CN107318593B - Combined press force compensating douche between a kind of washable pipe - Google Patents

Abstract

The invention relates to a detachable and washable combined pressure compensation emitter between pipes, which includes an emitter main body, a pressure compensation film, a water outlet ring cavity and a movable coil; The other end is threaded to the movable coil; on the outer wall of the emitter body between the fixed coil and the movable coil, a first labyrinth channel is arranged, and the beginning and end of the first labyrinth channel communicate with the interior of the emitter body The water inlet; the water outlet ring cavity is set outside the emitter body between the fixed coil and the movable coil; the pressure compensation film ring is set between the water outlet ring cavity and the emitter body, and the two ends are limited to the fixed coil and movable coils; a second labyrinth flow channel is set on the inner wall of the water outlet ring cavity, and the end of the second labyrinth flow channel is a water outlet communicating with the outside of the water outlet ring cavity; The flow channel and the membrane flow hole of the second labyrinth flow channel.

Description

A detachable and washable combined pressure compensation emitter between pipes

technical field

The invention relates to a detachable and washable combined pressure compensation sprinkler between pipes, which belongs to the technical field of agricultural irrigation.

Background technique

my country is facing a severe shortage of water resources. As a large water user, agricultural irrigation has become increasingly prominent, and the effective utilization rate of agricultural irrigation water is low. Water-saving irrigation has emerged as the times require. Drip irrigation is the micro-irrigation method with the highest water-saving efficiency at present, and the water utilization rate can be as high as 95%. It is an important technical measure to ensure the sustainable development of agriculture in our country. The emitter is the core and key part of the entire drip irrigation system, and its structure has a great influence on the uniformity of irrigation, the anti-clogging ability and life of the system. There are many types of emitters used in drip irrigation systems, and pressure compensated emitters are one of the most widely used types. The pressure compensation emitter is a drip irrigation terminal device that can achieve constant flow of water within a certain pressure range through the adjustment of the internal pressure compensation gasket. It has the advantages of good compensation performance, uniform irrigation, long laying length, and wide application range. Especially It is suitable for situations with large terrain fluctuations, unbalanced system pressure and long capillary pipes. Usually, in order to ensure better hydraulic performance, the internal flow channel size of the pressure compensation emitter is generally small. Currently, the pressure compensation emitters that combine the labyrinth flow channel and the pressure compensation structure in the market currently have a flow channel size in the Between 0.7 and 1.5mm, it is easy to cause blockage, and the flow rate is too small, so it is not suitable for irrigation of mountain economic forests. Moreover, although the existing pressure-compensated emitters have certain pressure compensation performance and good uniformity, their compensation intervals are small, and the compensation intervals cannot be matched with mountain height differences and complex terrains when applied to self-pressure irrigation in mountainous areas. Compatible, can not give full play to the advantages of its high uniformity of irrigation, resulting in poor uniformity of emitters and poor irrigation effects. Therefore, it is of great significance to solve the problems of easy blockage, small flow rate and poor compensation performance of emitters.

Common clogging methods of emitters mainly include physical clogging, chemical clogging, biological clogging, etc., and physical clogging is generally the most common. An effective way to solve the physical blockage caused by sediment particles is to increase the size of the inlet and flow channel, but increasing the size of the inlet and flow channel will sacrifice part of the hydraulic performance of the flow channel. The Chinese patent application with the application number 201610532350.1 discloses a compensating drip irrigation emitter, which optimizes the internal structure of the emitter cavity, improves irrigation efficiency and water resource utilization, but its flow adjustment range is small, It cannot meet the requirements of large-flow irrigation, and its structure is an orifice-on-pipe type. When it is applied to mountainous areas with complex terrain, it takes time and effort to assemble.

Contents of the invention

In view of the above problems, the object of the present invention is to provide a detachable and washable combined pressure compensation emitter between pipes, which can solve the problem of anti-clogging of the emitter without changing the size of the flow channel, so as not to affect the emitter. hydraulic performance.

