JP3633030B2 - Evaporator for air conditioner - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an air conditioner evaporator used in a refrigeration cycle, and more particularly to an air conditioner evaporator in which a plurality of refrigerant evaporating channels are connected in parallel.
[0002]
[Background Art and Problems to be Solved by the Invention]
A refrigeration cycle system used in an air conditioner for automobiles is composed of, for example, a compressor, a condenser, a liquid receiver (receiver), an expansion valve (decompression unit), an evaporator, and the like. Then, the refrigerant is circulated in the sealed circuit, heat is exchanged between the room air and the evaporator, and the room is cooled. The refrigerant adiabatically expanded through the expansion valve becomes a two-phase flow of gas and liquid, enters the evaporator, absorbs heat from the outside, evaporates (evaporates), continues the isothermal expansion, and cools the indoor air It becomes superheated steam and is sucked into the compressor.
[0003]
As this evaporator, as disclosed in, for example, Japanese Patent Laid-Open No. 2-50059, tubular members and fins that are formed by superposing two flat core plates to form a refrigerant evaporation flow path through which the refrigerant passes are alternately formed. There are several layers. However, since the refrigerant entering the evaporator is in a gas-liquid mixed state, the gas-liquid is easily separated. Therefore, even if the refrigerant is distributed to a plurality of pipes in the evaporator, the ratio of gas and liquid may be different for each pipe. A liquid refrigerant has a higher heat transfer rate and a higher cooling capacity than a gaseous refrigerant. Therefore, when the gas-liquid ratio is uneven, the heat exchange efficiency is lowered particularly on the downstream side of the evaporator, and the cooling of the indoor air may become uneven. In particular, in an air conditioner for automobiles, it is difficult to secure a space for stirring the blown air, so the influence is great.
[0004]
Further, as shown in FIGS. 14 to 16 of the above-mentioned Japanese Patent Application Laid-Open No. 2-50059, the conventional evaporator has two tank portions disposed above, and the tubular member has these two tank portions U. Although it arrange | positions in parallel so that it may communicate in a letter shape, the partition wall is provided in the middle of one tank part, and is divided | segmented into 2 chambers. Therefore, the flow of the refrigerant supplied from the inflow port first goes down only through the refrigerant evaporation channel communicating with one of the divided chambers connected to the inflow port, turns into a U-shape, and turns into the other tank portion. To. And it moves in the other tank part and reaches the refrigerant evaporating flow path side communicating only with the other divided chamber connected to the outflow port. Thereafter, the refrigerant evaporating flow path is moved downward, turned into a U shape, and reaches the other divided chamber. And it will be discharged | emitted from an outflow port.
[0005]
When such a refrigerant evaporation channel configuration (hereinafter also referred to as a three-turn system for convenience of explanation) is used, for example, even if there are ten tubular members, all ten refrigerant channels can be used. However, it was necessary to divide the inflow side and the outflow side into 5 pieces each, or 7 inflow sides and 3 outflow sides. On the other hand, the above-mentioned partition wall is removed, the inside of the tank is formed by only one chamber, the refrigerant flows in from one tank portion, and the refrigerant evaporates so as to flow out from the other tank portion that has made a single U-turn. With the flow path configuration, if there are 10 tubular members, 10 refrigerant evaporating flow paths can be secured (hereinafter, this method is called an all-pass method for convenience of explanation). A comparison of these two cases is shown below.
[0006]
(1)In the case of the 3-turn method, it is necessary to turn three times, and the refrigerant can be flowed into only a part of the tubular member, whereas the all-pass method allows the refrigerant to flow into all the refrigerant evaporation channels. In addition, since only one turn is required, the pressure loss can be lowered relatively, which is preferable in terms of performance improvement.
[0007]
(2)However, if the all-pass method is used, a large amount of liquid-phase refrigerant flows into the tubular member on the front side after the refrigerant flows into the tank, but a large amount of vapor-phase refrigerant flows into the tubular member on the back side. End up. For this reason, the temperature difference increases in the stacking direction, causing problems such as a reduction in heat exchange efficiency and uneven cooling of the room air.
[0008]
Regarding this point, the temperature difference in the stacking direction can still be reduced in the case of 3 turns. Therefore, if the temperature distribution in the stacking direction can be made closer to the uniform, it is advantageous to improve the performance by adopting the configuration in which the tubular member is made to flow in the refrigerant as the refrigerant evaporation channel as in the all-pass method. is there.
[0009]
Therefore, the present invention aims to solve the above-mentioned problems, and provides an evaporator for a cooling device that can make the temperature distribution uniform even while adopting an all-pass method and does not cause a decrease in cooling performance. There is.
[0010]
[Means for Solving the Problems]
In order to achieve this object, the present invention has the following configuration as means for solving the problems. That is, the invention according to claim 1 is an evaporator for a cooling device provided downstream of a pressure reducing valve in a refrigeration cycle for circulating a refrigerant, and an inflow side tank having an interior formed by only one chamber,The interior was formed with only one roomAn outflow side tank at the bottom, the inflow side tank andTheA refrigerant evaporating section configured such that a plurality of tubular members provided with refrigerant evaporating passages communicating with the outflow side tank in an inverted U shape are stacked with fins interposed therebetween, and the refrigerant evaporating passages are arranged in parallel. And a dryness adjusting means that is provided between the pressure reducing valve and the inflow side tank and adjusts the dryness of the refrigerant at the inflow side tank inlet to a range of 0.01 to 0.2.The heat formed so as to be capable of exchanging heat between the cooled flow path that connects the pressure reducing valve and the inflow side tank and the cooling flow path that is connected to the outflow side tank and guides the refrigerant to the outlet. One end is connected between the exchanging part, the pressure reducing valve and the heat exchanging part, the other end is connected to the downstream side of the heat exchanging part, and an open / close valve or a constant pressure valve is interposed. Effective bypass flow pathAndThe thickness in the stacking direction of the tubular member of the refrigerant evaporating part is in the range of 1.6 to 3.4 mm.This is an evaporator for a cooling device.
