JP2004278935A - Evaporator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the heat exchanging efficiency by approximately uniformly distributing a liquid phase and a gas phase of a refrigerant to refrigerant passages of a plurality of tubes, regardless of a refrigerant flowing condition. <P>SOLUTION: This evaporator comprises the plurality of refrigerant passages 2c mounted in the plurality of stacked tubes 2, an inlet tank 10 communicated with one end side of each refrigerant passage 2c, an outlet tank 11 communicated with the other end side of each refrigerant passage 2c, and a refrigerant inlet pipe 3 having an inner pipe part 12 inserted to the whole area in the inlet tank 10 to supply the refrigerant into the inlet tank 10 from refrigerant holes 14 of the inner pipe part 12. The refrigerant holes 14 of the inner pipe part 12 inserted into the inlet tank 10 are formed on at least two positions, that is, an upper position with respect to a lowermost point a in the inner pipe part 12 in the circumferential direction and a lower position with respect to an uppermost point b in the inner pipe part 12 at equal intervals to the axial direction L1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an evaporator in which an inner pipe portion is inserted into an inlet tank that supplies a refrigerant into a plurality of tubes.
[0002]
[Prior art]
Examples of this type of evaporator include those shown in FIGS. 13 to 15 (for example, see Patent Document 1). As shown in FIG. 13, the evaporator 100 includes a plurality of stacked tubes 101, a plurality of corrugated fins 102 disposed between the tubes 101, and an inlet tank 103 fixed to the upper ends of the plurality of tubes 101. And an outlet tank 104, a refrigerant inlet pipe 105 connected to one end of the inlet tank 103, and a refrigerant outlet pipe 106 connected to one end of the outlet tank 104. A U-shaped refrigerant passage (not shown) is formed in each tube 101 and arranged in the longitudinal direction of the tube. One end of the refrigerant passage is located in the inlet tank 103, and the other end of the refrigerant passage is located in the header outlet tank 104. Are connected to each other.
[0003]
As shown in FIG. 15, the inside of the inlet tank 103 is divided into three chambers 108a, 108b, and 108c (areas of A, B, and C) by two partition walls 107. Further, the refrigerant inlet pipe 105 has an inner pipe section 109 inserted over the entire area inside the inlet tank 103, and the inner pipe section 109 passes through the chambers 108a, 108b, 108c of A, B, C. ing. Refrigerant holes 109a, 109b, and 109c are formed in the inner pipe portion 109 at three locations so as to open to the respective chambers 108a, 108b, and 108c of A, B, and C.
[0004]
Next, the flow of the refrigerant in the evaporator 100 will be described. FIG. 14 schematically shows the flow of the refrigerant. The refrigerant flowing from the refrigerant inlet pipe 105 flows into the inlet tank 103 through the refrigerant holes 109a, 109b, and 109c of the inner pipe portion 109, and each refrigerant flows from the inlet tank 103. The refrigerant flows into a refrigerant passage (not shown) of the tube 101. The refrigerant flowing into the refrigerant passage flows along a U-shaped path, and heat exchange is performed between the refrigerant and an external fluid during the flow. The refrigerant flowing through the refrigerant passage flows into the outlet tank 104, where it joins with the refrigerant circulating through the refrigerant passages of the other tubes 101, and then flows out of the refrigerant outlet pipe 106.
[0005]
According to the evaporator 100, the supply of the refrigerant from the refrigerant inlet pipe 105 into the inlet tank 103 is divided not from one place but from a plurality of places by using the plurality of coolant discharge holes 109a, 109b, and 109c of the inner pipe portion 109. This is intended to improve the heat exchange efficiency by minimizing the uneven distribution of the liquid phase and the gas phase of the refrigerant supplied into each tube 101.
[0006]
That is, in a structure in which the refrigerant inlet pipe 105 is simply connected to one end of the inlet tank 103 without using the inner pipe portion 109 and the refrigerant is supplied from one place, the liquid phase having a large specific gravity in the refrigerant flows downward. Due to the stagnation, a large amount of the liquid phase of the refrigerant flows into the refrigerant passage of the tube 101 near the refrigerant inlet pipe 105, and a large amount of the gas phase of the refrigerant flows into the refrigerant passage of the tube 101 farther from the refrigerant inlet pipe 105.
