the temperature exceeds the set temperature.   2. The heat source cooling system according to claim 1, wherein the control unit determines that the rapid heating condition is satisfied when a temperature change per unit time of the cooling medium becomes a set increase rate or more.   The control means determines that the rapid heating condition is satisfied when a temperature of the cooling medium is equal to or higher than a set temperature and a temperature change per unit time of the cooling medium is equal to or higher than a set increase rate. The cooling system for a heat source according to 1.

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