Gas-liquid mixer

Abstract

To provide a small gas-liquid mixer capable of cooling refrigerant superheated gas by evaporating refrigerant saturated liquid.SOLUTION: The flow path 70 of the gas-liquid mixer 60 has at least the first flow path 71 on the upstream side along the first direction and the second flow path 72 on the downstream side along the second direction different from the first direction, the second flow path has a smaller flow path area than the first flow path, and the baffle plates 31 and 32 are provided in the first flow path and the second flow path SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a gas-liquid mixer that mixes a superheated refrigerant gas and a saturated refrigerant liquid in a refrigeration cycle. [Background technology]

[0002] Gas-liquid mixers are used in refrigeration cycles, for example, to cool superheated refrigerant gas. Specifically, gas-liquid mixers are used for low-pressure control by hot gas mixing in hot gas bypass test equipment, as gas coolers in the intermediate piping of reciprocating two-stage compressors, and to prevent liquid backflow in the suction piping of compressors.

[0003] In a gas-liquid mixer applied to a refrigeration cycle, for example, when superheated refrigerant gas is flowing in a main pipe, saturated refrigerant liquid is injected into the main pipe to cool it, thereby evaporating the saturated refrigerant droplets and cooling the superheated refrigerant gas.

[0004] Meanwhile, various static mixers (static mixers, in-line mixers) that mix two fluids have been developed, including those equipped with elements or baffle plates for mixing two fluids, as described in Patent Documents 1 and 2, for example. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 11-90197 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-120973 Summary of the Invention [Problem to be solved by the invention]

[0006] When saturated refrigerant liquid is injected into the main pipe of a gas-liquid mixer, a very long mixing distance is required to mix the superheated refrigerant gas and saturated refrigerant liquid, which results in an increased size of the gas-liquid mixer.Furthermore, in gas-liquid mixers in refrigeration systems, it is necessary to completely evaporate the saturated refrigerant liquid to prevent damage to the compressor due to liquid backflow.

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a small-sized gas-liquid mixer that can evaporate saturated refrigerant liquid to cool superheated refrigerant gas. [Means for solving the problem]

[0008] The above object of the present invention can be achieved by the following means.

[0009] A gas-liquid mixer having a flow path that mixes a superheated refrigerant gas and a saturated refrigerant liquid in a refrigeration cycle and evaporates the saturated refrigerant liquid, the flow path includes at least a first flow path on an upstream side along a first direction and a second flow path on a downstream side along a second direction different from the first direction; The second flow path has a flow path area smaller than that of the first flow path, The gas-liquid mixer comprises a baffle plate provided in at least one of the first flow path and the second flow path. [Effects of the Invention]

[0010] According to the present invention, the flow path has an upstream first flow path along a first direction and a downstream second flow path along a second direction different from the first direction. Therefore, the gas-liquid mixer can be made smaller than a gas-liquid mixer having a flow path configured in one direction. Furthermore, the flow path area of ​​the downstream second flow path is smaller than the flow path area of ​​the upstream first flow path, so the flow velocity on the downstream side can be increased. Therefore, it is possible to prevent the liquid ratio from decreasing downstream due to evaporation of droplets, which leads to a decrease in the heat transfer coefficient. As a result, it is possible to provide a small-sized gas-liquid mixer that can evaporate saturated refrigerant liquid and cool superheated refrigerant gas. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a system diagram showing a refrigeration device provided with a gas-liquid mixer according to an embodiment of the present invention. [Figure 2] FIG. 1 is a schematic perspective view showing a gas-liquid mixer according to the present embodiment. [Figure 3] FIG. 2 is a front view showing the gas-liquid mixer according to the present embodiment. [Figure 4] FIG. 2 is a front cross-sectional view showing the gas-liquid mixer according to the present embodiment. [Figure 5] FIG. 5 is a cross-sectional view taken along line 5-5 in FIG. [Figure 6] FIG. 6 is a cross-sectional view taken along line 6-6 in FIG. 4. [Figure 7] FIG. 10 is a schematic perspective view showing a gas-liquid mixer according to a comparative example. [Figure 8] FIG. 5 is a view corresponding to FIG. 3 of a gas-liquid mixer according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of the present invention will be described with reference to Figs. 1 to 6. In the description of the drawings, the same elements are denoted by the same reference numerals, and duplicate description will be omitted. Furthermore, the dimensional proportions in the drawings are exaggerated for the convenience of explanation and may differ from the actual proportions. Fig. 1 is a system diagram showing a refrigeration system 1 provided with a gas-liquid mixer 60 according to an embodiment of the present invention. Fig. 2 is a schematic perspective view showing the gas-liquid mixer 60 according to this embodiment. Fig. 3 is a front view showing the gas-liquid mixer 60 according to this embodiment. Fig. 4 is a front cross-sectional view showing the gas-liquid mixer 60 according to this embodiment. Fig. 5 is a cross-sectional view taken along line 5-5 in Fig. 4. Fig. 6 is a cross-sectional view taken along line 6-6 in Fig. 4.

