JP2009127888A - Heat exchanger and engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To keep a fluid after heat exchange at a proper temperature, regardless of a state of the introduced fluid. <P>SOLUTION: This heat exchanger 1 includes a plurality of tubular bodies 2 disposed in parallel with each other, an inlet-side tank 3 and an outlet-side tank 4 communicated by the plurality of tubular bodies 2, a first solenoid valve 5 and a second solenoid valve 6 changing use regions of the tubular bodies 2, and an ECU 7 controlling opening/closing states of the first solenoid valve 5 and the second solenoid valve 6 on the basis of the information on flow rate, pressure and temperature of the first fluid flowing into the inlet-side tank 3. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a heat exchanger that performs heat exchange between a low-temperature fluid and a high-temperature fluid, and an engine including the heat exchanger.

  2. Description of the Related Art Conventionally, an engine cooling device employs a forced circulation system in which liquid refrigerant cooled by a radiator is pumped by a water pump and circulated in a water jacket to cool each part of the engine. As a cooling method different from such a cooling method, Patent Document 1 discloses a method of cooling a cooling part by evaporation of supplied refrigerant. Since such a cooling method by evaporation of the refrigerant uses latent heat when the refrigerant evaporates, the amount of heat exchange between the cooling part and the refrigerant is much larger than that of the forced circulation method, and the same amount of refrigerant can be obtained with a smaller amount of refrigerant. A cooling effect is obtained.

  By the way, such a cooling device is provided with a condenser that condenses and liquefies the evaporated refrigerant. When the capacity of such a condenser is small, the amount of heat released from the refrigerant decreases, and when the capacity of the condenser is large, the amount of heat released from the refrigerant increases. That is, the amount of heat released from the refrigerant depends on the capacity of the condenser. For this reason, when the amount of heat radiated from the refrigerant is suitable for the amount of heat released from the condenser, such a condenser can maintain a good cooling state. However, since the temperature of the refrigerant varies depending on the operating state of the engine, the amount of heat radiated from the refrigerant is not constant. For this reason, in a condenser with a constant heat radiation amount, the refrigerant may be excessively cooled or insufficiently cooled.

  A boiling cooling device that solves such a problem is disclosed in Patent Document 2. The boiling cooling device disclosed in Patent Document 2 includes a radiator separately from the condenser, and supplies a part of the cooling water to the radiator when the refrigerant temperature in the water jacket exceeds an appropriate value. In such a boiling cooling device, the capacity of the condenser can be set, and the purpose is to use the capacity of the condenser without excess or deficiency.

Japanese Utility Model Publication No. 57-18714 Japanese Utility Model Publication No. 3-24827

  By the way, since the cooling system that cools the engine by evaporation uses latent heat when the refrigerant evaporates, it is necessary to supply the refrigerant that can absorb heat and evaporate from the engine body into the water jacket. However, in the boiling cooling device of Patent Document 2, when the refrigerant is introduced into the radiator, information on the temperature of the refrigerant cooled by the radiator is not considered, so that the refrigerant having a temperature not more than suitable for evaporation is contained in the water jacket. It is possible to be supplied to. Further, as described above, in the method of cooling the engine by evaporation of the refrigerant, the amount of refrigerant used for cooling is small with respect to the volume of the condenser. As described above, when the amount of the refrigerant flowing through the condenser is small, the influence of the surface tension received by the refrigerant becomes large, and the refrigerant may stay in the condenser. Thereby, it is considered that the circulation of the refrigerant is delayed.

  In addition, when a radiator different from the condenser is provided as in the boiling cooling device of Patent Document 2, a configuration of a cooling water passage for connecting a water jacket, a radiator and the like is necessary, and the inside of the engine becomes complicated. At the same time, production costs increase.

  Accordingly, an object of the present invention is to maintain the temperature of the fluid after heat exchange at an appropriate temperature regardless of the state of the introduced fluid.

