Fluid distributor and heat pump cycle apparatus

Abstract

The present invention further suppresses variation in flow distribution using a simple configuration. A fluid distributor 20 comprises a cylindrical section 23, an inflow pipe 22 that allows the inflow of a fluid through the inflow end of the cylindrical section 23, and at least one branch pipe 26 that radially extends from the cylindrical section, wherein the cylindrical section 23 and the inflow pipe 22 are connected together so as to have a common central axis C, the central axis of the branch pipe 26 is orthogonal to the central axis C of the cylindrical section 23, and the downstream end side of the cylindrical section 23 in a flow direction functions as a buffer section 25 that blocks the downstream direction in the flow direction. The ratio of a cylindrical section length d2 to a cylindrical section outer diameter d1 is 3.4-4.1, the ratio of a header section length d3, which is the length from the inflow end of the cylindrical section 23 to the connection center position of the branch pipe 26, to 1 / 2 of the cylindrical section length d2 is 0.9-1.3, the ratio of the cross-sectional area S1 of the cylindrical section 23 to the cross-sectional area S4 of the inflow pipe 22 is not less than 2.5, and the ratio of an inflow pipe length d5 to an inflow pipe outer diameter d4 is 2.2-4.8.

Description

Fluid distributor and heat pump cycle device

[0001] The present invention relates to an optimal fluid distributor that can further suppress variations in flow rate distribution with a simple configuration, and a heat pump cycle device using the same.

[0002] When compressors of a heat pump cycle device used in a heat pump type steam generator or the like are connected in parallel, a refrigerant distributor is used to distribute refrigerant to the suction sections of each compressor, thereby suppressing variations in refrigerant distribution and reducing a decrease in the heating output of the heat pump cycle device.

[0003] In Patent Document 1 (JPA 1994-42522), a cylindrical portion, an inlet pipe connected to the cylindrical portion on the same central axis, and branch pipes on the side of the cylindrical portion are provided to make the pipe friction value from the inlet pipe to each branch pipe the same, resulting in a structure that achieves uniform and average diffusion.In addition, in Patent Document 2 (JPA 2014-222143), multiple inlet pipes are installed at the bottom of the cylinder to generate a spiral flow and suppress distribution variations.

[0004] Japanese Patent Laid-Open No. 6-42522 Japanese Patent Laid-Open No. 2014-222143

[0005] However, Patent Document 1 does not take into consideration the influence of drift in the piping, and if the flow velocity distribution is not uniform, the flow rate distribution may become uneven. Furthermore, Patent Document 2 requires multiple inlet pipe ports, and the inlet pipes must be installed so as not to be parallel to the central axis of the cylindrical portion and not to intersect with it, resulting in many restrictions and a complex device configuration.

[0006] The present invention has been made in consideration of the above, and aims to provide an optimal fluid distributor that can further suppress flow distribution variations with a simple configuration, and a heat pump cycle device using the same.

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

[0008] The heat pump cycle device according to the present invention is characterized in that the fluid distributor described above is used to distribute refrigerant to each compressor in a heat pump cycle device in which a plurality of compressors are arranged in parallel.

[0009] According to the present invention, it is possible to provide an optimum fluid distributor that can further suppress variations in flow rate distribution with a simple configuration, and a heat pump cycle apparatus using the same.

[0010] FIG. 1 is a diagram showing a schematic circuit configuration of a heat pump steam generating device using a fluid distributor according to an embodiment of the present invention. FIG. 2 is a front view showing the structure of the fluid distributor. FIG. 3 is a perspective view showing the structure of the fluid distributor. FIG. 4 is a diagram showing the relationship between the ratio of the cylindrical portion length to the cylindrical portion outer diameter and the distribution variation versus the ratio of the header portion length to 1 / 2 the cylindrical portion length. FIG. 5 is a diagram showing the relationship between the ratio of the header portion length to 1 / 2 the cylindrical portion length. FIG. 6 is a diagram showing the relationship between the ratio of the cylindrical portion cross-sectional area to the inflow pipe cross-sectional area and the distribution variation versus the ratio of the inflow pipe length to the inflow pipe outer diameter and the distribution variation versus the ratio of the inflow pipe length to the inflow pipe outer diameter. FIG. 8 is a diagram showing the analysis results of the static pressure distribution of the fluid distributor. FIG. 9 is a diagram showing the analysis results of the flow velocity distribution of the fluid distributor. FIG. 10 is a perspective view showing an example of a fluid distributor in which branch pipes are not arranged at equal intervals. FIG. 11 is a diagram showing the analysis results of the static pressure distribution in the YZ plane of the fluid distributor shown in FIG. 10. FIG. 12 is a diagram showing the analysis results of the static pressure distribution in the XY plane of the fluid distributor shown in FIG. 10. Fig. 13 is a diagram showing the analysis results of flow velocity distribution in the YZ plane of the fluid distributor shown in Fig. 10. Fig. 14 is a diagram showing the analysis results of flow velocity distribution in the XY plane of the fluid distributor shown in Fig. 10. Fig. 15 is a perspective view of a heat pump type steam generator. Fig. 16 is a front view of a heat pump type steam generator. Fig. 17 is a side view of a heat pump type steam generator. Fig. 18 is a perspective view showing a fluid distributor and connecting pipes from the fluid distributor to an inlet and an intermediate pressure inlet.

