CN116837571B - A method for designing air duct of a setting machine and air duct of the setting machine - Google Patents

Abstract

The invention relates to the technical field of textile shaping, in particular to a shaping machine air channel design method and a shaping machine air channel. The method comprises the following steps: setting target output of an initial setting machine air duct according to target fabric; adjusting the structural parameters of the initial setting machine air channel to obtain the actual output of the initial setting machine air channel after adjustment; evaluating the influence degree of the structural parameter according to the actual output and the target output; and determining the optimal structural parameters according to the influence degree. The novel design method of the air duct of the setting machine improves the heat energy utilization rate in the drying and heating process of the setting machine, reduces the energy loss of the setting machine, and solves the problems of poor setting quality of fabrics and the like.

Description

A method for designing air duct of a setting machine and air duct of the setting machine

The invention relates to the technical field of textile shaping, and in particular to a design method for an air duct of a shaping machine and the air duct of the shaping machine.

Background Art

The setting machine is an important textile equipment in the printing and dyeing factory, mainly used for drying and stentering knitted fabrics and woven fabrics. In the natural humid state, the fabric still has a certain fabric ductility. By applying appropriate tension, the high internal stress deformation and high elastic tensile deformation of the fabric can be effectively eliminated. Then, the air duct in the setting machine oven applies 180 to 220 degrees Celsius hot air to the fabric surface for ironing, which can form high-quality fabric products. Among them, the uniformity of the airflow of the setting machine has a significant impact on the dimensional stability, fabric shaping quality, fabric feel and other aspects of the fabric.

At present, due to the excessive number of fabric types, the airflow and drying temperature required for different fabrics are different. However, due to the single structure of the current setting machine air duct, it cannot meet the drying and setting needs of various types of fabrics. The current setting machine has serious turbulence losses inside the air duct and insufficient energy utilization. When the airflow ejected from the air duct nozzle is uneven, it may also cause the overall temperature difference of the fabric to be too large, and the heat in a local position of the fabric is too small or too large, resulting in mold or browning. At the same time, excessive temperature differences will also lead to different shrinkage rates of the fabric, which will reduce the feel of the fabric, resulting in unstable quality of the shaped fabric products, and finally reduce economic benefits.

Summary of the invention

In view of the defects of the existing methods and the shortcomings of practical applications, the present invention increases adjustable guide plates and wedge plate angles for different types of fabrics, adjusts the angle and size of the guide plates to meet the drying requirements under different working conditions, optimizes the uniformity of the air flow inside the setting machine duct, and further reduces the internal turbulence loss, thereby reducing the energy loss of the setting machine. It effectively solves the problems of energy waste in the setting machine and poor fabric setting quality, and improves economic benefits and energy utilization. In the first aspect, the present invention provides a setting machine duct design method, which includes the following steps: setting a target output of an initial setting machine duct according to a target fabric; adjusting the structural parameters of the initial setting machine duct to obtain the actual output of the initial setting machine duct after adjustment; evaluating the degree of influence of the structural parameters according to the actual output and the target output; and determining the optimal structural parameters according to the degree of influence. The present invention proposes for the first time a method based on fluid simulation calculation and analysis, and under a specific working condition, analyzes the flow field and temperature field of the duct by using different wedge plate inclination angles, guide plate lengths, guide plate installation angles and duct openings of the duct of the setting machine, and uses the correlation coefficient to obtain the optimal design scheme of the duct of the setting machine, thereby improving the energy utilization efficiency of fabric setting.

Optionally, the adjusting the structural parameters of the initial shaping machine air duct includes: adding a guide plate to the initial shaping machine air duct; adjusting the guide plate, including adjusting the installation angle of the guide plate and adjusting the length of the guide plate. The present invention optimizes the structure of the initial air duct model by adding device components, changing angles and adjusting lengths through simulation, and optimizes and improves the structure based on simulation, which greatly reduces the cost of manual experiments and improves the efficiency of optimization.

Optionally, the adjusting the structural parameters of the initial shaping machine air duct includes: presetting the structural parameters of the guide plate, the structural parameters including the angle at which the guide plate is installed and the length of the guide plate; and adding the pre-set structural parameter guide plate to the initial shaping machine air duct. The present invention simulates the initial shaping machine air duct by adjusting the structural parameters thereof to obtain output data related to the structural parameters, thereby reducing the cost of manual testing and improving the accuracy and reliability of the data.