[0011]
And in the point of size reduction, it is preferable to make the thickness of the lamination direction of a tubular member into the range of 1.6-2.5 mm.
[0012]
[0013]
[Operation and effect of the invention]
According to the cooling device evaporator of the present invention, the refrigerant flowing out of the pressure reducing valve passes through the dryness adjusting means, and the dryness of the refrigerant at the inlet tank entrance is in the range of 0.01 to 0.2. The refrigerant is introduced into the inflow side tank of the refrigerant evaporation section in a state adjusted to. Then, the refrigerant reaches the outflow side tank through the refrigerant evaporation flow path that connects the inflow side tank and the outflow side tank in an inverted U shape.
[0014]
A plurality of the refrigerant evaporation channels are arranged in parallel, and the refrigerant is distributed from the inflow side tank to each refrigerant evaporation channel, and heat exchange is performed when passing through each refrigerant evaporation channel. In the case of the present invention, first, the refrigerant flows in with the dryness adjusted to a range of 0.01 to 0.2. When nothing is adjusted, the dryness is generally about 0.3 to 0.5, and at that dryness, the gas and liquid easily separate and flow in. On the other hand, adjusting the dryness to a range of 0.01 to 0.2 improves the distribution of the refrigerant, which is advantageous in terms of reducing the pressure loss.
[0015]
In addition, since the inflow side tank is disposed at the lowermost part of the refrigerant evaporation section, the refrigerant that has flowed into the inflow side tank, in particular the liquid phase refrigerant, enters the deep side of the inflow side tank and then moves up each refrigerant evaporation channel. Will go. As explained in the section of the prior art, when the tank is arranged on the upper side and the refrigerant descends the flow path, the liquid-phase refrigerant flows in an uneven manner on the near side and the air on the far side. Only the phase refrigerant flows in, and the temperature difference increases in the stacking direction.
[0016]
On the other hand, in the present invention, since the refrigerant evaporating channels are raised after the liquid phase refrigerant has penetrated all the way to the inflow side tank, the liquid phase refrigerant is less biased, and even in the all-pass system, The temperature distribution in the direction becomes nearly uniform. Therefore, the heat exchange efficiency is improved and the cooling of the room air is uniform.
[0017]
Furthermore, since the refrigerant evaporation channel of the present invention is the above-described all-pass system, the pressure loss can be relatively reduced, which is preferable in terms of performance improvement. Next, considering the thickness of the tubular member in the stacking direction, if the thickness in the stacking direction is reduced to narrow the refrigerant evaporation flow path, the refrigerant flow rate increases but the pressure loss also increases. For this reason, in the three-turn system, the optimum thickness considering the balance between the two is generally set to 3.5 mm.
[0018]
On the other hand, in the present invention, since it is an all-pass system, the pressure loss can be relatively reduced. Therefore, even if the thickness of the tubular member in the stacking direction is reduced, the same performance as that of the conventional three-turn type can be exhibited. As a result, the size of the refrigerant evaporation section itself can be reduced, which is preferable in terms of miniaturization. Therefore, the thickness in the stacking direction of the tubular member is preferably smaller than the conventional 3.5 mm and in the range of 1.6 to 3.4 mm. In terms of miniaturization, the thickness in the stacking direction of the tubular member is set to 1. More preferably, it is in the range of 6 to 2.5 mm.
[0019]
Further, the dryness adjusting means is formed to be capable of exchanging heat between a cooled flow path that communicates the pressure reducing valve and the inflow side tank and a cooling flow path that is connected to the outflow side tank and guides the refrigerant to the outlet. You may implement | achieve by a heat exchange part. In this case, in the heat exchange unit, heat exchange is performed between the cooling channel into which the refrigerant flows from the outflow tank of the refrigerant evaporation unit and the channel to be cooled, and the refrigerant in the channel to be cooled is cooled. Therefore, liquefaction of the refrigerant in the channel to be cooled is promoted, and the dryness of the refrigerant at the inlet side tank inlet is adjusted to a range of 0.01 to 0.2.
[0020]
[0021]
[0022]
[0023]
【Example】
Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram of a refrigeration cycle to which an evaporator according to a first embodiment of the present invention is applied. The compressor 1 compresses the gaseous refrigerant and sends it to the condenser 2, and the condenser 2 is connected to cool the refrigerant with external air and send it to the receiver 4 as a liquid refrigerant. When applied to a vehicle, the compressor 1 is rotationally driven by an internal combustion engine (not shown).
[0024]
The receiver 4 temporarily stores the refrigerant and removes dust and moisture in the refrigerant. Then, the refrigerant exiting the receiver 4 is sent to the expansion valve 6. The expansion valve 6 depressurizes the sent refrigerant. Further, as shown in FIG. 2, the expansion valve 6 has a configuration in which the opening degree can be adjusted by the movement of the valve body 7. In this embodiment, the expansion valve 6 functions as a pressure reducing valve. However, the pressure reducing valve is not limited to one whose opening degree can be adjusted, and can be implemented even with a fixed throttle valve.