[0007]
On the contrary, when the refrigerant inlet pipe 105 is disposed at the lower end side of the tube 101, a gas phase having a low specific gravity stays upward in the refrigerant, so that a tube close to the refrigerant inlet pipe 105 The refrigerant has a large gas phase in the refrigerant passage 101 and a large liquid phase of the refrigerant flows into the refrigerant passage of the tube 101 farther from the refrigerant inlet pipe 105. When refrigerants having different ratios of the liquid phase and the gas phase flow through the plurality of tubes 101 in this manner, efficient heat exchange is not performed in the entire area of the evaporator 100.
[0008]
Therefore, a plurality of outflow points of the refrigerant from the refrigerant inlet pipe 105 into the inlet tank 103 are provided to minimize the uneven distribution of the liquid phase and the gas phase of the refrigerant supplied into each tube 101.
[0009]
[Patent Document 1]
JP-A-9-166368, page 4, FIG.
[0010]
[Problems to be solved by the invention]
However, the conventional evaporator 100 has a structure in which a single refrigerant hole 109a, 109b, 109c is provided at each of spaced positions, and the same refrigerant hole 109a, 109b, 109c allows the refrigerant liquid phase to be formed. Since the gas phase is ejected at the same time, the liquid phase receives the dynamic pressure of the gas phase, and the liquid phase is discharged according to the strength of the gas pressure. Therefore, there is a problem that the distribution becomes non-uniform depending on the refrigerant flow condition (the magnitude of the refrigerant flow rate) and the heat exchange efficiency is reduced.
[0011]
Therefore, the present invention provides an evaporator capable of improving the heat exchange efficiency by substantially uniformly distributing the liquid phase and the gas phase of the refrigerant to the refrigerant passages of the plurality of tubes regardless of the refrigerant flow conditions. With the goal.
[0012]
[Means for Solving the Problems]
The invention according to claim 1, wherein a plurality of stacked tubes, an inlet tank in which one ends of the plurality of tubes are respectively connected, an outlet tank in which the other ends of the plurality of tubes are connected, and the inlet tank Having an inner pipe portion inserted over the entire area, a refrigerant inlet pipe for supplying a refrigerant from the refrigerant hole of the inner pipe portion into the inlet tank, and a refrigerant outlet pipe connected to the outlet tank. Wherein the inlet tank is an evaporator disposed above or below the plurality of tubes, and the refrigerant hole of the inner pipe portion is located at a position lower than a lowest point in the inner pipe portion with respect to a circumferential direction. It is characterized in that it is provided at at least two height positions between an upper position and a position below the uppermost point.
[0013]
The invention according to claim 2 is the evaporator according to claim 1, wherein the refrigerant holes of the inner pipe portion are arranged so as to correspond to the same number of the plurality of tubes in the axial direction. It is characterized by having.
[0014]
According to a third aspect of the present invention, in the evaporator according to the first or second aspect, the refrigerant holes are provided at three height positions with respect to a circumferential direction of the inner pipe portion. A lower hole located at a position higher than the lowest point in the portion, and lower than a center position of the inner pipe portion; an intermediate hole having substantially the same height as the center position of the inner pipe portion; And an upper hole located below the uppermost point and above the center position of the inner pipe portion.
[0015]
According to a fourth aspect of the present invention, in the evaporator according to any one of the first to third aspects, the lower hole is lower than a horizontal line having the lower hole as an intersection with the entire cross-sectional area in the inner pipe portion. Is set at a position where the cross-sectional area in the inner pipe portion located at about 1/3 is about one third.
[0016]
According to a fifth aspect of the present invention, in the evaporator according to any one of the first to fourth aspects, the upper hole is higher than a horizontal line having the upper hole as an intersection with the entire cross-sectional area in the inner pipe portion. Is set at a position where the cross-sectional area in the inner pipe portion located at about 1/3 is about one third.
[0017]
The invention according to claim 6 is the evaporator according to any one of claims 1 to 5, wherein an axial interval between the coolant holes is an integer of a pitch interval of the tubes. It is characterized by an interval of double or 1/2 pitch.
[0018]
The invention according to claim 7 is the evaporator according to any one of claims 1 to 6, wherein the refrigerant holes are provided at symmetrical positions of the inner pipe portion. It is characterized by.
[0019]
The invention according to claim 8 is the evaporator according to any one of claims 1 to 6, wherein the inlet tank is disposed at an upper end of the plurality of tubes, and an outer peripheral surface of the inner pipe portion. Is characterized in that a concave / convex surface for allowing the refrigerant discharged from each of the refrigerant holes to be dropped from directly below each of the holes is formed.
