Heat pump cycle device

Abstract

The fluid distributor 20 further suppresses flow rate distribution variations with a simple configuration. The fluid distributor 20 comprises a cylindrical section 23, an inlet pipe 22 through which fluid flows in from the inlet end of the cylindrical section 23, and one or more branch pipes 26 extending radially from the cylindrical section, the cylindrical section 23 and the inlet pipe 22 are connected by the same central axis C, the central axis of the branch pipe 26 is perpendicular to the central axis C of the cylindrical section 23, and the rear end side of the cylindrical section 23 in the flow direction functions as a buffer section 25 that blocks the rear in the flow direction, the ratio of the length d2 of the cylindrical section to the outer diameter d1 of the cylindrical section is 3.4 to 4.1, the ratio of the length d3 of the header section, which is the length from the inlet end of the cylindrical section 23 to the connection center position of the branch pipe 26, to 1 / 2 of the length d2 of the cylindrical section is 0.9 to 1.3, the ratio of the cross-sectional area S1 of the cylindrical section 23 to the cross-sectional area S4 of the inlet pipe 22 is 2.5 or more, and the ratio of the length d5 ​​of the inlet pipe to the outer diameter d4 of the inlet pipe is 2.2 to 4.8.

Description

Technical Field

[0001] The present invention relates to a heat pump cycle device that can further suppress variations in flow rate distribution with a simple configuration. Ruhi - to a heat pump cycle device.

Background Art

[0002] When parallelizing the compressors of a heat pump cycle device used in a heat pump type steam generator or the like, a refrigerant distributor that distributes the refrigerant to the suction parts of each compressor is used to suppress variations in refrigerant distribution and suppress a decrease in the heating output of the heat pump cycle device.

[0003] In Patent Document 1 (Japanese Patent Application Laid-Open No. 1994-42522), a cylindrical part, an inflow pipe connected on the same central axis of the cylindrical part, and a branch pipe on the side surface of the cylindrical part are provided, so that the pipe friction values from the inflow pipe to each branch pipe are the same, and it has a structure that diffuses evenly without unevenness. Further, in Patent Document 2 (Japanese Patent Application Laid-Open No. 2014-222143), a spiral flow is generated by installing a plurality of inflow pipes at the lower part of the cylinder, and distribution variations are suppressed.

Prior Art Documents

Patent Documents

[0004] s

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in Patent Document 1, the influence of uneven flow in the pipe is not considered, and when the flow velocity distribution is not uniform, the flow rate distribution may become non-uniform. Further, in Patent Document 2, a plurality of inflow pipe ports are required, and the inflow pipes need to be installed so as not to be parallel to and not to intersect the central axis of the cylindrical part, which has many restrictions and the device configuration is complicated.

[0006] The present invention has been made in view of the above, and can further suppress variations in flow rate distribution with a simple configuration. Ruhi The objective is to provide a pump cycle device. [Means for solving the problem]

[0007] To achieve the above objective, the fluid distributor according to the present invention comprises a cylindrical portion, an inlet pipe into which fluid flows from the inlet end of the cylindrical portion, and a plurality of branch pipes extending radially from near the rear end in the flow direction of the cylindrical portion, wherein the cylindrical portion and the inlet pipe are connected by the same central axis, and the central axis of the branch pipes is perpendicular to the central axis of the cylindrical portion, characterized in that the header length, which is the length from the inlet end to the connection center position of the branch pipes, is greater than the buffer length from the connection center position to the rear end.

[0008] Furthermore, the heat pump cycle device according to the present invention is characterized in that it uses the fluid distributor described above for distributing refrigerant to each compressor in a heat pump cycle device in which multiple compressors are arranged in parallel. [Effects of the Invention]

