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CN-115618513-B - Water spraying nozzle uniformity prediction and optimization method applying 3D printing technology

CN115618513BCN 115618513 BCN115618513 BCN 115618513BCN-115618513-B

Abstract

The invention relates to a uniformity prediction and optimization method of a sprinkler head applying a 3D printing technology, which comprises the following steps of S1, manufacturing sprinkler heads with different geometric dimensions of the sprinkler heads by applying the 3D printing technology, S2, measuring the water spraying intensity of the 3D printing sprinkler head through a water collecting box experiment, S3, establishing a uniformity prediction model based on a uniform distribution rule for experimental data linear return analysis, and S4, optimizing the uniformity of the sprinkler head based on the prediction model. The invention plays the advantages of flexible design and quick forming of the 3D printing technology, improves the diversity of spray head samples, provides a dimensionless parameter describing the water splashing disc structure of the water sprinkling nozzle for the first time, namely the water splashing disc tooth space ratio, has higher reliability based on a uniformity prediction model of a flow distribution rule, and can guide the design of the same kind of water sprinkling nozzles to meet different engineering requirements.

Inventors

  • LI KAIYUAN
  • YANG TIANQI
  • TU JINPING
  • ZOU YANYAN

Assignees

  • 武汉理工大学

Dates

Publication Date
20260505
Application Date
20221014

Claims (6)

  1. 1. A method for predicting and optimizing uniformity of a sprinkler head by applying a 3D printing technology is characterized by comprising the following steps: S1, manufacturing water spraying nozzles with water spraying plates of different geometric dimensions by applying a 3D printing technology; s2, measuring the water spraying intensity of the 3D printing spray head through a water collecting box experiment; S3, establishing a uniformity prediction model based on a uniform distribution rule for linear return analysis of experimental data; s4, optimizing the uniformity of the sprinkler head based on a prediction model; The sprinkler heads with the different geometric size splash plates manufactured in the step S1 are different in the widths of the splash plate slots, and a dimensionless parameter describing the widths of splash plate tooth grooves is provided for the structures of the splash plate tooth grooves, namely the ratio of the splash plate tooth grooves, wherein the calculation formula is as follows: Wherein, the The tooth space ratio is indicated by the ratio, Indicating the width of the slot and, Representing the width of the tooth; In the step S3, the experimental data linear return analysis step is as follows: s301, calculating the water spraying intensity of each water collecting box; s302, calculating the flow fractions of the near-field flow and the tank line flow of the sprinkler head; s303, performing multiple linear regression analysis on the near-field flow fraction and the tooth space ratio of the sprinkler head; S304, performing multiple linear regression analysis on the slot line flow fraction and the slot ratio of the sprinkler; the near-field flow of the sprinkler head refers to the flow in a circular area which is less than 2.5m away from the central axis of the sprinkler head, and the groove line flow refers to the flow of water which is separated from a splash tray from a slot; the multiple linear regression analysis includes two control factors, the inside and outside tooth space ratios.
  2. 2. The method for predicting and optimizing the uniformity of the sprinkler head by using the 3D printing technology according to claim 1 is characterized in that in the step S2, the single release time of the experimental sprinkler head measured by the water collecting box is longer than 180S, the water collecting box is arranged in a fan shape with a central angle of 90 degrees, the water collecting box is in a circular shape, the radius of the water collecting box is 4-8cm, the height of the water collecting box is 10-15cm, the center of the fan shape coincides with the central axis of the sprinkler head, the central axis of the fan shape is perpendicular to the normal direction of a yoke arm of the sprinkler head, the radial interval distance of the fan shape is 0.5m, and the circumferential interval angle of the fan shape is half of the included angle between two adjacent slots of a splash disc of the sprinkler head.
  3. 3. The method for predicting and optimizing the uniformity of a sprinkler head using a 3D printing technique according to claim 1, wherein in the step of performing a multiple linear regression analysis on the score of the slotline flow and the ratio of the slotlines of the sprinkler head, a slot flow distribution rule analysis model is used to define the slot flow of the sprinkler as the coupling result of the two parts of the slot internal flow and the slot sidewall flow, and the influence caused by the difference of the ratio of the slotlines on the inner side and the outer side of the sprinkler is considered.
  4. 4. The method for predicting and optimizing the uniformity of a sprinkler head using a 3D printing technique according to claim 1, wherein in the step of linear return analysis of experimental data, the slopes of the inside and outside spline ratios of two control factors are controlled by the length of the slot of the splash box, and the expression is as follows: Wherein, the The slope of the inside spline ratio is shown, Represents the slope of the outside spline ratio, r represents the splash plate radius, Indicating the splash plate slot length.
  5. 5. The method for predicting and optimizing the uniformity of a sprinkler head using a 3D printing technique according to claim 1, wherein in the step S3, the uniformity prediction model based on the uniformity distribution rule is as follows: the uniform distribution rule means that when the sprinkler head is completely uniformly distributed, the actual flow fraction of a certain area in the spray field is equal to the area fraction of the area, and the mathematical expression of the uniformity prediction model is as follows: Wherein, the Finger number The number of areas in the region of the substrate, Is that Flow rate of the zone; is the total flow; Is that The area of the region; Is the total coverage area of the sprinkler head.
  6. 6. The method for predicting and optimizing the uniformity of a sprinkler head using 3D printing technology according to claim 5, wherein the step S4 includes the steps of: s401, predicting the optimal flow fraction of the spraying near field through a uniformity prediction model; s402, reversely pushing the tooth space ratio of the sprinkler head according to a linear regression analysis result to determine the tooth space ratio of a splash plate of the sprinkler head with optimal uniformity; s403, verifying the reliability of the optimized result through the standard deviation of the water spraying intensity of all the water collecting boxes; s404, uniformity optimization of the sprinkler head is achieved.

