Plate type heat exchanger and refrigeration cycle device

Abstract

To properly divide flow according to various conditions.SOLUTION: A plate type heat exchanger comprises: a heat exchanger body having a first flow passage and a second flow passage which are formed by laminating a plurality of plates and arranged alternately along a laminating direction of the plurality of plates; and a dividing pipe unit formed in the shape of a pipe. A first fluid is circulated between the plates adjacent to each other in the first flow passage, and a second fluid is circulated between the plates adjacent to each other in the second flow passage. The dividing pipe unit comprises: a first refrigerant inflow port through which the first fluid flows in; a second refrigerant inflow port through which the first fluid flows in; a first dividing part that divides the first fluid; a first refrigerant flow passage in which a refrigerant flowing in from the first refrigerant inflow port flows out to outside of the dividing pipe unit by passing through the first dividing part and dividing the refrigerant; and a second refrigerant flow passage in which the refrigerant flowing in from the second refrigerant inflow port flows out to the outside of the dividing pipe unit without passing through the first dividing part. The first fluid flows in either of the first flow passage and the second flow passage, or both of the first flow passage and the second flow passage.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The embodiments relate to a plate heat exchanger and a refrigeration cycle apparatus. [Background technology]

[0002] Conventionally, when a plate heat exchanger is used as an evaporator, the fluid is a two-layer refrigerant, so that a technique for flowing the fluid, for example, the refrigerant evenly between the plates, that is, a so-called flow splitting technique, has been researched for many years. For example, a technique in which a plurality of openings (flow splitting holes) are provided in the axial direction of a pipe shape is known as such a flow splitting technique. In addition, for example, a technique in which a shielding plate is provided in the flow path and the flow splitting is controlled by the shielding plate is known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5946991 [Patent Document 2] Patent No. 5665983 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above technology, the diameter of the flow dividing hole is fixed, and the dimensions of the shielding plate are fixed. Because they are fixed, there is a problem that when an optimal shape is selected under certain conditions, the optimal shape may not be obtained under other conditions.

[0005] An object of the embodiments is to provide a plate heat exchanger and a refrigeration cycle apparatus that can perform appropriate flow division depending on conditions. [Means for solving the problem]

[0006] According to one embodiment, the plate heat exchanger includes a first heat exchanger formed by stacking a plurality of plates and arranged alternately along a stacking direction of the plurality of plates.fluid Channel and second fluid The first fluid The flow path allows a first fluid to flow between adjacent plates, and the second fluid The flow path is The first fluid flow path is disposed between the plates different from the plate between which the first fluid flow path is disposed. A heat exchanger body for passing a second fluid between adjacent plates, and a tubular heat exchanger and arranged only on the inlet side of the first fluid flow path through which the first fluid flows into the heat exchanger body when the heat exchanger body functions as an evaporator. The distribution pipe unit includes a first inlet into which the first fluid flows, a second inlet into which the first fluid flows, a first branching section that branches the first fluid, and a distribution pipe unit configured to divide the first fluid that flows in from the first inlet. The above A first fluid passes through the first branch portion. Let me Diversion and circulating the first fluid through the first fluid flow path. The first flow path and the second inlet The above The first fluid is not passed through the first dividing portion. Distributing the first fluid through the first fluid flow path and a second flow path. The first fluid flows through one of the first flow path and the second flow path, or through both the first flow path and the second flow path. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram showing an example of a schematic configuration of a refrigeration cycle device according to an embodiment. [Diagram 2] FIG. 2 is a perspective view showing an example of a plate heat exchanger according to the embodiment. [Diagram 3] FIG. 2 is an exploded perspective view showing an example of a plate heat exchanger according to the embodiment. [Figure 4] 3 is a side cross-sectional view showing an example of a plate heat exchanger taken along line AA in FIG. 2. [Diagram 5] FIG. 4 is a side cross-sectional view showing an example of a distribution pipe unit according to the embodiment. [Figure 6] FIG. 4 is a diagram showing an example of an evaporation temperature comparison according to the embodiment. [Figure 7] FIG. 4 is a diagram showing an example of a comparison of pressure losses in a dividing portion according to the embodiment. [Figure 8] 4 is a flowchart showing an example of opening and closing control of an on-off valve according to the embodiment. [Figure 9] FIG. 6 is a diagram showing an example of the configuration of a refrigeration cycle device according to a second embodiment. [Figure 10] FIG. 11 is a side cross-sectional view showing an example of a distribution pipe unit according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, the embodiments will be described with reference to the drawings. Note that the disclosure is merely an example, and the invention is not limited to the contents described in the following embodiments. Modifications that a person skilled in the art can easily conceive are naturally included in the scope of the disclosure. In order to make the explanation clearer, the size, shape, etc. of each part may be changed from the actual embodiment and shown diagrammatically. In multiple drawings, corresponding elements may be given the same reference numerals, and detailed explanations may be omitted.