  The heat exchanger of the present invention that solves such a problem includes a heat exchange unit that exchanges heat between the first fluid and the second fluid, and a control unit that increases or decreases the use area of the heat exchange unit. (Claim 1). By setting it as such a structure, the heat exchanger can change the heat exchange capability according to the heat exchange amount required for the 1st fluid at that time. For example, when the first fluid is a refrigerant that cools the engine, the heat exchanger can change the usage area of the heat exchange unit to exhibit a cooling capacity corresponding to the amount of heat release required for the refrigerant at that time. Can do. Thereby, the heat exchanger can cool the refrigerant so that the refrigerant has a temperature suitable for cooling the engine. In addition, by adapting the use area of the heat exchange unit to the flow rate of the fluid, poor circulation due to fluid retention can be suppressed.

  In such a heat exchanger, the heat exchange part is arranged in parallel, and introduces the plurality of first fluid circulation parts through which the first fluid flows, and the first fluid into the first fluid circulation part. A fluid introduction part, and the control means may be an on-off valve disposed in the fluid introduction part (claim 2). By setting it as such a structure, a 1st fluid can be allowed to pass through only a part of parallel heat exchange part. That is, a part of the heat exchange part can be used. Only the heat exchange section through which the first fluid passes is used for heat exchange. Thereby, the cooling capacity of the heat exchanger can be controlled. Such a heat exchange part can be comprised from the pipe | tube body, plate body, etc. which were formed so that a 1st fluid might exist inside and a 2nd fluid might exist outside.

  Furthermore, in such a heat exchanger, the heat exchange part is arranged in parallel, and a plurality of first fluid circulation parts through which the first fluid circulates, and the first fluid to the first fluid circulation part. A fluid introduction part to be introduced, wherein the control means comprises an electromagnetic valve disposed in the fluid introduction part, and at least one of information on the flow rate, pressure, and temperature of the first fluid flowing into the fluid introduction part. The electromagnetic valve can be configured to switch the open / closed state of the electromagnetic valve based on the above (claim 3). By adopting such a configuration, the amount of heat exchange necessary for setting the first fluid flowing into the heat exchanger to the target temperature is calculated, and the heat exchange unit is configured so as to obtain the calculated heat exchange amount. The use area can be controlled. Thereby, the heat exchanger can perform control which makes the 1st fluid after heat exchange the target temperature.

  Further, in the heat exchanger according to the present invention, the heat exchanging section is a tubular body in which the first fluid is present and the second fluid is present outside, and the control means is disposed in the tubular body. The switching valve can be configured to switch the flow path of the first fluid based on the temperature information of the first fluid existing in the tubular body (claim 4). By setting it as such a structure, a refrigerant | coolant can be allowed to pass through only a part of tubular body. That is, in the heat exchanger, a part of the heat exchange part can be used.

  Furthermore, an engine of the present invention includes the heat exchanger of the present invention described above, and an evaporation section that is formed in the engine and in which the first fluid flows and the first fluid evaporates due to the waste heat of the engine. And the heat exchanger liquefies the first fluid evaporated in the evaporation section by heat exchange with a second fluid (Claim 5). By setting it as such a structure, the temperature of the refrigerant | coolant supplied in an engine can be made into the temperature suitable for engine cooling irrespective of the driving | running state of an engine. The heat exchanger cools the refrigerant supplied into the engine to a temperature suitable for cooling the engine. Thereby, the refrigerant evaporates inside the engine, and cools the inside of the engine to a temperature suitable for operation. Thus, the engine provided with the heat exchanger of the present invention is maintained at an appropriate temperature.

  The heat exchanger of the present invention can maintain the temperature of the fluid after heat exchange at an appropriate temperature.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram showing a schematic configuration of a heat exchanger 1 of the present embodiment. The heat exchanger 1 is a device that cools a high-temperature refrigerant by exchanging heat with air. The heat exchanger 1 includes a plurality of tubular bodies 2, an inlet side tank 3, and an outlet side tank 4.