[0009] According to the present invention, it is possible to further suppress variations in flow rate distribution with a simple configuration. Ruhi We can provide a pump cycle device. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 shows an overview of the circuit configuration of a heat pump type steam generator using a fluid distributor, which is an embodiment of the present invention. [Figure 2] Figure 2 is a front view showing the structure of the fluid distributor. [Figure 3] Figure 3 is a perspective view showing the structure of a fluid distributor. [Figure 4]Figure 4 is a diagram showing the relationship of the distribution variation with respect to the ratio of the length of the cylindrical portion to the outer diameter of the cylindrical portion. [Figure 5] Figure 5 is a diagram showing the relationship of the distribution variation with respect to the ratio of the length of the header portion to half of the length of the cylindrical portion. [Figure 6] Figure 6 is a diagram showing the relationship of the distribution variation with respect to the ratio of the cross-sectional area of the cylindrical portion to the cross-sectional area of the inlet pipe. [Figure 7] Figure 7 is a diagram showing the relationship of the distribution variation with respect to the ratio of the length of the inlet pipe to the outer diameter of the inlet pipe. [Figure 8] Figure 8 is a diagram showing the analysis result of the static pressure distribution of the fluid distributor. [Figure 9] Figure 9 is a diagram showing the analysis result of the flow velocity distribution of the fluid distributor. [Figure 10] Figure 10 is a perspective view showing an example of a fluid distributor in which the branch pipes are not arranged at equal intervals. [Figure 11] Figure 11 is a diagram showing the analysis result of the static pressure distribution in the YZ plane of the fluid distributor shown in Figure 10. [Figure 12] Figure 12 is a diagram showing the analysis result of the static pressure distribution in the XY plane of the fluid distributor shown in Figure 10. [Figure 13] Figure 13 is a diagram showing the analysis result of the flow velocity distribution in the YZ plane of the fluid distributor shown in Figure 10. [Figure 14] Figure 14 is a diagram showing the analysis result of the flow velocity distribution in the XY plane of the fluid distributor shown in Figure 10. [Figure 15] Figure 15 is a perspective view of a heat pump type steam generation device. [Figure 16] Figure 16 is a front view of a heat pump type steam generation device. [Figure 17] Figure 17 is a side view of a heat pump type steam generation device. [Figure 18] Figure 18 is a perspective view showing the fluid distributor and the connecting pipelines from the fluid distributor to the suction port and the intermediate pressure suction port.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments for implementing this invention will be described with reference to the accompanying drawings.

[0012] <Heat pump type steam generation device: Circuit configuration> FIG. 1 is a diagram showing a schematic circuit configuration of a heat pump type steam generation device using a fluid distributor according to an embodiment of the present invention. The actual configuration of the heat pump type steam generation device 1 will be described later. The heat pump type steam generation device 1 shown in FIG. 1 generates steam using a heat pump cycle device 2. The heat pump cycle device 2 has four compressors 11 to 14 (10) arranged in parallel. Each compressor 10 is a two-stage type composed of a low-pressure side compressor 10a and a high-pressure side compressor 10b.

[0013] The number of compressors 10 may be determined according to the required power specification of the system, and there is no need to newly manufacture dedicated products depending on the specification. Depending on the operating state of the system, some of the plurality of compressors 10 may be stopped.

[0014] The evaporator 9 recovers the heat of the exhaust warm water to evaporate the refrigerant and distributes the refrigerant to each of the compressors 11 to 14 (the suction port 10d of the low-pressure side compressor 10a (see FIG. 15)) via the fluid distributor 20. Each of the compressors 11 to 14 compresses the refrigerant, the refrigerant from each of the compressors 11 to 14 merges via the confluence unit 3, and the merged refrigerant flows out to the condenser 4. The condenser 4 heats the water supplied for steam generation. Further, the refrigerant flows into the subcooler 5 and preheats the supplied water. This preheated water flows into the condenser 4. The refrigerant flowing out from the subcooler 5 flows out to the gas-liquid separator 7 via the high-stage expansion valve 6.

[0015] The liquid-phase refrigerant in the gas-liquid separator 7 is further expanded via the low-stage expansion valve 8 and flows into the evaporator 9. On the other hand, the gas-phase refrigerant in the gas-liquid separator 7 is sent as intermediate-pressure refrigerant to the suction ports of the high-stage compressors of each of the compressors 11 to 14. At this time, the intermediate-pressure refrigerant is distributed to each of the compressors 11 to 14 via the fluid distributor 21.

[0016] As described above, the water supplied for steam generation is preheated in the supercooler 5, further heated in the condenser 4, and flows into the gas-liquid separator 30 as gas-liquid two-phase water. The gas-phase water is then output to the outside as output steam via the output control valve 31. Meanwhile, the liquid-phase water in the gas-liquid separator 30 merges with the water preheated by the supercooler 5 and becomes circulating water that is heated again in the condenser 4.

[0017] The internal heat exchangers 16 and 17 are heat exchangers installed to improve thermal efficiency. In addition, the oil from the oil separator 15 installed before the condenser 4 is supplied to each of the compressors 11 to 14 for lubrication of the compressors, sealing of the refrigerant, and rust prevention.

[0018] Here, the fluid distributors 20 and 21 suppress variations in refrigerant distribution and reduce the decrease in heating output of the heat pump cycle device 2.

[0019] <Fluid distributor> Figure 2 is a front view showing the structure of the fluid distributor 20. Figure 3 is a perspective view showing the structure of the fluid distributor 20. The fluid distributor 21 has a similar structure to the fluid distributor 20, but is a different size. In Figure 3, the three orthogonal axis directions are indicated by the X, Y, and Z arrows. The Y axis is in the same direction as the central axis C, which will be described later. The X axis is the extension direction of two of the four branch pipes 26, which will be described later, and the Z axis is the extension direction of the remaining two. Figure 10 follows the same principle.

