JPH10217754A - Heat exchanger for vehicle heating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently heat air for a heater to a great extent by means of the calorific power of an electric exothermic body integrated with a vehicle heating heat exchanger heating air while warm water is being used as a heating source. SOLUTION: In the heat exchanger for vehicle heating where a PTC heater 9 having positive resistant temperature characteristics the resistance value of which is rapidly increased at a specified temperature T0 , is set in one area out of a plurality of set positions formed out of flat tubes in a heat exchanger core part 2, in regard to a temperature distribution at corrugate fins 7 located between the PTC heater 9 and each flat tube 6 out of the corrugate fins 7 at the time of heating the PTC heater 9, the set temperature of the PTC heater 9 is so set up in such a way that the temperature of the fins over the end part at the side of the flat tubes 6 is identical to the temperature Tw of warm water within the flat tubes 6 under a condition that the temperature of warm water within the flat tubes 6 is equal to or more than 60 deg.C, and the temperature of intake air for the heater to the heat exchanging core part 3 is equal to or less than 0 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle heat exchanger for heating air using hot water (engine cooling water) heated by a vehicle engine (internal combustion engine) as a heat source. The present invention relates to a heat exchanger in which an electric heating element (hereinafter abbreviated as a PTC heater) having a positive resistance-temperature characteristic in which the temperature increases rapidly is integrated.

[0002]

2. Description of the Related Art Conventionally, a heat exchanger integrating a PTC heater of this type has been proposed in Japanese Patent Application Laid-Open No. 63-203411. According to this conventional device, by integrating a PTC heater into a heating heat exchanger that heats air using hot water (engine cooling water) as a heat source, when the hot water temperature is low, such as immediately after starting the engine, the PTC heater is connected to the PTC heater. , The heat generated by the PTC heater can be radiated into the air via the high-performance corrugated fins of the heat exchanger, and the heat radiation structure of the PTC heater can be simplified.

[0003] Separately from the heat exchanger for heating, PT
Since there is no need to install the C heater, it is possible to prevent an increase in pressure loss in the ventilation system of the heating device due to the installation of the PTC heater. Further, since the PTC heater has a positive resistance temperature characteristic in which the resistance value rapidly increases at a predetermined set temperature T ₀ , the PTC heater has a self-temperature control function of self-controlling the heat generation temperature to the set temperature T _0. Therefore, there is no need to separately provide a temperature control circuit or the like, and there is an advantage that the electric circuit configuration can be simplified.

[0004]

In the conventional apparatus described in the above publication, the set temperature (Curie point temperature) T ₀ of the PTC heater is only exemplified as 80 ° C., for example. It does not disclose the idea of setting ₀ . However, according to the experimental study of the present inventors, it has been found that depending on the set temperature T ₀ of the PTC heater, the heat generated by the PTC heater may not be effectively used for heating the heating air.

That is, in a heat exchanger for heating a vehicle, a number of flat tubes through which hot water flows are arranged in parallel,
A heat exchange core is formed by joining corrugated fins between the plurality of flat tubes. Therefore, when a part of the flat tube is abolished and a PTC heater is provided instead, the PTC heater becomes in a state where it can conduct heat with the adjacent flat tube via the corrugated fin.

Here, considering the temperature distribution of the corrugated fins thermally joined to the PTC heater, if the PTC heater is energized when the temperature of the hot water is low,
Among the corrugated fins, the end on the PTC heater side has the highest temperature, and the adjacent flat tube side end has the lowest temperature. At that time, when the set temperature T ₀ of the PTC heater is too high, among the corrugated fins, the lowest temperature, is higher in the fin temperature from the hot water temperature in the flat tubes end, the heating value of the PTC heater is heated The heat is absorbed by the PTC heater, and the amount of heat generated by the PTC heater cannot be effectively used for heating the heating air.