  The tube body 2 corresponds to the first fluid circulation part of the present invention. The plurality of pipe bodies 2 are arranged in parallel, and each communicates the inlet side tank 3 and the outlet side tank 4 in parallel. A refrigerant corresponding to the first fluid of the present invention flows through the inside of the tube body 2. The refrigerant passes through the pipe body 2 from the inlet side tank 3 and flows to the outlet side tank 4. Further, corrugated fins (not shown) are disposed between the adjacent tube bodies 2. Air corresponding to the second fluid of the present invention passes through the gap between the corrugated fins, that is, the outside of the tube body 2. Thereby, the refrigerant and air exchange heat through the tube body 2.

  The inlet side tank 3 corresponds to the fluid introduction part of the present invention. A first electromagnetic valve 5 and a second electromagnetic valve 6 are provided in the inlet side tank 3. The first solenoid valve 5 is disposed closer to the inlet 3 a side of the inlet side tank 3 than the second solenoid valve 6. The first solenoid valve 5 and the second solenoid valve 6 are electrically connected to an ECU (Electronic Control Unit) 7, and the open / close state is changed based on a signal from the ECU 7. When the first electromagnetic valve 5 and the second electromagnetic valve 6 are in the open state, the refrigerant can reach the entire inlet side tank 3. In this case, the refrigerant can flow into all the pipe bodies 2. On the other hand, when the first electromagnetic valve 5 is in the closed state, the refrigerant can flow between the introduction part 3 a in the inlet side tank 3 and the first electromagnetic valve 5. When the second electromagnetic valve 6 is in a closed state, the refrigerant can flow between the introduction portion 3a in the inlet side tank 3 and the second electromagnetic valve 6. Depending on the open / closed state of these solenoid valves, a pipe body 2 through which refrigerant flows and a pipe body 2 through which refrigerant does not flow are generated. That is, the use area of the heat exchange part of the refrigerant is changed. Such first electromagnetic valve 5 and second electromagnetic valve 6 correspond to the on-off valve of the present invention.

  Further, the inlet side tank 3 is provided with a flow rate sensor 8, a pressure sensor 9, and a temperature sensor 10 that acquire information on the state of the refrigerant flowing into the inlet side tank 3. Each of these sensors is electrically connected to the ECU 7. The ECU 7 determines the open / close state of the first electromagnetic valve 5 and the second electromagnetic valve 6 based on the information on the flow rate, pressure, and temperature of the refrigerant flowing into the inlet side tank 3 acquired from these sensors. FIG. 1 shows a state in which the first electromagnetic valve 5 is in an open state and the second electromagnetic valve 6 is in a closed state.

The heat exchanger 1 having such a configuration introduces a refrigerant in a superheated steam state, a saturated steam state, a liquid phase state, or a state in which a plurality of states are mixed. Further, the heat exchanger 1 changes the refrigerant led out from the outlet 4a of the outlet side tank 4 to a liquid phase and cools the refrigerant so that the refrigerant reaches the target temperature _Tt .

  Next, the control of the first solenoid valve 5 and the second solenoid valve 6 performed by the ECU 7 will be described in detail. FIG. 2 is a flowchart showing an example of control performed by the ECU 7.

  In step S1, the ECU 7 acquires information on the pressure P, temperature T, and flow rate V of the refrigerant flowing into the inlet side tank 3 from the flow sensor 8, the pressure sensor 9, and the temperature sensor 10. Next, the ECU 7 determines whether or not the refrigerant is superheated steam in step S2. Whether the refrigerant is in a superheated steam state, a saturated steam state, or a liquid phase state is calculated from the information on the pressure P and the temperature T acquired in step S1. FIG. 3 is an explanatory diagram showing a saturated vapor pressure curve of the refrigerant. The solid line shown in FIG. 3 shows a saturated vapor pressure curve. When the information on the pressure P and the temperature T is plotted in the gas phase region in FIG. 3, the refrigerant is mainly in a superheated steam state. ECU7 judges the state of a refrigerant | coolant based on the relationship between the pressure in the saturated vapor | steam of such a refrigerant | coolant, and temperature. When the ECU 7 determines YES in step S2, that is, when it is determined that the refrigerant is superheated steam, the process proceeds to step S3.