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0012] <Heat Pump Steam Generator: Circuit Configuration> Figure 1 is a diagram showing the general circuit configuration of a heat pump steam generator using a fluid distributor according to an embodiment of the present invention. The actual configuration of the heat pump steam generator 1 will be described later. The heat pump steam generator 1 shown in Figure 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 consisting of a low-pressure side compressor 10a and a high-pressure side compressor 10b.

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

[0014] The evaporator 9 recovers heat from the waste hot water to evaporate the refrigerant, and distributes the refrigerant to each compressor 11 to 14 (suction port 10d of low-pressure side compressor 10a (see FIG. 15)) via a fluid distributor 20. Each compressor 11 to 14 compresses the refrigerant, and the refrigerants from each compressor 11 to 14 are combined via a combiner 3, and the combined refrigerant flows into a condenser 4. The condenser 4 heats water supplied to generate steam. Furthermore, the refrigerant flows into a supercooler 5, where it preheats the supplied water. This preheated water flows into the condenser 4. The refrigerant flowing out of the supercooler 5 flows into a gas-liquid separator 7 via a high-stage expansion valve 6.

[0015] The liquid-phase refrigerant in the gas-liquid separator 7 is further expanded through 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, and at this time, the intermediate-pressure refrigerant is distributed to each of the compressors 11 to 14 via a fluid distributor 21.

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

[0017] The internal heat exchangers 16 and 17 are heat exchangers provided to improve thermal efficiency. The oil from the oil separator 15 provided in the upstream stage of the condenser 4 is supplied to each of the compressors 11 to 14 to lubricate the compressors, seal the refrigerant, and prevent rust.

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

[0019] <Fluid Distributor> Fig. 2 is a front view showing the structure of the fluid distributor 20. Fig. 3 is a perspective view showing the structure of the fluid distributor 20. Note that the fluid distributor 21 has a similar structure to the fluid distributor 20, but is a different size. In Fig. 3, three orthogonal axial directions are indicated by arrows X, Y, and Z. The Y axis is 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, that are mutually extending, and the Z axis is the extension direction of the remaining two. Fig. 10 is similar to this.

[0020] As shown in FIGS. 2 and 3 , the fluid distributor 20 includes an inlet pipe 22, a cylindrical portion 23, and branch pipes 26. The inlet pipe 22 is a cylindrical pipe that introduces a fluid (refrigerant) into the cylindrical portion 23 from an inlet end 23a. The inlet pipe 22 and the cylindrical portion 23 are connected along the same central axis C, and the cross-sectional area S1 of the cylindrical portion 23 is larger than the cross-sectional area S4 of the inlet pipe 22. The branch pipes 26 are multiple cylindrical pipes that extend radially from the circumferential surface of the cylindrical portion 23 midway along the flow direction. The central axes of the branch pipes 26 are perpendicular to the central axis C of the cylindrical portion 23. Therefore, each branch pipe 23 is aligned along the X-Z plane. Note that there are four branch pipes 26, which are arranged at equal angular intervals (90°) around the cylindrical portion 23. Although this depends on the pipe diameters of the cylindrical portion 23 and the branch pipes 26, the fluid distributor 20 is easier to manufacture if the branch pipes 26 are spaced at equal intervals (e.g., four branches at 90° intervals). Moreover, the branch pipes 26 all have the same diameter.