On the other hand, if the set temperature of the PTC heater is too low, the heat transfer from the PTC heater to the heating air becomes insufficient, resulting in insufficient heating capacity. The present invention has been made in view of the above points, and has a PTC heater integrated with a heating heat exchanger that heats air using hot water (engine cooling water) heated by an engine as a heat source.
An object of the present invention is to enable heating air for heating to be maximized efficiently by the heat generation amount of a PTC heater.

[0008]

In order to achieve the above object, according to the first aspect of the present invention, a plurality of flat tubes (6) through which hot water from a vehicle engine flows are arranged in parallel, and the plurality of flat tubes (6) are arranged. A fin member (7) is arranged between the tubes (6) to form a heat exchange core (3), and a part of a portion where a number of flat tubes (6) are installed. And a flat tube (6)
Instead of a fin member (7) in a vehicle heat exchanger in which a PTC heater (9) having a positive resistance temperature characteristic whose resistance value increases rapidly at a predetermined set temperature (T ₀ ) is installed.
Of the fin member (7) located between the PTC heater (9) and the flat tube (6),
Regarding temperature distribution during heat generation, flat tube (6)
Temperature of the hot water in the inside (T _W ) ≧ 60 ° C., temperature of the suction air for heating sucked into the heat exchange core (3) (T _air ) ≦
Under the condition of 0 ° C., the fin temperature at the end on the side of the flat tube (6) is the hot water temperature (T _W ) in the flat tube (6).
It is characterized in that the set temperature (T ₀ ) of the PTC heater (9) is set to be equivalent to the above.

[0009] By the way, during heating in winter, as is well known, in a vehicle heating device, in order to prevent fogging of a vehicle window glass,
Usually, outside air having a lower humidity than that of the inside air is introduced to heat the interior of the vehicle. Therefore, outside air is introduced into the heat exchange core portion (3) as heating air. Therefore, in the first aspect of the present invention, a condition is set such that the temperature of the suction air for heating (T _air ) ≦ 0 ° C. of the heat exchange core portion (3) from the average outside temperature in winter.

[0010] Among the vehicle engines, in the case of a diesel engine having good combustion efficiency, the temperature of the hot water does not sufficiently rise even after the warm-up, and a shortage of the heating heat source occurs. Therefore, the PTC heater (9) is used as the auxiliary heating heat source. )Is required. In such a high-efficiency (low heat source) engine, the temperature of hot water becomes 6 in normal load operation during winter heating.
In some cases, the temperature rises only up to about 0 ° C.

Therefore, according to the first aspect of the present invention, in addition to the condition that the suction air temperature for heating (T _air ) ≦ 0 ° C.,
The condition that the hot water temperature (T _W ) in the flat tube (6) ≧ 60 ° C. is set, and even at a relatively low temperature of this hot water temperature (T _W ) = 60 ° C., the end of the flat tube (6) side Fin temperature is equal to the hot water temperature (T
The set temperature (T ₀ ) of the PTC heater (9) is set to be equal to _W ).

As a result, even when the temperature (T _W ) of the hot water in the flat tube (6) rises only to around 60 ° C., the calorific value of the PTC heater (9) is not absorbed by the hot water. In addition, the amount of heat generated by the PTC heater can be effectively used for heating the heating air. Further, the set temperature (T ₀ ) of the PTC heater (9) based on the above concept is
More specifically, the temperature becomes 85 ° C. or higher as described in claim 2 and a sufficient temperature difference can be provided between the temperature and the heating suction air at 0 ° C. or lower. The ability improvement effect can be fully exhibited.

According to the second aspect of the present invention, a corrugated fin (7) is used as a fin member disposed between a plurality of flat tubes (6), and the fin height of the corrugated fin (7) is increased. hf = the distance between the flat tubes (6)) is 3.9 mm to 5 mm, and P
The set temperature (T ₀ ) of the TC heater (9) is set to 85 ° C. to 11
The temperature is set to 0 ° C.