[0009] In this specification, the X-direction, Y-direction, and Z-direction of the Cartesian coordinate system are defined as follows (see FIG. 2). The X-direction is the stacking direction of the multiple plates 14 in the plate heat exchanger 10. The +X-direction is the inflow direction of the refrigerant to the first refrigerant inlet / outlet 11 or the second refrigerant inlet / outlet 12 of the plate heat exchanger 10. The Z-direction is the direction in which the first refrigerant inlet / outlet 11 and the second refrigerant inlet / outlet 12 of the plate heat exchanger 10 are aligned. The +Z-direction is the direction from the first refrigerant inlet / outlet 11 to the second refrigerant inlet / outlet 12. For example, the Z-direction is the vertical direction, and the +Z-direction is the upward direction. The Y-direction is a direction perpendicular to the X-direction and the Z-direction. The Y-direction is the direction in which the first refrigerant inlet / outlet 11 and the second water inlet / outlet 92 of the plate heat exchanger 10 are aligned. The +Y-direction is the direction from the first refrigerant inlet / outlet 11 to the second water inlet / outlet 92.

[0010] (First embodiment) FIG. 1 is a diagram showing an example of a schematic configuration of a refrigeration cycle device according to the present embodiment. The refrigeration cycle device 1 includes a compressor 2, a four-way valve 3, a first heat exchanger 4, an expansion device 5, a second heat exchanger 6, and a refrigerant pipe 8 connected in this order to these. A refrigerant (first fluid) such as R410A, R32, or carbon dioxide (CO2) flows through the refrigerant pipe 8. The refrigerant circulates through the refrigeration cycle device 1 while undergoing a phase change.

[0011] The four-way valve 3 reverses the flow direction of the refrigerant in the refrigerant pipe 8. When the four-way valve 3 is in the state shown in FIG. 1, the refrigerant flows through the compressor 2, the first heat exchanger 4, the expansion device 5, and the second heat exchanger 6 in that order. At this time, the second heat exchanger 6 functions as a heat absorber (for example, an evaporator). The following describes the case where the second heat exchanger 6 functions as an evaporator. Based on the flow direction of the refrigerant in this case, the upstream side and the downstream side of the flow direction of the refrigerant are defined.

[0012] The compressor 2 is, for example, a rotary compressor. The compressor 2 compresses the low-pressure gas refrigerant taken in to produce high-temperature, high-pressure gas refrigerant. An accumulator (gas-liquid separator) 2a is disposed upstream of the compressor 2.

[0013] The first heat exchanger 4 functions as a heat radiator (for example, a condenser). The first heat exchanger 4 radiates heat from the high-temperature, high-pressure gas refrigerant discharged from the compressor 2, and turns the high-temperature, high-pressure gas refrigerant into a high-pressure liquid refrigerant. A fan 4a that blows air to the first heat exchanger 4 is installed adjacent to the first heat exchanger 4.

[0014] The expansion device 5 reduces the pressure of the high-pressure liquid refrigerant sent from the first heat exchanger 4, and converts the high-pressure liquid refrigerant into a low-temperature, low-pressure gas-liquid two-phase refrigerant. The expansion device 5 is controlled by a control unit 50, which will be described later (control lines are omitted in FIG. 1).

[0015] The second heat exchanger 6 functions as a heat absorber (e.g., an evaporator). The second heat exchanger 6 converts the gas-liquid two-phase refrigerant sent from the expansion device 5 into a low-pressure gas refrigerant. When the low-pressure gas-liquid two-phase refrigerant evaporates in the second heat exchanger 6, it absorbs heat of vaporization from the surroundings, thereby cooling the surroundings. The low-pressure gas refrigerant that has passed through the second heat exchanger 6 is taken into the compressor 2 described above via the accumulator 2a.