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

[0022] <Parameters of Component Elements of Fluid Distributor> Figure 4 is a diagram showing the relationship between the ratio of the cylindrical portion length d2 to the cylindrical portion outer diameter d1 and the distribution variation. Note that the distribution variation is shown as the absolute value of the distribution ratio of the branch pipe with the least fluid flowing, 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 reaches a minimum value when the ratio of the cylindrical portion length d2 to the cylindrical portion outer diameter d1 is near 3.8, and the range in which the distribution variation is 1.0 or less is when the ratio of the cylindrical portion length d2 to the cylindrical portion outer diameter d1 is 3.4 to 4.1.

[0023] 5 is a diagram showing the relationship between the ratio of the header length d3, which is the length from the inlet end 23a of the cylindrical portion 23 to the connection center position (central axis) of the branch pipe 26, to 1 / 2 of the cylindrical portion length d2, and the distribution variation. As shown in FIG. 5, the ratio of the header length d3 to 1 / 2 of the cylindrical portion 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 length d3 to 1 / 2 of the cylindrical portion length d2 is 0.9 to 1.3. Note that when the branch pipe 26 is located in the center of the cylindrical portion length d2, the ratio of the header length d3 to 1 / 2 of the cylindrical portion length d2 is 1.0. The buffer portion length corresponds to d2-d3.

[0024] 6 is a diagram showing the relationship between the distribution variation and the ratio of the cross-sectional area S1 of the cylindrical portion 23 to the cross-sectional area S4 of the inflow pipe 22. As shown in Fig. 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 portion 23 to the cross-sectional area S4 of the inflow pipe 22 is 2.5 or more.

[0025] 7 is a diagram showing the relationship between the ratio of the inlet pipe length d5 ​​to the inlet pipe outer diameter d4 and the distribution variation. As shown in Fig. 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 2.2 to 4.8.

[0026] Therefore, by setting the ratio of the cylindrical portion length d2 to the cylindrical portion outer diameter d1 to 3.4 to 4.1, the ratio of the header portion length d3 to 1 / 2 of the cylindrical portion length d2 to 0.9 to 1.3, the ratio of the cross-sectional area S1 of the cylindrical portion 23 to the cross-sectional area S4 of the inlet pipe 22 to 2.5 or more, and the ratio of the inlet pipe length d5 ​​to the inlet pipe outer diameter d4 to 2.2 to 4.8, it is possible to suppress the distribution variation to 1.0 or less.

[0027] <Analysis Results Using Specific Structural Parameters> Here, the static pressure distribution and flow velocity distribution were analyzed when the structural parameter values ​​of the fluid distributor 20 were set to a ratio of the cylindrical portion length d2 to the cylindrical portion outer diameter d1 of 3.4 to 4.1, a ratio of the header portion length d3 to 1 / 2 of the cylindrical portion length d2 of 0.9 to 1.3, a ratio of the cross-sectional area S1 of the cylindrical portion 23 to the cross-sectional area S4 of the inflow pipe 22 of 2.5 or more, and a ratio of the inflow pipe length d5 ​​to the inflow pipe outer diameter d4 of 2.2 to 4.8.

[0028] FIG. 8 shows the analysis results of the static pressure distribution of the fluid distributor 20. As shown in FIG. 8, the dynamic pressure decreases and the static pressure increases in region E1 of the buffer section 25. FIG. 9 shows the analysis results of the flow velocity distribution of the fluid distributor 20. As shown in FIG. 9, the presence of a bent pipe upstream of the inlet pipe 22 causes a drift in region E2 of the inlet pipe 22. However, because the cross-sectional area of ​​the cylindrical section 23 is larger than that of the inlet pipe 22, the flow velocity decreases in region E3 of the header section 24, and the flow velocity fluctuations are reduced in region E4 of the buffer section 25. Furthermore, the flow velocity (flow rate) of each branch pipe 26 is nearly uniform, and even if the refrigerant state changes, the distribution variation is kept to 3.0% or less. Similar results were obtained even when the number of branches of the branch pipe 26 was increased.

[0029] <Arrangement of branch pipes> The branch pipes 26 do not have to be arranged at equal intervals in the circumferential direction of the cylindrical portion 23. Fig. 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 pipe 26 extending in the -Z direction of the fluid distributor 20 shown in Figs. 2 and 3 and by using three branch pipes 26.