In order to achieve the above object, the present invention adopts the following technical solutions: a detachable and washable combined pressure compensation emitter between pipes, which is characterized in that it includes the emitter main body, a pressure compensation membrane, a water outlet ring cavity and a movable coil; One end of the emitter body is provided with a fixed coil, and the other end of the emitter body is threaded to the movable coil; A first labyrinth flow channel is arranged, and the beginning and end of the first labyrinth flow channel is a water inlet communicating with the interior of the emitter body; the water outlet ring cavity is arranged between the fixed coil and the movable coil The outside of the emitter main body; the pressure-compensating film ring is set between the water outlet ring cavity and the emitter body, and the two ends are limited to the fixed coil and the movable coil; in the water outlet ring cavity A second labyrinth channel is set on the inner wall of the second labyrinth channel, and the end of the second labyrinth channel is a water outlet communicating with the outside of the water outlet ring cavity; The membrane flow hole of the second labyrinth channel.

The emitter main body is a hollow cylindrical structure, and the first labyrinth flow channel is arranged on the outer wall of the hollow cylindrical structure; the first labyrinth flow channel and the second labyrinth flow channel are tooth-shaped labyrinth flow channels.

The fixed coil and the movable coil are respectively connected to the capillary by threads.

An adjustment ring cavity is provided at the end of the second labyrinth channel, and a ring boss is arranged at the center of the adjustment ring cavity, and the water outlet is located at the hollow part of the ring boss; A through groove is arranged on the side wall of the ring boss.

The water outlet ring cavity is a hollow cylindrical structure with large diameters at both ports and a small diameter in the middle, wherein the large diameter part is used to position the water outlet ring cavity between the fixed coil and the movable coil, and the small diameter part The inner diameter is equal to the outer diameter of the pressure compensating membrane. The area of the membrane flow hole is the same as the cross-sectional water flow area of the first labyrinth channel and the second labyrinth channel.

A plurality of grooves for material saving are opened on the emitter main body.

A filter grid is arranged on the water inlet.

The height of the ring boss is smaller than the height of the adjusting ring cavity.

The parameters of the toothed labyrinth channel satisfy the following geometric relationship:

f=0.7776w+0.0307, n=-181.64w ² +390.9w-70.51, a=-0.7857w ² +1.6753w+0.3852

In the formula, w is the channel width; f is the local head loss coefficient; a is the tooth width; n is the number of channel units.

Due to the adoption of the above technical solutions, the present invention has the following advantages: 1. The present invention realizes the separation of the main body of the emitter, the pressure-compensating membrane, and the water outlet ring cavity, and has the advantages of convenient disassembly and cleaning. Therefore, when the flow channel is blocked, it can be Rotate the movable coil, take the emitter body out of the water outlet ring cavity, and clean the pressure compensation film and the emitter body separately. The operation is simple, so that the problem of emitter clogging can be well solved, and the improvement of anti-clogging performance can extend the life of the emitter. The service life of the system greatly reduces the cost of drip irrigation. 2. On the basis of the orifice-on-pipe pressure-compensated emitter structure, the present invention proposes a pipe-type pressure-compensated emitter that combines a labyrinth channel and a pressure-compensated structure, wherein the inner chamber of the emitter main body can be used as a capillary passage The labyrinth flow channel is arranged on the outer wall, making full use of the structural advantages of the cylindrical emitter. At the same time, the thread structure is used to separate the capillary tube from the emitter, which changes the design concept of the integrated emitter and capillary tube. 3. On the basis of the gland of the conventional pressure-compensated emitter, the present invention proposes a hollow cylindrical water outlet ring cavity, which plays the role of fixing the film. At the same time, a labyrinth flow channel and an adjustment ring cavity are arranged on the inner wall, increasing the The deformable area of the pressure-compensated film under stress greatly increases the pressure compensation range. 4. During use, the pressure-compensated membrane can be deformed to varying degrees according to the change of incoming water pressure, so that the second labyrinth channel on the outlet water ring cavity and the depth of water passing through the adjustment ring cavity will change with the change of pressure , the interaction between fluid movement and pressure-compensated film deformation adjusts the flow rate at the outlet of the channel to achieve a constant flow at the outlet. 5. When assembling the emitter of the present invention, install the emitter on one side of the capillary first, and then place the capillary in the corresponding position when installing in the field, and the staff only need to connect the side of the capillary that is not installed with the emitter The spiral tube of the sprinkler can be screwed and connected, which greatly reduces the installation workload. 6. Each component part of the present invention is a separate part. When a certain part is seriously damaged, only the damaged part needs to be replaced, and the production concept of the disposable product of the conventional cylindrical labyrinth emitter is changed, so as to realize the serialization of this type of new emitter. standardization. 7. The water outlet ring cavity and the emitter main body of the present invention can be put into mass production, and the different flow requirements in agricultural production can be met by changing the structure and size of the labyrinth flow channel. 8. The lower end of the water outlet of the present invention is a ring boss, and an adjustment ring cavity is provided outside the ring boss. A through groove is arranged on the boss to prevent the film from blocking the water outlet and obstructing the outflow. 9. The present invention can meet the irrigation requirements within a certain flow range, and the uniformity of irrigation is high. It is suitable for agricultural production drip irrigation and small flow irrigation in areas with obvious changes in water pressure in various mountains, hills, etc., and has a wide range of applications. .