[0020]
【The invention's effect】
According to the first aspect of the invention, the liquid phase of the refrigerant flowing into the inner pipe portion is stored in the entire lower region of the inner pipe portion, and the gas phase is stored in the entire upper region of the inner pipe portion. When the liquid level of the liquid phase reaches the lower refrigerant hole, the liquid phase overflows from each lower refrigerant hole due to the overflow of the liquid phase. A substantially equal amount of the liquid phase flows out from each of the refrigerant holes provided below. On the other hand, the gas phase stored in the inner pipe portion flows out from the upper refrigerant holes due to the gas pressure, but the refrigerant holes are provided at equal intervals by acting as filters for the gas flow. The refrigerant is almost uniformly discharged from each of the upper coolant holes. Therefore, the liquid phase and the gas phase of the refrigerant are almost uniformly distributed to each tube regardless of the refrigerant flow conditions, and the heat exchange efficiency can be improved.
[0021]
According to the invention described in claim 2, in addition to the effect of the invention described in claim 1, the refrigerant holes of the inner pipe portion are arranged corresponding to the same number of each of the plurality of tubes in the axial direction. Therefore, the liquid phase and the gas phase flowing into each tube can be substantially evenly distributed.
[0022]
According to the third aspect of the invention, in addition to the effects of the first aspect, the liquid phase of the refrigerant mainly flows out of the lower hole, the gas phase of the refrigerant mainly flows out of the upper hole, and Both the liquid phase and the gas phase of the refrigerant will flow out of the holes. Therefore, the liquid phase is hardly affected by the dynamic pressure of the gas phase, and contributes to uniform distribution to each tube.
[0023]
According to the fourth aspect of the invention, in addition to the effect of the third aspect of the present invention, a one-third volume of the liquid phase is stored in the inner pipe portion, so that a stable outflow of the liquid phase due to overflow is expected. it can.
[0024]
According to the fifth aspect of the present invention, in addition to the effect of the fourth aspect of the present invention, since a gas phase having a volume of one third is stored in the inner pipe portion, a stable outflow of the gas phase by the filter action can be achieved. Can be expected.
[0025]
According to the invention of claim 6, in addition to the effect of the invention of claim 5, since the coolant holes are arranged at intervals corresponding to the number of tubes, it is possible to achieve uniform distribution of the coolant to each tube. it can.
[0026]
According to the invention of claim 7, in addition to the effect of the invention of claim 6, since the liquid phase and the gas phase of the refrigerant can flow out from the left and right positions of the inner pipe portion, respectively, the liquid phase and the gas phase of the refrigerant from inside the inner pipe portion The phase can flow out smoothly. Further, it is possible to prevent a pressure difference from occurring between the left and right positions in the inner pipe portion and the inlet tank.
[0027]
According to the invention of claim 8, in addition to the effect of the invention of claim 7, when the inlet tank is located above, even if the inner pipe portion has a slight inclination or the like, it flows out from each refrigerant hole. Since the liquid phase flows down from a position directly below each refrigerant hole in the inner pipe portion, the distribution of the refrigerant to each tube can be made uniform.
[0028]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0029]
(First Embodiment)
1 to 4 show a first embodiment of the present invention, FIG. 1 is a sectional view of an evaporator, FIG. 2 is a perspective view of an inner pipe portion, FIG. 3 is a sectional view taken along line AA of FIG. FIG. 4 is an enlarged sectional view of the vicinity of the inner pipe portion and the inlet side tank.
[0030]
As shown in FIG. 1, the evaporator 1 </ b> A includes a plurality of stacked tubes 2, a plurality of outer fins 5 disposed between the tubes 2, and an inlet side connected to upper ends of the plurality of tubes 2. A refrigerant inlet pipe 3 connected to the tank 10 and a refrigerant outlet pipe (not shown) connected to the outlet tank 11 are provided.
[0031]
As shown in FIGS. 1 and 3, each tube 2 has straight refrigerant passages 2c and 2c in which inner fins 2e are disposed between an inlet tank 10 and an outlet tank 11, and a U-turn connecting these refrigerant passages. A refrigerant passage 2f is provided. The upper ends of the refrigerant passages 2c, 2c communicate with the inlet tank 10 and the outlet tank 11.
[0032]
As shown in FIGS. 1 and 2, the inlet pipe 3 includes an inner pipe portion 12 inserted over the entire area of the inlet-side tank 10. The outer diameter of the inner pipe portion 12 is set smaller than the inner diameter of the inlet-side tank 11, and the tip is closed by a closing cap 13.