[0025]
In the expansion valve 6, the valve body 7 is biased by the spring 10 in the valve closing direction by the biasing force Ps, and one end of the valve body 7 is engaged with the diaphragm 12. Furthermore, a temperature sensing cylinder 8 provided downstream of the evaporator 16 described later is provided, and when the refrigerant temperature on the downstream side of the evaporator 16 rises, the pressure Pf in the temperature sensing cylinder 8 rises, that is, the cooling load is increased. When the pressure Pf increases, the pressure Pf acts on one side of the diaphragm 12 via the capillary tube 14 to move the valve body 7 in the valve opening direction so that the opening degree is adjusted so as to increase the amount of the refrigerant. It is configured.
[0026]
The expansion valve 6 is provided with an outer equalizing pipe 17 for introducing the refrigerant pressure P0 on the downstream side of the evaporator 16 to the other side of the diaphragm 12. The refrigerant pressure and the refrigerant temperature on the downstream side of the evaporator 16 are compensated by a balance between the power Ps, the pressure P0 from the outer equalizing pipe 17, and the pressure Pf from the capillary tube 14 (Pf = Ps + P0). Yes.
[0027]
The refrigerant discharged from the expansion valve 6 is sent to the evaporator 16 and then connected to be sucked into the compressor 1 as a gaseous refrigerant. The evaporator 16 includes a refrigerant evaporation unit 18 and a heat exchange unit 20, and the refrigerant evaporation unit 18 includes an inflow channel 22 and an outflow channel 24 at the bottom as shown in FIG. . This lowest part means the lowest part in the direction of gravity. The two flow paths 22 and 24 are communicated with each other by a plurality of parallelly connected refrigerant evaporating flow paths 26, and heat exchange is performed between the refrigerant passing through the refrigerant evaporating flow paths 26 and the air supplied to the vehicle interior. Is configured to be performed. The configuration of the refrigerant evaporation unit 18 will be described in detail later.
[0028]
On the other hand, a cooled channel 28 that communicates the expansion valve 6 and the inflow channel 22 of the refrigerant evaporation section 18 is provided, and a first throttle 30 is formed downstream of the cooled channel 28. In addition, a cooling flow path 32 having one end connected to the outflow flow path 24 of the refrigerant evaporation unit 18 is provided, and the other end of the cooling flow path 32 is connected to the discharge flow path 36 via the outlet hole 34. . Heat exchange is made possible between the refrigerant in the cooled channel 28 and the cooling channel 32 on the upstream side of the first throttle 30, thereby forming the heat exchange unit 20.
[0029]
The temperature sensing cylinder 8 and the outer equalizing pipe 17 (see FIG. 2) are attached to the discharge flow path 36, and the discharge flow path 36 leads the refrigerant discharged from the outlet hole 34 to the compressor 1. It is connected. Furthermore, one end of a bypass flow path 38 is connected to the cooled flow path 28 between the expansion valve 6 and the heat exchanging unit 20 and branches, and the other end of the bypass flow path 38 is connected to the first throttle 30. It is connected and merged with the channel 28 to be cooled further downstream. In addition, an opening / closing valve 40 is interposed in the bypass flow path 38.
[0030]
Next, the specific configuration of the heat exchanging unit 20 of the evaporator 16 described above will be described with reference to FIGS. 4 to 9, and the specific configuration of the refrigerant evaporation unit 18 will be described with reference to FIGS. 4 and 10 to 12. Will be described in detail. First, the heat exchange unit 20 will be described. As shown in FIG. 4, a plurality of sets of first and second plates 50 and 52 are stacked between the first and second side plates 46 and 48, and one set of both plates 50 and 52 is symmetrical. I am doing.
[0031]
The first and second plates 50 and 52 are formed with a large number of corrugated irregularities, and by laminating, the inner side of the first plate 50 and the inner side of the second plate 52 are formed as shown in FIG. Many first flow paths 54 are formed therebetween. Similarly, a large number of second flow paths 56 are formed between the outside of the second plate 52 and the outside of the first plate 50.
[0032]
As shown in FIGS. 5 and 7, an inlet hole 57 and an inflow hole 58 are formed above the first side plate 46 and a part of the first plate 50. The inflow hole 58 is configured to communicate with the first flow path 54, and the first flow path 54 is connected to a first communication hole 60 formed below the first and second plates 50 and 52. It is connected.
[0033]
In addition, in the first plate 50, one first plate 50 a provided on the second side plate 48 side is provided with a first diaphragm 30 formed by an orifice instead of the first communication hole 60. It has been. The first throttle 30 is connected to the inflow channel 22 of the refrigerant evaporation unit 18 via the first communication hole 60 of the second plate 52 and the first connection hole 62 formed in the second side plate 48. . The inflow hole 58, the first flow path 54, the first communication hole 60, and the first connection hole 62 form the cooled flow path 28 shown in FIG.
[0034]
Further, as shown in FIG. 9, second connection holes 63 and 64 communicating with the outflow passage 24 of the refrigerant evaporation unit 18 are formed below the first and second plates 50 and 52 and the second side plate 48. The second connection holes 63 and 64 are configured to communicate with the second flow path 56. As shown in FIG. 7, the second flow path 56 is connected to the outflow hole 66 and the outlet hole 34 formed above the first and second plates 50 and 52 and the first side plate 46.
[0035]
A cooling flow path 32 is formed by the second connection holes 63 and 64, the second flow path 56, and the outflow hole 66. And the heat exchange part 20 made heat-exchangeable between the refrigerant | coolants which pass the to-be-cooled flow path 28 and the cooling flow path 32 via the 1st, 2nd plates 50 and 52 is formed.