[0016] The refrigerant flowing through the second heat exchanger 6 cools the fluid to be cooled. For example, the fluid to be cooled is water. Inside the second heat exchanger 6, in addition to the refrigerant flow path 15, a water flow path 95 is formed. The refrigerant flow path 15 is connected to the refrigerant pipe 8, and the water flow path 95 is connected to the water pipe 90. The water pipe 90 is provided with a pump 98 that circulates water. This allows the refrigeration cycle apparatus 1 to function as a chiller (cooling water circulator). The fluid to be cooled may be a fluid other than water. The second heat exchanger 6 is a plate heat exchanger 10 .

[0017] Next, the plate heat exchanger 10 will be described in detail. Fig. 2 is a perspective view showing an example of a plate heat exchanger. Fig. 3 is an exploded perspective view showing an example of a plate heat exchanger. Note that the distribution pipe unit 20 is omitted in Fig. 3. Fig. 4 is a side cross-sectional view showing an example of a plate heat exchanger 10 taken along line AA in Fig. 2. As shown in Fig. 2, the plate heat exchanger 10 has a heat exchanger body 10a and a distribution pipe unit 20.

[0018] The heat exchanger body 10 a has a plurality of plates 14 . The plate 14 is arranged parallel to the YZ plane. The plate 14 is formed in a rectangular shape with the Z direction as the longitudinal direction and the Y direction as the transverse direction. The plate 14 has circular holes at the four corners. The holes in the -Y and -Z directions are the first refrigerant inlet / outlet 11. The holes in the -Y and +Z directions are the second refrigerant inlet / outlet 12. The holes in the +Y and +Z directions are the first water inlet / outlet 91. The holes in the +Y and -Z directions are the second water inlet / outlet 92. When the plate heat exchanger 10 functions as an evaporator, the first refrigerant inlet / outlet 11 is the inlet for the refrigerant, and the second refrigerant inlet / outlet 12 is the outlet for the refrigerant. The first water inlet / outlet 91 is the inlet for the water, and the second water inlet / outlet 92 is the outlet for the water. The second water inlet / outlet 92 may be the inlet for the water, and the first water inlet / outlet 91 may be the outlet for the water.

[0019] The heat exchanger body 10a is formed by stacking a plurality of plates 14 in the X direction. The peripheral portions of the stacked plates 14 are joined. The refrigerant inlet / outlet 11, 12 and the water inlet / outlet 91, 92 are continuous in the X direction. The -X direction ends of the refrigerant inlet / outlet 11, 12 and the water inlet / outlet 91, 92 are open and connected to the refrigerant piping 8. As shown in FIG. 3, the +X direction ends of the refrigerant inlet / outlet 11, 12 and the water inlet / outlet 91, 92 are closed by an end plate 14z.

[0020] The first plate 14a, the second plate 14b, and the third plate 14c are stacked in this order from the end in the -X direction to the +X direction. As shown in FIG. 4, the peripheral portions of the refrigerant inlet / outlet 11, 12 are blocked between the first plate 14a and the second plate 14b. As a result, the refrigerant R flowing through the refrigerant inlet / outlet 11, 12 does not flow between the first plate 14a and the second plate 14b. Conversely, openings are formed in the peripheral portions of the water inlet / outlet 91, 92 between the first plate 14a and the second plate 14b. As a result, a water flow path 95 is formed between the first plate 14a and the second plate 14b as shown in FIG. 3.

[0021] Meanwhile, the peripheral portions of the water inlet / outlet 91, 92 are closed between the second plate 14b and the third plate 14c. As a result, the water W flowing through the water inlet / outlet 91, 92 does not flow between the second plate 14b and the third plate 14c. Conversely, as shown in Fig. 4, openings are formed in the peripheral portions of the refrigerant inlet / outlet 11, 12 between the second plate 14b and the third plate 14c. As a result, the refrigerant flow path 15 is formed between the second plate 14b and the third plate 14c.