In step S3, the ECU 7 calculates a heat release amount Q necessary for cooling the refrigerant to the target temperature _Tt . Here, the heat quantity Q is represented by the following equation.

Q = Q _a + Q _b + Q _c (1)
Q _a = m · C _a · Δt _a (2)
Q _b = m · C _b (3)
Q _c = m · C _c · Δt _c (4)

m : Mass of refrigerant
C _a : constant pressure specific heat of gas-phase refrigerant
C _b : latent heat between gas phase and liquid phase of refrigerant
C _c : Specific heat of liquid phase refrigerant
Δt _a : temperature difference between superheated steam temperature and saturated steam temperature Δt _c : temperature difference between target temperature and saturated liquid temperature

Q _{a in} equation (2) indicates the amount of heat that the refrigerant dissipates to make the superheated steam saturated steam. Q _{b in the} equation (3) indicates the amount of heat that the refrigerant dissipates when changing the state of the vapor phase saturated vapor to the liquid phase saturated solution. Further, Q _c in the equation (4) indicates the amount of heat that the refrigerant dissipates so that the liquid refrigerant at the saturated liquid temperature becomes the liquid refrigerant at the target temperature. That is, as shown in the equation (1), the amount of heat release required for the refrigerant in the superheated steam state to be the liquid phase refrigerant at the target temperature T _t is the sum of Q _a , Q _b , and Q _c . FIG. 4 is an explanatory diagram showing these amounts of heat in correspondence with saturated vapor pressure curves. Superheated steam to dissipate heat of Q _a to a saturated vapor, dissipates heat of Q _b to a state change from a saturated vapor to saturated liquid, to become the target temperature, radiating heat of Q _c . After calculating the heat dissipation amount Q in step S3, the ECU 7 proceeds to step S7.

  By the way, when the ECU 7 determines NO in step S2, that is, when it is determined that the refrigerant is not superheated steam, the process proceeds to step S4.

  The ECU 7 determines whether or not the refrigerant is saturated steam in step S4. Here, as in step S2, the state of the refrigerant is calculated from information on the pressure P and temperature T acquired in step S1. When the information on the pressure P and the temperature T is plotted on the saturated vapor pressure curve in FIG. 3, the refrigerant is saturated steam. When the ECU 7 determines YES in step S4, that is, when the refrigerant is saturated steam, the process proceeds to step S5.

In step S5, the ECU 7 calculates a heat release amount Q necessary for cooling the refrigerant to the target temperature _Tt . Here, the heat dissipation amount Q is represented by the following equation.

Q = Q _b + Q _c (4)
Q _b = m · C _b (2)
Q _c = m · C _c · Δt _c (3)

m : Mass of refrigerant
C _b : latent heat between gas phase and liquid phase of refrigerant
C _c : Specific heat of liquid phase refrigerant
Δt _c : temperature difference between target temperature and saturated liquid temperature

Q _{b in} equation (2) indicates the amount of heat that the refrigerant dissipates when changing the state of the vapor phase saturated vapor to the liquid phase saturated liquid, and Q _{c in} equation (3) is the liquid phase refrigerant at the saturated liquid temperature. Represents the amount of heat that the refrigerant dissipates to make the liquid phase refrigerant at the target temperature. Here, the heat radiation amount necessary for making the refrigerant in the state of saturated vapor and liquid phase refrigerant of the target temperature T _t, as shown in equation (4), the sum of the Q _b and Q _c. When the ECU 7 calculates the heat dissipation amount Q in step S5, the ECU 7 proceeds to step S7.

  On the other hand, when the ECU 7 determines NO in step S4, that is, when the refrigerant is not saturated vapor, the refrigerant is in a liquid phase. In such a case, the ECU 7 proceeds to step S6.