According to the study of the present inventor, the fin height (h
By setting f) and the PTC heater set temperature (T ₀ ) as described above, the heating suction air temperature (T _air ) ≦ 0 ° C. and the flat tube hot water temperature (T _W ) ≧ 60 ° during winter heating. Under the condition of C, the amount of heat generated by the PTC heater (9) is not absorbed by the warm water side, and the same operation and effect as the first aspect of the invention can be achieved.

Moreover, the fin height (hf) is 3.9 mm.
By setting the range to 5 mm, the flat tube (6)
The heat radiation performance of the heat exchange core portion (3) itself, which is formed by a combination of the heat exchange core and the corrugated fin (7), can also be satisfactorily secured. That is, if the fin height (hf) is less than 3.9 mm, the heat transfer area of the corrugated fins (7) for the number of flat tubes (6) installed becomes insufficient, and the required heat dissipation capacity cannot be obtained.

On the other hand, when the fin height (hf) is more than 5 mm, the fin temperature at the central portion of the fin height (hf) of the corrugated fin (7) is lower than that at the tube side end. The width becomes large, the temperature difference between the fin temperature and the air temperature becomes small, and the heat exchange efficiency is reduced. For the reasons described above, the fin height (hf) of the corrugated fin (7) is practically preferably set in the range of 3.9 to 5.0 mm, and the fin height (hf) falls within such a range. ), The heat radiation performance of the corrugated fin-type heat exchange core (3) is ensured, and P
Efficient heating of the heating air by the heat generated by the TC heater (9) can be achieved.

According to the third aspect of the present invention, the heat exchange core (3) has an integral brazing structure of an aluminum alloy, and the PTC heater (9) has an elongated flat plate-like P-type.
A three-layer sandwich structure comprising a TC element (9a) and elongated flat plate-shaped electrode plates (9b, 9c) disposed on both front and back surfaces of the PTC (9a), and a heat exchange core (3) After the integral brazing, the two electrode plates (9b, 9c) of the PTC heater (9) are adhesively fixed to the bent tops of the corrugated fins (7).

Thus, the PTC heater (9) can be easily and reliably assembled to the heat exchange core (3) having the integral brazing structure. In addition, the code | symbol in the parenthesis of each said means shows the correspondence with the concrete means of embodiment mentioned later.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a specific example of a heat exchanger for heating a vehicle, in which a hot water inlet side tank 1, a hot water outlet side tank 2, and a heat exchange core 3 provided between the two tanks 1, 2. have. The hot water inlet tank 1 is provided with an inlet pipe 4 through which hot water (cooling water) from a vehicle engine (not shown) flows in, and the hot water outlet tank 2 has an outlet pipe 5 through which hot water flows out and is returned to the engine. Is provided. Since the heat exchanger of this example is symmetrical as shown in FIG. 1, the hot water inlet side tank 1 and the hot water outlet side tank 2 may be reversed left and right.

Each of the tanks 1 and 2 has a tank body 1
a and 2a, and a sheet metal 1b and 2b for closing the opening end surfaces of the tank main bodies 1a and 2a, and has a well-known tank structure in which the vertical direction in FIG. A large number of flat tube insertion holes (not shown) are formed in the sheet metal 1b, 2b in one or more rows in the vertical direction of FIG.

The heat exchanging core 3 has a plurality of flat tubes 6 formed in a flat shape parallel to the flow direction of heating air (perpendicular to the plane of FIG. 1) and arranged in parallel in the vertical direction of FIG. ing. Corrugated fins (fin members) 7 formed in a wave shape are arranged and joined between the plurality of flat tubes 6. This corrugated fin 7
As is well known, a large number of louvers 7a (see FIG. 2) are cut and raised obliquely at a predetermined angle with respect to the flow direction of the heating air, and the louvers 7a are formed to improve the fin heat transfer coefficient. I have.

Openings at both ends of the flat tube 6 are inserted into tube insertion holes of the sheet metals 1b and 2b, respectively.
Joined. Further, on the outer side of the outermost corrugated fins 7 of the core portion 3, a side plate 8a having a U-shaped cross section is provided.
8b, the side plates 8a and 8b are provided with the outermost corrugated fins 7 and the sheet metals 1b and 2b.
Joined to.