[0013] As shown in FIG. 1, the refrigeration system 1 includes a compressor 10, a condenser 20, an expansion valve 30, an evaporator 40, a receiver 50, and a gas-liquid mixer 60.

[0014] The compressor 10 compresses the sucked refrigerant gas and discharges the compressed refrigerant gas at a high temperature and pressure. The compressor 10 is a two-stage compressor and has a low-stage compressor 11 and a high-stage compressor 12. As shown in Fig. 1 , a gas-liquid mixer 60 according to this embodiment is disposed between the low-stage compressor 11 and the high-stage compressor 12.

[0015] The condenser 20 exchanges heat between the high-temperature, high-pressure refrigerant gas discharged from the high-stage compressor 12 and the outside air, dissipates heat from the refrigerant gas at constant pressure, and discharges it as a low-temperature, high-pressure saturated refrigerant liquid.

[0016] The expansion valve 30 expands the saturated refrigerant liquid flowing out of the condenser 20 to reduce its pressure.

[0017] The evaporator 40 evaporates and gasifies the saturated refrigerant liquid expanded by the expansion valve 30, and the refrigerant gas is sucked into the low-stage compressor 11 of the compressor 10.

[0018] The receiver 50 separates the refrigerant gas and saturated refrigerant liquid coming out of the condenser 20 .

[0019] A lower portion 52 of the receiver 50, in which the liquid is stored, is connected by a first line L1 to a line between the low-stage compressor 11 and the gas-liquid mixer 60. A liquid injection valve V is disposed on the first line L1.

[0020] The saturated refrigerant liquid supplied from the receiver 50 to the gas-liquid mixer 60 has a low temperature of, for example, -4.4°C, and therefore cools, for example, the 70°C superheated refrigerant gas flowing out of the low-stage compressor 11 to 5.6°C. By temporarily cooling the refrigerant gas flowing out of the low-stage compressor 11 in this way, it is possible to suppress an increase in the discharge temperature of the high-stage compressor 12. The refrigerant flowing from the gas-liquid mixer 60 to the high-stage compressor 12 must be only gas, and must not contain any liquid. Therefore, it is required that the saturated refrigerant liquid completely evaporates in the gas-liquid mixer 60.

[0021] The configuration of the gas-liquid mixer 60 according to this embodiment will be described below with reference to Figures 2 to 6. Hereinafter, in this specification, the direction in which the gas-liquid mixer 60 extends (the left-right direction in Figure 3) will be referred to as the axial direction, the left side in Figure 3 will be referred to as the upstream side, the right side in Figure 3 will be referred to as the downstream side, and the inlet side when the gas-liquid mixture flows inside the gas-liquid mixer 60 will be referred to as the upstream side, and the outlet side will be referred to as the downstream side.

[0022] As shown in Figures 2 to 4, the gas-liquid mixer 60 has a main pipe 61, a branch pipe 62, an inner pipe 63 arranged on the outer periphery of the main pipe 61, and an outer pipe 64 arranged on the outer periphery of the inner pipe 63.

[0023] As shown in Figures 2 and 4, the main pipe 61 is configured in a hollow cylindrical shape. A refrigerant gas inlet 61A, through which superheated refrigerant gas flows, is formed upstream of the main pipe 61. Furthermore, a refrigerant saturated liquid inlet 62A, through which saturated refrigerant liquid flows, is formed at the upper end of the branch pipe 62. Note that the saturated refrigerant liquid may be sprayed from the upper end of the branch pipe 62 using a spray nozzle (not shown) and injected into the main pipe 61. With this configuration, spraying using the spray nozzle produces fine droplets, which promotes evaporation of the saturated refrigerant liquid.