In step S6, the ECU 7 calculates a heat release amount Q necessary for cooling the refrigerant to the target temperature _Tt . Here, the heat dissipation amount Q is represented by the following equation.

Q = M · C _c · Δt (5)

m : Mass of refrigerant
C _c : Specific heat of liquid phase refrigerant
Δt : Temperature difference between liquid-phase refrigerant temperature and target temperature

  Q in the equation (5) indicates the amount of heat released using the liquid phase refrigerant as the liquid phase refrigerant at the target temperature. FIG. 4 shows this amount of heat. The Q required for lowering the refrigerant by Δt ° C. is as shown in FIG. When the ECU 7 calculates the heat dissipation amount Q in step S5, the ECU 7 proceeds to step S7.

ECU7 in step S7, step S3, step S5, or by comparing the heat radiation amount Q and _{Q 1,} calculated in the step S6, the heat radiation amount Q is equal to or is _{Q 1} or less. Here, Q ₁ is the amount of heat that the refrigerant exchanges heat with the atmosphere and dissipates heat when the heat exchanger 1 closes the first electromagnetic valve 5. ECU7 If determines YES in step S7, i.e., if the heat radiation amount Q is _{Q 1} or less, the process proceeds to step S8.

In step S8, the ECU 7 closes the first electromagnetic valve 5. Thereby, in the heat exchanger 1, a refrigerant | coolant flows in only into the pipe body 2 connected to the introduction part 3a side rather than the 1st solenoid valve 5. FIG. Thus, the heat exchanger 1 changes the cooling capacity, dissipates heat equivalent to Q ₁ from the introduced refrigerant. Thereby, since the amount of heat radiation can be suppressed as compared with the cooling in which the refrigerant is passed through all the tubular bodies 2 of the heat exchanger 1, the refrigerant can be brought close to the target temperature _Tt without excessively cooling the refrigerant. Further, when the heat dissipation amount Q is small, the flow rate of the refrigerant is small. At this time, when the refrigerant is circulated through all the tubes 2 of the heat exchanger 1, the refrigerant flows in the middle of the tube 2 because the flow rate of the refrigerant is small with respect to the capacity of the flow path. Can no longer circulate. However, even if the flow rate of the refrigerant is small, the flow rate of the refrigerant with respect to the volume of the flow path is increased by reducing the number of the pipe bodies 2 to be used, and the refrigerant is prevented from staying in the pipe body 2. The circulation of the refrigerant can be maintained. The ECU 7 returns after completing the process of step S8.

However, ECU 7 when it is determined that NO in step S7, i.e., if the heat radiation amount Q is greater than _{Q 1,} the flow proceeds to step S9. ECU7 in step S9, step S3, step S5, or by comparing the heat radiation amount Q, _{Q 2} calculated in step S6, the heat radiation amount Q is equal to or is _{Q 2} or less. Here, Q ₂ is the amount of heat that the refrigerant exchanges heat with the atmosphere and dissipates heat when the heat exchanger 1 opens the first electromagnetic valve 5 and closes the second electromagnetic valve 6. is there. ECU7 If judged YES in step S9, i.e., if the heat radiation amount Q is _{Q 2} or less, the process proceeds to step S10.

The ECU 7 opens the first electromagnetic valve 5 in step S10. Subsequently, the ECU 7 proceeds to step S11, and the second electromagnetic valve 6 is closed in step S11. Thereby, a refrigerant | coolant flows in into the pipe body 2 of the introduction part 3a side rather than the 2nd solenoid valve 6, and a refrigerant | coolant is cooled. When the ECU 7 reaches step S10, the heat release amount Q for setting the target temperature T _t is greater than Q _{1 and} less than or equal to Q ₂ , so the first electromagnetic valve 5 is opened to dissipate more than Q _1. . On the other hand, Q ₂ or more heat by closing the second solenoid valve 6 is radiated suppresses be excessively cooled. Thereby, the heat exchanger 1 can bring the refrigerant close to the target temperature _Tt . The ECU 7 returns after completing the processing of step S10 and step S11.

