JPH0739895B2 - Refrigerant evaporator - Google Patents

Description

The present invention relates to a refrigerant evaporator, and can be used as, for example, a refrigerant evaporator in a refrigeration cycle of an automobile air conditioner.

[Conventional technology]

Conventionally, as disclosed in, for example, JP-A-60-122891, a pair of plates are faced to each other and joined to each other to form a refrigerant passage therein, and a refrigerant formed by stacking the pair of plates in a plurality of stages. Evaporators are known.

Consider a case where such a refrigerant evaporator having a plurality of stacked tubes is configured as shown in FIG. 6, for example. In the refrigerant evaporator shown in FIG. 6, the gas-liquid two-phase refrigerant is introduced through the inlet pipe 121 and first introduced into the first tank group A. The refrigerant introduced into the first tank group A is U
It flows through the refrigerant passage having a letter shape and flows into the second tank group B. Then, it further flows into the third tank group C from the second tank group B, and flows out from the third tank group C to the fourth tank group D through a U-shaped passage. Then, it is guided from the fourth tank group D through an outlet pipe 122 to a compressor (not shown). The first tank group and the third tank group are called inlet tank groups because they introduce the refrigerant and distribute them to the tubes, and are called output tank groups because the second tank group and the fourth tank group collect and discharge the refrigerant. .

The flow of the refrigerant is shown by arrow F in FIG.

In such a refrigerant evaporator, the second tank group B to the third tank group B
FIG. 8 shows the state of the refrigerant flowing in the tank group C. FIG. 8 is a diagram schematically showing the flow rate of the refrigerant and the temperature of the air passing through the evaporator. The arrow Q in FIG. 8 shows the relative amount of the refrigerant flowing from each tank portion into each tube. Further, below the arrow Q, there is shown an air blowing temperature which communicates the respective stages when the refrigerant evaporator from the tank side to the lower side is divided into approximately three equal parts in the upper, middle and lower stages.

Other publications showing the prior art include, for example,
There are 56-20766 and JP 58-50216.

[Problems to be solved by the invention]

The gas-liquid two-phase refrigerant adiabatically expanded by the pressure reducing means of the refrigeration cycle flows into the first tank group A of the refrigerant evaporator as described above. When the cooling load is high, such as in summer, the flow rate of the refrigerant flowing through the refrigeration cycle is large, and therefore the flow velocity of the gas-liquid two-phase refrigerant flowing into the refrigerant evaporator is also large. Therefore, most of the liquid-phase refrigerant out of the gas-liquid two-phase refrigerant that has flowed into the first tank group A flows into the tube group at the innermost portion that is relatively far from the inlet pipe due to its inertia, while
Most of the vapor-phase refrigerant flows from the inlet pipe into the tube group in a relatively close region. The refrigerant evaporator takes heat from the surroundings by evaporating the liquid-phase refrigerant and acts as a cooler, and the gas-phase refrigerant hardly contributes to the cooling operation. Therefore, if there is a large variation in the liquid-vapor phase ratio of the refrigerant flowing into each tube group, it will result in a variation in the temperature distribution of the air temperature after passing through the evaporator, and if this variation is significant, However, there is a problem that fog is generated due to the interference between the high temperature air and the low temperature air, or the passenger feels uncomfortable.

Such a phenomenon is more remarkable even in the same inlet tank group, especially in the third tank group C. That is, the heat exchange of the refrigerant flowing through the first tank group A through the refrigerant passage to the second tank group B is performed, and the refrigerant reaching the second tank group B has a relatively high gas ratio. Is increasing. Therefore, the flow velocity of the refrigerant flowing from the second tank group B to the third tank group C is relatively high. As a result, the 8th
As shown in the figure, in the third tank group C, the amount of refrigerant flowing into the tube group 800 located substantially in the center of each tube connected to the third tank group C is relatively small, and A large amount of liquid refrigerant flows into the tubes 801, 802, etc. connected to the innermost portion of the three tank group C. That is, there is a shortage of the amount of the liquid refrigerant flowing into the tube connected to the substantially middle position of the third tank group C, and as a result, the temperature of the air temperature passing through the evaporator is also reduced as shown in FIG. There is a problem that the distribution varies.