[0020] As shown in Figures 2 and 3, the fluid distributor 20 has an inlet pipe 22, a cylindrical section 23, and branch pipes 26. The inlet pipe 22 is a cylindrical pipe that allows fluid (refrigerant) to flow into the cylindrical section 23 from its inlet end 23a. The inlet pipe 22 and the cylindrical section 23 are connected by the same central axis C, and the cross-sectional area S1 of the cylindrical section 23 is larger than the cross-sectional area S4 of the inlet pipe 22. The branch pipes 26 are a plurality of cylindrical pipes that extend radially from the circumferential surface of the cylindrical section 23 in the flow direction. The central axis of the branch pipes 26 is perpendicular to the central axis C of the cylindrical section 23. Therefore, each branch pipe 23 is aligned with the XZ plane. In this case, there are four branch pipes 26, which are arranged at equal angle (90°) intervals in the circumferential direction of the cylindrical section 23. Depending on the diameter of the cylindrical section 23 and the branch pipes 26, the fluid distributor 20 is easier to manufacture if the branch pipes 26 are spaced equally (for example, four branches at 90° intervals). Furthermore, all branch pipes 26 have the same diameter.

[0021] The cylindrical section 23 consists of a header section 24 and a buffer section 25. The header section 24 is the upstream region of the cylindrical section 23 and extends from the fluid inlet end 23a to the central axis of the branch pipe 26. The header section 24 has the function of reducing the flow velocity by increasing the cross-sectional area. The buffer section 25 is the downstream region of the cylindrical section 23 and extends from the central axis of the branch pipe 26 to the rear end 23b in the direction of fluid flow. The buffer section 25 functions as a fluid reservoir region that reduces flow rate fluctuations.

[0022] <Component parameters of a fluid distributor> Figure 4 shows the relationship between distribution variation and the ratio of the cylindrical section length d2 to the cylindrical section outer diameter d1. The distribution variation is shown as the absolute value of the distribution ratio of the branch pipe with the least fluid flow, with the distribution ratio when the fluid is evenly distributed to each branch pipe 26 being 0%. As shown in Figure 4, the distribution variation takes a minimum value when the ratio of the cylindrical section length d2 to the cylindrical section outer diameter d1 is around 3.8, and the range in which the distribution variation is 1.0 or less is when the ratio of the cylindrical section length d2 to the cylindrical section outer diameter d1 is between 3.4 and 4.1.

[0023] Figure 5 shows the relationship between distribution variation and the ratio of the header section length d3 (length from the inlet end 23a of the cylindrical section 23 to the connection center position (central axis) of the branch pipe 26) to half of the cylindrical section length d2. As shown in Figure 5, the ratio of the header section length d3 to half of the cylindrical section length d2 takes a minimum value near 1.1, and the range in which the distribution variation is 1.0 or less is when the ratio of the header section length d3 to half of the cylindrical section length d2 is between 0.9 and 1.3. Note that when the branch pipe 26 is in the center of the cylindrical section length d2, the ratio of the header section length d3 to half of the cylindrical section length d2 is 1.0. The buffer section length corresponds to d2-d3.

[0024] Figure 6 shows the relationship between distribution variation and the ratio of the cross-sectional area S1 of the cylindrical section 23 to the cross-sectional area S4 of the inlet pipe 22. As shown in Figure 6, the range in which the distribution variation is 1.0 or less is when the ratio of the cross-sectional area S1 of the cylindrical section 23 to the cross-sectional area S4 of the inlet pipe 22 is 2.5 or more.

[0025] Figure 7 shows the relationship between distribution variation and the ratio of the inlet pipe length d5 ​​to the inlet pipe outer diameter d4. As shown in Figure 7, the range in which the distribution variation is 1 or less is when the ratio of the inlet pipe length d5 ​​to the inlet pipe outer diameter d4 is between 2.2 and 4.8.

[0026] Therefore, by setting the ratio of the length d2 of the cylindrical section to the outer diameter d1 of the cylindrical section to 3.4 to 4.1, the ratio of the length d3 of the header section to half the length d2 of the cylindrical section to 0.9 to 1.3, the ratio of the cross-sectional area S1 of the cylindrical section 23 to the cross-sectional area S4 of the inlet pipe 22 to 2.5 or more, and the ratio of the length d5 ​​of the inlet pipe to the outer diameter d4 of the inlet pipe to 2.2 to 4.8, it is possible to suppress the distribution variation to 1.0 or less.