On the other hand, if the ECU7 determines NO in step S9, i.e., if the heat radiation amount Q is greater than _{Q 2,} the process proceeds to step S12. The ECU 7 opens the first electromagnetic valve 5 in step S12. Subsequently, the ECU 7 proceeds to step S13, and in step S13, the second electromagnetic valve 6 is opened. Thereby, the heat exchanger 1 distribute | circulates a refrigerant | coolant to all the pipe bodies 2, and cools a refrigerant | coolant. ECU7 may reach the step S12, it is necessary to perform a Q ₂ or more heat radiation to the target temperature T _t of the refrigerant. Therefore, the first solenoid valve 5 and the second solenoid valve 6 are opened. Thereby, the refrigerant is cooled and cooled to a temperature close to the target temperature T _t . The ECU 7 returns after completing the processing of step S12 and step S13.

In this way, the heat exchanger 1 calculates the amount of heat radiated by cooling for cooling the refrigerant to the target temperature _Tt , and the first electromagnetic valve 5 and the second electromagnetic valve so as to have a cooling capacity corresponding to this amount of heat. The valve 6 is controlled. As a result, the refrigerant is cooled to a temperature close to the target temperature _Tt . In such a heat exchanger 1, the temperature of the refrigerant after heat exchange can be made closer to the target temperature _Tt by adding a solenoid valve so that the pipe body 2 to be used is subdivided. Further, such a heat exchanger 1 may be a so-called plate heat exchanger provided with a solenoid valve. A plate heat exchanger is a heat exchanger in which plates are stacked and a refrigerant and a heat exchange medium are alternately circulated in a space formed between the plates. By providing an electromagnetic valve for blocking the refrigerant passage of such a heat exchanger, the refrigerant can be cooled to a suitable temperature.

  Next, a second embodiment of the present invention will be described. FIG. 5 is an explanatory diagram showing a schematic configuration of the heat exchanger 21 of the present embodiment. The heat exchanger 21 includes a cooling pipe 22, an introduction part 23, and a lead-out part 24 corresponding to the heat exchange part of the present invention. Inside the cooling pipe 22, a refrigerant corresponding to the first fluid of the present invention flows. The refrigerant passes through the cooling pipe 22 from the introduction part 23 and flows to the outlet part 24.

  The cooling pipe 22 is a metal pipe formed in a meandering manner by combining the straight pipe portion 221 and the U-shaped pipe portion 222, and the refrigerant passes through the inside thereof. The periphery of the cooling pipe 22 is covered with a heat exchange medium corresponding to the second fluid of the present invention. Such a refrigerant and the heat exchange medium exchange heat through the cooling pipe 22.

  A part of the U-shaped pipe portion 222 of the cooling pipe 22 is disposed in the lead-out portion 24. Further, a first opening 22 a and a second opening 22 b that open toward the lead-out portion 24 are formed in a part of the U-shaped tube portion 222 arranged in the lead-out portion 24 in this way. The refrigerant can be discharged from the first opening 22a and the second opening 22b to the outlet 24. The first opening 22 a is formed on the upstream side of the second opening 22 b, that is, on the side closer to the introduction part 23.

  A switching valve 25 that closes either the first opening 22a or the cooling pipe 22 is disposed in the vicinity of the first opening 22a. Further, a switching valve 25 that closes either the second opening 22b or the cooling pipe 22 is also arranged in the vicinity of the second opening 22b. 6A and 6B are explanatory views showing a schematic configuration of such a switching valve 25. FIG. FIG. 6A is an explanatory view showing a state in which a path for discharging the refrigerant from the cooling pipe 22 to the outlet 24 is formed, and FIG. 6B forms a path through which the refrigerant flows in the cooling pipe 22. It is explanatory drawing which showed the state.