[0024] As shown in Figures 2 and 4, first baffle plates 31 are arranged inside the main pipe 61. As shown in Figures 2, 4, 5, and 6, the first baffle plates 31 have a circular shape when viewed from the upstream side, with approximately 90-degree sectors cut out at 180-degree intervals. In this embodiment, six first baffle plates 31 are provided along the axial direction, but the number of first baffle plates 31 is not particularly limited. The cross-sectional views shown in Figures 5 and 6 are taken at the point where adjacent baffle plates 31, 32, and 33 are arranged along the axial direction.

[0025] The first baffle plates 31 adjacent to each other in the axial direction are arranged in a staggered manner so as to be rotated by 90 degrees around the axis, as shown in Figures 5 and 6. With this configuration, the gas-liquid mixture flowing in the main pipe 61 from the upstream side to the downstream side in the axial direction collides with the first baffle plates 31 successively, generating turbulence and promoting mixing of the gas and liquid.

[0026] As shown in Figures 2 and 4, a first tube sheet 21 is disposed at the downstream end of the main pipe 61 and the downstream end of the inner pipe 63. The first tube sheet 21 has a solid disk shape. A predetermined gap is formed between the main pipe 61 and the first tube sheet 21. The inner pipe 63 and the first tube sheet 21 are connected without any gaps by, for example, welding.

[0027] 2 and 4, the inner pipe 63 is disposed around the outer periphery of the main pipe 61 with a predetermined gap formed therebetween. The inner pipe 63 is formed in a hollow cylindrical shape.

[0028] As shown in Figures 2 and 4, a second baffle plate 32 is disposed between the inner periphery of the inner pipe 63 and the outer periphery of the main pipe 61. As shown in Figures 2, 4, 5, and 6, the second baffle plate 32 has a shape in which approximately 90-degree sectors are cut out at 180-degree intervals from a hollow cylinder when viewed from the upstream side. In this embodiment, six second baffle plates 32 are provided along the axial direction, but the number of second baffle plates 32 provided is not particularly limited.

[0029] The second baffle plates 32 adjacent to each other in the axial direction are arranged in a staggered manner so as to be rotated by 90 degrees around the axis, as shown in Figures 5 and 6. With this configuration, the gas-liquid mixture flowing between the inner pipe 63 and the main pipe 61 from downstream to upstream in the axial direction collides with the second baffle plates 32 successively, generating turbulence and promoting mixing of the gas and liquid.

[0030] As shown in Figures 2 and 4, the second tube sheet 22 is disposed at the upstream end of the inner pipe 63 and the upstream end of the outer pipe 64. The second tube sheet 22 has a hollow disk shape to allow the main pipe 61 to pass through. A predetermined gap is formed between the inner pipe 63 and the second tube sheet 22. The outer pipe 64 and the second tube sheet 22 are connected without any gaps by, for example, welding.

[0031] 2 and 4, the outer pipe 64 is disposed on the outer periphery of the inner pipe 63 with a predetermined gap formed therebetween. The outer pipe 64 is formed in a hollow cylindrical shape.

[0032] As shown in Figures 2 and 4, a third baffle plate 33 is disposed between the inner periphery of the outer pipe 64 and the outer periphery of the inner pipe 63. As shown in Figures 2, 4, 5, and 6, the third baffle plate 33 has a hollow cylindrical shape with approximately 90-degree sectors cut out at 180-degree intervals when viewed from the upstream side. In this embodiment, six third baffle plates 33 are provided along the axial direction, but the number of third baffle plates 33 provided is not particularly limited.

[0033] The third baffle plates 33 adjacent to each other in the axial direction are arranged in a staggered manner so as to be rotated by 90 degrees around the axis, as shown in Figures 5 and 6. With this configuration, the gas-liquid mixture flowing from the upstream side to the downstream side along the axial direction between the outer pipe 64 and the inner pipe 63 sequentially collides with the third baffle plates 33, generating turbulence and promoting mixing of the gas and liquid.

[0034] 2 and 4, the first baffle plate 31, the second baffle plate 32, and the third baffle plate 33 are arranged at the same pitch along the axial direction. The first baffle plate 31, the second baffle plate 32, and the third baffle plate 33 are arranged in a staggered manner.