[0022] As shown in Figs. 3 and 4, refrigerant flow paths 15 and water flow paths 95 are alternately arranged along the X direction. The refrigerant flow paths 15 allow refrigerant to flow between adjacent plates 14. The water flow paths 95 allow water to flow between adjacent plates 14. The refrigerant flowing through the refrigerant flow paths 15 and the water flowing through the water flow paths 95 exchange heat via the plate 14 arranged therebetween. As shown in Fig. 3, herringbone (V-shaped) concave-convex patterns 17, 18 are formed continuously in the Z direction on the plate 14. The V-shaped patterns 17, 18 of adjacent plates 14 are formed in opposite directions to each other. The concave-convex patterns 17, 18 increase the surface area of ​​the plate 14, improving heat exchange efficiency.

[0023] The refrigerant flows through the refrigerant flow passage 15 from the -Z direction to the +Z direction. By flowing the refrigerant against gravity, the division of the refrigerant in the refrigerant flow passage 15 is improved, and the heat exchange efficiency is improved. On the other hand, the water flows through the water flow passage 95 from the +Z direction to the -Z direction. That is, the refrigerant and the water flow in opposite directions (counter flow). As a result, the refrigerant and the water flow with a temperature difference between them, which increases the opportunities for heat exchange and improves the heat exchange efficiency.

[0024] Next, a detailed description will be given of the distribution pipe unit 20. Fig. 5 is a side cross-sectional view showing an example of the distribution pipe unit 20. 5, the distribution pipe unit 20 is formed in a cylindrical shape. The distribution pipe unit 20 is disposed so that its central axis is along the X direction. The distribution pipe unit 20 has a head portion 20a and a body portion 20b.

[0025] The head 20a is disposed at the end of the distribution pipe unit 20 in the -X direction. The outer diameter of the head 20a is larger than the inner diameter of the first refrigerant inlet / outlet 11. The head 20a is disposed in the -X direction of the heat exchanger body 10a. The head 20a is fixed to the heat exchanger body 10a by welding or the like. The head 20a closes the end of the first refrigerant inlet / outlet 11 in the -X direction. The end of the head 20a in the -X direction is provided with a first refrigerant inlet E1 through which the first fluid flows in and a second refrigerant inlet E2 through which the first fluid flows in. The first refrigerant inlet E1 is connected to the expansion device 5 via the refrigerant piping 8, and the second refrigerant inlet E2 is connected to the expansion device 5 via the opening / closing unit 52 and the refrigerant piping 8.

[0026] The body 20b is disposed in the +X direction of the head 20a. The outer diameter of the body 20b is smaller than the inner diameter of the first refrigerant inlet / outlet 11 and is constant along the X direction. The body 20b is disposed inside the first refrigerant inlet / outlet 11. The end of the body 20b in the +X direction is closed. The body 20b has a plurality of through holes 22 at the end in the -Z direction. The plurality of through holes 22 are formed in the pipe wall of the distribution pipe unit 20 and are arranged side by side in the X direction. The plurality of through holes 22 form a diversion section (first diversion section) D1. The head 20a and the body 20b also include a first refrigerant flow path R1 through which the refrigerant flowing in from the first refrigerant inlet E1 is diverted through the diversion section D1 and flows out of the distribution pipe unit 20. The head 20a also includes a second refrigerant flow passage R2 through which the refrigerant flowing in from the second refrigerant inlet E2 flows out of the distribution pipe unit 20 without passing through the distribution section D1. As shown in FIG. 1, the first refrigerant flow passage R1 and the second refrigerant flow passage R2 are each connected to the above-mentioned refrigerant pipe 8. The hole diameter of the distribution pipe unit 20 is set to a hole diameter that can ensure sufficient pressure loss under low load conditions. Specifically, it is desirable to set the pressure loss so that the performance is good under the IPLVc50 condition in FIG. 7 described later. In this embodiment, the hole diameter of the first refrigerant inlet E1 is formed larger than the hole diameter of the second refrigerant inlet E2, that is, the hole diameter of the first refrigerant flow passage R1 and the hole diameter of the second refrigerant flow passage R2 are formed larger.