By the way, in the heat exchanger of the present embodiment, all of the above-mentioned components 1 to 8b are formed of an aluminum alloy, and the joining between the components is performed integrally by using a brazing material clad in an aluminum alloy. Perform it with This integral brazing is performed without the PTC heater 9 described below being assembled. Here, at the installation site of the PTC heater 9 (four locations in the example of FIG. 1), the flat tube 6 is abolished, and a dummy made of a material having a size equivalent to that of the PTC heater 9 and not brazed is used instead. Is temporarily assembled, and the assembly position of the corrugated fin 7 is maintained.

Then, while maintaining the temporary assembly state of the entire heat exchanger with an appropriate jig, the heat exchanger is carried into a furnace and heated to a brazing temperature in the furnace to integrally braze the entire heat exchanger. I do. After the brazing is completed, the dummy plate member is removed from the core portion 3 of the heat exchanger joined to the integral structure,
Instead, as shown in FIG. 1, the PTC heaters 9 are arranged at equal intervals at four locations of the core portion 3 and assembled.

In FIG. 1, for convenience, the location of the PTC heater 9 is indicated by hatching. FIG. 2 shows a specific structure of a portion where the PTC heater 9 is disposed. The PTC heater 9 includes an elongated flat PTC element (heating element) 9a and this PTC element 9a.
The C element 9a has a three-layer sandwich structure composed of elongated flat plate-shaped electrode plates 9b and 9c arranged and joined on both front and back surfaces of the C element 9a. Here, the PTC element 9a is made of a resistor material (for example, barium titanate) having a positive resistance temperature characteristic whose resistance value rapidly increases at a predetermined set temperature T ₀ . By applying a voltage from the vehicle-mounted power supply during 9c, the PTC element 9a is energized and generates heat.

The two electrode plates 9b and 9c of the PTC element 9a are bonded and fixed to the bent tops of the adjacent corrugated fins 7 with an insulating adhesive 10. Both ends of the PTC element 9a in the longitudinal direction (the left-right direction in FIG. 1) are bonded and fixed to the sheet metals 1b and 2b with an insulating adhesive 10. Here, the insulating adhesive 10 performs an electrical insulating action, and has a good heat conducting action thermally.
It is made of a resin-based adhesive. Therefore, the heat generated by the PTC element 9a is transmitted to the corrugated fins 7, and is radiated from the corrugated fins 7 to the heating air.

FIG. 3 shows an energizing circuit of the PTC heater 9. The four PTC heaters 9 are electrically connected in parallel.
Power is supplied from the vehicle-mounted power supply 12 through the switch 11. The switch 11 is opened and closed by a control circuit 13. The control circuit 13 receives signals from a water temperature sensor 14 for detecting the temperature of hot water flowing into the heating heat exchanger from the engine, a switch 15 linked to the heating operation, and the like. And it is a heating operation and the hot water temperature is a predetermined temperature (for example, 80 ° C.).
In the following cases, the control circuit 13 closes the switch 11 to energize the four PTC heaters 9.

Next, the operation of the above configuration will be described.
The heat exchanger of FIG. 1 is installed in a heater case (not shown) of a vehicle air conditioner, and an air conditioner blower is operated at the time of heating, so that a gap between the flat tube 6 of the core portion 3 and the corrugated fin 7 is provided. Heating air is blown to the section. On the other hand, when a water pump (not shown) of the vehicle engine is operated, hot water is supplied from the engine to the hot water inlet side tank 1 through the inlet pipe 4.
Flows into. Then, the hot water is distributed to a number of flat tubes 6 in the inlet-side tank 1, and the flat tubes 6
Are simultaneously radiated to the heating air via the corrugated fins 7. The hot water that has passed through the many flat tubes 6 flows into the hot water outlet side tank 2 and is collected there.
The hot water flows out of the heat exchanger from the outlet pipe 5 and returns to the engine.