[0033]
The inner pipe portion 12 is a coolant hole 14 preferably having a diameter of about 0.5 mm to several millimeters. In this embodiment, a large number of 1 mm holes are provided. The large number of refrigerant holes 14 are located at equal intervals in the axial direction L1, which is the laminating direction of the tubes 2, and at three height positions in the circumferential direction (the direction orthogonal to the axial direction L1). Is provided. Specifically, as shown in FIG. 4, each of the refrigerant holes 14 is provided at a position symmetrical to the left and right of the inner pipe portion 12, at a position above the lowest point a in the inner pipe portion 12, and A lower hole 14a located below the center position O of the portion 12, an intermediate hole 14b having substantially the same height as the center position O of the inner pipe portion 12, and an uppermost point located above the center position O of the inner pipe portion 12 and an upper hole 14c located below b. The lower hole 14a is located at a position where the cross-sectional area in the inner pipe portion 12 located below the horizontal line H intersecting the lower hole 14a is about one third of the entire cross-sectional area in the inner pipe portion 12. Is set.
[0034]
In addition, the interval in the axial direction L1 where the coolant holes 14a, 14b, and 14c are provided is set to an integral multiple of the pitch interval P of the tube 2 or to a half pitch. A two-fold example is shown.
[0035]
Next, the flow of the refrigerant in the evaporator 1A will be described. The refrigerant flowing from the inlet pipe 3 flows into the inlet-side tank 10 through the refrigerant hole 14 of the inner pipe portion 12, and flows into the refrigerant passage 2 c of each tube 2. The refrigerant flowing into each refrigerant passage 2c flows downward through each refrigerant passage 2c, flows upward through the refrigerant passage 2c via the U-turn refrigerant passage 2f, enters the outlet side tank 11, and the refrigerant in the other tubes 2 The refrigerant merges with the refrigerant circulating in the passage 2 c and flows out from the outlet pipe 4. In the process of flowing through the refrigerant passage, heat exchange is performed with an external fluid.
[0036]
The operation of supplying the refrigerant from the inner pipe portion 12 into the inlet tank 10 during the refrigerant circulation process will be described in detail.
[0037]
As shown in FIG. 4, the liquid phase A of the refrigerant flowing into the inner pipe section 12 is stored in the entire lower area of the inner pipe section 12, and the gas phase B is stored in the entire upper area of the inner pipe section 12. Will be stored. When the liquid level of the liquid phase A reaches the lower holes 14a, the liquid phase A flows out of the lower holes 14a provided at equal intervals due to overflow.
Because of the overflow, the refrigerant flows out from the lower refrigerant holes 14a, and is substantially unaffected by the dynamic pressure of the gas phase. The liquid phase will be drained.
[0038]
On the other hand, the gas phase B stored in the inner pipe portion 12 flows out from each refrigerant hole 14 by gas pressure. Here, since each refrigerant hole 14 serves as a filter for a gas flow, it flows out almost equally from each upper hole 14a provided at equal intervals. Either the liquid phase A or the gas phase B or a mixture thereof flows out from the intermediate hole 14b according to the gas pressure and the amount of the liquid phase in the inner pipe portion 12. As described above, the liquid phase A and the gas phase B of the refrigerant are almost uniformly distributed to the plurality of tubes 2 irrespective of the refrigerant flow conditions, and the heat exchange efficiency can be improved.
[0039]
In the first embodiment, the refrigerant hole 14 is configured by the lower hole 14a, the intermediate hole 14b, and the upper hole 14c provided at three height positions with respect to the circumferential direction of the inner pipe portion 12. Therefore, the liquid phase A of the refrigerant mainly flows out from the lower hole 14a, the gas phase B of the refrigerant mainly flows out from the upper hole 14c, and the liquid phase A and the gas phase B of the refrigerant flow from the intermediate hole 14b. Both will be spilled. Therefore, the liquid phase A is hardly affected by the dynamic pressure of the gas phase B, and contributes to uniform distribution to each tube 2.
[0040]
In the first embodiment, the lower hole 14a has a cross-sectional area of three minutes below the horizontal line H intersecting the lower hole 14a with respect to the entire cross-sectional area of the inner pipe 12. Since the liquid phase A is set at a position where the liquid phase A is about one third, the liquid phase A having a volume of one third is constantly stored in the inner pipe portion 12, so that a stable outflow of the liquid phase A due to overflow can be expected.