Optionally, the adjusting the structural parameters of the air duct of the initial setting machine further comprises: adjusting the opening of the air duct of the initial setting machine; and/or adjusting the wedge plate of the air duct of the initial setting machine, including adjusting the inclination angle of the wedge plate. The present invention adjusts the structural parameters of the initial setting machine based on fluid simulation calculation analysis, and its rich physical model, advanced numerical method and powerful pre- and post-processing functions are conducive to obtaining the optimal structural parameters of the setting machine.

Optionally, the obtaining of the actual output of the adjusted initial shaping machine air duct includes: obtaining the fluid velocity of the adjusted initial shaping machine air duct; obtaining the fluid temperature of the adjusted initial shaping machine air duct. The present invention utilizes the actual output data such as the velocity and temperature of the adjusted initial shaping machine air duct to directly obtain the specific situation and change trend of the actual output, which is beneficial to the subsequent optimization and improvement of the air duct structure, and can be used as a reference in similar fields.

Optionally, the duct design method for the setting machine further includes: setting an evaluation index; and using the evaluation index to evaluate the influence of the structural parameter. The present invention evaluates and analyzes the duct model of the setting machine by setting the evaluation index. The working condition, temperature change, fabric drying condition and other information of the duct of the setting machine can be directly obtained through the index data, thereby improving the effect of the optimization design of the duct of the setting machine.

Optionally, the setting of evaluation indicators includes:

The energy utilization rate is set, and the energy utilization rate formula is as follows:

Among them, η is the energy utilization coefficient, _th is the average temperature of the working area, _t0 is the fabric surface temperature, and _tn is the supply air temperature.

The temperature non-uniformity coefficient is set, and the temperature non-uniformity coefficient formula is as follows:

Where _kt is the temperature non-uniformity coefficient, _σt is the arithmetic mean of temperature, is the temperature RMS deviation.

The speed unevenness coefficient is set, and the speed unevenness coefficient formula is as follows:

Where M is the velocity non-uniformity coefficient, σ _v is the standard deviation of all monitoring points, and v is the velocity of the monitoring point. is the overall mean of all monitoring points, and n is the number of nozzle outlets. The present invention uses coefficient formulas to evaluate energy utilization, temperature, and speed uniformity, making the acquisition process of related values simpler, faster, and more convenient, improving the efficiency of adjusting the duct of the setting machine, and having high practicality in related fields; the evaluation index is used to feedback the quality of the duct structure of the setting machine, which is conducive to adjusting the duct of the setting machine to achieve the best drying effect.

Optionally, the step of evaluating the influence of the structural parameters according to the actual output and the target output includes: obtaining a change trend of the actual output evaluation index according to the actual output, the target output and the evaluation index; and obtaining a contribution rate of the structural parameters to the evaluation index according to the actual output, the evaluation index and the change trend. The present invention obtains the actual output at different levels, and can consider the direction of adjustment and the degree of improvement in many aspects, which is conducive to effectively solving the problems of energy waste of the setting machine and poor fabric setting quality.

Optionally, the step of determining the optimal structural parameters according to the influence degree to obtain the optimal setting machine air duct comprises: adjusting the adjusted structural parameters of the setting machine air duct by using the change trend and the contribution rate to obtain the optimal structural parameters; and obtaining the optimal setting machine air duct according to the optimal structural parameters. The present invention analyzes the evaluation index values and the significant influence degree of the structural parameters of the setting machine air duct, and can accurately and quickly adjust the relevant data of the setting machine air duct, which is conducive to obtaining the optimal structural parameters of the setting machine air duct, saving costs and improving work efficiency.

In a second aspect, the present invention further provides a setting machine air duct, which is designed by the setting machine air duct design method described in the first aspect of the present invention, effectively solving the problems of energy waste in the setting machine and poor fabric setting quality, and improving economic benefits and energy utilization.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a flow chart of a method for designing an air duct of a molding machine according to the present invention;

FIG2 is a diagram showing a change trend of energy utilization rate according to the present invention;

FIG3 is a diagram showing a variation trend of the temperature non-uniformity coefficient of the present invention;

FIG4 is a variation trend diagram of the velocity non-uniformity coefficient of the present invention;

FIG5 is a graph showing the contribution of the air duct structural parameters of the setting machine to the energy utilization rate of the present invention;

FIG6 shows the contribution rate of the air duct structural parameters of the setting machine of the present invention to the temperature non-uniformity coefficient;

FIG. 7 is a graph showing the contribution of the air duct structural parameters of the setting machine to the velocity non-uniformity coefficient of the present invention;

FIG8 is a graph showing a variation trend of the temperature distribution non-uniformity coefficient of the wedge plate inclination angle of the present invention;

FIG. 9 is a graph showing the trend of turbulence loss rate changes with the inclination angle of the wedge plate of the present invention.