[Means for solving problems]

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to solve the problem of non-uniformity of the liquid refrigerant flowing into each tube from the inlet tank group such as the first tank group or the third tank group. The purpose is to correct the variation in the temperature distribution of the air temperature passing through the evaporator by suppressing the variation in the amount of liquid refrigerant flowing into the.

In order to achieve this object, in the first invention of the present invention, the tubular space formed inside has an inlet tank into which the gas-liquid two-phase refrigerant is introduced, and the inlet tank has a gas-liquid two-phase refrigerant. A tube having a flat cross section, which is formed by joining the inlet port for introducing the gas and the outer peripheral edge of a pair of bowl-shaped plates, and through which the refrigerant introduced into the inlet tank flows, Corrugated fins that combine with each other to promote heat exchange between the refrigerant flowing inside the tube and air, an outlet tank that collects the refrigerant flowing inside the tube into a cylindrical space formed inside, and a refrigerant from the outlet tank. A plurality of the tubes are laminated so that the longitudinal direction of the flat cross section of the tube is along the flow direction of the air that exchanges heat with the refrigerant, and the longitudinal direction of the inlet tank is empty. Is disposed so as to be substantially orthogonal to the flow direction of the inlet tank, the inner surface of the inlet tank, at least one throttle portion for reducing the flow area of the refrigerant flowing in the longitudinal direction of the inlet tank is adopted technical means, According to the second aspect of the invention, a first tank having an inlet for the refrigerant and in which the refrigerant is introduced into a cylindrical space formed inside, and a plurality of first tanks are connected side by side in the longitudinal direction of the first tank, A tube into which the refrigerant in one tank is distributed, a second tank that collects the refrigerant flowing in the tube into a tubular space formed inside, and a tube that is longitudinally connected to the second tank, A third tank into which the refrigerant in the second tank is introduced, a plurality of tubes that are connected side by side in the longitudinal direction of the third tank, and into which the refrigerant in the third tank is distributed, The flowing refrigerant And a fourth tank having a discharge port for discharging this refrigerant, and at least one throttle portion for reducing the flow area of the refrigerant flowing in the longitudinal direction is formed on the inner surface of the third tank. We adopted the technical means.

[Operation and effect of the invention]

As described above, according to the first aspect of the present invention, since the throttle portion is formed on the inner surface of the inlet tank, the speed of the refrigerant flowing at a relatively high speed through the inlet tank portion can be suppressed by the throttle portion, and as a result, As a result, the amount of liquid refrigerant flowing into the tube connected to the central part of the tank part and the tube connected to the innermost part of the tank part can be made uniform. As a result, the temperature distribution of the air flowing in the direction substantially perpendicular to the tube stacking direction and passing through the refrigerant evaporator can be made uniform.

Further, in the second aspect of the invention, since the throttle portion is formed on the inner surface of the third tank, this throttle restricts the flow of the liquid refrigerant flowing into the third tank with a large momentum as compared with the vapor phase refrigerant. Can be suppressed. And as a result, the third
It is possible to suppress variations in the amount of liquid refrigerant distributed to the plurality of tubes connected to the tank.

〔Example〕

FIG. 2 is a plan view showing a single plate forming a tank portion and a refrigerant passage, and FIGS. 3 and 4 are views showing a III-III section and a IV-IV section of FIG. Also, FIGS. 6 and 7
The drawings are a top view and a front view of a refrigerant evaporator formed by stacking a plurality of passage units in each of which one plate shown in FIG. 2 faces each other to form a tank portion and a passage portion.

First, the plate 100 will be described with reference to FIG.
The plate 100 is made of a double-sided clad material having a plate thickness of 0.5 to 0.6. Specifically, the core material is made of A3003 material or the like, and the clad skin material is made of A4004 material, which is press-formed from a plate material having a clad rate on one side of 10 to 15%.

The plate 100 is formed with a U-shaped passage forming recess 101 by press molding. Since the passage forming recess 101 is U-shaped, a partition rib 108 is formed at the center thereof. In addition, a plurality of ribs 107 that are raised above the plane of the paper in FIG.