[0036]
On the other hand, as shown in FIG. 7, the one first plate 50 a is provided with an on-off valve 40 instead of the inflow hole 58, and the on-off valve 40 is provided via the inflow hole 58 of the second plate 52. The third flow path 68 is formed between the second plate 52 and the second side plate 48.
[0037]
As shown in FIG. 9, the third flow path 68 communicates with the first connection hole 62 of the second side plate 48 and is connected to the cooled flow path 28. The inflow hole 58, the third flow path A bypass channel 38 is formed by 68. This channel is effective when the load is low, particularly in the winter mode, and may be omitted when considering only the normal time used in summer.
[0038]
Next, the refrigerant evaporation unit 18 will be described. The refrigerant evaporating unit 18 is formed by laminating corrugated fins 44 (hereinafter simply referred to as fins 44) for efficiently cooling indoor air and a plate 42 shown in FIG. A cross section in a stacked state is shown in FIG. 11 (cross sectional view taken along line EE in FIG. 10) and FIG. 12 (cross sectional view taken along line FF in FIG. 11). FIG. 11 shows only a part of the side opposite to the side connected to the heat exchange unit 20.
[0039]
As shown in FIG. 10, the plate 42 has a substantially rectangular plate shape, and a substantially cylindrical inlet tank 73 and outlet tank 74 are formed at the lowermost part thereof. The inlet tank 73 is provided at a position aligned with the first connection hole 62 of the heat exchange unit 20 described above, and a circular hole 75 is formed in the center thereof, so that the refrigerant sent from the heat exchange unit 20 is introduced. It becomes a part to be done. The outlet tank 74 is provided at a position aligned with the second connection holes 63 and 64 of the heat exchanging unit 20, and a horizontally long circular hole 76 is formed in the center thereof, and the second connection hole 63 of the heat exchanging unit 20. , 64 is a part for sending out the refrigerant.
[0040]
The center of the plate 42 is recessed with respect to the outer periphery so that a refrigerant flow path is formed between the plates 42 when stacked. The central concave surface 77, which is the central portion, is formed with a plurality of cross ribs 78 for promoting heat transfer of the refrigerant and a central partition wall 79 that guides the refrigerant downward and further redirects it to the outlet tank 74. ing. As shown in FIG. 10, the central partition wall 79 is formed in an oblique direction in accordance with expansion due to evaporation of the refrigerant in order to make the pressure loss uniform.
[0041]
A narrow groove 79a is formed between the inlet tank 73 and the central concave portion 77 to connect the two. For this reason, the refrigerant in the inlet tank 73 flows through the groove 79 a and flows into the central concave portion 77. The refrigerant evaporating unit 18 includes the plate 42 described above between the end plate 71 (see FIGS. 4, 11, and 12) serving as an end surface and the second side plate 48 of the heat exchange unit 20 as illustrated in FIGS. 11 and 12. The flow path of the refrigerant is formed so as to face each other, and corrugated fins 44 are attached between the back surfaces of the respective plates 42 to be formed by brazing. At this time, the groove | channel 79a formed in each plate 42 opposes, and the aperture | diaphragm | squeeze part 80 which narrows the flow path area of a refrigerant | coolant is formed. Each fin 44 is formed with a plurality of thin grooves 82 for promoting heat exchange between the refrigerant and room air. In addition, the shape of the plate 42 brazed facing each other is opposite to the left and right, that is, the shape of the other plate 42 with respect to one plate 42 is reflected in a mirror. However, the cross ribs 78 facing each other are formed in a direction crossing each other.
[0042]
The flow of the refrigerant in the plate 42 when the plates 42 are stacked in this way is indicated by arrows e, f, and g in FIG. The refrigerant sent from the heat exchanging unit 20 to the respective inlet tanks 73 (hereinafter, the refrigerant reservoir formed by overlapping the inlet tanks 73 is referred to as the inflow side tank 70) is distributed to the respective throttle units 80. Passes through and flows upward between the central concave portions 77 (arrow e), further changes direction at the uppermost portion and faces downward (arrow f), and the outlet tanks 74 (hereinafter, the outlet tanks 74 are overlapped). The formed refrigerant reservoir flows into the outflow side tank 90 (arrow g), joins, and is sent to the upper outlet refrigerant tank 41 of the heat exchange unit 20.
[0043]
With the above configuration, the refrigerant evaporating unit 18 has the inflow side tank 70 and the outflow side tank 90 at the lowermost part, and the refrigerant evaporative flow that communicates both tanks 70 and 90 in an inverted U shape by the pair of plates 42. The tubular member of the present invention that becomes a path is formed. Then, a plurality of the refrigerant evaporation channels 26 are arranged in parallel by stacking a plurality of the fins 44 therebetween.
[0044]
At this time, between the central concave surface portions 77 of the plate 42, the refrigerant is dispersed by the intersecting cross ribs 78 and spreads widely throughout. In FIG. 12, reference numeral 83 denotes an upward refrigerant flow path, and reference numeral 84 denotes a downward refrigerant flow path (the flow paths 83 and 84, that is, the refrigerant flow path between the central concave portions 77 is the above figure). 3 is a refrigerant evaporation passage 26 in FIG. When the refrigerant flows through the refrigerant evaporation channel 26, the refrigerant exchanges heat with room air via the fins 44, and continues isothermal expansion while part of the refrigerant evaporates.