DETAILED DESCRIPTION

The specific embodiments of the present invention will be described in detail below. It should be noted that the embodiments described herein are only for illustration and are not intended to limit the present invention. In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is obvious to those of ordinary skill in the art that these specific details do not need to be adopted to implement the present invention. In other examples, in order to avoid confusing the present invention, known circuits, software or methods are not specifically described.

Throughout the specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "in one embodiment," "in an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily all refer to the same embodiment or example. In addition, particular features, structures, or characteristics may be combined in one or more embodiments or examples in any suitable combination and/or subcombination. In addition, it should be understood by those of ordinary skill in the art that the figures provided herein are for illustrative purposes and that the figures are not necessarily drawn to scale.

Please refer to Figure 1. In order to reduce the energy consumption of the setting machine, improve the fabric setting quality and fabric feel, and effectively solve the problems of energy waste of the setting machine and poor fabric setting quality, the present invention provides a setting machine air duct design method, which includes the following steps:

S1. Set the target output of the initial setting machine air duct according to the target fabric;

In this embodiment, based on the material type, material properties and drying requirements of the target fabric, the target outputs are set for the outlet fluid velocity and outlet fluid temperature of the setting machine air duct required by the target fabric. Furthermore, the target output of the setting machine air duct can be set by FLUENT simulation software, and the target output includes the outlet fluid velocity, fluid temperature and other restrictive conditions of the setting machine air duct, thereby establishing an initial finite element model of the setting machine air duct, and then using the finite element model of the initial setting machine air duct to perform fluid simulation and obtain relevant simulation output data of the initial setting machine air duct.

Furthermore, the simulation software used and the target output set in the above embodiments are only preferred conditions of the present invention. In other embodiments, the simulation software and the setting of the target output can be flexibly selected according to actual needs.

S2. Adjust the structural parameters of the initial shaping machine air duct to obtain the actual output of the initial shaping machine air duct after adjustment;

In this embodiment, the structural parameters of the initial setting machine air duct are adjusted, and the actual output of the initial setting machine air duct after adjustment is obtained. The specific implementation steps are as follows:

In this embodiment, the structural parameters of the initial shaping machine air duct include: adding a guide plate structure and finding a suitable installation angle and installation length of the guide plate; selecting a proper opening method of the shaping machine air duct; and changing the inclination angle of the wedge plate.

Furthermore, the specific setting of the structural parameters in this embodiment can be adjusted according to practical needs to ensure the accuracy and applicability of the actual production results. The guide plate added in this embodiment and the adjustment of the angle and length of the guide plate installation and the angle of the wedge plate are only preferred conditions of the present invention. In one or some other embodiments, the composition and adjustment of the structure can be modified according to practical needs.

In this embodiment, the structural parameters of the air duct of the initial setting machine are adjusted, and the specific adjustment implementation contents are as follows:

In one embodiment, the adjustment method of the structural parameters of the initial shaping machine air duct can be: first, randomly adding a guide plate to the initial shaping machine air duct; then, adjusting the installation angle of the guide plate or the installation length of the guide plate; or the installation angle and length of the guide plate can be adjusted at the same time.

In another embodiment, the adjustment method of the initial shaping machine air duct structural parameters may be: first, setting the guide plate installation angle or the guide plate length in advance; or setting the guide plate installation angle and length in advance; and then adding the pre-set guide plate to the initial shaping machine air duct.

Furthermore, in this embodiment, adjusting the structural parameters of the air duct of the initial setting machine also includes:

The shape, size and other conditions of the air duct opening of the initial setting machine are adjusted, and the inclination angle of the wedge plate is adjusted at the same time; or a local structural adjustment is made to one of the air duct opening mode and the inclination angle of the wedge plate of the initial setting machine.

In this embodiment, the adjustment method of the initial setting machine air duct structural parameters is only for the full implementation of the present invention. In other embodiments, other different implementation methods can be used to adjust the structural parameters. The steps of changing the structural parameters in the above embodiment are only the preferred conditions of the present invention. In other embodiments, the adjustment process and steps of the setting machine air duct structural parameters can be flexibly selected according to actual needs.

According to the adjusted initial shaping machine air duct, the actual output of the adjusted shaping machine air duct is obtained.

In this embodiment, the actual output specific data of the adjusted initial setting machine air duct is as follows: the fluid velocity at the outlet of the adjusted initial setting machine air duct is obtained; and the outlet fluid temperature of the adjusted initial setting machine air duct is obtained.