[0041]
In the first embodiment, the upper hole 14c has a cross-sectional area in the inner pipe portion located above the horizontal line I intersecting the upper hole 14c with respect to the entire cross-sectional area in the inner pipe portion 12. Since the gas phase B is set at a position where the gas phase B is set to be about one third, the gas phase B having a volume of one third is always stored in the inner pipe portion 12, so that a stable outflow of the gas phase B due to overflow can be expected. .
[0042]
In the first embodiment, since the pitch in the axial direction L1 where the coolant holes 14 are provided is twice the pitch pitch of the tubes 2, the coolant holes 14 are spaced at intervals corresponding to the number of tubes 2. Is arranged, the distribution of the refrigerant to each tube 2 can be made uniform.
[0043]
In the first embodiment, the refrigerant holes 14 are provided at symmetric positions of the inner pipe 12, respectively, so that the liquid phase A and the gas phase B of the refrigerant are respectively transferred from the left and right positions of the inner pipe 12. Since the refrigerant can flow out, the liquid phase A and the gas phase B of the refrigerant flow out smoothly from the inner pipe portion 12. Further, it is possible to prevent a pressure difference from occurring at the left and right positions in the inner pipe portion 12 and the inlet tank 10.
[0044]
FIG. 5 is a perspective view of a first modified example of the inner pipe portion 12. As shown in FIG. 5, an uneven surface 15 is formed at the lower end of the outer peripheral surface of the inner pipe portion 12 in accordance with the pitch of the coolant holes 14. Protrusions 15a of the uneven surface 15 are arranged directly below the lower holes 14c.
[0045]
The same operation and effect as in the first embodiment can be obtained by using the inner pipe portion 12 of the first modification. In addition, when the inner pipe portion 12 of the first modified example is used, even if the inner pipe portion 12 has a slight inclination or the like, the liquid phase flowing out from each refrigerant hole 14 a travels along the uneven surface 15. It is guided to each convex part 15a, and flows down from the tip of each convex part 15a, that is, the position directly below each refrigerant hole 14a. Therefore, the distribution of the refrigerant to each tube 2 can be made uniform. The uneven surface 15 formed on the outer peripheral surface of the inner pipe portion 12 may have any shape as long as the refrigerant discharged from each of the refrigerant holes 14 is dropped from a position directly below each of the holes.
[0046]
FIG. 6 is a perspective view of a second modified example of the inner pipe portion 12. As shown in FIG. 6, the inner pipe portion 12 has a shape that tapers gradually toward the tip. That is, the cross-sectional area of the inner pipe portion 12 is maximum on the inlet side, and gradually decreases toward the tip.
[0047]
The same operation and effect as in the first embodiment can be obtained by using the inner pipe portion 12 of the second modification.
[0048]
7 to 9 show a second embodiment of the present invention. FIG. 7 is a sectional view of an evaporator, FIG. 8 is a sectional view taken along line BB of FIG. 7, and FIG. It is an expanded sectional view.
[0049]
As shown in FIGS. 7 and 8, the evaporator 1B shows a case where the positions of the inlet tank 10 and the refrigerant inlet pipe 3 are on the lower end side as compared with those of the first embodiment.
[0050]
As shown in FIG. 7, the evaporator 1 </ b> B includes a plurality of stacked tubes 2, a plurality of outer fins 5 disposed between the tubes 2, and a refrigerant inlet connected to lower ends of the plurality of tubes 2. It has a pipe 3 and a refrigerant outlet pipe 4 connected to the upper ends of the tubes 2.
[0051]
As shown in FIGS. 7 and 8, each tube 2 is provided with header chambers 2a and 2b at upper and lower ends thereof, and both sides of each header chamber 2a and 2b are opened by a substantially circular through hole 2d. I have. In the stacked state of the tubes 2, the left and right header chambers 2 a and 2 b are communicated with each other through the through holes 2 d, respectively. Outlet tanks 11 are formed by the collection of the upper end header chambers 2b. The inside of the inlet tank 10 and the inside of the outlet tank 11 are closed spaces.
[0052]
In each tube 2, a straight refrigerant passage 2c is provided between the upper and lower header chambers 2a and 2b, and an inner fin 2e is disposed in the refrigerant passage 2c. The lower end of the refrigerant passage 2c communicates with the header chamber 2a, that is, the inlet tank 11, and the upper end of the refrigerant passage 2c communicates with the header chamber 2b, that is, the outlet tank 12.