Description of drawings

Fig. 1 is the overall structural representation of the present invention;

Fig. 2 is a structural schematic diagram of the main body of the emitter of the present invention;

Fig. 3 is the structural representation of movable coil of the present invention;

Fig. 4 is a schematic diagram of the installation of the pressure compensation membrane and the emitter main body of the present invention;

Fig. 5 is a schematic cross-sectional structure diagram of the water outlet ring cavity of the present invention;

Fig. 6 is a half-sectional schematic diagram of A-A direction in Fig. 5;

Fig. 7 is a half-sectional schematic diagram of B-B direction in Fig. 5; wherein, the line corresponding to ① represents the schematic diagram of the pressure-compensated film in the first stage without deformation, and the line corresponding to ② represents the schematic diagram of the film deformed in the second stage , at this time, the water passing area of the flow channel decreases, and the emitter plays the role of pressure compensation;

Fig. 8 is the structural representation of capillary of the present invention;

Fig. 9 is a schematic diagram of a geometric model of the (first/second) labyrinth flow channel of the present invention;

Figure 10 is a graph showing the relationship between the channel width w and the change of the average head loss coefficient f;

Fig. 11 is a graph showing the relationship between the number n of flow channel units and the width w of the flow channel;

Fig. 12 is a graph showing the relationship between the tooth width a and the channel width w.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

As shown in FIGS. 1-4 , the present invention includes an emitter main body 1 , a pressure-compensating membrane 2 , a water outlet ring chamber 3 and a movable coil 4 . One end of the emitter main body 1 is provided with a fixed coil 5, and the other end of the emitter main body 1 is connected with a movable coil 4 by threads. A first labyrinth channel 6 is arranged on the outer wall of the emitter body 1 between the fixed coil 5 and the movable coil 4, and the beginning and end of the first labyrinth channel 6 is a water inlet communicating with the interior of the emitter body 1 7. The water outlet annular cavity 3 is arranged outside the emitter main body 1 between the fixed coil 5 and the movable coil 4 . The pressure-compensating membrane 2 ring is set between the water outlet ring chamber 3 and the emitter main body 1 and both ends are limited to the fixed coil 5 and the movable coil 4 . A second labyrinth flow channel 8 is arranged on the inner wall of the water outlet ring cavity 3 , and the end of the second labyrinth flow channel 8 is a water outlet 9 communicating with the outside of the water outlet ring cavity 3 . A membrane flow hole 10 communicating with the first labyrinth channel 6 and the second labyrinth channel 8 is provided on the pressure compensation membrane 2 .

Further, the emitter main body 1 is a hollow cylindrical structure, and the first labyrinth channel 6 is arranged on the outer wall of the hollow cylindrical structure. Both the first labyrinth channel 6 and the second labyrinth channel 8 are toothed labyrinth channels.