In this embodiment, in order to further obtain the outlet fluid velocity and outlet fluid temperature required by the target fabric, the embodiment uses FLUENT simulation software to obtain the fluid velocity and fluid temperature at the outlet of the duct of the setting machine at different levels after adjustment. Furthermore, in this embodiment, FLUENT simulation software is also widely used in other fields such as dynamic analysis and motion control system design in practical applications.

Furthermore, in this embodiment, A is set to represent the opening mode of the guide plate, B is set to represent the inclination angle of the guide plate, and C is set to represent the length of the guide plate, and four levels of structural parameters are obtained within a certain range, and the intervals between each level are equal. Please refer to Table 1, which shows the opening mode of the duct of the setting machine, the inclination angle of the guide plate, and the length of the guide plate, and the specific structural parameters corresponding to different levels, and is specifically presented using the level table of the structural parameters of the duct of the setting machine.

Table 1

Structural parameter level table of the duct of the setting machine

In this embodiment, the structural parameters of the duct of the sizing machine are respectively intercepted into four levels, and the intervals between each level are set equally as a specific implementation condition, so as to fully implement the present invention and obtain the actual output and change of the structural parameters of the duct of the sizing machine. In one or some other embodiments, a different number of levels can be set, and other methods different from this horizontal spacing method can be used for analysis.

In this embodiment, please refer to Table 2, which shows the outlet fluid velocity of the initial setting machine air duct at different levels after adjustment.

Table 2

Table of outlet fluid velocity at different levels

In this embodiment, please refer to Table 3, which shows the outlet fluid temperature of the initial setting machine air duct at different levels after adjustment.

Table 3

Table of outlet temperature velocity at different levels

Furthermore, in this embodiment, the velocity and temperature of the fluid at the outlet of the duct of the setting machine after adjustment are obtained by using FLUENT simulation software only to facilitate the full implementation of the present invention. The outlet velocity data set and temperature data set at different levels presented in this embodiment are only the relevant output data collected for fabric processing under a specific working condition. In other embodiments, the relevant information can also be analyzed and adjusted by using different types and working conditions of the fabric.

S3. Evaluate the influence of the structural parameters according to the actual output and the target output.

In this embodiment, based on the outlet fluid velocity of the initial setting machine air duct at different levels after adjustment in Table 2 and the outlet fluid temperature of the initial setting machine air duct at different levels after adjustment in Table 3, the target outlet fluid velocity and target outlet fluid temperature required by the target fabric are compared and referenced, and the outlet fluid velocity and outlet fluid temperature requirements of the target fabric are selected from Table 2 and Table 3 of this embodiment to meet the requirements as much as possible, so as to ensure the quality and feel of the target fabric after setting and drying, and form a high-quality fabric product.

In this embodiment, the duct design method of the setting machine further includes setting an evaluation index; and using the evaluation index to evaluate the influence of the structural parameters. The specific implementation steps are as follows:

In this embodiment, an evaluation index is first set, which includes three indicators: energy utilization rate, temperature non-uniformity coefficient, and speed non-uniformity coefficient. Based on this, the specific contents of the corresponding indicators are as follows:

In this embodiment, most of the energy of the setting machine is used for drying during operation, and excellent energy utilization is of great significance for energy saving and environmental protection of the setting machine. In the drying process of the embodiment, the energy utilization is defined by the actual output outlet fluid temperature, outlet fluid temperature and working area temperature.

The specific formula of energy utilization rate in this embodiment is as follows:

Among them, η is the energy utilization coefficient, _th is the average temperature of the working area, _t0 is the fabric surface temperature, and _tn is the supply air temperature.

Based on this, uniformity is an important indicator for evaluating the quality of fabric drying and setting. Uneven gas flow at the duct outlet will lead to uneven temperature, which in turn leads to uneven drying of the entire fabric during setting, low heat setting drying efficiency, and poor hand feel of the fabric after setting. The speed non-uniformity coefficient and temperature non-uniformity coefficient are important indicators for measuring the setting efficiency.

The specific formula of the temperature non-uniformity coefficient in this embodiment is as follows:

Where _kt is the temperature non-uniformity coefficient, _σt is the arithmetic mean of temperature, is the temperature RMS deviation.

The specific formula of the speed non-uniformity coefficient in this embodiment is as follows:

Where M is the velocity non-uniformity coefficient, σ _v is the standard deviation of all monitoring points, and v is the velocity of the monitoring point. is the overall mean of all monitoring points, and n is the number of nozzle outlets.

Furthermore, in this embodiment, the setting of the specific content of the evaluation index and the design and application of the relevant formula can be adjusted according to practical needs to ensure the accuracy and authenticity of the evaluation index value.