[0045]
Next, the operation of the cooling device evaporator of the first embodiment will be described together with the operation of the refrigeration cycle. FIG. 13 is a Mollier diagram showing the state of the refrigerant on the refrigeration cycle. The high-pressure refrigerant compressed by driving the compressor 1 (part m in the figure) dissipates heat in the condenser 2 (part n in the figure), and changes phase from a gaseous refrigerant to a liquid refrigerant. In the normal refrigeration cycle, the expansion valve 6 expands the line o up to the point W, so that the refrigerant is in a gas-liquid two-phase state of gas and liquid at the inlet of the evaporator 16. Thus, the refrigerant is not evenly distributed. Therefore, in the evaporator 16 of the present embodiment, an inlet refrigerant that passes through the cooling channel 28 and an outlet refrigerant that passes through the cooling channel 32 in the heat exchanging unit 20 (described later, from the inlet refrigerant by the throttle unit 80). The refrigerant at the inlet is cooled by exchanging heat to the point X along the line p and shifted in the liquid phase direction.
[0046]
For this reason, the expansion of the expansion valve 6 simply reduces the refrigerant to a dryness x = 0.3 to 0.5, but according to the first embodiment, the refrigerant has a dryness x = 0.01 to 0.00. 2 and is evenly distributed from the inflow side tank 70 of the refrigerant evaporating unit 18 to the refrigerant evaporating flow path 26 between the plates 42. At this time, the refrigerant is depressurized to the point Y along the line q by the throttle 80 serving as the inlet of the refrigerant evaporating flow path 26, and becomes a gas-liquid two-phase state with a further lower temperature. Heat exchange with air begins to evaporate (part r in the figure). A part of the refrigerant is evaporated (point Z1), that is, when the dryness x is less than 1, the refrigerant merges in the outflow side tank 90 of the refrigerant evaporation unit 18 and is sent to the heat exchange unit 20. This refrigerant (exit refrigerant) is exchanged with the inlet refrigerant by passing through the cooling flow path 32 formed in the heat exchange unit 20. For this reason, the dryness x of the refrigerant in the cooling channel 32 becomes 1 or more (point Z2), the refrigerant becomes superheated steam (parts s1 and s2 in the figure), and is sent to the compressor 1 through the temperature sensing cylinder 8. It is done.
[0047]
That is, the refrigerant in the gas-liquid two-phase state (inlet refrigerant) sent from the expansion valve 6 is cooled by exchanging heat with the low-temperature refrigerant (outlet refrigerant) flowing in the cooling channel 32 when flowing in the cooling target channel 28. As a result, the liquid phase is further shifted to the inflow passage 22 of the refrigerant evaporation section 18. In FIG. 1, the liquid state portion of the refrigerant is hatched. And while flowing uniformly into each refrigerant | coolant evaporation flow path 26, it is pressure-reduced by the expansion | squeezing part 80, heat-exchanges with room air, and expands isothermally, a part vaporizing. The refrigerant is sent to the outflow passage 24 of the refrigerant evaporation section 18 and merges in the gas-liquid two-phase state, and flows through the cooling passage 32 of the heat exchange section 20. At this time, the refrigerant (outlet refrigerant) is heated by exchanging heat with the inlet refrigerant flowing through the channel to be cooled 28, and becomes all superheated steam having a dryness of 1 or more. That is, heat is exchanged between the refrigerant on the line p in FIG. 13 and the refrigerant on the lines s1 and s2.
[0048]
According to the cooling device evaporator 16 of the first embodiment, the refrigerant that has flowed out of the pressure reducing valve 6 passes through the heat exchanging unit 20 as the dryness adjusting means, whereby the refrigerant at the inlet of the inflow side tank 70 is obtained. It is introduced into the inflow side tank 70 of the refrigerant evaporation section in a state where the dryness is adjusted to a range of 0.01 to 0.2. The inflow side tank 70 and the outflow side tank 90 reach the outflow side tank 90 through a refrigerant evaporation channel that communicates in an inverted U shape.
[0049]
A plurality of the refrigerant evaporation channels are arranged in parallel, and the refrigerant is distributed from the inflow side tank 70 to each refrigerant evaporation channel 26, and heat exchange is performed when passing through each refrigerant evaporation channel 26. In the case of the present invention, first, the refrigerant flows in with the dryness adjusted to a range of 0.01 to 0.2. When nothing is adjusted, the dryness is generally about 0.3 to 0.5, and at that dryness, the gas and liquid easily separate and flow in. On the other hand, adjusting the dryness to a range of 0.01 to 0.2 improves the distribution of the refrigerant, which is advantageous in terms of reducing the pressure loss.
[0050]
In addition, since the inflow side tank 70 is arranged at the lowermost part (when viewed in the direction of gravity) of the refrigerant evaporation section 18, the refrigerant that has flowed into the inflow side tank 70, particularly the liquid phase refrigerant, is located at the back of the inflow side tank 70. Each refrigerant evaporating flow path 26 is lifted after entering. As explained in the section of the prior art, when the tank is arranged on the upper side and the refrigerant descends the flow path, the liquid-phase refrigerant flows in an uneven manner on the near side and the air on the far side. Only the phase refrigerant flows in, and the temperature difference increases in the stacking direction.
[0051]
On the other hand, in the first embodiment, the liquid-phase refrigerant moves up each refrigerant evaporating channel after intrusion to the depth of the inflow side tank 70, so that the liquid-phase refrigerant is less biased and the all-pass method is used. Even in this case, the temperature distribution in the stacking direction becomes nearly uniform. As an experimental result regarding this point, a distribution state of the refrigerant flowing into the inflow side tank 70 in a state where the dryness x is set to 0.1, etc., to the respective refrigerant evaporation channels 26, and the like are shown.
