JP2018112203A - Branch pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce occurrence of a vortex in a branch part of a branch pipe.SOLUTION: A branch pipe 5 comprises a first flow passage 51a extending along a predetermined axis X, a second flow passage 52a branching from the first flow passage 51a, and a branch part 53 branching from the first flow passage 51a to the second flow passage 52a. The branch part 53 comprises a plurality of inflow openings 53a through which fluid flows from the first flow passage 51a into the second flow passage 52a.SELECTED DRAWING: Figure 4

Description

  The technique disclosed here relates to a branch pipe.

  Conventionally, branch pipes have been used in various devices for circulating fluid. Patent Document 1 discloses a steam heating device. For example, also in this steam heating apparatus, a branch pipe is used between the circulation pump and the ejector. In detail, in the branch pipe, the 2nd flow path which goes to a condenser has branched from the 1st flow path which goes to the nozzle of an ejector from a circulation pump.

JP 2013-204877 A

  By the way, in such a branch pipe, a vortex may be generated at a branch portion that branches from the first flow path to the second flow path. Thereby, the disturbance of a flow may generate | occur | produce in the downstream part rather than a branch part among 1st flow paths. When the generated vortex is large, the turbulence of the flow is also large, and there is a possibility of adversely affecting the equipment on the downstream side of the first flow path.

  The technology disclosed herein has been made in view of such a point, and the object is to reduce the generation of large vortices that adversely affect the downstream side of the branching portion of the branch pipe. is there.

  The technology disclosed herein includes a first flow path extending along a predetermined axis, a second flow path that branches from the first flow path, and a branch from the first flow path to the second flow path. A branch pipe provided with a branch part is an object. The branch pipe has a plurality of inflow openings through which fluid flows from the first flow path to the second flow path.

  According to the said branch pipe, generation | occurrence | production of the big eddy which has a bad influence on the downstream in a branch part can be reduced.

FIG. 1 is a piping system diagram showing a schematic configuration of a steam heating system. 2 is a cross-sectional view of the branch pipe taken along line II-II in FIG. 3 is a cross-sectional view of the branch pipe taken along line III-III in FIG. FIG. 4 is a perspective view in which a branch pipe is partially cut. FIG. 5 is a cross-sectional view corresponding to FIG. 3 of a branch pipe 205 according to a modification.

  Hereinafter, exemplary embodiments will be described in detail with reference to the drawings. FIG. 1 is a piping system diagram showing a schematic configuration of the steam heating system 100.

  The steam heating system 100 includes a reaction tank 1 to which steam is supplied and a vacuum generator 2 that sucks drain from the reaction tank 1. The steam heating system 100 heats an object inside the reaction vessel 1 with steam.

  The reaction tank 1 has a tank body 11 in which an object is accommodated, and a jacket portion 12 formed over substantially the entire circumference of the tank body 11. A steam supply rod 13 is connected to the jacket portion 12. The steam supply basket 13 is provided with a supply valve 14 that is an on-off valve. Steam generated by a steam generation unit (not shown) is supplied to the jacket unit 12 via the steam supply pipe 13. In the reaction tank 1, the steam supplied to the jacket portion 12 is indirectly heat-exchanged with the object inside the tank body 11 to condense (liquefy), and the object is heated. That is, the target object is heated by being given the latent heat of condensation of steam.

  The vacuum generator 2 includes a drain tank 21 that stores drain, a pump 22 that pumps the drain in the drain tank 21, an ejector 3 that sucks the drain, and a pipe 4 that connects the drain tank 21, the pump 22, and the ejector 3. And have. The jacket portion 12 of the reaction tank 1 and the ejector 3 are connected by a discharge pipe 15. The vacuum generator 2 circulates the drain stored in the drain tank 21 through the pump 22 and the ejector 3, thereby generating a suction force in the ejector 3 and sucking the drain from the reaction tank 1. A drain supply rod 23 for supplying drain to the drain tank 21 is connected to the drain tank 21. The drain supply rod 23 is provided with a supply valve 24 which is an on-off valve.

  The ejector 3 includes a nozzle 31 that ejects the first fluid, a suction chamber 32 that sucks the second fluid by the negative pressure generated by the ejection of the first fluid from the nozzle 31, and the first fluid ejected from the nozzle 31 and the suction The diffuser 33 discharges the second fluid sucked into the chamber 32 while increasing the pressure.