The switching valve 25 is a so-called thermostat, and includes a valve portion 25a, a spring 25b, wax 25c, and a valve body 25d. The switching valve 25 is in a state as shown in FIG. The valve portion 25a is maintained in a closed state by the urging force of the spring 25b. Further, the wax 25c is in a solid state at this time. This wax 25c becomes a liquid state at T _s ° C, expands with the phase change, and presses the valve body 25d toward the first opening 22a side. That is, when the switching valve 25 reaches T _s ° C or higher, as shown in FIG. 6B, the first opening 22a is closed, the valve 25a is opened, and the flow path in the cooling pipe 22 is closed. Form. The temperature of the wax 25c depends on the temperature of the refrigerant passing through the switching valve 25. When the temperature of the refrigerant becomes equal to or higher than T _s ° C, the wax 25c enters a liquid state and the flow path around the switching valve 25 is switched. It has become. That is, the switching valve 25 closes the flow path in the cooling pipe 22 and discharges the refrigerant from the cooling pipe 22 to the outlet 24 when the refrigerant is lower than T _s ° C. On the other hand, the switching valve 25 closes the first opening 22 a and the second opening 22 b and causes the refrigerant to circulate in the cooling pipe 22 when the refrigerant reaches T _s ° C or higher. Here, the temperature T _s at which the wax 25c undergoes a phase change is the temperature of the refrigerant targeted by the heat exchanger 21.

  The refrigerant introduced into the heat exchanger 21 configured as described above is in any of a superheated steam state, a saturated steam state, and a liquid phase state, depending on the operating state of the engine on which the heat exchanger is mounted, or A state in which a plurality of states are mixed. The heat exchanger 21 cools so that the refrigerant discharged from the outlet 24 is in a liquid phase.

Next, the flow of the refrigerant depending on the temperature of the refrigerant in the heat exchanger 21 will be described. The refrigerant flows from the introduction portion 23 into the cooling pipe 22. The refrigerant flowing into the cooling pipe 22 dissipates heat and is cooled while passing through the cooling pipe 22. When the refrigerant thus cooled passes through the switching valve 25 and is at or below T _s ° C., the switching valve 25 closes the cooling pipe 22 and opens the first opening 22a. Thus, when the refrigerant is T _s ° C or lower, only a part of the cooling pipe 22 from the introduction part 23 to the part where the first opening part 22a is formed is used. Thereby, since a refrigerant | coolant is discharged | emitted to the derivation | leading-out part 24, heat exchange is complete | finished and it does not cool too much. On the other hand, when the refrigerant passes through the switching valve 25 and is at a temperature higher than T _s ° C, the switching valve 25 closes the first opening 22a, opens the cooling pipe 22, and forms a refrigerant flow path. . Thereby, the refrigerant passes through the cooling pipe 22 and further dissipates heat and is cooled. When such a refrigerant passes through the switching valve 25 disposed in the second opening 22b, the switching valve 25 of the second opening 22b performs the same operation. That is, if the temperature of the refrigerant passing therethrough is equal to or lower than T _s ° C, the refrigerant is led out from the second opening 22b to the lead-out part 24. On the other hand, if the refrigerant is higher than T _s ° C., it continues to flow through the cooling pipe 22. Thus, the heat exchanger 21, if the refrigerant when passing through the switching valve 25 is only to be cooled to the target temperature T _s, ends the cooling of the refrigerant, and discharges the refrigerant from the outlet portion 24. For this reason, the refrigerant is maintained at an appropriate temperature without being insufficiently cooled or excessively cooled.

  Next, Embodiment 3 of the present invention will be described. FIG. 7 is an explanatory diagram showing a schematic configuration of the engine 30 of the present embodiment. The engine 30 includes the heat exchanger 1 described in the first embodiment. The engine 30 includes a water jacket 31, a tank 32, and a water pump 33.

  The water jacket 31 is formed in the engine 30, and a refrigerant | coolant distribute | circulates it. This refrigerant evaporates due to waste heat from the engine body. The water jacket 31 corresponds to the evaporation unit of the present invention.