[0053]
The outer diameter of the inner pipe portion 12 protruding from the refrigerant inlet pipe 3 is smaller than the inner diameter of the through hole 2d. As in the first embodiment, a large number of refrigerant holes 14 are provided. Although a large number of refrigerant holes 14 are set at positions similar to those of the first embodiment as a result, the setting conditions will be described. It is provided at three height positions with respect to the direction (perpendicular to the axial direction L1). Specifically, as shown in FIG. 9, each coolant hole 14 is provided at a position symmetrical to the left and right of the inner pipe portion 12, at a position below the highest point b in the inner pipe portion 12, and An upper hole 14c located above the center position O of the inner pipe 12, an intermediate hole 14b having substantially the same height as the center position O of the inner pipe portion 12, and a lower hole located at a position lower than the center position O of the inner pipe portion 12. 14a. The upper hole 14c is located at a position where the cross-sectional area in the inner pipe portion 12 located above the horizontal line H intersecting the upper hole 14c with respect to the entire cross-sectional area in the inner pipe portion 12 is about one third. Is set.
[0054]
The intervals in the axial direction L1 where the coolant holes 14a, 14b, 14c are provided are different from those in the first embodiment, and are set at the pitch intervals of the tubes 2.
[0055]
Other configurations are substantially the same as those of the first embodiment, and therefore, the same reference numerals are given to the same components in the drawings, and the description thereof will be omitted.
[0056]
Next, the flow of the refrigerant in the evaporator 1B will be described. The refrigerant flowing from the refrigerant inlet pipe 3 flows into the inlet tank 10 through the refrigerant hole 14 of the inner pipe portion 12, and flows into the refrigerant passage 2c of each tube 2 from the header inlet tank 10. The refrigerant flowing into each of the refrigerant passages 2c flows upward through each of the refrigerant passages 2c, and exchanges heat with an external fluid in the process of flowing through the refrigerant passages 2c. The refrigerant flowing through the refrigerant passage 2 c flows into the outlet tank 11, merges with the refrigerant circulating through the refrigerant passage 2 c of the other tube 2, and flows out from the refrigerant outlet pipe 4.
[0057]
The operation of supplying the refrigerant from the inner pipe portion 12 into the inlet tank 10 during the refrigerant circulation process will be described in detail.
[0058]
As shown in FIG. 9, the liquid phase A of the refrigerant flowing into the inner pipe portion 12 is stored in the entire lower region of the inner pipe portion 12, and the gas phase B is stored in the upper entire region of the inner pipe portion 12. Will be stored. The liquid phase A stored in the inner pipe portion 12 gradually flows out into the header inlet tank 10 when the liquid level rises from the lower hole 14a, and the inside of the inlet tank 10 is filled with the liquid phase A flowing out. The liquid phase A in the header inlet tank 10 does not flow back into the inner pipe 12 due to the pressure of the gas phase B stored in the inner pipe 12. In addition, since the liquid phase is stored only in the inner pipe portion 12 up to the liquid level of the lower hole 14a and the storage amount is small, the gas phase B and the liquid phase A do not affect each other from a low flow rate to a high flow rate.
[0059]
In such a state, the gas phase B stored in the inner pipe portion 12 flows out of each upper hole 14c due to overflow, but is substantially equal to each upper hole 14c provided at equal intervals due to the overflow. A large amount is discharged. The gas phase B flowing out from each upper hole 14c rises in the liquid phase A and is mixed with the liquid phase A near the liquid level of the liquid phase A. As described above, the liquid phase A and the gas phase B of the refrigerant are almost uniformly distributed to each tube 2 irrespective of the refrigerant flow conditions, and the heat exchange efficiency can be improved.
[0060]
In the second embodiment, the refrigerant hole 14 is configured by the lower hole 14a, the intermediate hole 14b, and the upper hole 14c provided at three height positions with respect to the circumferential direction of the inner pipe portion 12. Therefore, the liquid phase A of the refrigerant mainly flows out from the lower hole 14a, the gas phase B of the refrigerant mainly flows out from the upper hole 14c, and both the liquid phase A and the gas phase B of the refrigerant flow from the intermediate hole 14b. Will be leaked. Therefore, the liquid phase A is hardly affected by the dynamic pressure of the gas phase B, and contributes to uniform distribution to each tube 2.
[0061]
In the second embodiment, the cross-sectional area of the upper hole 14c in the inner pipe portion 12 located above the horizontal line I intersecting the upper hole 14c with respect to the entire cross-sectional area of the inner pipe portion 12 is 3%. Since the gas phase B is set at a position where the gas phase B is set to about one-third, the gas phase B having a volume of one third is stored in the inner pipe portion 12, so that a stable gas phase B can be expected to flow out due to overflow.