[0052]
FIG. 14 shows, as a comparative example, an individual flow rate Global for each refrigerant evaporation channel when the inflow side tank 70 of the first embodiment is arranged on the upper side of the refrigerant evaporation unit 18 and the refrigerant is supplied as a downward flow. This shows the temperature change ΔTa. (A) shows the case of high flow rate (150 kg / h), and (B) shows the case of low flow rate (50 kg / h).
[0053]
As can be seen from the experimental results, the liquid-phase refrigerant is biased in the vicinity of the inlet into which the refrigerant has flowed, that is, the front side, and only the gas-phase refrigerant flows in the back side. In addition, the flow rate itself is considerably larger on the near side. Therefore, there is almost no temperature difference on the front side where there are many liquid-phase refrigerants, but a large temperature difference occurs from the middle to the back. In particular, in the case of the low flow rate shown in (B), the liquid-phase refrigerant flows only into the two or three refrigerant evaporation channels on the front side, and the remainder becomes almost a gas-phase refrigerant. In this way, the temperature difference in the stacking direction becomes large.
[0054]
On the other hand, FIG. 15 shows the individual flow rate Global for each refrigerant evaporation channel 26 and the temperature change Δ when the inflow side tank 70 is arranged at the lowest position and the refrigerant is supplied as an upward flow as in the first embodiment. Ta is shown. Similarly to FIG. 14, (A) shows the case of a high flow rate (150 kg / h), and (B) shows the case of a low flow rate (50 kg / h).
[0055]
In this case, since the inflow side tank 70 is disposed at the lowermost part of the refrigerant evaporating unit 18, the refrigerant that has flowed into the inflow side tank 70, particularly the liquid phase refrigerant, penetrates to the depth of the inflow side tank 70 and then enters each refrigerant evaporative flow. The road 26 will rise. For this reason, the refrigerant evaporating flow path on the back side is somewhat opposite to the case where the refrigerant descends the flow path as in the comparative example in which the inflow side tank 70 is arranged on the upper side. Although a large amount of liquid refrigerant flows into the liquid, the liquid refrigerant flows into the near side. In particular, in the case of the low flow rate shown in (B), the amount of inflow of the liquid phase refrigerant into each refrigerant evaporation channel 26 is almost the same, the liquid phase refrigerant is less biased, and the temperature distribution in the stacking direction is It turns out that it becomes almost uniform. Therefore, the heat exchange efficiency is improved and the cooling of the room air is uniform.
[0056]
Furthermore, since the refrigerant evaporating unit 18 of the present embodiment has the above-described “all-pass type” refrigerant evaporating flow path 26, the pressure loss can be relatively reduced, which is preferable in terms of performance improvement. Next, the thickness of the tubular member in the stacking direction will be considered. As described above, the pair of plates 42 forms the tubular member of the present invention that forms the refrigerant evaporation channel 26 that communicates both tanks 70 and 90 in an inverted U shape. If the thickness is reduced and the refrigerant evaporation channel 26 is narrowed, the refrigerant flow rate increases but the pressure loss also increases. Therefore, in the above three-turn system, the optimum thickness considering the balance between the two is generally set to a lower limit of 3.5 mm.
[0057]
On the other hand, since this refrigerant | coolant evaporation part 18 is an all-pass system, it can reduce pressure loss relatively. Therefore, even if the thickness of the tubular member in the stacking direction is reduced, the same performance as that of the conventional three-turn type can be exhibited. The experimental results supporting this are shown in FIG.
[0058]
In FIG. 16A, the change in ventilation resistance ΔP when the thickness Tt in the stacking direction of the tubular member constituted by the pair of plates 42 is changed in the configuration of the first embodiment is triangular. The change in unit performance Q / front area F is indicated by a circle (◯). The front wind speed is 2 m / s. FIG. 16B shows the ventilation resistance ΔP arranged in an equivalent manner. In FIG. 16B, a numerical value in the case of Tt = 3.5 mm in a conventional so-called three-turn system is entered for comparison.
[0059]
As can be seen from this graph, by adopting the configuration of the first embodiment, the single unit performance Q / front surface area F can be improved by making the stacking direction thickness Tt smaller than 3.5 mm. Therefore, the thickness Tt in the stacking direction of the tubular member is preferably smaller than the conventional 3.5 mm and in the range of 1.6 to 3.4 mm. In terms of downsizing, it is more preferable that Tt be in the range of 1.6 to 2.5 mm. By making it thin in this way, the size of the refrigerant evaporation section 18 itself can be reduced as a result while exhibiting equivalent performance, and the whole can be made compact.
[0060]
[0061]
[0062]
[0063]
[0064]
[0065]
[0066]
[0067]
[0068]
[0069]
[0070]
Next, still another embodiment will be described. In the first embodiment, the first throttle 30 (see FIGS. 1, 3, 6, 9 and the like) is used as a decompression means, and the refrigerant in the channel to be cooled 28 is decompressed.FIG.As illustrated in the schematic configuration diagram of the refrigeration cycle, it is possible to employ decompression means having another configuration without providing the first throttle 30 in FIG. For example,Second and third embodimentsShown in
[0071]
FIG.IsSecond embodimentIt is a disassembled perspective view showing the structure of the evaporator 316 of.FIG.As shown in FIG. 5, the plurality of core plates 342 and 343 forming the refrigerant evaporation flow path are alternately stacked with the fins 344 interposed therebetween to form the evaporation unit 318. A plurality of first to fourth plates 350 a, 352 a, 350 b, and 352 b are sequentially stacked between the side plate 346 and the center plate 348.