  The refrigerant evaporated in the water jacket 31 flows into the heat exchanger 1 and is cooled. The refrigerant that has passed through the heat exchanger 1 has a temperature suitable for evaporating in the water jacket 31. Thus, the refrigerant that has passed through the heat exchanger 1 is stored in the tank 32. The tank 32 maintains the refrigerant at an appropriate temperature. The water pump 33 pumps the refrigerant in the tank 32 into the water jacket 31. The refrigerant thus supplied absorbs waste heat in the water jacket 31 and evaporates to cool the engine body to a temperature suitable for operation.

  Thus, the engine 30 provided with the heat exchanger 1 maintains the temperature at which the refrigerant cools the water jacket 31 at an appropriate temperature in the heat exchanger 1. As a result, the refrigerant evaporates in the water jacket 31 and cools the engine body, whereby the engine body is maintained at a temperature suitable for operation. Moreover, such a heat exchanger 1 can be used as the heat exchanger 21 of the second embodiment.

  The above-described embodiments are merely examples for carrying out the present invention, and the present invention is not limited thereto. Various modifications of these embodiments are within the scope of the present invention. It is apparent from the above description that various other embodiments are possible within the scope.

It is explanatory drawing which showed schematic structure of the heat exchanger of Example 1. FIG. It is an example of the flow of control which ECU performs. It is explanatory drawing which showed the saturated vapor pressure curve of the refrigerant | coolant. It is explanatory drawing which showed the thermal radiation amount of the refrigerant | coolant corresponding to the saturated vapor pressure curve. It is explanatory drawing which showed schematic structure of the heat exchanger of Example 2. FIG. It is explanatory drawing which showed schematic structure of the switching valve, Comprising: (a) is explanatory drawing which showed the state in which the path | route which distribute | circulates a refrigerant | coolant from a cooling pipe to a derivation | leading-out part was formed, (b) is a refrigerant | coolant in a cooling pipe. It is explanatory drawing which showed the state which formed the path | route which distribute | circulates. It is explanatory drawing which showed schematic structure of the engine of Example 3. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,21 Heat exchanger 2 Tubing body 3 Inlet side tank 4 Outlet side tank 5 1st solenoid valve 6 2nd solenoid valve 7 ECU
22 Cooling Pipe 23 Introduction Portion 24 Leading Portion 25 Switching Valve 30 Engine 31 Water Jacket 32 Tank 33 Water Pump

Claims (5)

A heat exchanging section for exchanging heat between the first fluid and the second fluid;
Control means for increasing / decreasing the use area of the heat exchange section;
A heat exchanger characterized by comprising: The heat exchanger according to claim 1, wherein
The heat exchange section is arranged in parallel, and a plurality of first fluid circulation sections through which the first fluid circulates;
A fluid introduction part for introducing the first fluid into the first fluid circulation part,
The heat exchanger is characterized in that the control means is an on-off valve disposed in the fluid introduction part. The heat exchanger according to claim 1, wherein
The heat exchange section is arranged in parallel, and a plurality of first fluid circulation sections through which the first fluid circulates;
A fluid introduction part for introducing the first fluid into the fluid circulation part,
The control means includes an electromagnetic valve disposed in the fluid introduction part, and based on at least one of information on the flow rate, pressure, and temperature of the first fluid flowing into the fluid introduction part, A heat exchanger characterized by switching between open and closed states. The heat exchanger according to claim 1, wherein
The heat exchange section includes a tube body in which the first fluid is present inside and the second fluid is present outside.
The control means is a switching valve that is arranged in the tubular body and is a switching valve that switches a flow path of the first fluid based on temperature information of the first fluid existing in the tubular body. vessel. The heat exchanger according to any one of claims 1 to 4,
An evaporation section formed in the engine, through which the first fluid flows, and the first fluid evaporates due to waste heat of the engine,
The engine is characterized in that the heat exchanger liquefies the first fluid evaporated in the evaporation section by heat exchange with a second fluid.

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