[0027] The refrigerant flows in the +X direction inside the distribution pipe unit 20 (each of the first refrigerant flow path R1 and the second refrigerant flow path R2). In the first refrigerant flow path R1, the refrigerant flows in the +X direction of the body 20b, and is sequentially discharged from the diverter section D1 (the multiple through holes 22) to the first refrigerant inlet / outlet 11. In addition, the refrigerant flows in the +X direction in the second refrigerant flow path R2, and is discharged from the head section 20a to the first refrigerant inlet / outlet 11. As a result, the refrigerant is distributed to the multiple refrigerant flow paths 15, improving the heat exchange efficiency. The refrigerant is discharged in the -Z direction from the diverter section D1 (the multiple through holes 22). The discharge direction of the refrigerant from the diverter section D1 (the multiple through holes 22) is the gravity direction, which is opposite to the flow direction of the refrigerant flowing in the refrigerant flow path 15 from the -Z direction to the +Z direction. As a result, the refrigerant is diverted in the refrigerant flow path 15, improving the heat exchange efficiency. In the X direction, it is desirable that the multiple through holes 22 are arranged in the same positions as the multiple refrigerant flow paths 15, but this is not necessary, and it is also desirable that the number of refrigerant flow paths and through holes be the same, but this may also be varied as necessary.

[0028] As shown in FIG. 1, the refrigeration cycle device 1 has an opening / closing unit 52 (pressure pipe 52a and opening / closing valve 52b) and a control unit 50. The pressure pipe 52a communicates the refrigerant pipe 8 with the distribution pipe unit 20. The opening / closing valve 52b is provided in the pressure pipe 52a. The refrigerant pipe 8 between the expansion device 5 and the distribution pipe unit 20 has two paths: a first refrigerant flow path R1 that does not have the opening / closing valve 52a, and a second refrigerant flow path R2 that passes through the pressure pipe 52a that has the opening / closing valve 52b. When the opening / closing valve 52b is closed, the refrigerant flows only through the first refrigerant flow path R1, and the refrigerant is introduced into the distribution pipe unit 20. When the opening / closing valve 52b is opened, the refrigerant flows through the first refrigerant flow path R1 and the second refrigerant flow path R2, and the refrigerant is introduced into the distribution pipe unit 20.

[0029] 1 is a microcomputer including a processor such as a CPU and a memory. The control unit 50 is realized by a processor such as a CPU executing a program stored in the memory. In addition, a part or the whole of the control unit 50 may be realized by hardware such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), or an FPGA (Field-Programmable Gate Array), or may be realized by a combination of software and hardware.

[0030] The control unit 50 controls the operation of the compressor 2 and monitors the rotation speed of the compressor 2. The control unit 50 controls the opening and closing of the on-off valve 52b based on the rotation speed of the compressor 2. In this embodiment, the control unit 50 controls the opening and closing of the on-off valve 52b according to the rotation speed of the compressor 2 (in other words, according to the load of the refrigeration cycle device).

[0031] Here, the results of tests performed on a plate heat exchanger with a large pressure loss (hereinafter referred to as pressure loss) in the flow division structure and a plate heat exchanger with a small pressure loss in the flow division structure will be described with reference to Figs. 6 and 7. The test conditions were IPLVc conditions (rated conditions) described in JRA4066 issued by the Japan Refrigeration and Air Conditioning Industry Association. Fig. 6 is a diagram showing an example of evaporation temperature comparison, showing evaporation temperatures for IPLVc conditions. Specifically, a comparison is made between a case where the pressure loss is small and a case where the pressure loss is large for each of IPLVc100, 75, 50, and 25 (in other words, load factors of 100%, 75%, 50%, and 25%). Fig. 7 is a diagram showing an example of compression comparison of the flow division section, showing pressure loss for IPLVc conditions. Specifically, a comparison is made between a case where the pressure loss in the flow division section is small and a case where the pressure loss is large for each of IPLVc100, 75, 50, and 25%.

[0032] According to Figure 6, the evaporation temperature decreases when the pressure loss is large under the condition of 100% load rate, the evaporation temperature is almost the same under the condition of 75% load rate, and the evaporation temperature increases when the pressure loss is large under the condition of 50% load rate and 25% load rate. In the calculation method of IPLVc, which is the partial load efficiency, the contribution rate to the performance of the load rate of 75%, 50%, and 25% is 90% in total. Therefore, in order to ensure the performance according to the specifications, a split flow structure with a large pressure loss should be selected. However, if the evaporation temperature decreases at a high load such as the load rate of 100%, the maximum capacity of the plate heat exchanger will decrease. For example, problems such as the time until the refrigerant temperature reaches the target value will be longer, or the number of plate heat exchangers to be installed will need to be increased will occur. In other words, it can be seen that the split flow structure when the plate heat exchanger is used as an evaporator is required to have a small pressure loss under a high load and a large pressure loss under a low load.