[0027] <Analysis results based on specific configuration parameters> Here, the static pressure distribution and flow velocity distribution were analyzed when the configuration parameters of the fluid distributor 20 were set as follows: the ratio of the length d2 of the cylindrical section to the outer diameter d1 of the cylindrical section was 3.4 to 4.1; the ratio of the length d3 of the header section to half the length d2 of the cylindrical section was 0.9 to 1.3; the ratio of the cross-sectional area S1 of the cylindrical section 23 to the cross-sectional area S4 of the inlet pipe 22 was 2.5 or more; and the ratio of the length d5 ​​of the inlet pipe to the outer diameter d4 of the inlet pipe was 2.2 to 4.8.

[0028] Figure 8 shows the analysis results of the static pressure distribution of the fluid distributor 20. As shown in Figure 8, the dynamic pressure decreases and the static pressure increases in region E1 of the buffer section 25. Figure 9 shows the analysis results of the flow velocity distribution of the fluid distributor 20. As shown in Figure 9, because there is a bent pipe before the inlet pipe 22, a flow deviation occurs in region E2 of the inlet pipe 22. However, because the cross-sectional area of ​​the cylindrical section 23 is larger than the cross-sectional area of ​​the inlet pipe 22, the flow velocity decreases in region E3 of the header section 24, and the flow velocity fluctuation is reduced in region E4 of the buffer section 25. As a result, the flow velocity (flow rate) of each branch pipe 26 becomes almost uniform, and even when the state of the refrigerant changes, the distribution variation can be kept below 3.0%. Similar results were obtained even when the number of branches of the branch pipe 26 was increased.

[0029] <Arrangement of branch pipes> Note that the branch pipes 26 do not need to be arranged at equal intervals in the circumferential direction of the cylindrical section 23. Figure 10 is a perspective view showing an example of a fluid distributor 20' in which the branch pipes 26 are not arranged at equal intervals. This fluid distributor 20' is configured by removing the branch pipes 26 extending in the -Z direction from the fluid distributor 20 shown in Figures 2 and 3, and consisting of three branch pipes 26.

[0030] Figure 11 shows the analysis results of the static pressure distribution in the YZ plane of the fluid distributor 20'. Figure 12 shows the analysis results of the static pressure distribution in the XY plane of the fluid distributor 20'. Furthermore, Figure 13 shows the analysis results of the velocity distribution in the YZ plane of the fluid distributor 20'. Finally, Figure 14 shows the analysis results of the velocity distribution in the XY plane of the fluid distributor 20'.

[0031] As shown in Figures 11 and 12, in region E10 of the buffer section 25 of the fluid distributor 20', the dynamic pressure is reduced and the static pressure is increased, regardless of whether it is in the YZ or XY plane. Furthermore, as shown in Figures 13 and 14, despite the presence of flow deviation in the inlet pipe 22 of the fluid distributor 20', the flow velocity in the buffer section 25 is reduced, and the flow velocities in regions E11 to E13 of each branch pipe 26 are nearly identical, suppressing distribution variation. It was found that the distribution variation of the fluid distributor 20' could be kept below 3.1%.

[0032] <Heat pump type steam generator: Actual configuration> The actual configuration of the heat pump type steam generator 1 will be described below. Figure 15 is a perspective view of the heat pump type steam generator 1. Figure 16 is a front view of the heat pump type steam generator 1. Figure 17 is a side view of the heat pump type steam generator 1. In this application, the view from the direction of the central axis C of the cylindrical part 23 is considered the front view, and the view from the direction perpendicular to the central axis C is considered the side view. Figures 15, 16, and 17 show the fluid distributors 20, 21, the four compressors 11-14 (10) and related parts, while the condenser 4, subcooler 5, high-stage expansion valve 6, gas-liquid separator 7, low-stage expansion valve 8, etc. are omitted.

[0033] In Figures 15, 16, and 17, the three orthogonal axis directions are indicated by arrows α, β, and γ. The α axis is in the same direction as the central axis C and the X axis. The β axis is perpendicular to the α axis in the horizontal plane. In other words, the α-β axis forms the horizontal plane. The γ axis is vertical. The β and γ axes are inclined at 45° with respect to the X and Z axes.