At both ends of the U-shaped passage forming recess 101, a first tank forming recess 102 and a second tank forming recess 103 having a deeper depth than the passage forming recess 101 are formed. ing.

A first communicating hole 104 having a substantially elliptical shape is provided through the bottom of the first tank forming recess 102. Further, a second communication hole 105 having a substantially elliptical shape is also formed through the bottom of the second tank forming recess 103. A flange portion 106 is formed on the peripheral portion of the second communication hole 105 so as to be positioned when the plates are faced to each other and joined, and the passage units formed thereby are stacked in a plurality of stages.

In this way, the tank forming recessed portions 102 and 103 and the passage forming recessed portion 101 are joined by facing a pair of the plates 100 formed by press forming. At this time, the outer peripheral portion of the plate 100 and the partition ribs 108 and 107 are in contact with each other. In this way, a pair of plates 100
As shown in FIGS. 6 and 7, the passage unit 300 formed by the above is laminated in a plurality of stages such that the communication holes 104 and 105 overlap each other. Aisle unit 30 with multiple layers stacked
Corrugated fins 123 that are bent in a wave shape for increasing the contact area with air and promoting the heat dissipation effect are arranged between the respective 0s. Further, side plates 131 and 132 are arranged at both ends of the passage unit 300 in the stacking direction. An inlet pipe 121 joined to the first communication hole 104 is joined to the passage unit located at the end of the passage unit 300 in the stacking direction. The second communication hole 105 of this passage unit 300 is in a closed state.

Further, an outlet pipe 122 is connected to the first communication hole 104 at the other end (right side in the drawing) of the passage unit 300 in the stacking direction, and the second communication hole 105 is closed.

The first communication hole 10 of the passage unit thus laminated
4, the second communication hole 105 is in communication with each other, and the first tank forming recessed portion 102 and the second tank forming recessed portion 105 form an elliptic cylindrical tank portion extending in the longitudinal direction. There is. Further, the passages formed by the passage forming recesses 107 are connected to the tank portions side by side in the longitudinal direction.

It should be noted that, of the plurality of stacked passage units 300, the two passage units 401 and 402 located substantially at the center in the stacking direction.
The first communicating hole 104 is closed at the joint surface with the
The refrigerant flowing into the tank group A does not flow into the fourth tank group D, but flows into the second tank group B through the U-shaped refrigerant passage.

Further, in the third tank group C, the passage unit located at the third position from the right end in FIG. 6 is formed by joining the special plates 200 as shown in FIG. That is, the plate 200 shown in FIG. 5 is a diagram showing a part of the plate forming recessed portion side, but the throttle portion 203 having the throttle hole 201 at the position corresponding to the second communication hole of the special plate 200. Are formed.

Although the diaphragm hole 201 shown in FIG. 5 has a circular shape, the shape is not limited to such a circular shape and can be modified to another shape. Further, the passage area of the throttle hole 201 of the throttle portion 203 is smaller than the passage area of the second communication hole 105, and the throttle amount is appropriately selected according to the amount of the refrigerant flowing in the refrigerant evaporator and the like. It is a thing.

FIG. 1 is a schematic diagram showing the flow of the refrigerant amount in this embodiment.
FIG. 9 is a view seen from the direction of an arrow W in the figure and corresponds to FIG. 8 described above. As can be seen from FIG. 1, the third
Since the liquid refrigerant flowing in the tank group C is prevented from flowing rapidly by the throttle portion 203 formed inside the third tank group, the liquid refrigerant flows to the innermost portion of the third tank group C as shown in FIG. It is possible to prevent such a phenomenon that the refrigerant suddenly flows in. That is, the liquid refrigerant is in a state of being dammed on the upstream side of the throttle portion 203, and since a large amount of the liquid refrigerant is prevented from flowing into the innermost portion on the downstream side of the throttle portion 203, as a result. The amount of liquid refrigerant flowing into each tube connected to the third tank group C is made relatively uniform as shown in FIG.