Then, according to the actual output and target output of the initial setting machine air duct, the actual output value of the structural parameter is evaluated and analyzed using the evaluation index to obtain the relevant data and change trend of the evaluation index. The specific implementation steps are as follows:

In this embodiment, based on Table 1, the three structural parameters of the guide plate opening mode (A), the inclination angle (B), and the guide plate length (C) of the air duct of the initial setting machine are further analyzed, and the corresponding actual output results are obtained;

Based on the specific structural parameters corresponding to the opening mode, guide plate inclination angle and guide plate length of the sizing machine air duct at different levels in Table 1. Please refer to Table 4. The structural parameter level table includes the working conditions, opening mode, inclination angle, length of each structural parameter of the sizing machine air duct, and also organizes the temperature non-uniformity coefficient, velocity non-uniformity coefficient, energy utilization rate, turbulence dissipation rate and other data corresponding to the structural parameters. The specific situation is shown in Table 4:

Table 4

The actual output table of structural parameters at each level

Furthermore, the temperature non-uniformity coefficient, velocity non-uniformity coefficient, energy utilization rate, turbulence dissipation rate and other data included in the calculation data in this embodiment only belong to the priority conditions of the embodiment of the present invention, and can be adjusted and changed according to actual needs in one or some other embodiments.

Then, using the data output of the structural parameters at each level in Table 4, according to the actual output of the structural parameters and the evaluation index, the specific change trend of the evaluation index is obtained, and the implementation content is as follows:

Based on the actual output of the duct structure parameters of the sizing machine at various levels in Table 4, please refer to Figure 2 to obtain the trend diagram of energy utilization rate changing with the structural parameter level.

Based on the actual output of the duct structure parameters of the setting machine at various levels in Table 4, please refer to Figure 3 to obtain the trend diagram of the temperature non-uniformity coefficient with the level of the structure parameters.

Based on the actual output of the duct structural parameters of the sizing machine at various levels in Table 4, please refer to Figure 4 to obtain the trend diagram of the velocity non-uniformity coefficient with the structural parameter level.

Furthermore, in this embodiment, the actual output of the structural parameters and the evaluation index are used to further specifically analyze the changing trend of the evaluation index in order to fully implement the present invention. In other embodiments, different analysis method steps may be used for processing.

In this embodiment, the contribution rate of the structural parameter to the evaluation index is then obtained according to the actual output, the evaluation index and the change trend.

Based on the actual output of the duct structure parameters of the setting machine at various levels, as well as the changing trend chart of energy utilization, temperature non-uniformity coefficient and speed non-uniformity coefficient.

Based on this, please refer to FIG5 for the contribution rate of the structural parameters of the air duct of the setting machine of the present invention to the energy utilization rate. From the figure, it can be seen that the opening method of the air duct of the setting machine has the largest contribution rate to the energy utilization rate, that is, the opening method of the air duct of the setting machine determines the capacity utilization rate of the setting machine.

Based on this, please refer to Figure 6 for the contribution rate of the structural parameters of the duct of the sizing machine of the present invention to the temperature non-uniformity coefficient. From Figure 6, it can be obtained that the inclination angle of the guide plate of the duct of the sizing machine has the largest contribution rate to the temperature non-uniformity coefficient, that is, the inclination angle of the guide plate of the duct of the sizing machine is the key structural parameter for maintaining uniform temperature balance.

Based on this, please refer to FIG. 7 for the contribution rate of the structural parameters of the duct of the sizing machine of the present invention to the velocity non-uniformity coefficient; FIG. 7 shows that the opening mode of the duct of the sizing machine, the inclination angle and the length of the guide plate all contribute to the velocity non-uniformity coefficient.

Based on this, please refer to Table 5 for the energy utilization significance analysis table of each structural parameter of the present invention. From the table, it can be obtained that the inclination angle of the guide plate of the air duct of the shaping machine is highly significant to the energy utilization, and the inclination angle and length of the guide plate have a significant influence on the energy utilization.

Table 5

Energy utilization significance analysis table

Based on this, please refer to Table 6 for the significance analysis table of temperature non-uniformity of various structural parameters of the present invention. From the table, it can be obtained that the inclination angle of the guide plate is highly significant to the temperature non-uniformity, and the opening method and the inclination length of the guide plate have no significant effect on the energy utilization rate.

Table 6

Temperature non-uniformity significance analysis table

Based on this, please refer to Table 7 for the velocity non-uniformity significance analysis table of various structural parameters of the present invention. From the table, it can be obtained that the inclination angle and length of the guide plate have a significant influence on the velocity non-uniformity coefficient, and the opening method has no significant effect on the velocity non-uniformity coefficient.