[0034] The four compressors 10 are mounted on a rack (not shown) in two tiers, upper and lower. Compressors 11 and 12 are arranged in parallel along the β axis on the upper tier, and compressors 13 and 14 are arranged in parallel along the β axis on the lower tier. Compressor 11 on the upper tier and compressor 13 on the lower tier are at the same position in the β direction. Compressor 12 on the upper tier and compressor 14 on the lower tier are at the same position in the β direction. Compressors 11 and 12 are positioned slightly offset from compressors 13 and 14 along the α axis towards the front side (left side in Figure 17). Further below compressors 13 and 14 are two motors 40a and 40b. Motor 40a is located approximately below compressor 11, and motor 40b is located approximately below compressor 14. Motor 40a synchronously drives compressors 11 and 12 by belt 41a. Motor 40b synchronously drives compressors 13 and 14 by belt 41b. Depending on the system status, motor 40a or 40b may be stopped, and the number of operating compressors 10 may be reduced to two.

[0035] The compressor 10 is driven by belts 41a and 41b via an input shaft 10c located on the rear side, which is aligned with the α-axis. The front of the compressor 10 is provided with a refrigerant inlet 10d, a discharge port 10e, a first intermediate port 10g, and a second intermediate port 10f. These are all oriented in the same direction as the α-axis, i.e., the central axis C. In a front view (see Figure 16), the input shaft 10c is approximately at the center of gravity of the compressor 10, and relative to the input shaft 10c, the inlet 10d is diagonally below it, and the discharge port 10e is on the opposite side. The first intermediate port 10g and the second intermediate port 10f are connected by an intermediate pipe 42. The inlet 10d is the inlet of the low-pressure side compressor 10a (see Figure 1).

[0036] An intermediate pressure inlet 10h is provided in the diagonally upper part of the compressor 10's casing. Refrigerant flowing out from the intermediate pressure inlet 10h flows through the intermediate piping 42 into the inlet of the high-pressure side compressor 10b (see Figure 1). The intermediate pressure inlet 10h is aligned with the X-axis. In other words, the intermediate pressure inlet 10h is oriented in a different direction from the central axis C of the cylindrical section 23. The intermediate pressure inlet 10h has a smaller diameter than the inlet 10d. After flowing into the intermediate inlet 10h, the refrigerant cools each bearing of the compressor 10, and then flows from the first intermediate inlet 10g to the second intermediate inlet 10f. On the other hand, a single compressor 10 has a low-stage compression chamber and a high-stage compression chamber. Refrigerant flowing into the low-stage inlet 10d is compressed in the low-stage compression chamber, merges with the refrigerant flowing out from the second intermediate inlet 10f, flows into the high-stage compression chamber, and finally the refrigerant is discharged from the high-stage discharge 10e.

[0037] Fluid distributor 20 is approximately twice the size of fluid distributor 21 in terms of dimensions. Fluid distributors 20 and 21 are located on the front side (left side in Figure 17) of the compressors 11-14, and the central axis C of each cylindrical section 23 is horizontal, and as described above, the central axis C is aligned with the α axis. In this embodiment, in a side view (see Figure 17), the distance between fluid distributor 20 and compressors 13 and 14 is approximately the length d2 of the cylindrical section (see Figure 2), and the cylindrical section 23 of fluid distributor 21 is located between fluid distributor 20 and compressors 13 and 14. Fluid distributor 21 is located almost on the extension of the input shaft 10c in compressor 11 (see Figure 16).

[0038] The fluid distributors 20 and 21 are positioned so that the central axis C of the cylindrical portion 23 is horizontal. If the buffer portion 25 were facing upward, it would be necessary to raise the oil, which has a higher specific gravity, along with the refrigerant, resulting in a large pressure loss and a decrease in the performance of the heat pump cycle device 2. Conversely, if the buffer portion 25 were facing downward, the buffer portion 25 would be at the bottom, causing oil to accumulate and resulting in variations in fluid distribution, which would reduce efficiency due to friction losses in the sliding parts of the compressor 10. In contrast, in this embodiment, since the central axis C of the cylindrical portion 23 of the fluid distributors 20 and 21 is horizontal, pressure loss and friction loss can be suppressed.

[0039] Figure 18 is a perspective view showing fluid distributors 20 and 21 and the connecting pipelines from the fluid distributors 20 and 21 to the inlet 10d and the intermediate pressure inlet 10h. While the branch pipes 26 of the fluid distributors 20 and 21 are set to a moderately short length for storage and transport as individual components, they are extended by welding, fittings, etc., when assembled as the heat pump type steam generator 1. In the explanation based on Figure 18, the branch pipe 26 is defined as extending to the first bend. The branch pipe 26 of the fluid distributor 20 is extended to approximately three times its original length up to the first bend. The branch pipe 26 of the fluid distributor 21 is extended to approximately five times its original length up to the first bend. The pipelines from the branch pipe 26 to the inlet 10d and the intermediate pressure inlet 10h are connected by welding and fittings as appropriate, but in the following explanation, the before and after of the connection points will not be distinguished. The pipeline from the fluid distributor 20 to the inlet 10d has a constant diameter. The diameter of the pipeline from the fluid distributor 21 to the intermediate pressure inlet 10h is constant. The diameter of the pipeline from the fluid distributor 20 to the inlet 10d is larger than the diameter of the pipeline from the fluid distributor 21 to the intermediate pressure inlet 10h.