[0062]
In the second embodiment, the interval between the refrigerant holes 14 in the axial direction L1 is equal to the pitch interval P of the tubes 2 and is set immediately below the tubes 2, so that the distribution of the refrigerant to the tubes 2 is made uniform. Can be achieved.
[0063]
In the second embodiment, the refrigerant holes 14 are provided at the left and right symmetric positions of the inner pipe portion 12, respectively, so that the liquid phase A and the gas phase B of the refrigerant flow out of the left and right positions of the inner pipe portion 12, respectively. Therefore, the liquid phase A and the gas phase B of the refrigerant can flow out smoothly from the inner pipe portion 12. Further, it is possible to prevent a pressure difference from occurring between the left and right positions in the inner pipe portion 12 and the inlet tank 10.
[0064]
FIG. 10 is a diagram showing the results of the measurement of the ratio characteristics to the position where the lower hole 14a is provided (the center angle θ of the position of the lower hole 14a with respect to the vertical line). As shown in FIG. 10, it is understood that the value of the ratio increases as the center angle θ increases, that is, as the lower hole 14a is provided above the lowermost position a.
[0065]
FIG. 11 shows a third embodiment of the present invention. FIG. 11A is a sectional view of an evaporator, and FIG. 11B is a sectional view of a tube. As shown in FIGS. 11A and 11B, the evaporator 1C according to the third embodiment uses a tube 2 having a U-shaped refrigerant passage 2c. The difference is that the inlet tank 10, the outlet tank 11, and the tube 2 have an integral structure.
[0066]
The configurations of the refrigerant inlet pipe 3 and the inner pipe portion 12 protruding therefrom are the same as those of the second embodiment, and a description thereof will be omitted to avoid redundant description.
[0067]
The same operation and effect can be obtained in the third embodiment.
[0068]
FIG. 12 shows a fourth embodiment of the present invention. FIG. 12 (a) is a sectional view of an evaporator, and FIG. 12 (b) is a sectional view of a tube. As shown in FIGS. 12A and 12B, the evaporator 1D according to the fourth embodiment uses a tube 2 having an inverted U-shaped refrigerant passage 2c. This is a type in which both header chambers 2a and 2b, that is, an inlet tank 10 and an outlet tank 11 are provided on the side. The configurations of the refrigerant inlet pipe 3 and the inner pipe portion 12 protruding therefrom are the same as those of the second embodiment, and a description thereof will be omitted to avoid redundant description.
[0069]
Also in the fourth embodiment, the same operation and effect can be obtained except that the refrigerant flows in an inverted U shape in the refrigerant passage 2c of the tube 2.
[0070]
In the above embodiments, the coolant holes 14 are provided at three height positions, but may be provided at at least two height positions. However, it is preferable to provide the liquid phase and the gas phase through different coolant holes 14 by providing them at three height positions or at three or more height positions as in each of the above embodiments. In each embodiment, one refrigerant hole 14 on the left and right is provided at one height position, but two or more refrigerant holes 14 on the left and right may be provided.
[0071]
In each of the above embodiments, the cross-sectional shape of the inner pipe portion 12 is circular, but the cross-sectional shape may be any shape, such as a rectangle, a triangle, or an ellipse.
[0072]
In the first to fourth embodiments, the refrigerant passage 2c in the tube 2 has a straight shape or a U-shape. However, the refrigerant passage 2c may have any shape. It is.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an evaporator, showing a first embodiment of the present invention.
FIG. 2 shows the first embodiment of the present invention, and is a perspective view of an inner pipe portion.
FIG. 3 shows the first embodiment of the present invention, and is a sectional view taken along line AA of FIG.
FIG. 4 shows the first embodiment of the present invention, and is an enlarged sectional view of the vicinity of an inner pipe portion and an inlet tank.
FIG. 5 is a perspective view of a first modification of the inner pipe portion.
FIG. 6 is a perspective view of a first modification of the inner pipe portion.
FIG. 7 shows a second embodiment of the present invention and is a cross-sectional view of an evaporator.
FIG. 8 shows a second embodiment of the present invention, and is a cross-sectional view taken along the line BB of FIG.
FIG. 9 shows the second embodiment of the present invention, and is an enlarged sectional view near the inner pipe portion and the inlet tank.
FIG. 10 is a diagram illustrating a result of actually measuring a ratio characteristic to a position where a lower hole is provided (a center angle θ from the lowest position to the lower hole) according to the second embodiment of the present invention.