On the other hand, when the temperature of the hot water from the engine is low during heating, the switch 11 is closed in the electric circuit of FIG. 3 and the four PTC heaters 9 are energized.
The PTC heater 9 generates heat. Here, the PTC heater 9 rises to the self-controlling set temperature T _0, and radiates the calorific value to the heating air via the adjacent corrugated fin 7, thereby quickly heating the heating air even at a low temperature of the hot water. To effect immediate heating.

By the way, in order to effectively use the calorific value of the PTC heater 9 for heating the heating air, it is important to determine the self-control set temperature T ₀ of the PTC heater 9 as described above. Becomes Therefore, first, consider the temperature distribution in the corrugated fins 7 transferred from the PTC heater 9. FIG. 4 shows that the corrugated fins interposed between the wall surface of the PTC heater 9 and the wall surface of the adjacent flat tube 6. 7 is a model diagram schematically illustrating a temperature distribution of FIG. Here, it flows in the direction perpendicular to the plane of FIG.
The temperature of the suction air for heating sucked into the heat exchanger is T _air ,
The set temperature (wall surface temperature) of the PTC heater 9 is T ₀ , the fin height of the corrugated fin 7 is hf, and the corrugated fin 7 is
Is an arbitrary fin height x, and this arbitrary fin height x
It is known that when the fin temperature at is represented by θ, the following equations 1 and 2 hold.

[0031]

(Equation 1)

[0032]

(Equation 2) Here, m is a dimensionless number obtained by the following Expression 3.

[0033]

(Equation 3)

In Equation 3, h _{0 is} the heat transfer coefficient of the fin surface, b is the fin plate thickness, and λf is the heat conductivity of the fin material. In order to effectively use the calorific value of the PTC heater 9 for heating the air for heating, at the end of the flat tube 6 of the corrugated fin 7 (i.e., at the position of x = hf), the fin temperature θ It is important that the heat value of the PTC heater 9 is not absorbed by the hot water side so as to be equal to the wall surface temperature Tw (that is, the hot water temperature in the tube).

Therefore, when x = hf and θ = Tw are applied to Equation 1, Equation 1 can be expressed by Equation 4 below.

[0036]

(Equation 4) From Equation 4, the set temperature T ₀ of the PTC heater 9 that satisfies the above condition can be calculated by Equation 5 below.

[0037]

T ₀ = (Tw−T _air ) cosh (m · hf) + T _{air For the} above equation 5, Tw = 60 ° C., heat transfer coefficient h ₀ on the fin surface = 300 W / m ² · K, Fin thickness b = 0.
06 mm, thermal conductivity λf of fin material (A3003 material) =
Using 193 W / m · K, the set temperature T ₀ of the PTC heater 9 was calculated by computer simulation using the fin height hf and the air temperature T _air as parameters. FIG. 5 shows the calculation results. Here, m = 227.626 in Expression 3 by applying the above numerical values.

In the air conditioner for a vehicle, during a heating operation in winter, in order to prevent fogging of the window glass, outside air having a low humidity is usually introduced to heat the vehicle interior. Therefore, T _air is set to the outside air temperature in winter. In addition, even after the warm-up of the vehicle engine has been completed due to the improvement in fuel efficiency of the vehicle engine in recent years, the temperature of the hot water in the tube may only rise to about 60 ° C. during the heating operation in winter. The temperature was 60 ° C.

FIG. 5 shows that when the fin height hf is changed in the range of ₀ to 9 mm under the condition of Tw = 60 ° C., the set temperature T ₀ of the PTC heater 9 obtained from the above equation 5 is T Three cases of _air = 0 ° C, -10 ° C, and -20 ° C are shown. FIG. 6 shows Tw = 80 ° C.
Under the condition (1), the set temperature T ₀ of the PTC heater 9 obtained from the above equation (5) is similarly shown.