[0030] Fig. 11 is a diagram showing the analysis results of the static pressure distribution in the YZ plane of the fluid distributor 20'. Fig. 12 is a diagram showing the analysis results of the static pressure distribution in the XY plane of the fluid distributor 20'. Fig. 13 is a diagram showing the analysis results of the flow velocity distribution in the YZ plane of the fluid distributor 20'. Fig. 14 is a diagram showing the analysis results of the flow velocity distribution in the XY plane of the fluid distributor 20'.

[0031] As shown in Figures 11 and 12, in the 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 plane or the XY plane. Furthermore, as shown in Figures 13 and 14, despite the occurrence of drift 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 the regions E11 to E13 of each branch pipe 26 are approximately the same, suppressing distribution variation. It was found that the distribution variation of the fluid distributor 20' was suppressed to 3.1% or less.

[0032] <Heat Pump Steam Generator: Actual Configuration> The actual configuration of the heat pump steam generator 1 will be described. Fig. 15 is a perspective view of the heat pump steam generator 1. Fig. 16 is a front view of the heat pump steam generator 1. Fig. 17 is a side view of the heat pump steam generator 1. In the present application, the state seen from the direction of the central axis C of the cylindrical portion 23 is referred to as the front, and the state seen from a direction perpendicular to the central axis C is referred to as the side. Figs. 15, 16, and 17 show the fluid distributors 20, 21, the four compressors 11 to 14 (10), and related parts, but omit the condenser 4, the subcooler 5, the high-stage expansion valve 6, the gas-liquid separator 7, the low-stage expansion valve 8, etc.

[0033] In Figures 15, 16, and 17, the three orthogonal axial 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 in a direction perpendicular to the α axis in a horizontal plane. In other words, the α axis - β axis form a horizontal plane. The γ axis is in the vertical direction. The β axis and γ axis are inclined at 45° with respect to the X axis and Z axis.

[0034] The four compressors 10 are mounted in two upper and lower tiers on a rack (not shown). Compressors 11 and 12 are arranged side by side along the β axis on the upper tier, and compressors 13 and 14 are arranged side by side along the β axis on the lower tier. The upper compressor 11 and the lower compressor 13 are positioned at the same position in the β direction. The upper compressor 12 and the lower compressor 14 are positioned at the same position in the β direction. Compressors 11 and 12 are positioned slightly forward (left side in FIG. 17 ) relative to compressors 13 and 14 along the α axis. Two motors 40a and 40b are provided on a tier below compressors 13 and 14. 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 via belt 41a. Motor 40b synchronously drives compressors 13 and 14 via belt 41b. Depending on the state of the system, the motor 40a or 40b may be stopped, and the number of operating compressors 10 may be two.

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

[0036] An intermediate-pressure suction port 10h is provided in a diagonally upper portion of the housing of the compressor 10. Refrigerant flowing out of the intermediate-pressure suction port 10h passes through an intermediate pipe 42 and flows into the suction port of the high-pressure compressor 10b (see FIG. 1). The intermediate-pressure suction port 10h is aligned along the X-axis. That is, the intermediate-pressure suction port 10h is oriented in a direction different from the central axis C of the cylindrical portion 23. The intermediate-pressure suction port 10h has a smaller diameter than the suction port 10d. After flowing into the intermediate port 10h, the refrigerant cools the bearings of the compressor 10 and then flows from the first intermediate port 10g to the second intermediate port 10f. Each compressor 10 has a low-stage compression chamber and a high-stage compression chamber. The refrigerant flowing into the low-stage inlet 10d is compressed in the low-stage compression chamber, merges with the refrigerant flowing out of the second intermediate port 10f, flows into the high-stage compression chamber, and is finally discharged from the high-stage discharge port 10e.

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

[0038] The fluid distributors 20, 21 are provided so that the central axis C of the cylindrical portion 23 is horizontal. If the buffer portion 25 were facing upward, oil, which has a high specific gravity, would need to rise along with the refrigerant, resulting in increased pressure loss and reduced performance of the heat pump cycle device 2. Conversely, if the buffer portion 25 were facing downward, the buffer portion 25 would become the bottom, causing oil to stagnate and resulting in uneven fluid distribution, resulting in reduced efficiency due to friction loss in the sliding portions of the compressor 10. In contrast, in this embodiment, the central axis C of the cylindrical portion 23 of the fluid distributors 20, 21 is horizontal, making it possible to suppress pressure loss and friction loss.