[0035] Specifically, in the cross section shown in Fig. 5, the first baffle plate 31 and the third baffle plate 33 exist as a pair in the vertical direction, while the second baffle plate 32 exists as a pair in the horizontal direction. On the other hand, in the cross section shown in Fig. 6, the first baffle plate 31 and the third baffle plate 33 exist as a pair in the horizontal direction, while the second baffle plate 32 exists as a pair in the vertical direction.

[0036] 2 to 4, a reducer 65 and a downstream main pipe 66 are arranged downstream of the outer pipe 64. The outer pipe 64, the reducer 65, and the downstream main pipe 66 are fixed to one another by welding or the like.

[0037] At the downstream end of the downstream main pipe 66, a cooling gas outlet 66H is formed through which the cooling gas flows out.

[0038] The gas-liquid mixer 60 according to this embodiment is configured with a triple pipe of a main pipe 61, an inner pipe 63, and an outer pipe 64. This configuration increases the mixing distance of the superheated refrigerant gas and the saturated refrigerant liquid while reducing the axial length of the gas-liquid mixer 60. Furthermore, since the temperature of the gas-liquid mixture decreases in the order of the first outward path 71, the return path 72, and the second outward path 73, the temperature of the outer periphery of the outer pipe 64 decreases, making it safe for workers to touch the gas-liquid mixer 60. On the other hand, in the case of a gas-liquid mixer 960 according to a comparative example shown in FIG. 7 , the flow path 970 is configured linearly along the axial direction, and therefore the outer periphery of the main pipe 961 near the upstream becomes hot, making it difficult for workers to work.

[0039] Next, the flow path 70 of the gas-liquid mixer 60 will be described with reference to Fig. 4. As shown in Fig. 4, the flow path 70 has a first outward path (corresponding to the first flow path) 71 heading from the upstream side to the downstream side, a return path (corresponding to the second flow path) 72 continuing from the first outward path 71 and heading from the downstream side to the upstream side, and a second outward path 73 continuing from the return path 72 and heading from the upstream side to the downstream side.

[0040] The first outward path 71 is formed inside the main pipe 61. The return path 72 is formed between the outer periphery of the main pipe 61 and the inner periphery of the inner pipe 63. The second outward path 73 is formed between the outer periphery of the inner pipe 63 and the inner periphery of the outer pipe 64.

[0041] The first baffle plate 31 is arranged on the first outward path 71 , the second baffle plate 32 is arranged on the return path 72 , and the third baffle plate 33 is arranged on the second outward path 73 .

[0042] The superheated refrigerant gas injected through the refrigerant gas inlet 61A and the saturated refrigerant liquid injected through the saturated refrigerant liquid inlet 62A pass through the first outward path 71 of the main pipe 61, collide with the first tube plate 21, flow through the return path 72, collide with the second tube plate 22, flow through the second outward path 73, pass through the reducer 65, and reach the cooling gas outlet 66H of the downstream main pipe 66. At this time, the saturated refrigerant liquid evaporates, leaving only the refrigerant gas.

[0043] The flow path area (openings) of the first baffle plate 31 is larger than the flow path area (openings) of the second baffle plate 32. The flow path area of ​​the second baffle plate 32 is also larger than the flow path area (openings) of the third baffle plate 33.

[0044] Since the flow path area is set as described above, the flow velocity of the gas-liquid mixture increases from the first outward path 71 to the return path 72 and the second outward path 73. This prevents the saturated refrigerant liquid from evaporating downstream and reducing the liquid volume fraction, which would otherwise occur in the downstream direction, thereby preventing a decrease in the heat transfer coefficient.

[0045] As described above, the gas-liquid mixer 60 according to this embodiment includes a flow path that mixes superheated refrigerant gas and saturated refrigerant liquid in a refrigeration cycle and evaporates the saturated refrigerant liquid. The flow path includes at least a first flow path 71 on the upstream side along a first direction and a second flow path 72 on the downstream side along a second direction different from the first direction. The second flow path 72 has a smaller flow path area than the first flow path 71. Baffle plates 31 and 32 are provided in the first flow path 71 and the second flow path 72. The gas-liquid mixer 60 configured in this manner includes the downstream second flow path 72 along the second direction different from the first direction. This allows the gas-liquid mixer 60 to be more compact than a gas-liquid mixer with flow paths configured along a single direction. Furthermore, because the flow path area of ​​the downstream second flow path 72 is smaller than the flow path area of ​​the upstream first flow path 71, the flow velocity downstream can be increased. This prevents the liquid ratio from decreasing due to evaporation of droplets downstream, which reduces the heat transfer coefficient. As a result, it is possible to provide a small-sized gas-liquid mixer 60 that can evaporate saturated refrigerant liquid and cool superheated refrigerant gas.