Table 7

Velocity non-uniformity significance analysis table

Furthermore, in this embodiment, the significance analysis of each structural parameter is obtained based on the actual output of the evaluation function and the structural parameter. This analysis method is convenient for fully implementing the present invention. In other embodiments, different analysis methods can be used to process data.

S4. Determine optimal structural parameters according to the degree of influence.

In this embodiment, based on the change trend of the above-mentioned actual output evaluation index and the contribution rate of the evaluation index; and using the change trend and the contribution rate, the adjusted duct structural parameters of the setting machine are further adjusted to obtain the optimal structural parameters.

Based on the changing trend of the evaluation index and the contribution rate of the evaluation index.

In this embodiment, the inclination angle of the wedge plate of the initial setting machine air duct is first evaluated and analyzed:

Based on this, please refer to Figure 8 for the variation diagram of the temperature distribution non-uniformity coefficient of the wedge plate inclination angle of the present invention, and please refer to Figure 9 for the variation trend diagram of the turbulence loss rate of the wedge plate inclination angle of the present invention. According to Figures 8 and 9, it can be analyzed that: if the wedge plate inclination angle of the initial setting machine air duct is adjusted, that is, the higher the wedge plate inclination angle, the higher its turbulence loss rate is, and the higher its internal energy loss is; in this way, the structural parameter wedge plate inclination angle is optimized and adjusted. When the wedge plate inclination angle is selected to be 3°, the temperature distribution uniformity of the nozzle outlet area is improved, and the temperature non-uniformity coefficient is reduced from 4.73% to 2.75%.

Furthermore, in this embodiment, energy utilization and temperature uniformity are given priority, and the inclination angle of the wedge plate is finally selected to be 3°, which is the optimal adjustment angle of the wedge plate.

Furthermore, the definition of turbulence loss in this embodiment is: in the turbulent state, the movement of gas particles is very chaotic. In addition to the movement parallel to the pipeline axis, there is also violent lateral movement. Therefore, when the gas in the air duct is in turbulent motion, there will be resistance loss along the way and local resistance loss. The specific calculation formulas are as follows:

Where, _hf is the turbulent loss along the way, _λf is the resistance coefficient along the way, l is the length of the pipeline, v is the fluid velocity, d is the equivalent diameter of the pipeline, ρ is the fluid density, _hj is the local turbulent loss, and _λj is the local resistance coefficient.

The drag coefficient λ _f along the way is usually related to the Reynolds number Re and the relative roughness. It is usually calculated using an empirical formula. Since the friction of the wall is not considered in the simulation of this model, the calculation formula of the drag coefficient λ _f along the way is as follows:

λ _f = 0.0032 + 0.221Re ^{- 0.237}

Among them, _λf is the drag coefficient along the way, and Re is the Reynolds number.

In this embodiment, the calculation formula of the local resistance coefficient λ _j is as follows:

Among them, _λj is the local resistance coefficient, d is the inner diameter, D is the outer diameter, and θ is the bending angle.

The turbulent dissipation rate reflects the way in which the kinetic energy of the fluid is consumed during turbulent motion and can measure the energy loss of the fluid. Its value is related to the fluid temperature and fluid velocity. The calculation formula is:

Among them, ω is the turbulence dissipation rate, k is the turbulent kinetic energy, l is the turbulence scale, and c is an empirical constant, usually taken as 0.09.

Furthermore, in the present embodiment, the turbulence loss inside the air duct of the present invention is as follows: the turbulent resistance loss along the way is due to the viscosity of the fluid causing resistance between each flow layer and between the fluid and the boundary, while the flow state of the air duct gas of the present invention is turbulent, there is no stratified flow between the fluids, and at the same time the flow rate of the fluid is relatively fast, which makes the viscous resistance between the fluids and the wall of the air duct greater, resulting in a decrease in the fluid velocity and a dramatic loss of kinetic energy.

The local resistance loss is usually caused by the gas inside the pipeline hitting the wall and the eddy current generated by the turbulent fluid movement. Since the air duct of the present invention is wedge-shaped, the initial movement direction of the gas is horizontal. When the gas collides with the wedge plate, it causes a certain amount of local energy loss. At the same time, eddy currents are likely to occur after hitting the wall at the end of the air duct, resulting in large eddy current losses. The total turbulent loss is the sum of the resistance loss along the way and the local resistance loss.