[0039] FIG. 18 is a perspective view showing the fluid distributors 20, 21 and the connecting pipes from the fluid distributors 20, 21 to the suction port 10d and the intermediate-pressure suction port 10h. The branch pipes 26 of the fluid distributors 20, 21 are set to be appropriately short for easy storage and transportation when used as individual components, but are extended by welding, fittings, etc. when assembled into the heat pump steam generator 1. In the description based on FIG. 18, the branch pipes 26 are defined as those extending to the first bend. The branch pipes 26 of the fluid distributor 20 are extended approximately three times their original length to the first bend. The branch pipes 26 of the fluid distributor 21 are extended approximately five times their original length to the first bend. The pipes from the branch pipes 26 to the suction port 10d and the intermediate-pressure suction port 10h are connected by welding or fittings as appropriate, but the following description will not distinguish between before and after the connection. The pipes from the fluid distributor 20 to the suction port 10d have a constant diameter. The diameter of the pipe from the fluid distributor 21 to the intermediate pressure suction port 10h is constant. The diameter of the pipe from the fluid distributor 20 to the suction port 10d is larger than the diameter of the pipe from the fluid distributor 21 to the intermediate pressure suction port 10h.

[0040] The four branch pipes 26 in the fluid distributor 21 are identified as branch pipes 43a, 43b, 43c, and 43d. Each branch pipe 43a, 43b, 43c, and 43d has the same length. In Fig. 18, the branch pipe 43a extends diagonally upward to the left, the branch pipe 43b extends diagonally upward to the right, the branch pipe 43c extends diagonally downward to the left, and the branch pipe 43d extends diagonally downward to the right.

[0041] The branch pipe 43a is connected to the intermediate-pressure suction port 10h of the compressor 11 via a short suction port connecting pipe 44aa. A horizontal relay pipe 44ab connects the branch pipe 43a and the suction port connecting pipe 44aa. The branch pipe 43a, the relay pipe 44ab, and the suction port connecting pipe 44aa are bent at 90 degrees from each other. The branch pipe 43a, the relay pipe 44ab, and the suction port connecting pipe 44aa from the fluid distributor 21 to the intermediate-pressure suction port 10h of the compressor 11 form a first intermediate-pressure distribution pipe 46a.

[0042] The branch pipe 43b is connected to the intermediate-pressure suction port 10h of the compressor 12 via a short suction port connecting pipe 44ba. A horizontal relay pipe 44bb connects the branch pipe 43b and the suction port connecting pipe 44ba. The branch pipe 43b, the relay pipe 44bb, and the suction port connecting pipe 44ba are bent at 90 degrees from each other. The branch pipe 43b, the relay pipe 44bb, and the suction port connecting pipe 44ba from the fluid distributor 21 to the intermediate-pressure suction port 10h of the compressor 12 form a second intermediate-pressure distribution pipe 46b.

[0043] The branch pipe 43c is connected to the intermediate-pressure suction port 10h of the compressor 13 via a short suction port connecting pipe 44ca. The branch pipe 43c and suction port connecting pipe 44ca are connected by a horizontal first relay pipe 44cb and a vertical second relay pipe 44cc. The suction port connecting pipe 44ca and the first relay pipe 44cb are bent at 90 degrees. The first relay pipe 44cb and the second relay pipe 44cc are bent at 90 degrees. The branch pipe 43c and the second relay pipe 44cc are bent at approximately 120 degrees. The branch pipe 43c, the second relay pipe 44cc, the first relay pipe 44cb, and the suction port connecting pipe 44ca from the fluid distributor 21 to the intermediate-pressure suction port 10h of the compressor 13 form a third intermediate-pressure distribution pipe 46c.

[0044] The branch pipe 43d is connected to the intermediate-pressure suction port 10h of the compressor 14 via a short suction port connecting pipe 44da. The branch pipe 43d and the suction port connecting pipe 44da are connected by a horizontal first relay pipe 44db and a vertical second relay pipe 44dc. The suction port connecting pipe 44da and the first relay pipe 44db are bent at 90 degrees. The first relay pipe 44db and the second relay pipe 44dc are bent at 90 degrees. The branch pipe 43d and the second relay pipe 44dc are bent at approximately 120 degrees. The branch pipe 43d, the second relay pipe 44dc, the first relay pipe 44db, and the suction port connecting pipe 44da from the fluid distributor 21 to the intermediate-pressure suction port 10h of the compressor 14 form a fourth intermediate-pressure distribution pipe 46d.