Further, as shown in Figures 5-7, an adjustment ring chamber 12 is provided at the end of the second labyrinth channel 8, and a ring boss 13 is arranged at the center of the adjustment ring chamber 12, and the water outlet 9 is located on the ring boss. 13 hollow parts. The height of the annular boss 13 is smaller than the height of the adjusting ring cavity 12 to prevent excessive deformation of the pressure compensation membrane 2 at the position of the adjusting ring cavity 12 . A through groove 14 is provided on the side wall of the annular boss 13 to prevent the pressure compensation membrane 2 from being deformed and blocking the water outlet 9 to block the outflow.

Further, the fixed coil 5 and the movable coil 4 are respectively connected to the capillary 11 (as shown in FIG. 8 ) through threads.

Further, the water outlet ring chamber 3 is a hollow cylindrical structure with large diameters at both ports and a small diameter in the middle, wherein the large diameter part is used to position the water outlet ring chamber 3 between the fixed coil 5 and the movable coil 4, and the small diameter part The inner diameter of the inner diameter is equal to the outer diameter of the pressure compensating membrane 2, so that the second labyrinth channel 8 is sealed by the pressure compensating membrane 2.

Furthermore, the area of the film flow hole 10 is the same as the cross-sectional water flow area of the first labyrinth flow channel 6 and the second labyrinth flow channel 8, so that the hydraulic performance of the water flow can be avoided due to the change of the flow flow area.

Further, a plurality of grooves 15 for saving material are provided on the emitter main body 1 .

Further, a filtering grid is arranged on the water inlet 7, which can filter impurities in the irrigation water to reduce clogging.

The working principle of the present invention is: the water flow enters the first labyrinth flow channel 6 of the emitter main body 1 from the water inlet 7, and enters the second labyrinth flow channel 8 of the water outlet ring cavity 3 through the film flow hole 10 of the pressure compensation type membrane 2, Then the water outlet 9 on the upper part is reached through the water collecting area of the adjusting ring cavity 12 at the middle position of the water outlet ring cavity 3 . With the continuous change of the water inlet pressure, the lower part of the pressure compensation membrane 2 is deformed by the impact of the water pressure, resulting in corresponding changes in the second labyrinth channel 8 and the water passage section of the adjustment ring chamber 12 on the upper part of the pressure compensation membrane 2 , the internal pressure of the second labyrinth flow channel 8 on the water outlet ring chamber 3 and the internal pressure of the adjustment ring chamber 12 change in turn to resist the extrusion of the pressure compensation film 2, and through this interaction, the flow rate of the emitter is jointly adjusted to make the water outlet more uniform . Under normal pressure, the area of the second labyrinth channel 8 on the inner wall of the water outlet ring chamber 3 and the cross-section of the adjustment ring chamber 12 are the largest, and the outlet of the emitter flows normally. When the pressure increases, the pressure compensation membrane 2 moves upward. At this time, the pressure compensating film 2 squeezes the second labyrinth flow channel 8 and the adjustment ring cavity 12, blocking a part of the outlet section of the flow channel, and the water outlet area of the second labyrinth flow channel 8 and the adjustment ring cavity 12 changes, which in turn affects fluid in the flow channel. At this time, the water inlet pressure, the internal pressure of the second labyrinth flow channel 8 on the water outlet ring cavity 3, and the internal pressure of the adjustment ring cavity 12 press the film against each other, and the joint action reduces the water passing area of the second labyrinth flow channel 8 and the adjustment ring cavity 12. , the flow rate decreases accordingly, this compensation method relying on changing the cross-sectional area of the water greatly increases the pressure compensation range, improves the water uniformity of drip irrigation in mountainous areas, and also improves the adjustment accuracy and reliability.

The invention realizes the separation of the emitter main body 1 from the pressure-compensating membrane 2 and the water outlet ring chamber 3, and is convenient for disassembly and cleaning. Therefore, when the flow channel is blocked, the movable spiral tube 4 can be rotated to separate the emitter body 1 from the water outlet ring. The cavity 3 is taken out, and the pressure compensation film 2 and the emitter main body 1 are cleaned separately. The operation is simple, and the problem of the blockage of the emitter can be solved well. The improvement of the anti-clogging performance can prolong the service life of the emitter and greatly reduce the use of drip irrigation. cost.