[0046] Furthermore, the first flow path 71 of the flow path is a first outward path 71 heading from the upstream side to the downstream side, and the second flow path 72 of the flow path is a return path 72 continuing from the first outward path 71 and heading from the downstream side to the upstream side, and the flow path further has a second outward path 73 continuing from the return path 72 and heading from the upstream side to the downstream side. According to the gas-liquid mixer 60 configured in this manner, the axial length of the gas-liquid mixer 60 can be made shorter, and the gas-liquid mixer 60 can be made more compact.

[0047] Furthermore, the first outward path 71, the return path 72, and the second outward path 73 are configured as triple pipes. With the gas-liquid mixer 60 configured in this manner, the mixing distance of the superheated refrigerant gas and the saturated refrigerant liquid can be increased while reducing the axial length of the gas-liquid mixer 60. Furthermore, since the temperature of the gas-liquid mixture decreases in the order of the first outward path 71, the return path 72, and the second outward path 73, the temperature of the outer periphery of the outer pipe 64 also decreases, ensuring safety for workers.

[0048] The baffle plates 31, 32 are arranged in a staggered pattern along the first direction or the second direction. In the gas-liquid mixer 60 configured in this manner, the gas and liquid collide with the baffle plates 31, 32 sequentially, generating turbulence and promoting mixing of the gas and liquid.

[0049] As described above, the gas-liquid mixer 60 according to this embodiment has been described. However, it goes without saying that those skilled in the art can make appropriate additions, modifications, and omissions within the scope of the technical concept of the present invention.

[0050] For example, in the above-described embodiment, the gas-liquid mixer 60 is disposed between the low-stage compressor and the high-stage compressor of the two-stage reciprocating compressor. However, the gas-liquid mixer is not particularly limited as long as it is a device that mixes superheated refrigerant gas and saturated refrigerant liquid in a refrigeration cycle, and may be used for low-pressure control by hot gas mixing, prevention of liquid backflow in the suction piping of the compressor, etc.

[0051] Furthermore, in the above-described embodiment, the first flow path is the first outward path 71 and the second flow path is the return path 72, but the flow paths are not limited to this as long as they are configured to meander in any direction rather than being configured linearly along the axial direction (see FIG. 7).

[0052] In the above-described embodiment, the first outward path 71, the return path 72, and the second outward path 73 are configured as triple pipes. However, as shown in Fig. 8, the first outward path 171, the return path 172, and the second outward path 173 may be configured as a single pipe. [Explanation of symbols]

[0053] 1 refrigeration equipment, 10 compressor, 21 first tube sheet, 22 second tube sheet, 31 first baffle plate, 32 second baffle plate, 33 third baffle plate, 60 Gas-liquid mixer, 61 Master, 62 branch pipes, 63 inner tube, 64 outer tube, 70 flow paths, 71, 171 First outbound route (first flow path), 72, 172 return route (second flow path), 73, 173 Second outbound journey.

Claims

1. A gas-liquid mixer having a flow path that mixes a superheated refrigerant gas and a saturated refrigerant liquid in a refrigeration cycle and evaporates the saturated refrigerant liquid, the flow path includes at least a first flow path on an upstream side along a first direction and a second flow path on a downstream side along a second direction different from the first direction; The second flow path has a flow path area smaller than that of the first flow path, A gas-liquid mixer, wherein a baffle plate is provided in at least one of the first flow path and the second flow path.

2. The first flow path of the flow path is a first outward path from the upstream side to the downstream side, The second flow path of the flow path is continuous with the first outward path and is a return path extending from the downstream side to the upstream side, The gas-liquid mixer according to claim 1 , wherein the flow path further includes a second outward path that is continuous with the return path and runs from the upstream side to the downstream side.

3. The gas-liquid mixer according to claim 2 , wherein the first outward path, the return path, and the second outward path are configured as triple pipes.

4. The gas-liquid mixer according to claim 1 or 2, wherein the baffle plates are arranged in a staggered pattern along the first direction or the second direction.

Images