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

[0046] The four branch pipes 26 in the fluid distributor 20 are identified as branch pipes 26a, 26b, 26c, and 26d. Each branch pipe 26a, 26b, 26c, and 26d has the same length. In Fig. 18, the branch pipe 26a extends diagonally upward to the left, the branch pipe 26b extends diagonally upward to the right, the branch pipe 26c extends diagonally downward to the left, and the branch pipe 26d extends diagonally downward to the right.

[0047] Branch pipe 26a is connected to intermediate-pressure suction port 10h of compressor 11 via horizontal suction port connecting pipe 45aa. There is a 90-degree bend between branch pipe 26a and suction port connecting pipe 45aa. Branch pipe 26a and suction port connecting pipe 45aa from fluid distributor 20 to suction port 10d of compressor 11 form first low-pressure distribution pipe 47a.

[0048] The branch pipe 26b is connected to the intermediate-pressure suction port 10h of the compressor 12 via a horizontal suction port connecting pipe 45ba. The branch pipe 26b and the suction port connecting pipe 45ba are bent at 90 degrees. The branch pipe 26b and the suction port connecting pipe 45ba from the fluid distributor 20 to the suction port 10d of the compressor 12 form a second low-pressure distribution pipe 47b.

[0049] The branch pipe 26c is connected to the intermediate-pressure suction port 10h of the compressor 13 via a horizontal suction port connecting pipe 45ca. The branch pipe 26c and the suction port connecting pipe 45ca are connected via a vertical relay pipe 45cb. The suction port connecting pipe 45ca and the relay pipe 45cb are bent at 90 degrees. The branch pipe 26c and the relay pipe 45cb are bent at approximately 120 degrees. The branch pipe 26c, the relay pipe 45cb, and the suction port connecting pipe 45ca from the fluid distributor 20 to the suction port 10d of the compressor 13 form a third low-pressure distribution pipe 47c.

[0050] Branch pipe 26d is connected to intermediate-pressure suction port 10h of compressor 14 via horizontal suction port connecting pipe 45da. Branch pipe 26d and suction port connecting pipe 45da are connected via vertical relay pipe 45db. The suction port connecting pipe 45da and relay pipe 45db are bent at 90 degrees. The branch pipe 26d and relay pipe 45db are bent at approximately 120 degrees. The branch pipe 26d, relay pipe 45db, and suction port connecting pipe 45da from the fluid distributor 20 to suction port 10d of compressor 14 form a fourth low-pressure distribution pipe 47d.

[0051] The suction port connecting pipes 45aa, 45ba have the same length. The suction port connecting pipes 45ca, 45da have the same length but are shorter than the suction port connecting pipes 45aa, 45ba. The suction port connecting pipes 45aa to 45da are oriented in the same direction as the central axis C of the cylindrical portion 23. The relay pipes 45cb, 45db have the same length.

[0052] 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 all approximately equal in length. Furthermore, 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 all approximately equal in length. This ensures that the pressure losses from the fluid distributors 20 and 21 to the respective suction ports 10d or the respective intermediate-pressure suction ports 10h are approximately the same, enabling the refrigerant to be distributed more evenly.

[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 larger diameters than the medium-pressure distribution pipes 46a and 46b, it is preferable that they have fewer bends in processing, and therefore they are given priority over the medium-pressure distribution pipes 46a and 46b in terms of layout.

[0054] In a front view as shown in FIG. 16 , that is, when viewed from the direction of the central axis C of the cylindrical portion 23 of the fluid distributor 20, the fluid distributor 20 is within a quadrangle (polygon) R1 with the refrigerant suction ports 10d of the four compressors 10 as corners, making it easier to set the lengths of the low-pressure distribution pipes 47a-47d equal. Generally speaking, when three or more compressors 10 are installed, it is advisable to install the fluid distributor 20 within a polygon with the suction ports 10d as corners. Furthermore, because the branch pipes 26a-26d of the fluid distributor 20 are arranged at equal angular intervals, they are well-balanced, making it even easier to set the lengths of the low-pressure distribution pipes 47a-47d equal. Arranging the branch pipes 26a-26d of the fluid distributor 20 at equal angular intervals makes it versatile and easy to apply to a variety of systems.