  At least the ejection port of the nozzle 31 is accommodated in the suction chamber 32. The suction chamber 32 also accommodates at least the upstream end of the diffuser 33. The flow passage cross-sectional area of the diffuser 33 increases from upstream to downstream. Therefore, the fluid passing through the diffuser 33 decelerates and pressurizes as it flows through the diffuser 33 from upstream to downstream. Further, the downstream end of the discharge pipe 15 is connected to the suction chamber 32.

  In the suction chamber 32, the second fluid is sucked from the discharge pipe 15 by the negative pressure (pressure drop) generated when the first fluid is ejected from the nozzle 31. That is, in the suction chamber 32, a suction force for sucking the second fluid is generated by the negative pressure generated by the jet pump effect of the first fluid. The drain generated in the jacket portion 12 of the reaction tank 1 is thus sucked into the ejector 3 and collected in the drain tank 21.

  The pipe 4 includes a branch pipe 5 that branches a part of the drain supplied from the pump 22 to the ejector 3. The branch pipe 5 is connected to the pump 22 via the first pipe 41 and is connected to the nozzle 31 of the ejector 3 via the second pipe 42. A drain branch pipe 16 is connected to the branch pipe 5. The drain branch pipe 16 is connected to the steam supply pipe 13 (specifically, a downstream portion of the supply valve 14). The drain branch pipe 16 is provided with a control valve 17 for adjusting the flow rate of the drain supplied to the steam supply pipe 13. The drain supplied from the drain branch pipe 16 to the steam supply pipe 13 functions as temperature-reduced water. That is, the superheated steam flowing through the steam supply pipe 13 is reduced by the drain supplied from the drain branch pipe 16 and becomes saturated steam. At this time, the flow rate of the drain supplied from the drain branch pipe 16 to the steam supply pipe 13 is adjusted by the control valve 17 so that the superheated steam becomes saturated steam, preferably saturated dry steam.

  The drain branch pipe 16 is connected to a discharge pipe 18 that discharges excess drain. The discharge pipe 18 is provided with a control valve 19 that adjusts the flow rate of the drain discharged from the discharge pipe 18. When there is a large amount of drain stored in the drain tank 21, excess drain is discharged from the discharge pipe 18.

  As described above, the branch pipe 5 branches a part of the drain supplied from the pump 22 to the drain branch pipe 16, while allowing the remaining drain to flow to the ejector 3.

  Hereinafter, the branch pipe 5 will be described in more detail. 2 is a cross-sectional view of the branch pipe 5 taken along the line II-II in FIG. 3 is a cross-sectional view of the branch pipe 5 taken along line III-III in FIG. FIG. 4 is a perspective view in which the branch pipe 5 is partially cut.

  The branch pipe 5 includes a first flow channel 51a extending along the linear axis X and a second flow channel 52a branched from the first flow channel 51a. That is, the branch pipe 5 is a T-shaped pipe having a first pipe 51 that extends linearly and a second pipe 52 that branches from the first pipe 51. The first tube 51 is formed in a substantially cylindrical shape. Flange 51b and 51c are provided in the upstream end and downstream end of the 1st pipe | tube 51, respectively. The first pipe 41 is connected to the upstream flange 51b. A second pipe 42 is connected to the downstream flange 51c. A first flow path 51 a is formed inside the first pipe 51. A second flow path 52 a is formed inside the second pipe 52. The second flow path 52a extends vertically from the first flow path 51a along the linear axis Y. A branch portion (that is, a portion facing the first flow path 51a in the second flow path 52a) 53 that branches from the first flow path 51a to the second flow path 52a is formed by three inflow openings 53a.

  Specifically, the second pipe 52 has a fixed pipe 54 connected to the first pipe 51, an attachment 55 inserted into the fixed pipe 54, and a connection portion 56 connected to the fixed pipe 54 by a nut 57. ing.

  The fixed pipe 54 is fixed to the first pipe 51 by welding or the like. The fixed tube 54 opens to the first flow path 51a. That is, the internal space of the fixed tube 54 communicates with the first flow path 51a. The inner diameter of the downstream end of the fixed tube 54 is increased, and a step 54 a is formed at the downstream end of the fixed tube 54. A male screw 54 b is formed on the outer peripheral surface of the fixed tube 54. A nut 57 is fastened to the male screw 54b.

  The attachment 55 is formed in a cylindrical shape and is loosely fitted to the fixed tube 54. A flange 55 a is provided at the downstream end of the attachment 55. The attachment 55 loosely fitted to the fixed tube 54 has a flange 55a locked to the step 54a. The upstream end surface of the attachment 55 is curved so as to be flush with the inner peripheral surface of the first pipe 51. The attachment 55 is formed with three inflow openings 53 a extending along the axis Y.