Description

Water spraying nozzle uniformity prediction and optimization method applying 3D printing technology Technical Field The invention relates to the field of fire-fighting sprinkler heads, in particular to a sprinkler head uniformity prediction and optimization method applying a 3D printing technology. Background Automatic sprinkler systems are currently one of the most effective automatic fire extinguishing facilities recognized in the world. The automatic water spraying fire extinguishing system consists of sprinkler, pipeline, fire response unit, alarm unit, water supply unit, etc. When the automatic water spraying fire extinguishing system is started, the fire-fighting water is sprayed out from the water spraying nozzle under high pressure, and the sprayed liquid drops quickly cover the protected area to play a role in inhibiting and extinguishing fire. At present, for the spray uniformity of a sprinkler head, national standards prescribe that the measurement is carried out through a water distribution experiment, the experiment uses 100 water collecting boxes to collect the water spray intensity under the cross action of 4 sprinkler heads with the same specification above, and the uniformity of the sprinkler head is evaluated according to the number of the water collecting boxes which are lower than the standard water spray density by 50 percent. In the method, the water distribution performance of the spray heads cannot be reflected by using 4 spray heads with the same specification, and the uniformity of the spray heads is evaluated through the number of the water collecting boxes with the water distribution density lower than 50% of the standard water distribution density, so that the method has a large limitation. The criterion does not consider the influence of the occurrence position of the unqualified water collecting box on the uniformity of the evaluated sprinkler head, and the water distribution uniformity of the sprinkler head is not quantitatively reflected. It is worth noting that, at present, the structure and shape of the sprinkler head circulating in the market are uneven, and although the water distribution performance requirement of the sprinkler head GB5135.1-2019 in the 1 st part of the automatic sprinkler system is met, a great deal of researches show that the water distribution uniformity of the sprinkler head is poor, obvious non-uniformity exists when the radial and annular spray distribution is influenced by the slot of the water splashing disc, and the fire control blind spot in the spray coverage range can be caused. From the foregoing, it can be seen that there is a need for a method for optimizing the uniformity of distribution of water from a sprinkler head. Disclosure of Invention The invention aims to solve the technical problem of providing a method for predicting and optimizing the uniformity of a sprinkler head by applying a 3D printing technology, which can solve the problem that the distribution of the water spray intensity of the existing sprinkler head is uneven. The invention solves the technical problems by adopting the technical scheme that a method for predicting and optimizing the uniformity of a sprinkler head by applying a 3D printing technology is constructed, and comprises the following steps: S1, manufacturing water spraying nozzles with water spraying plates of different geometric dimensions by applying a 3D printing technology; s2, measuring the water spraying intensity of the 3D printing spray head through a water collecting box experiment; S3, establishing a uniformity prediction model based on a uniform distribution rule for linear return analysis of experimental data; and S4, optimizing the uniformity of the sprinkler head based on the prediction model. According to the above scheme, the sprinkler heads with different geometry of the splash plates manufactured in the step S1 are different in the widths of the slots of the splash plates. Aiming at the splash box tooth space structure, the invention provides a dimensionless parameter describing the width of the splash box tooth space, namely the splash box tooth space ratio, the calculation formula is as follows Wherein, the The tooth space ratio is indicated by the ratio,Indicating the width of the slot and,Representing the width of the tooth. According to the scheme, in the step S2, the single release time of the water collecting box measurement experiment spray head is larger than 180S, the water collecting box is arranged in a sector shape with the central angle of 90 degrees, the water collecting box is in a circular shape, the radius is 4-8 cm, the height is 10-15 cm, the circle center of the sector is coincident with the central axis of the spray head, the central axis of the sector is perpendicular to the normal direction of a yoke arm of the spray head, the radial interval distance of the sector is 0.5m, and the circumferential interval angle of the sector is half of the included angle between a