11A and 11B show a third embodiment of the present invention, wherein FIG. 11A is a sectional view of an evaporator, and FIG. 11B is a sectional view of a tube.
FIG. 12 shows a fourth embodiment of the present invention, wherein (a) is a sectional view of an evaporator, and (b) is a sectional view of a tube.
FIG. 13 shows a conventional example, and is a perspective view of an evaporator.
FIG. 14 is a diagram showing a refrigerant flow in a conventional evaporator.
15 shows a conventional example, and is a cross-sectional view taken along line CC of FIG.
[Explanation of symbols]
1A, 1B, 1C, 1D Evaporator
2 tubes
2c refrigerant passage
3 Refrigerant inlet pipe
4 Refrigerant outlet pipe
10 Inlet tank
11 outlet tank
12 Inner pipe section
14 Hole for refrigerant
14a Down hole
14b Intermediate hole
14c Upper hole
15 Uneven surface
A liquid phase
B gas phase
a lowest point
O center position
H horizon
L1 axial direction
P Pitch interval

Claims (8)

A plurality of laminated tubes (2), an inlet tank (10) in which one ends of the plurality of tubes (2) are respectively connected, and an outlet tank (10) in which the other ends of the plurality of tubes (2) are connected respectively. 11), and an inner pipe portion (12) inserted over the entire area of the inlet tank (10), and a refrigerant is supplied from the inlet tank (10) through a refrigerant hole (14) of the inner pipe portion (12). ), And a refrigerant outlet pipe (4) connected to the outlet tank (11), wherein the inlet tank (10) is located above the plurality of tubes (2). Alternatively, in the evaporator (1A, 1B, 1C, 1D) disposed below, the refrigerant hole (14) of the inner pipe portion (12) is provided with the inner pipe portion (12) in the circumferential direction. The lowest point in ( ) Than in the upper position, the evaporator, characterized in that provided at the height position of the at least two locations between the lower position than the uppermost point (b) (1A, 1B, 1C, 1D). The evaporator (1A, 1B, 1C, 1D) according to claim 1, wherein the refrigerant hole (14) of the inner pipe portion (12) is provided with the plurality of tubes (1) in an axial direction (L1). The evaporators (1A, 1B, 1C, 1D), which are arranged so as to correspond to the same number in each of 2). The evaporator (1A, 1B, 1C, 1D) according to claim 1 or 2,
The coolant holes (14) are provided at three height positions with respect to the circumferential direction of the inner pipe portion (12), and are located above the lowest point (a) in the inner pipe portion (12). And a lower hole (14a) located below the center position (O) of the inner pipe portion (12), and an intermediate hole having substantially the same height as the center position (O) of the inner pipe portion (12). (14b) and the upper hole (14c) located below the uppermost point (b) of the inner pipe portion (12) and above the center position (O) of the inner pipe portion (12). An evaporator (1A, 1B, 1C, 1D) characterized by being constituted. The evaporator (1A, 1B, 1C, 1D) according to any one of claims 1 to 3,
The lower hole (14a) is located below the horizontal line (H) intersecting the lower hole (14a) with respect to the entire cross-sectional area in the inner pipe portion (12). The evaporator (1A, 1B, 1C, 1D) characterized in that the cross-sectional area inside the evaporator is set to a position where the cross-sectional area is about one third. The evaporator (1A, 1B, 1C, 1D) according to claim 1 to claim 4,
The upper hole (14c) is located above the horizontal line (I) where the upper hole (14c) intersects with the entire cross-sectional area in the inner pipe portion (12). The evaporator (1B, 1D) characterized in that the cross-sectional area inside the evaporator is set at a position where the cross-sectional area is about one third. An evaporator (1A, 1B, 1C, 1D) according to any one of claims 1 to 5, wherein
The evaporator is characterized in that the interval in the axial direction (L1) in which the coolant holes (14) are provided is an integral multiple or a half pitch of the pitch interval (P) of the tubes (2). (1A, 1B, 1C, 1D). An evaporator (1A, 1B, 1C, 1D) according to any one of claims 1 to 6, wherein
The evaporator (1A, 1C), wherein the coolant holes (14) are provided at symmetric positions of the inner pipe portion (12). The evaporator (1A, 1C) according to any one of claims 1 to 7, wherein
The inlet tank (10) is disposed at an upper end of the plurality of tubes (2), and a refrigerant discharged from each of the refrigerant holes (14) is provided on an outer peripheral surface of the inner pipe portion (12). An evaporator (1A, 1C), wherein an uneven surface (15) to be dropped from one side is formed.

Images