  The connection part 56 is formed in a cylindrical shape. A flange 56 a is provided at the upstream end of the connecting portion 56. A male screw 56 b is formed on the outer peripheral surface of the connecting portion 56. The connecting portion 56 is attached to the fixed tube 54 with a nut 57. At this time, the flange 56 a is pressed toward the fixed tube 54 by the nut 57. Since the upstream end of the connecting portion 56 is in contact with the flange 55 a of the attachment 55, the flange 55 a is pressed against the step 54 a of the fixed pipe 54 by the pressing force of the nut 57. The discharge pipe 15 is connected to the connection portion 56 via a male screw 56b.

  In the branch pipe 5 configured in this way, the upstream end face of the attachment 55 is formed flush with the flow path wall of the first flow path 51a, so that the flow path of the first flow path 51a is substantially the same. Three inflow openings 53a are opened in the wall. If an opening is formed in the flow path wall of the first flow path 51a, a vortex is generated in the opening. The larger the opening, the larger the vortex is generated. When a vortex is generated at the branching portion 53 to the second flow path 52a, the flow is disturbed on the downstream side of the branching section 53 in the first flow path 51a. As a result, the performance of the equipment on the downstream side of the first flow path 51a may be adversely affected. For example, in the steam heating system 100, the nozzle 31 of the ejector 3 is connected to the downstream end of the first flow path 51a via the second pipe. If a large vortex is generated in the first flow path 51a, the flow of drain flowing into the nozzle 31 is disturbed, and the nozzle 31 cannot exhibit desired performance. Therefore, it is necessary to take measures such as lengthening the second pipe 42, which increases the restrictions on system design.

  On the other hand, in the branch pipe 5, the opening of the second flow path 52a in the flow path wall of the first flow path 51a is formed by a plurality of inflow openings 53a. The cross-sectional area of the opening of the second flow path 52 a is determined by the required flow rate of the drain that flows into the drain branch pipe 16. By forming the opening of the second flow path 52a with a plurality of inflow openings 53a, it is possible to reduce the cross-sectional area required for each inflow opening 53a in order to achieve the required flow rate of the drain. The adverse effect on the flow on the downstream side of the first flow path 51a is smaller when a plurality of small openings are formed than when one large opening is formed in the flow path wall of the first flow path 51a. That is, as the number of openings increases, the number of places where vortices are generated increases. However, since the sectional area of the openings is small, the vortices are small. The smaller the generated vortex, the smaller the adverse effect on the flow on the downstream side of the first flow path 51a. Thus, by reducing the generation of large vortices in the branching portion 53, it is possible to reduce the adverse effects on the equipment on the downstream side of the first flow path 51a. Further, since measures such as lengthening the second pipe 42 are not necessary, restrictions on system design can be reduced.

  Further, as shown in FIGS. 3 and 4, the plurality of inflow openings 53 a are arranged so as to be shifted from each other in the direction of the axis X of the first flow path 51 a. That is, the plurality of inflow openings 53a are not arranged on a straight line in the direction of the axis X. Thereby, since the places where vortices are generated can be dispersed, the generation of large vortices at the branch portion 53 can be further reduced.

  Further, the plurality of inflow openings 53 a are arranged so as to be line symmetric with respect to a straight line extending in parallel with the axis X. Thereby, the place where a vortex is generated can be distributed in a balanced manner in the circumferential direction of the axis X.

  As described above, the branch pipe 5 includes the first flow path 51a extending along the predetermined axis X and the second flow path 52a branched from the first flow path 51a. The branch portion 53 that branches into the two flow paths 52a is formed by a plurality of inflow openings 53a through which fluid flows from the first flow path 51a to the second flow path 52a.

  According to this configuration, the branch portion 53 from the first flow path 51a to the second flow path 52a is formed by the plurality of inflow openings 53a, so that the flow rate of the second flow path 52a is secured and the branch portion 53 The generation of large vortices can be reduced. As a result, it is possible to reduce the adverse effect on the equipment on the downstream side of the first flow path 51a.

  In addition, the plurality of inflow openings 53a are arranged so as to be shifted from each other in the direction of the axis X.

  According to this configuration, it is possible to further reduce the generation of large vortices at the branch portion 53 by dispersing the places where vortices are generated.

  Further, the plurality of inflow openings 53 a are arranged so as to be line symmetric with respect to a straight line extending in parallel with the axis X.