FIG. 7 shows the fin height hf = 4.5.
mm, the PTC calculated from Equation 5 above
The set temperature T ₀ of the heater 9 is indicated by using the heating suction air temperature (outside air temperature) T _air and the hot water temperature Tw as parameters, and the hot water temperature Tw = 60 ° C. to 80 ° C. and the heating suction air When the temperature (outside air temperature) T _air = 0 ° C. or less, the set temperature T ₀ of the PTC heater 9 is 96 ° C.
To 126 ° C.

FIG. 8 shows the fin height hf = 4.0 m.
In the case of m, the PTC h
Temperature T of data 9₀The suction air temperature for heating (outside air
Temperature) T _airAnd the hot water temperature Tw as a parameter
And hot water temperature Tw = 60 ° C. to 80 ° C.
And heating suction air temperature (outside air temperature) T_air= 0 ° C or less
, The set temperature T of the PTC heater 9₀= 87 ° C
~ 118 ° C.

FIG. 9 shows the same fin height hf =
The temperature distribution on the fin under 4.5 mm is shown, and the horizontal axis is an arbitrary distance x on the fin from the wall surface of the PTC heater 9. In addition, the hot water temperature Tw = 60 ° C. and the heating suction air temperature (outside air temperature) T _air = 0 ° C. Under the condition of FIG. 9, when the set temperature T ₀ of the PTC heater 9 is higher than 100 ° C., the flat tube 6 side end (x = 4.5 mm)
Fin temperature is the hot water temperature T in the flat tube 6
_W (= 60 ° C.), and the heat of the corrugated fins 7 transmitted from the PTC heater 9 is absorbed by the warm water side, so that the heat generated by the PTC heater 9 cannot be effectively released into the suction air for heating. Therefore, in the case of the condition of FIG.
It is necessary to set the set temperature T ₀ of the C heater 9 to 100 ° C. or less in order to effectively use the heat generated by the PTC heater 9.

In the heat exchanger for heating a vehicle, the flow path width in the minor diameter direction in the elliptical cross section of the flat tube 6 is usually about 1.4 mm. In a case where the heat exchange core portion 3 is configured by combining the corrugated fins 7 with the tube 6, according to the study of the present inventors, the fin height hf of the corrugated fins 7 is determined.
Has been found to be preferably set to 3.9 mm or more in order to secure the air-side heat transfer area. If the fin height hf is less than 3.9 mm, the heat transfer area of the corrugated fins 7 for the number of the flat tubes 6 installed becomes insufficient, and the required heat dissipation capacity cannot be obtained.

On the other hand, the upper limit of the fin height hf is preferably 5 mm or less for practical use. Fin height hf is 5mm
When the size is excessively large, of the corrugated fins 7, the width of decrease in the fin temperature at the central portion of the fin height hf is larger than that at the tube side end, and the temperature difference between the fin temperature and the air temperature is small. This causes a decrease in heat exchange efficiency.

For the above reasons, the fin height hf of the corrugated fins 7 is preferably set in the range of 3.9 to 5.0 mm for practical use. Then, in FIG. 5 described above, when the heating suction air temperature (outside air temperature) T _air = 0 ° C., which is a typical use condition during winter heating, the fin height hf = 3.9 to When the range of 5.0 mm is applied, the set temperature T ₀ of the PTC heater 9 is 85 ° C. to 110 ° C.
° C.

According to the range of the set temperature T ₀ , the heat radiation performance of the heat exchange core 3 in the vehicle heating heat exchanger in which the heat exchange core 3 is formed by combining the flat tube 6 with the corrugated fins 7. Under the typical use conditions during winter heating, when the PTC heater 9 generates heat,
The heat generated by the PTC heater 9 is prevented from being absorbed by the warm water via the corrugated fins 7, and the heat generated by the PTC heater 9 can be effectively used for heating the suction air for heating.

(Other Embodiments) In the above embodiment, the case where corrugated fins 7 formed in a corrugated shape are used as the fin members of the heat exchanger core is described. The present invention can be practiced even when a plate fin is used. Also, P
The installation mode of the TC heater 9 is not limited to the mode shown in FIG. 2, and can be variously changed according to a change in the specification of the heating heat exchanger.