In one embodiment, based on the change trend of the evaluation index and the contribution rate of the evaluation index, the energy utilization coefficient of the air duct of the initial setting machine is evaluated and analyzed:

Based on Figure 5 and Table 5, we can see the influence trend of the changes in various structural parameters on the evaluation index coefficient. Among them, the structural parameter of the opening mode (A) has the greatest influence on the energy utilization rate. When the uniform opening (A1) is used, the energy utilization rate reaches the highest 93.406%, and when the interlayer opening (A4) is used, the temperature utilization rate is poor, reaching 92.86%; when the inclination angle reaches 15° (B4), the energy utilization rate reaches the lowest 92.79%.

According to the range analysis and the contribution rate of each structural parameter to the energy utilization rate, it can be seen that the opening method (A) has a highly significant effect on the energy utilization rate, while the inclination angle (B) has only a relatively significant effect on the energy utilization rate, and the guide plate length (C) has no obvious effect on the energy utilization rate. It can be seen from the image that the contribution rate of the opening method (A) reaches 52.5%, and the inclination angle (B) is secondary. According to the above analysis, energy utilization is given priority, and the adjusted combination at this time is A1B2C2.

In one embodiment, based on the change trend of the evaluation index and the contribution rate of the evaluation index, the temperature non-uniformity coefficient of the initial setting machine air duct is evaluated and analyzed:

Based on the contribution rate of the molding machine air duct structural parameters to the temperature non-uniformity coefficient in Figure 6 and the temperature non-uniformity significance analysis table of the molding machine air duct structural parameters in Table 6.

Based on this, it can be seen that the influence trend of the change of each structural parameter on the temperature non-uniformity coefficient, among which the structural parameter of the inclination angle (B) has the greatest influence on the temperature non-uniformity coefficient. Among the various structural parameters, the inclination angle (B) has the largest change trend. When the inclination angle is 5° (B1), the temperature non-uniformity coefficient reaches the lowest value of 0.3018, and when the inclination angle is 15° (B4), the temperature non-uniformity coefficient reaches the highest value of 0.3847.

According to the range analysis and the contribution rate of each structural parameter to the temperature non-uniformity coefficient, it can be seen that the inclination angle (B) has a highly significant effect on the temperature non-uniformity coefficient, while the opening method (A) and the guide plate length (C) have no obvious effect on the temperature non-uniformity coefficient. It can be seen from the figure that the contribution rate of the inclination angle (B) reaches 62.1%, the contribution rate of the opening method (A) reaches 12.6%, and the contribution rate of the guide plate length (C) reaches 18.3%. According to the above analysis, the temperature non-uniformity coefficient is given priority, and the adjusted combination is A4B1C1.

In one embodiment, based on the change trend of the evaluation index and the contribution rate of the evaluation index, the velocity non-uniformity coefficient of the air duct of the initial setting machine is evaluated and analyzed:

Based on the contribution rate of the shaping machine air duct structural parameters to the velocity non-uniformity coefficient in Figure 7 and the velocity non-uniformity significance analysis table of the shaping machine air duct structural parameters in Table VII.

It can be seen that the change of each structural parameter has an influence trend on the velocity non-uniformity coefficient. Among them, the structural parameter of the inclination angle (B) has the greatest influence on the temperature non-uniformity coefficient. Among the various structural parameters, the inclination angle (B) has the largest change trend. When the inclination angle is 5° (B1), the velocity non-uniformity coefficient reaches the lowest value of 1.028, and when the inclination angle is 15° (B4), the velocity non-uniformity coefficient reaches the highest value of 3.646.

According to the range analysis and the contribution rate of each structural parameter to the velocity non-uniformity coefficient, it can be seen that the influence of the guide plate length (C) and the inclination angle (B) on the temperature non-uniformity coefficient is more significant, and the opening method (A) has a weaker influence on the temperature non-uniformity coefficient. It can be seen from the figure that the contribution rate of the inclination angle (B) reaches 33.3%, the contribution rate of the guide plate length (C) reaches 29.9%, and the contribution rate of the opening method (A) reaches 28.2%. According to the above analysis, the velocity non-uniformity coefficient is given priority, and the adjusted combination is A3B2C2 at this time.

Furthermore, in this embodiment, according to the above analysis content and various evaluation indicators, it can be obtained that the inclination angle (B) has a certain significant influence, so the inclination angle of the guide plate is adjusted to 5° (B2). At this time, the energy utilization rate is optimal and the speed unevenness coefficient is lowest, both reaching the optimal value.