[0033] In this embodiment, the control unit 50 controls whether to flow the refrigerant through the first refrigerant flow path R1 or through the first refrigerant flow path R1 and the second refrigerant flow path R2 according to the load of the refrigeration cycle. That is, when the control unit 50 determines that the load is small, it controls to flow the refrigerant only through the first refrigerant flow path R1 in order to increase the pressure loss. When the control unit 50 determines that the load is large, it controls to flow the refrigerant through both the first refrigerant flow path R1 and the second refrigerant flow path R2 in order to reduce the pressure loss. Note that the control of the flow of the refrigerant is not limited to this, and the control unit 50 may control whether to flow the refrigerant through the second refrigerant flow path R2 or through the first refrigerant flow path R1 and the second refrigerant flow path R2. That is, the control unit 50 may control to flow the refrigerant through either the first refrigerant flow path R1 or the second refrigerant flow path R2, or through both the first refrigerant flow path R1 and the second refrigerant flow path R2.

[0034] Next, the opening and closing control of the on-off valve 52b will be described. As shown in FIG. 8, during operation of the refrigeration cycle device 1, the control unit 50 judges whether the load of the refrigeration cycle is large (ST101). The magnitude of the load of the refrigeration cycle may be judged, for example, based on whether the rotation speed of the compressor 2 is equal to or greater than a predetermined number of times. When the load is judged to be large (ST101: YES), for example, under the IPLVc100 condition and the IPLVc75 condition in FIG. 6, the control unit 50 opens the on-off valve 52b (ST102). As a result, the refrigerant flows through both the first refrigerant flow path R1 and the second refrigerant flow path R2. On the other hand, when the load is not large, that is, when the load is small (ST102: NO), for example, under the IPLVc50 condition and the IPLVc25 condition in FIG. 6, the control unit 50 closes the on-off valve 52b (ST103). As a result, the refrigerant does not flow through the second refrigerant flow path R2, and the refrigerant flows through the first refrigerant flow path R1.

[0035] According to the refrigeration cycle apparatus 1 configured as above, the pressure loss of the distribution pipe unit 20 can be selected according to the load of the refrigeration cycle. Therefore, the refrigeration cycle apparatus 1 can perform appropriate distribution according to various conditions, and can maximize the evaporation performance.

[0036] More specifically, the refrigeration cycle device 1 controls the refrigerant to flow through both the first refrigerant flow path R1 and the second refrigerant flow path R2 when the load of the refrigeration cycle is large, and controls the refrigerant to flow from the first refrigerant flow path R1 when the load of the refrigeration cycle is small, thereby maximizing the evaporation performance of the refrigeration cycle device 1.

[0037] Second embodiment The second embodiment differs from the first embodiment in the configuration of the refrigeration cycle device. Therefore, the different points of the configuration will be described. Note that the same components as those in the first embodiment are denoted by the same reference numerals.

[0038] FIG. 9 is a diagram showing an example of a control configuration of the refrigeration cycle apparatus 1 of the second embodiment. It is different from the first embodiment described above in that an expansion device 5a is provided instead of the on-off valve 52b. In this way, the control unit 50 is configured to be able to control the flow rate of the refrigerant of each of the expansion devices 5 and 5a individually (control lines to the expansion devices 5 and 5a are omitted from the illustration). In this way, even if the pressure loss of the distribution pipe unit 20 is selected according to the load of the refrigeration cycle, the same effect as the first embodiment can be achieved. Furthermore, the refrigeration cycle apparatus 1 can smoothly switch the flow path of the refrigerant between high load and low load.

[0039] Third embodiment In the third embodiment, the configuration of the body 20b of the distribution pipe unit 20 is different from that of the first embodiment. Therefore, the configuration of the body will be described in detail. Note that the same reference numerals will be used to designate the same components as those in the first embodiment.