[Brief description of the drawings]

FIG. 1 is a front view of a heating heat exchanger according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is an energization circuit diagram of the PTC heater shown in FIGS.

FIG. 4 is a model diagram showing a temperature distribution of corrugated fins in the PTC heater shown in FIG.

FIG. 5: PTC under the condition of hot water temperature = 60 ° C.
It is a graph which shows the relationship between the set temperature of a heater, and the fin height of a corrugated fin.

FIG. 6 shows PTC under the condition of hot water temperature = 80 ° C.
It is a graph which shows the relationship between the set temperature of a heater, and the fin height of a corrugated fin.

FIG. 7 shows P under the condition of fin height = 4.5 mm.
It is a graph which shows the relationship between the set temperature of TC heater, and the suction air temperature for heating.

FIG. 8 shows P under the condition of fin height = 4.0 mm.
It is a graph which shows the relationship between the set temperature of TC heater, and the suction air temperature for heating.

FIG. 9 is a graph illustrating a temperature distribution on a corrugated fin.

[Description of Signs] 3 ... heat exchange core, 6 ... flat tube, 7 ... corrugated fin, 9 ... PTC heater (electric heating element), 9a ... P
TC element (heating element), 9b, 9c ... electrode plate, 10 ...
Insulating adhesive.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Sadayuki Kamiya 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Inside Denso Corporation (72) Inventor Shinji Naruse 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Stock Association (72) Inventor Yoshifumi Aki 1-1-1, Showa-cho, Kariya-shi, Aichi Pref.

Claims (3)

[Claims] 1. A plurality of flat tubes (6) through which hot water from a vehicle engine flows are arranged in parallel, and a fin member (7) is provided between the plurality of flat tubes (6).
The heat exchange core part (3) is constituted by arranging a plurality of flat tubes (6). Some of the parts where the plurality of flat tubes (6) are installed are replaced with the flat tubes (6). A heat exchanger for heating a vehicle, in which an electric heating element (9) having a positive resistance temperature characteristic whose resistance value rapidly increases at a predetermined set temperature (T ₀ ) is provided; Regarding the temperature distribution of the fin member (7) located between the electric heating element (9) and the flat tube (6) when the electric heating element (9) generates heat, hot water in the flat tube (6) Temperature (T _W ) ≧ 60 °
C, under the condition that the temperature of the suction air for heating (T _air ) ≦ 0 ° C. to be sucked into the heat exchange core portion (3), the fin temperature at the end on the side of the flat tube (6) is A heat exchanger for heating a vehicle, wherein a set temperature (T ₀ ) of the electric heating element (9) is set so as to be equal to a hot water temperature (T _W ) in the parentheses. 2. A plurality of flat tubes (6) through which hot water from a vehicle engine flows are arranged in parallel, and corrugated fins (7) are arranged between the plurality of flat tubes (6) to generate heat. A replacement core part (3) is configured, and a predetermined set temperature is set in a part of a part where the plurality of flat tubes (6) are installed, instead of the flat tube (6). A heat exchanger for heating a vehicle, in which an electric heating element (9) having a positive resistance temperature characteristic whose resistance value increases rapidly at (T ₀ ) is provided between the flat tubes (6) of the corrugated fins (7). The fin height (hf), which is the distance, is 3.9 mm to 5 m
m, and the set temperature (T ₀ ) of the electric heating element (9) is 85 ° C. to 110 ° C. 3. The heat exchange core part (3) has an integral brazing structure made of an aluminum alloy. The electric heating element (9) includes an elongated flat heating element (9a) and the heating element. It has a three-layer sandwich structure including elongated plate-like electrode plates (9b, 9c) arranged on both front and back surfaces of the element (9a), and is integrally brazed to the heat exchange core (3). Later, the electric heating element (9) is inserted between the corrugated fins (7), and the two electrode plates (9b, 9c) are bonded and fixed to the bent tops of the corrugated fins (7). The heat exchanger for heating a vehicle according to claim 1.