In this embodiment, for the selection of the opening method, since the purpose of the present invention is to improve the environmental protection and energy-saving benefits of the setting machine and avoid energy loss, the energy utilization rate in the evaluation index is taken as a priority indicator. Since the opening method (A) contributes the most to the energy utilization rate, the percentage can reach 52.5%. That is, when selecting the opening method (A), the energy utilization rate is taken as the first consideration, and finally the opening method (A) is adjusted to a uniform opening (A1) after comprehensive consideration.

For the guide plate length (C), the guide plate length is selected to be 150 mm (C2). Since the contribution rate of the guide plate length (C) to each indicator is not high and the degree of influence is not significant, after comprehensive consideration, the length is finally adjusted to 150 mm (C2).

Furthermore, in this embodiment, after analyzing and comparing the finite element model data of multiple setting machine air ducts, the influence of each structural parameter on the internal temperature field and flow field is understood, the significance of the influence of each structural parameter on energy loss and drying efficiency is judged, and the final design scheme is obtained.

In this embodiment, the specific adjustment of the optimal setting machine air duct structural parameters is as follows: the inclination angle of the wedge plate is 3°, the air duct opening method is uniform opening, the guide plate length is 150mm, and the guide plate angle is 5°. The optimal setting machine air duct device will be further debugged in the future to obtain the size and structure we need.

In an optional embodiment, in order to meet the drying requirements of different working conditions, reduce the energy consumption of the setting machine, and improve the setting quality and the richness of the fabric's feel, the present invention also provides a setting machine air duct to make up for the defects and practical application deficiencies of the existing setting machine air duct, and solve the problems of energy waste of the setting machine and poor fabric setting quality.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims (4)

1. A method for designing an air duct of a setting machine, characterized in that it comprises the following steps: Set the target output of the initial setting machine air duct according to the target fabric; Adjusting the structural parameters of the air duct of the initial setting machine to obtain the actual output of the air duct of the initial setting machine after adjustment; According to the actual output and the target output, evaluating the influence of the structural parameters; Determining optimal structural parameters according to the degree of influence; The adjustment of the structural parameters of the air duct of the initial setting machine includes: Adding a guide plate to the air duct of the initial setting machine; Adjusting the guide plate, including adjusting the installation angle of the guide plate and adjusting the length of the guide plate; The adjustment of the structural parameters of the air duct of the initial setting machine includes: Presetting structural parameters of the guide plate, wherein the structural parameters include an installation angle of the guide plate and a length of the guide plate; Adding the guide plate with preset structural parameters to the air duct of the initial setting machine; The adjusting of the structural parameters of the air duct of the initial setting machine also includes: Adjusting the opening of the air duct of the initial setting machine; and/or Adjusting the wedge-shaped plate of the air duct of the initial setting machine, including adjusting the inclination angle of the wedge-shaped plate; The actual output of the adjusted initial setting machine air duct is obtained as follows: Obtaining the fluid velocity of the air duct of the initial setting machine after the adjustment; Obtaining the adjusted initial fluid temperature of the air duct of the setting machine; The duct design method of the setting machine also includes: Set evaluation indicators; Using the evaluation index to evaluate the influence of the structural parameters; The setting of evaluation indicators includes: The energy utilization rate is set, and the energy utilization rate formula is as follows: , in, is the energy utilization coefficient, is the average temperature of the working area, is the fabric surface temperature, is the supply air temperature; The temperature non-uniformity coefficient is set, and the temperature non-uniformity coefficient formula is as follows: , in, is the temperature non-uniformity coefficient, is the arithmetic mean temperature, is the temperature RMS deviation; The speed unevenness coefficient is set, and the speed unevenness coefficient formula is as follows: , in, is the velocity non-uniformity coefficient, is the standard deviation of all monitoring points, is the speed of the monitoring point, is the overall mean of all monitoring points, and n is the number of nozzle outlets. 2. The method for designing the air duct of a sizing machine according to claim 1, characterized in that the step of evaluating the influence of the structural parameters according to the actual output and the target output comprises: According to the actual output, the target output and the evaluation index, obtaining a change trend of the actual output evaluation index; The contribution rate of the structural parameter to the evaluation index is obtained according to the actual output, the evaluation index and the change trend. 3. The method for designing the duct of a setting machine according to claim 2, characterized in that the step of determining the optimal structural parameters according to the degree of influence to obtain the optimal duct of the setting machine comprises: Using the change trend and the contribution rate, adjusting the adjusted air duct structural parameters of the setting machine to obtain the optimal structural parameters; The optimal shaping machine air duct is obtained according to the optimal structural parameters. 4. A stenter air duct, characterized in that the stenter air duct is designed using the stenter air duct design method according to any one of claims 1 to 3.