[0055] As described above, the branch pipes 43a to 43d of the fluid distributor 21 are connected to the intermediate-pressure suction port 10h via the relay pipes (horizontal pipes) 44ab to 44db. When viewed from the front, the fluid distributor 21 is within the range of a rectangle R2 whose corners are the relay pipes 44ab to 44db, making it easier 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 β direction (horizontal direction) of the rectangle R1, so that the first low-pressure distribution pipe 47a and the second low-pressure distribution pipe 47b for the compressors 11 and 12 can use substantially the same pipeline, and the third low-pressure distribution pipe 47c and the third low-pressure distribution pipe 47d can use substantially the same pipeline. Furthermore, because the fluid distributor 21 is located at the center of the β direction of the rectangle R2, 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 are located at the vertical center of the rectangles R1 and R2, and 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, but the fluid distributor 20 is located at the center of the β direction of the rectangle R1, 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 and both ends in the β direction, each only require one 90-degree bend, thereby reducing the amount of work required for bending the pipes.

[0058] Note that the configurations illustrated in the above embodiments are merely functional schematics and do not necessarily have to be physically configured as shown. In other words, the distribution and integration of each device and component is not limited to that illustrated, and all or part of them can be functionally or physically distributed and integrated in any unit depending on various usage situations, etc.

[0059] REFERENCE SIGNS LIST 1 Heat pump type steam generating device 2 Heat pump cycle device 3 Concentrator 4 Condenser 5 Subcooler 6 High stage expansion valve 7, 30 Gas-liquid separator 8 Low stage expansion valve 9 Evaporator 10, 11 to 14 Compressor 15 Oil separator 16, 17 Internal heat exchanger 20, 20', 21 Fluid distributor 22 Inlet pipe 23 Cylindrical section 24 Header section 25 Buffer section 26 Branch pipe 31 Output adjustment valve C Central axis d1 Cylindrical section outer diameter d2 Cylindrical section length d3 Header section length d4 Inlet pipe outer diameter d5 Inlet pipe length E1 to E4, E10 to E13 Region S1, S4 Cross-sectional area

Claims

1. A fluid distributor comprising a cylindrical portion, an inlet pipe into which a fluid flows from the inlet end of the cylindrical portion, and a plurality of branch pipes extending radially from the cylindrical portion, the cylindrical portion and the inlet pipe being connected on the same central axis, the central axis of the branch pipes being perpendicular to the central axis of the cylindrical portion, wherein the ratio of the cylindrical portion length to the cylindrical portion outer diameter is 3.4 to 4.1, the ratio of the header portion length, which is the length from the inlet end to the connection center position of the branch pipes, to half the cylindrical portion length is 0.9 to 1.3, the ratio of the cylindrical portion cross-sectional area to the cross-sectional area of ​​the inlet pipe is 2.5 or more, and the ratio of the inlet pipe length to the inlet pipe outer diameter is 2.2 to 4.

8.

2. A heat pump cycle device in which a plurality of compressors are arranged in parallel, and in which the fluid distributor according to claim 1 is used to distribute refrigerant to each compressor.

3. The heat pump cycle device according to claim 2, wherein the refrigerant contains oil, and the central axis of the cylindrical portion of the fluid distributor is horizontal.

4. The heat pump cycle device according to claim 3, characterized in that three or more compressors are provided, the refrigerant intake ports of the plurality of compressors are oriented in the same direction as the central axis of the cylindrical portion, and when viewed from the direction of the central axis of the cylindrical portion, the fluid distributor is within a polygon whose corners are the refrigerant intake ports of the plurality of compressors.

5. The heat pump cycle device according to claim 3, characterized in that three or more compressors are provided, the refrigerant intake ports of the plurality of compressors are oriented in a direction different from the central axis of the cylindrical portion, the branch pipes are connected to the intake ports via horizontal pipes oriented in the same direction as the central axis of the cylindrical portion, and the fluid distributor is within a polygon whose corners are the plurality of horizontal pipes as viewed from the direction of the central axis of the cylindrical portion.

6. A heat pump cycle device according to claim 4 or 5, characterized in that the fluid distributor is located at the horizontal center or vertical center of the polygon when viewed from the direction of the central axis of the cylindrical portion.

7. The heat pump cycle device according to claim 2, wherein the branch pipes are arranged at equal angular intervals.

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