  According to this configuration, the places where vortices are generated can be distributed symmetrically, and the generation of large vortices at the branch portion 53 can be stably reduced.

  Further, the first flow path 51 a is connected to the nozzle 31 of the ejector 3.

  According to this configuration, it is possible to reduce the deterioration of the performance of the nozzle 31 due to the generation of vortices at the branch portion 53.

<< Other Embodiments >>
As described above, the embodiment has been described as an example of the technique disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can also be applied to an embodiment in which changes, replacements, additions, omissions, and the like are appropriately performed. Moreover, it is also possible to combine each component demonstrated by the said embodiment and it can also be set as a new embodiment. In addition, among the components described in the attached drawings and detailed description, not only the components essential for solving the problem, but also the components not essential for solving the problem in order to illustrate the technology. May also be included. Therefore, it should not be immediately recognized that these non-essential components are essential as those non-essential components are described in the accompanying drawings and detailed description.

  About the said embodiment, it is good also as following structures.

  For example, the branch pipe 5 can be applied not only to the steam heating system 1 but also to other systems and apparatuses.

  Moreover, although the ejector 3 to which the branch pipe 5 is connected distribute | circulates water, it is not restricted to a liquid ejector. That is, the ejector 3 may circulate a gas such as steam.

  Further, the branch pipe 5 may be connected to the upstream side of equipment other than the ejector 3. For example, the branch pipe 5 may be connected to the upstream side of the flow meter. When it is necessary to branch the flow path on the upstream side of the flow meter, the branch pipe 5 can be applied to secure a flow rate to the branch side and reduce adverse effects on the flow meter. In particular, when the flow path is branched on the upstream side of the vortex flow meter, it is required to secure a sufficient distance from the branch portion to the vortex flow meter in order to reduce the adverse effect of the vortex generated at the branch portion. On the other hand, since the generation of large vortices at the branching portion 53 is reduced by adopting the branch pipe 5, the restriction on the distance from the branching portion 53 to the vortex flow meter can be relaxed or eliminated.

  The configuration of the branch pipe 5 is not limited to the above-described configuration. The number of inflow openings 53a is not limited to three. The number of inflow openings 53a may be two, or four or more. Further, the arrangement of the inflow openings 53a is not limited to the above arrangement. A plurality of inflow openings 53a may be arranged in the direction of the axis X.

  The inflow opening 53a may not be circular. The inflow opening 53a may have a flat shape in which the dimension in the direction of the axis X is shorter than the dimension in the direction orthogonal to the axis. That is, the cross-sectional shape of the inflow opening 53a may be a horizontally long flat shape when the direction of the axis X is the vertical direction. For example, FIG. 5 is a cross-sectional view corresponding to FIG. 3 of a branch pipe 205 according to a modification. The cross-sectional shape of the inflow opening 253a (that is, the shape of the inflow opening 253a when viewed in the direction of the axis Y of the second flow path 52a) is substantially elliptical with the short axis extending in the direction of the axis X. ing. That is, the dimension of the inflow opening 53a in the fluid flow direction of the first flow path 51a is shortened. As the dimension in the flow direction becomes shorter, the size of the generated vortex can be reduced.

  Moreover, although the 2nd piping 42 of the branch pipe 5 is formed with the fixed pipe 54, the attachment 55, the connection part 56, and the nut 57 from a viewpoint of easiness to make, it is not restricted to this. As long as a plurality of inflow openings 53a can be formed at the upstream end portion of the second pipe 42, the second pipe 42 can have an arbitrary configuration. Moreover, the 1st flow path 51a does not need to extend linearly. That is, the axis X may be extended while curving instead of being linear.

  As described above, the technique disclosed herein is useful for a branch pipe.

DESCRIPTION OF SYMBOLS 100 Steam heating system 3 Ejector 31 Nozzle 5 Branch pipe 51a 1st flow path 52a 2nd flow path 53 Branch part 53a Inflow opening X Axis center

Claims (3)

A first flow path extending along a predetermined axis;
A second flow path branched from the first flow path;
A branch pipe having a branching portion that branches from the first flow path to the second flow path,
The branch pipe has a plurality of inflow openings through which fluid flows from the first flow path to the second flow path. The branch pipe according to claim 1,
The branch pipe, wherein the inflow opening has a flat shape whose dimension in the direction of the axis is shorter than the dimension in a direction perpendicular to the axis. The branch pipe according to claim 1 or 2,
The branch pipe, wherein the first flow path is connected to a nozzle of an ejector.

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