[0072]
The first to fourth plates 350a, 352a, 350b, 352b have the same basic configuration except that they are partially different in shape.FIG.Each plate 350a, 352a, 350b, 352b will be described after the description with reference to FIG.FIG.The plate is formed with a large number of corrugated irregularities that form the cooled flow path 28 and the cooling flow path 32, and further above the refrigerant flow path that connects the inlet hole 327 and each cooled flow path 328. Are formed, an upper inflow hole 354 that communicates with the constant pressure valve 340, a bypass hole 358 that forms a refrigerant flow path reaching the fifth plate 556, and an upper outflow hole 560 that communicates the outlet hole 534 with each cooling flow path 532. Has been. Further, at the lower part of the plate, a lower inflow hole 362 that communicates each cooled channel 328 and the fifth plate 356, a pair of through holes 364 and 366 that communicate the fifth plate 356 and the inflow channel 322, In addition, a lower outflow hole 368 that connects the outflow channel 324 and each cooling channel 332 is formed. The first plate 350a isFIG.In the plate having the structure shown in FIG. 4, the upper inflow hole 354 is closed. The second plate 352a is symmetrical with the first plate 350a. Meanwhile, the third plate 350b isFIG.In the plate having the configuration shown in FIG. 4, the lower inflow hole 362 is closed, and the fourth plate 352b is symmetrical with the second plate 352a.
[0073]
A block joint 341 is attached to the side plate 346, and a constant pressure valve 340, an inlet hole 327, and an outlet hole 334 provided at the inlet of the bypass flow path are provided in the block joint 341. The constant pressure valve 340, the inlet hole 327, and the outlet hole 334 are each attached with an expansion valve unit 306 having a communication path corresponding to its position.
[0074]
A conceptual diagram of this expansion valve unit 306FIG.Shown in In addition, the arrow in a figure shows the flow of a refrigerant | coolant. Receiver 4 (FIG.The refrigerant flowing in from the reference) passes through the expansion valve 6FIG.Flows out into the inlet hole 327. Also,FIG.The refrigerant from the outlet hole 334 flows out to the compressor 1. Here, after the refrigerant flowing in from the receiver 4 passes through the expansion valve 6, it flows out to the inlet hole 327 through the flow path 307, but the flow path 308 branched from the middle of the flow path 307. It flows into the constant pressure valve 340. Therefore, the bypass flow path 38 branched from the downstream of the expansion valve 6 is formed, and the constant pressure valve 340 is arranged at the inlet of the bypass flow path.
[0075]
FIG.The fifth plate 356 returns to the bypass channel 38 (FIG.A concave portion 396 that forms a reference) and a reinforcing rib 398 that reinforces the concave portion 396 are formed. Furthermore, at the lower part of the fifth plate 356, a through hole 402 that connects the through hole 66 of the first to fourth plates 350a to 352b and the inflow channel of the evaporation unit 18, and the first to fourth plates 350a to 350a. A through-hole 404 that connects the lower outflow hole 368 of 352b and the outflow channel of the evaporation section 318 is formed.
[0076]
The heat exchanger 320 of the evaporator 316 configured in this way has every other cooled channel 328 (between the first to fourth plates 350a to 352b.FIG.Then, the arrangement and direction are schematically indicated by arrows). The cooled channel 328 is formed downward as a whole between the first plate 350a and the side plate 346 and between the fourth plate 352b and the first plate 350a, and the second plate 352a The third plate 350b is formed upward as a whole. In addition, the channel to be cooled 328 is a single continuous channel as a whole. For this reason, the flow resistance applied to the refrigerant when flowing through the cooled channel 328 is relatively extremely large. Therefore, due to this flow resistance, the pressure of the refrigerant is point Y (in the Mollier diagram of FIG. 13 in the case of the first embodiment.FIG.It drops to the point d1) where it can be placed. Ie bookSecond embodimentThen, the to-be-cooled flow path 328 also has the function of a decompression means.
[0077]
Like thisSecond embodimentIn the refrigeration cycle to which the evaporator 316 is applied, the evaporator 316 does not have the first throttle 30 (see FIG. 1) in the first embodiment as the pressure reducing means, and the refrigerant passes through the cooling channel 328. At that time, the pressure is reduced. Therefore, the Mollier diagram of the refrigeration cycle isFIG.It comes to illustrate. That is, when passing through the channel 328 to be cooled, the refrigerant is simultaneously cooled and depressurized (b point-d1 point). For this reason, in the present embodiment, substantially the same function as that of the first embodiment can be achieved without the first diaphragm 30 (see FIG. 1 and the like).
[0078]
However, when a throttle provided between the channel to be cooled and the inflow channel of the evaporation unit is applied as the pressure reducing means as in the first throttle 30 of the first embodiment, the heat exchange efficiency in the heat exchange unit Can be made compact, and a heat exchanger evaporator with high heat exchange performance can be obtained.Second embodimentWhen the channel to be cooled itself has a function as a pressure reducing means like the channel to be cooled 328, unique actions and effects such as reducing the number of parts and reducing the manufacturing cost occur. .
[0079]
In addition, the above-described cooling flow path from the upper inflow hole 54 to the lower inflow hole 62 may be lengthened.Second embodimentIn the same way, the function of pressure reducing means can be given to the channel to be cooled.Third embodimentWill be described.FIG.IsThird embodimentIt is a disassembled perspective view showing the structure of the evaporator 516 of. In this example,Second embodimentIn the part configured in the same way,Second embodimentThe detailed description of the configuration is omitted by using the same reference numerals as those used in FIG. Further, the inflow channel 22, the outflow channel 24, the refrigerant evaporation channel 26, the cooling channel 32, and the bypass channel 38 described in the first embodiment are also shown in the drawing. further,Second embodimentThe expansion valve unit 306 in FIG.FIG.Is omitted.