[0040] FIG. 10 is a side cross-sectional view showing an example of a distribution pipe unit according to the third embodiment. As shown in FIG. 10, the distribution pipe unit 20 is provided with a distribution part (second distribution part) D2 in addition to the above-mentioned distribution part D1. The distribution part D2 is composed of a plurality of through holes 22a. In this embodiment, the plurality of through holes 22a are provided at equal intervals in a direction to flow the refrigerant downward, similar to the plurality of through holes 22. This distribution part D2 is used in connection with the distribution part D1. The pressure loss of the distribution part D2 is configured to be smaller than the pressure loss of the distribution part D1. In addition, the first refrigerant flow path R1 and the second refrigerant flow path R2 in the distribution pipe unit 20 are both configured to flow into the first refrigerant inlet / outlet 11 after passing through the distribution part D2. At this time, the pressure loss of the distribution pipe unit 20 is set to be such that the pressure loss at the time of high load is improved when the refrigerant flows in both the first refrigerant flow path R1 and the second refrigerant flow path R2. Specifically, the pressure loss is set to a value that improves the evaporation performance of the second heat exchanger 6 under the condition of IPLVc100 in FIG.

[0041] In this way, the distribution pipe unit 20 includes a diversion section D2 that divides the refrigerant, and the diversion section D2 is configured so that the refrigerant that has passed through the diversion section D1 flows into the diversion section D2, and further, the diversion section D2 is configured so that the pressure loss is smaller than that of the diversion section D1. Specifically, the hole diameter of the through hole 22a is made smaller than that of the through hole 22 of the diversion section D1. With this configuration, the refrigeration cycle apparatus 1 can improve the evaporation performance of the second heat exchanger 6 both under high load and low load. Furthermore, the refrigeration cycle apparatus 1 can further improve the diversion under high load.

[0042] In each of the above embodiments, the distribution pipe unit 20 has been described as having two flow paths, the first refrigerant flow path R1 and the second refrigerant flow path R2, but the number of flow paths is not limited to this and may be three or more.

[0043] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0044] Reference Signs List 1: refrigeration cycle device, 2: compressor, 6: second heat exchanger, 8: refrigerant pipe, 20: distribution pipe unit, 22, 22a: through hole, 50: control unit, 52b: on-off valve, D1, D2: flow division unit, R1: first refrigerant flow path, R2: second refrigerant flow path

Claims

1. a heat exchanger body formed by stacking a plurality of plates, the heat exchanger body having first and second fluid flow paths alternately arranged along a stacking direction of the plurality of plates, the first fluid flow path allowing a first fluid to flow between adjacent plates, and the second fluid flow path allowing a second fluid to flow between adjacent plates different from the gap between the plates between which the first fluid flow paths are arranged; a distribution pipe unit formed in a tubular shape and arranged only on an inlet side of the first fluid flow path through which the first fluid flows into the heat exchanger body when the heat exchanger body functions as an evaporator; Equipped with The distribution pipe unit includes: a first inlet through which the first fluid flows; a second inlet through which the first fluid flows; A first dividing section that divides the first fluid; a first flow path that divides the first fluid flowing in from the first inlet by passing the first branching portion and distributes the first fluid in the first fluid flow path; a second flow path that causes the first fluid flowing in from the second inlet to flow through the first fluid flow path without passing through the first branch portion; Equipped with The first fluid is caused to flow through one of the first flow path and the second flow path, or through both the first flow path and the second flow path. Plate heat exchanger.

2. a refrigerant pipe sequentially connecting a compressor, a first heat exchanger capable of functioning as a condenser, an expansion device, and a second heat exchanger having the plate-type heat exchanger according to claim 1 and capable of functioning as an evaporator; The first fluid is a refrigerant flowing through the refrigerant pipe, A control unit is provided to cause the refrigerant to flow through one of the first flow path and the second flow path, or through both the first flow path and the second flow path, depending on a load of a refrigeration cycle. Refrigeration cycle equipment.

3. The control unit causes the refrigerant to flow through the first flow path and the second flow path when a load on the refrigeration cycle is large, and causes the refrigerant to flow through the first flow path when the load on the refrigeration cycle is small. The refrigeration cycle device according to claim 2.

4. The control unit determines the magnitude of the load of the refrigeration cycle based on the rotation speed of the compressor. The refrigeration cycle device according to claim 3.

5. The distribution pipe unit includes: A second flow dividing section that divides the refrigerant is provided. the second branch portion is configured so that the refrigerant that has passed through the first branch portion and the second flow path flows into the second branch portion, The second branch portion has a smaller pressure loss than the first branch portion. The refrigeration cycle device according to claim 3.

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