In this way, by equalizing the amount of the liquid refrigerant flowing into each tube, the temperature distribution of the air temperature passing through the refrigerant evaporator is smoothed as shown in FIG. 1, resulting in a good air conditioning condition. Obtainable.

In this embodiment, the flow order of the refrigerant is exactly the same as that described in the section of the prior art, and the refrigerant flowing from the inlet pipe 121 passes from the first tank group A through the U-shaped refrigerant passage. It flows into the second tank group B. The third tank group B is formed continuously on the same line.
It flows into the tank group C, further flows through the U-shaped refrigerant passage, and then flows into the fourth tank group D. Then, it reaches the outlet pipe 122 from the fourth tank group D, and is guided to the compressor (not shown) from the outlet pipe 122.

Further, the operation of the evaporator itself is exactly the same as that of the conventional evaporator, and therefore its explanation is omitted.

Further, in the above-mentioned example, the passage unit including the special plate 200 is configured to be located at the third position from the right end in FIG. 6, but the arrangement position of the special plate 200 having the throttle portion may be changed according to other conditions. It is selected appropriately.
Further, as shown in FIG. 9, the throttle portions 201, 201 'may be formed in two or more places in the third tank group C, and both in the first tank group A and the third tank group C, or in the third tank group C. It may be formed only within one tank group A.

Further, in this embodiment, the second tank group B corresponds to the outlet tank section and the third tank group C corresponds to the inlet tank section.

In the above-mentioned example, the refrigerant flow shows the refrigerant evaporator including the first tank group, the second tank group, the third tank group, the fourth tank group and the four tank groups. As shown, it can also be used in a refrigerant evaporator including two tank groups, a first tank group E (inlet tank portion) and a second tank group F (outlet tank portion). That is, in this case, the inlet pipe 121 is connected to the first tank group E and the outlet pipe 22 is connected to the second tank group F. A plurality of throttle portions 201, 210 'are provided at appropriate positions in the first tank group E (two in this example).
It is arranged. In this example, the inlet tank portion has only the first tank group E into which the gas-liquid two-phase refrigerant is introduced,
Similar to the case of the third tank group C described above, the liquid refrigerant is equally distributed.

The present invention can also be applied to a refrigerant evaporator of the type shown in FIGS. 12 and 13. In the above-described example, the refrigerant passage has a substantially U shape, but in the present embodiment, the tanks 303 and 305 are formed at both ends of the linear refrigerant passage 304.

A partition wall 310 is formed at a substantially central portion of the tank 303, and the tank 303 is divided into a first inlet tank G and a second outlet tank group J. An inlet pipe 306 is connected to an end of the first inlet tank group G, and an outlet pipe 307 is connected to a terminal of the second outlet tank group J.

Since the first inlet tank group G and the second outlet tank group J are in communication with the tank 305 by a plurality of refrigerant passages 304, the refrigerant flowing from the inlet pipe 306 into the first inlet tank group G is in the refrigerant passage 304. To the second outlet tank group J through the refrigerant passage 304 from the tank 305. Then, it flows from the second outlet tank group J to the compressor (not shown) through the outlet pipe 307.

Due to such a refrigerant flow, the tank 305 receives the refrigerant flowing from the first tank group G and receives the first outlet tank group H.
And a second inlet tank group I that sends out the refrigerant toward the second outlet tank group J. Inside the second inlet tank group I, there is formed a throttle portion 201 similar to that used in the above-described embodiment.

Although the throttle portion 201 is formed only at one location in the structure shown in FIG. 13, it may be formed at a plurality of locations, or may be formed in the first inlet tank group G.