[0080]
FIG.As shown in the bookThird embodimentThen, a plurality of sets of first and second plates 550 and 552 are stacked between the side plate 346 and the center plate 348. And the side plate 346 isSecond embodimentAre stacked on the evaporator 18 via the fifth plate 356 similar to the above. Here, in this embodiment, the number of folded portions 556 of the channel to be cooled 528 formed on the surfaces of the first and second plates 550 and 552 is increased. For this reason, the to-be-cooled flow path 528 between the same 1st, 2nd plates 550 and 552 from the upper inflow hole 354 to the lower inflow hole 362 becomes long. Therefore, the flow resistance to the refrigerant as the entire cooled channel 528 increases,Second embodimentSimilarly to the above, a function as a decompression unit can be imparted to the cooled channel 528. In addition, the Mollier diagram of the refrigeration cycle to which this embodiment is applied,FIG.It becomes almost the same.
[0081]
The present invention is not limited to such embodiments as described above, and can be implemented in various modes without departing from the gist of the present invention.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a refrigeration cycle to which an evaporator for a cooling device as a first embodiment of the present invention is applied.
FIG. 2 is a schematic configuration diagram of an expansion valve according to the present embodiment.
FIG. 3 is a perspective view showing a schematic configuration of an evaporator according to the present embodiment.
FIG. 4 is a side view of the evaporator according to the present embodiment.
FIG. 5 is an enlarged cross-sectional view taken along line AA in FIG.
FIG. 6 is an enlarged front view of a second plate of the present embodiment.
7 is an enlarged cross-sectional view taken along line BB in FIG.
8 is an enlarged cross-sectional view taken along the line CC of FIG.
FIG. 9 is an enlarged cross-sectional view taken along line DD of FIG.
FIG. 10 is a plan view of an evaporator plate according to the present embodiment.
11 is a cross-sectional view taken along line EE of FIG. 10 of the refrigerant evaporation portion of the evaporator.
12 is a cross-sectional view taken along line FF in FIG.
FIG. 13 is a Mollier diagram showing the state of the refrigerant in the embodiment.
FIG. 14 is a graph showing the individual flow rate and temperature change for each refrigerant evaporation flow path when the tank is arranged on the upper side and the refrigerant is supplied as a downward flow.
FIG. 15 is a graph showing the individual flow rate and temperature change for each refrigerant evaporation channel in the case of the present embodiment in which the tank is arranged below and the refrigerant is supplied as a downward flow.
FIG. 16A is a graph showing changes in ventilation resistance and unit performance / front area when the thickness in the stacking direction of the tubular member in the configuration of this example is changed, and FIG. A) It is the graph which arranged ventilation resistance equally arranged.
[FIG.]Second embodimentIt is a schematic block diagram of the refrigerating cycle to which the evaporator for air conditioners is applied.
[FIG.]Second embodimentIt is a disassembled perspective view showing the structure of the evaporator for air conditioners.
[FIG.]Second embodimentIt is a front view for showing the structure of the 1st-4th plate of the evaporator for air conditioners.
[FIG.]Second embodimentIt is a conceptual diagram of an expansion valve unit.
[FIG.]Second embodimentIt is a graph showing the Mollier diagram in.
[FIG.]Third embodimentIt is a disassembled perspective view showing the structure of the evaporator for air conditioners.
[Explanation of symbols]
1 Compressor
2 Condenser
4 Receiver
6 Expansion valve
8 Temperature sensing tube
16 Evaporator
18 Refrigerant evaporation section
20 Heat exchange section
22 Inflow channel
24 Outflow channel
26 Refrigerant evaporation channel
28 Channel to be cooled
32 Cooling channel
36 Discharge flow path
38 Bypass channel
40 On-off valve
41 Upper outlet refrigerant tank
42 plates
44 Corrugated Fin
44 Fin
50 1st plate
52 2nd plate
70 Inflow side tank
73 Inlet tank
74 Outlet tank
77 Center concave part
78 Cross rib
79 Central bulkhead
80 Aperture
90 Outflow side tank
103 Gas-liquid separation chamber
103a, 103b plate
109 dimples
110 ribs
115 Entrance room
116 Exit side room

Claims (2)

In the evaporator for the cooling device provided downstream of the pressure reducing valve in the refrigeration cycle for circulating the refrigerant,
Internal has an outflow-side tank inflow-side tank and an internal formed only formed in only one room 1 room at the bottom, for communicating the flow-in side tank and said outlet-side tank inverted U-shaped A plurality of tubular members provided with refrigerant evaporating flow paths are stacked with fins sandwiched therebetween, and an all-pass refrigerant evaporating unit configured to arrange the refrigerant evaporating flow paths in parallel;
A dryness adjusting means which is provided between the pressure reducing valve and the inflow side tank and adjusts the dryness of the refrigerant at the inflow side tank inlet in a range of 0.01 to 0.2; A heat exchange section formed to be capable of exchanging heat between a cooled flow path communicating with the valve and the inflow side tank, and a cooling flow path connected to the outflow side tank and guiding the refrigerant to the outlet;
One end connected between the pressure reducing valve and the heat exchanging part, the other end connected downstream of the heat exchanging part, and an effective bypass flow at the time of low load in which an on-off valve or a constant pressure valve is interposed With roads ,
A cooling device evaporator, wherein the thickness of the refrigerant evaporating part in the stacking direction of the tubular members is in the range of 1.6 to 3.4 mm . The evaporator for a cooling device according to claim 1, wherein a thickness of the tubular member in a stacking direction is in a range of 1.6 to 2.5 mm.

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