[0040] The four branch pipes 26 in the fluid distributor 21 are distinguished as branch pipes 43a, 43b, 43c, and 43d. The lengths of each branch pipe 43a, 43b, 43c, and 43d are equal. In Figure 18, branch pipe 43a extends diagonally to the upper left, branch pipe 43b extends diagonally to the upper right, branch pipe 43c extends diagonally to the lower left, and branch pipe 43d extends diagonally to the lower right.

[0041] The branch pipe 43a is connected to the intermediate pressure inlet 10h of the compressor 11 by a short inlet connecting pipe 44aa. The branch pipe 43a and the inlet connecting pipe 44aa are connected by a horizontal intermediate pipe 44ab. The branch pipe 43a and the inlet connecting pipe 44aa are bent at a 90-degree angle from the intermediate pipe 44ab. The branch pipe 43a, intermediate pipe 44ab, and inlet connecting pipe 44aa from the fluid distributor 21 to the intermediate pressure inlet 10h of the compressor 11 are designated as the first intermediate pressure distribution pipe 46a.

[0042] The branch pipe 43b is connected to the intermediate pressure inlet 10h of the compressor 12 by a short inlet connecting pipe 44ba. The branch pipe 43b and the inlet connecting pipe 44ba are connected by a horizontal intermediate pipe 44bb. The branch pipe 43b and the inlet connecting pipe 44ba are bent at a 90-degree angle from the intermediate pipe 44bb. The branch pipe 43b, intermediate pipe 44bb, and inlet connecting pipe 44ba from the fluid distributor 21 to the intermediate pressure inlet 10h of the compressor 12 are designated as the second intermediate pressure distribution pipe 46b.

[0043] The branch pipe 43c is connected to the intermediate pressure intake port 10h of the compressor 13 by a short intake connection pipe 44ca. The branch pipe 43c and the intake connection pipe 44ca are connected by a horizontal first relay pipe 44cb and a vertical second relay pipe 44cc. The section between the intake connection pipe 44ca and the first relay pipe 44cb is bent at a 90-degree angle. The section between the first relay pipe 44cb and the second relay pipe 44cc is bent at a 90-degree angle. The section between the branch pipe 43c and the second relay pipe 44cc is bent at approximately a 120-degree angle. The branch pipe 43c, the second relay pipe 44cc, the first relay pipe 44cb, and the intake connection pipe 44ca from the fluid distributor 21 to the intermediate pressure intake port 10h of the compressor 13 are designated as the third intermediate pressure distribution pipe 46c.

[0044] The branch pipe 43d is connected to the intermediate pressure intake port 10h of the compressor 14 by a short intake connection pipe 44da. The branch pipe 43d and the intake connection pipe 44da are connected by a horizontal first relay pipe 44db and a vertical second relay pipe 44dc. The section between the intake connection pipe 44da and the first relay pipe 44db is bent at a 90-degree angle. The section between the first relay pipe 44db and the second relay pipe 44dc is bent at a 90-degree angle. The section between the branch pipe 43d and the second relay pipe 44dc is bent at approximately a 120-degree angle. The branch pipe 43d, the second relay pipe 44dc, the first relay pipe 44db, and the intake connection pipe 44da from the fluid distributor 21 to the intermediate pressure intake port 10h of the compressor 14 are designated as the fourth intermediate pressure distribution pipe 46d.

[0045] The inlet connecting pipes 44aa, 44ba, 44ca, and 44da are of equal length and oriented in the same direction as the branch pipes 43a and 43d. The intermediate pipes 44ab and 44bb are of equal length. The first intermediate pipes 44cb and 44db are of equal length and shorter than the intermediate pipes 44ab and 44bb. The second intermediate pipes 44cc and 44dc are of equal length. Intermediate pipes 44ab to 44db are oriented in the same direction as the central axis C of the cylindrical section 23.

[0046] The four branch pipes 26 in the fluid distributor 20 are distinguished as branch pipes 26a, 26b, 26c, and 26d. The lengths of each branch pipe 26a, 26b, 26c, and 26d are equal. In Figure 18, branch pipe 26a extends diagonally to the upper left, branch pipe 26b extends diagonally to the upper right, branch pipe 26c extends diagonally to the lower left, and branch pipe 26d extends diagonally to the lower right.