In the above example, it has been shown that the throttle portions may be formed in a plurality of places, but in this case, the respective throttle amounts of the plurality of throttle portions are appropriately selected, and all are the same. It does not have to be the aperture amount.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a refrigerant flow of an embodiment of the present invention, FIG. 2 is a plan view showing a plate of the embodiment, FIG. 3 is a sectional view taken along line III-III of FIG. 2, and FIG. 2 is a sectional view taken along the line IV-IV in FIG. 5, FIG. 5 is a plan view showing a main part of the special plate, FIG. 6 is a plan view showing a refrigerant evaporator of the embodiment, and FIG. 7 is a view of the embodiment shown in FIG. Front view, FIG. 8 is a diagram schematically showing a refrigerant flow in a conventional evaporator, FIG. 9 is a diagram schematically showing a refrigerant flow in another example, FIG. 10 is a plan view showing another example, FIG. 11 is a diagram schematically showing the refrigerant flow of the example shown in FIG. 10, FIG. 12 is a front view showing another example, and FIG. 13 is a schematic diagram of the refrigerant flow of the example shown in FIG. It is a figure. 100 ... Plate, 101 ... Indentation for passage formation, 102 ...
... 1st tank forming recess, 103 ... 2nd tank forming recess, 104 ... 1st communicating hole, 105 ... 2nd communicating hole,
121 …… Inlet pipe, 122 …… Outlet pipe, 200 …… Special plate, 201 …… Throttle hole, 203 …… Throttle section.

Claims (4)

[Claims] 1. An inlet tank for introducing the gas-liquid two-phase refrigerant into a cylindrical space formed inside, an inlet for introducing the gas-liquid two-phase refrigerant into the inlet tank, and a pair of bowl-shaped plates. A tube having a flat cross section, which is formed by joining the outer peripheral edges and through which the refrigerant introduced into the inlet tank flows, and the heat of the refrigerant and the air flowing inside the tube that are thermally coupled to the tube. A corrugated fin that facilitates exchange, an outlet tank that collects the refrigerant flowing in the tube into a cylindrical space formed inside, and an outlet that guides the refrigerant from the outlet tank, and the tube A plurality of laminated flat longitudinal sections are arranged along the flow direction of the air that exchanges heat with the refrigerant, and the longitudinal direction of the inlet tank is arranged so as to be substantially orthogonal to the air flow direction. The inner surface of the tank, the refrigerant evaporator, wherein a throttle portion for reducing the flow area of the refrigerant flowing in the longitudinal direction of the inlet tank is at least one formation. 2. The refrigerant evaporator according to claim 1, wherein the inlet tank, the outlet tank and the tube are formed by facing and joining a pair of plates having a tank recess and a passage recess. . 3. A first tank having a refrigerant introduction port, into which a refrigerant is introduced into a cylindrical space formed inside, and a plurality of first tanks connected in parallel in the longitudinal direction of the first tank, A tube into which the refrigerant in one tank is distributed, a second tank that collects the refrigerant flowing in the tube into a tubular space formed inside, and a tube that is longitudinally connected to the second tank, A third tank into which the refrigerant in the second tank is introduced, a plurality of tubes that are connected side by side in the longitudinal direction of the third tank, and into which the refrigerant in the third tank is distributed, A fourth tank having a discharge port for collecting the flowing refrigerant and discharging the refrigerant, and at least one throttle portion that reduces the flow area of the refrigerant flowing in the longitudinal direction is provided on the inner surface of the third tank. Individually formed refrigerant evaporation . 4. A first tank having a cylindrical space formed therein, an inlet for introducing a refrigerant into the first tank, and one end connected to a longitudinal side surface of the first tank, the first tank A plurality of tubes into which the refrigerant inside flows, a second tank that communicates with the other end of the tubes, and collects the refrigerant that has flowed inside the tubes into a cylindrical space formed inside, and the length of the second tank A third space which is connected to the end portion in the direction and forms a cylindrical space into which the refrigerant in the second tank is introduced
A tank, and a throttle portion formed at least one on the inner surface of the third tank to reduce the flow area of the refrigerant flowing in the longitudinal direction; one end connected to the longitudinal side surface of the third tank; A plurality of tubes into which the refrigerant flows, a fourth tank that communicates with the other end of the tubes and collects the refrigerant flowing in the tubes into a cylindrical space formed inside, and a fourth tank that is thermally coupled to the tubes. An evaporator that includes a fin that promotes vaporization of a liquid-phase refrigerant that flows through the tube, and an outlet that guides the refrigerant from the fourth tank.