[0047] The branch pipe 26a is connected to the intermediate pressure inlet 10h of the compressor 11 by a horizontal inlet connecting pipe 45aa. The section between the branch pipe 26a and the inlet connecting pipe 45aa is bent at a 90-degree angle. The branch pipe 26a and the inlet connecting pipe 45aa from the fluid distributor 20 to the inlet 10d of the compressor 11 are designated as the first low-pressure distribution pipe 47a.

[0048] The branch pipe 26b is connected to the intermediate pressure inlet 10h of the compressor 12 by a horizontal inlet connecting pipe 45ba. The section between the branch pipe 26b and the inlet connecting pipe 45ba is bent at a 90-degree angle. The branch pipe 26b and the inlet connecting pipe 45ba from the fluid distributor 20 to the inlet 10d of the compressor 12 are designated as the second low-pressure distribution pipe 47b.

[0049] The branch pipe 26c is connected to the intermediate pressure intake port 10h of the compressor 13 by a horizontal intake port connecting pipe 45ca. The branch pipe 26c and the intake port connecting pipe 45ca are connected by a vertical intermediate pipe 45cb. The section between the intake port connecting pipe 45ca and the intermediate pipe 45cb is bent at a 90-degree angle. The section between the branch pipe 26c and the intermediate pipe 45cb is bent at approximately a 120-degree angle. The branch pipe 26c, intermediate pipe 45cb, and intake port connecting pipe 45ca from the fluid distributor 20 to the intake port 10d of the compressor 13 are designated as the third low-pressure distribution pipe 47c.

[0050] The branch pipe 26d is connected to the intermediate pressure intake port 10h of the compressor 14 by a horizontal intake port connecting pipe 45da. The branch pipe 26d and the intake port connecting pipe 45da are connected by a vertical intermediate pipe 45db. The section between the intake port connecting pipe 45da and the intermediate pipe 45db is bent at a 90-degree angle. The section between the branch pipe 26d and the intermediate pipe 45db is bent at approximately a 120-degree angle. The branch pipe 26d, intermediate pipe 45db, and intake port connecting pipe 45da from the fluid distributor 20 to the intake port 10d of the compressor 14 are designated as the fourth low-pressure distribution pipe 47d.

[0051] The suction port connecting tubes 45aa and 45ba are of equal length. The suction port connecting tubes 45ca and 45da are of equal length and shorter than the suction port connecting tubes 45aa and 45ba. The suction port connecting tubes 45aa to 45da are oriented in the same direction as the central axis C of the cylindrical section 23. The intermediate tubes 45cb and 45db are of equal length.

[0052] Furthermore, in this embodiment, the first low-pressure distribution pipe 47a, the second low-pressure distribution pipe 47b, the third low-pressure distribution pipe 47c, and the third low-pressure distribution pipe 47d are approximately equal in length. In addition, the first intermediate-pressure distribution pipe 46a, the second intermediate-pressure distribution pipe 46b, the third intermediate-pressure distribution pipe 46c, and the third intermediate-pressure distribution pipe 46d are approximately equal in length. As a result, the pressure loss between the fluid distributors 20 and 21 and each inlet 10d or each intermediate-pressure inlet 10h becomes approximately the same, allowing for a more even distribution of the refrigerant.

[0053] The low-pressure distribution pipes 47a to 47d have fewer bends than the medium-pressure distribution pipes 46a and 46b. Since the low-pressure distribution pipes 47a to 47d have a larger diameter than the medium-pressure distribution pipes 46a and 46b, fewer bends are preferable for manufacturing purposes, and they are given priority over the medium-pressure distribution pipes 46a and 46b in terms of layout.

[0054] As shown in the front view in Figure 16, that is, as viewed from the direction of the central axis C of the cylindrical part 23 of the fluid distributor 20, the fluid distributor 20 is located within the range of a quadrilateral (polygon) R1 with the refrigerant inlets 10d of the four compressors 10 as corners, making it easy to set the lengths of the low-pressure distribution pipes 47a to 47d to be equal. In general, when three or more compressors 10 are installed, it is good to install the fluid distributor 20 within the range of a polygon with the inlets 10d as corners. Furthermore, since the branch pipes 26a to 26d of the fluid distributor 20 are installed at equal angular intervals, the balance is good, and it becomes even easier to set the lengths of the low-pressure distribution pipes 47a to 47d to be equal. Setting the branch pipes 26a to 26d of the fluid distributor 20 at equal angular intervals makes it versatile and easy to apply to various systems.

[0055] As described above, the branch pipes 43a to 43d of the fluid distributor 21 are connected to the intermediate pressure inlet 10h via the intermediate pipes (horizontal conduits) 44ab to 44db. When viewed from the front, the fluid distributor 21 is located within the range of a rectangle R2 with the intermediate pipes 44ab to 44db as corners, making it easy to set the lengths of the intermediate pressure distribution pipes 46a to 46d to be equal.

[0056] In the front view, the fluid distributor 20 is located at the center of the rectangle R1 in the β direction (horizontal direction). Therefore, the first low-pressure distribution pipes 47a and 47b for the compressor 11 and compressor 12 can use substantially the same piping, and the third low-pressure distribution pipes 47c and 47d can also use substantially the same piping. Furthermore, since the fluid distributor 21 is located at the center of the rectangle R2 in the β direction, it has the same effect on the medium-pressure distribution pipes 46a to 46d as on the low-pressure distribution pipes 47a to 47d. Note that if the β direction is vertical and the γ direction is horizontal, the fluid distributors 20 and 21 will be located at the vertical center of the rectangles R1 and R2, respectively, and will have the same effect.

[0057] In this embodiment, the third low-pressure distribution pipe 47c and the fourth low-pressure distribution pipe 47d each have two bends. However, the fluid distributor 20 is located at the center of the rectangle R1 in the β direction, and the first low-pressure distribution pipe 47a and the second low-pressure distribution pipe 47b, which are connected to the suction ports 10d of the two compressors 10(11,12) that form a pair at both ends in the β direction, each only have one 90-degree bend, thus reducing the number of steps required for pipe bending.

[0058] It should be noted that the configurations illustrated in the above embodiments are functional schematics and do not necessarily have to be physically represented as shown. In other words, the forms of distribution and integration of each device and component are not limited to those shown, and all or part of them can be functionally or physically distributed and integrated in any unit according to various usage situations. [Explanation of symbols]

[0059] 1. Heat pump type steam generator 2. Heat pump cycle device 3 Combiner 4. Condenser 5 Supercooler 6. High-stage expansion valve 7,30 Gas-liquid separator 8. Low-stage expansion valve 9 Evaporator 10, 11~14 Compressor 15 Oil separator 16,17 Internal heat exchanger 20,20´,21 Fluid distributor 22 Inflow pipe 23 Cylindrical section 24 Header section 25 Buffer section 26 Branch pipes 31 Output control valve C center axis d1 Outer diameter of the cylindrical part d2 length of cylindrical section d3 Header section length d4 Inflow pipe outer diameter d5 Inlet pipe length E1~E4,E10~E13 area S1, S4 cross-sectional areas

Claims

1. A heat pump cycle device using a fluid distributor for distributing refrigerant to a plurality of compressors arranged in parallel, The aforementioned refrigerant contains oil, The fluid distributor comprises a cylindrical section, an inlet pipe through which fluid flows in from the inlet end of the cylindrical section, and a plurality of branch pipes extending radially from the cylindrical section, wherein the cylindrical section and the inlet pipe are connected by the same central axis, and the central axis of the branch pipes is perpendicular to the central axis of the cylindrical section. The ratio of the length of the cylindrical part to the outer diameter of the cylindrical part is 3.4 to 4.

1. The ratio of the header section length, which is the length from the inlet end to the connection center position of the branch pipe, to half the length of the cylindrical section is 0.9 to 1.

3. The ratio of the cross-sectional area of ​​the cylindrical portion to the cross-sectional area of ​​the inlet pipe is 2.5 or more. The ratio of the length of the inlet pipe to the outer diameter of the inlet pipe is 2.2 to 4.

8. The central axis of the cylindrical part is horizontal. A heat pump cycle device characterized by the following features.

2. Three or more of the aforementioned compressors are provided. The refrigerant inlets in the multiple compressors are oriented in the same direction as the central axis of the cylindrical portion. Viewed from the direction of the central axis of the cylindrical portion, the fluid distributor is located within a polygonal area where the refrigerant inlets of the multiple compressors form the corners. The heat pump cycle device according to feature 1.

3. Three or more of the aforementioned compressors are provided. The refrigerant inlets in the multiple compressors are oriented in a direction different from the central axis of the cylindrical portion. The branch pipe is connected to the intake port via a horizontal conduit in the same direction as the central axis of the cylindrical portion. Viewed from the direction of the central axis of the cylindrical portion, the fluid distributor is located within the range of a polygon formed by the multiple horizontal pipes forming corners. The heat pump cycle device according to feature 1.

4. Viewed from the direction of the central axis of the cylindrical portion, the fluid distributor is located at the horizontal or vertical center of the polygon. The heat pump cycle device according to claim 2 or 3, characterized by the above.

5. Multiple branch pipes are provided at equal angular intervals. The heat pump cycle device according to feature 1.

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