The present invention also studies the structure of the tooth-shaped labyrinth flow channel, and limits the parameters of the tooth-shaped labyrinth flow channel structure, so as to reduce the frequency of flow channel blockage and reduce the number of flow channel units by increasing the flow channel width. , The purpose of reducing the project cost. As shown in Figure 9, the geometric relationship between the runner width and the tooth width, tooth height, and tooth bottom distance can be obtained from the plane geometric model:

Among them, the relationship between tooth width, tooth height and tooth tip angle satisfies the following relationship:

Before the deformation occurs, the water passing area A of the flow channel can be expressed as:

A=d×w (3)

The water flow Q of the flow channel can be expressed as:

In the formula: w is the width of the runner, mm; h is the height of the tooth, mm; a is the width of the tooth, mm; b is the pitch of the tooth bottom, mm; θ is the angle of the tip of the tooth, °; is the cross-sectional area of the flow channel, m ² ; Q is the flow rate of the flow channel, L/h; is the average velocity of the fluid, m． s ^-1 .

From the perspective of anti-clogging performance and production cost, the larger flow channel area and shorter flow channel length help to improve the anti-clogging performance of the emitter and reduce the cost, and at the same time can meet the large flow demand of the pressure compensation emitter , but increasing the channel width and reducing the number of channel units will reduce the energy dissipation effect of the channel. Therefore, the present invention proposes to increase the average head loss coefficient while increasing the channel width and reducing the number of channel units , so that increasing the flow area of the flow channel and reducing the number of flow channel units will not weaken the energy dissipation effect of the flow channel.

Considering that the water head loss along the flow through the flow channel can be ignored, the present invention only considers the local head loss in the calculation process. Since the local head loss coefficient is only related to the shape of the flow channel, for the same flow channel shape distributed according to the length of the flow channel As far as the local head loss is concerned, the pressure loss is evenly distributed on the length, which conforms to the law of linear superposition, so the entire head loss can be discretely and uniformly distributed in the entire flow channel, and it can be approximated by the Darcy-Weisbach formula (7) The head loss of the flow channel. In addition, since 90% of the water head loss occurs at the tooth tip structure, the present invention assumes that the local head loss coefficient is only related to the channel rotation angle α in the calculation process, based on the existing local head loss empirical coefficient table (see Table 1 ), it is found that the local head loss coefficient f and the channel rotation angle α satisfy the relational expression:

f＝0.7× ^10-4 ×α ^2.1441 (5)

Considering that the water flow through a tooth-shaped labyrinth flow channel unit needs to pass through two flow channel rotation angles α of the same angle, so α=90°-θ/2 is substituted into the formula (5), and the local head loss coefficient f and the inter-tooth angle θ are obtained satisfy the relation:

f＝1.4×10 ^-4 ×(90°-θ/2) ^2.1441 (6)

In the formula: H is the head loss, m; f is the local head loss coefficient, which is related to the flow channel rotation angle, check the local head loss experience coefficient table (Table 1); α is the flow channel rotation angle, °; n is the number of flow channel units number; l _i is the channel length of a single channel unit, mm; D is the hydraulic diameter, mm; g is the acceleration of gravity, which is 9.81m/s ² .

Substituting formulas (1), (3) and formulas (6) to (9) into formula (4), we get:

It can be seen from the formula (10) that the relationship between the flow rate Q, the channel width w, and the number n of channel units is very complicated. Therefore, the present invention proposes to use the The relationship between the geometrical parameters of the channel and the hydraulic formula roughly analyzes the relationship between the number n of channel units and the channel width w.

Without considering the deformation of the membrane, assuming that the working head of the water inlet is 10m, the geometric parameters are linearly adjusted so that the average head loss coefficient f increases approximately linearly with the increase of the channel width w. At this time, the number of channel units n and The relationship of the channel width w satisfies the parabolic relationship curve with the opening downward, and the change of the tooth width a also shows this rule, and the obtained results are shown in Figures 10-12. Through fitting, the obtained formulas are f=0.7776w+0.0307, n=-181.64w ² +390.9w-70.51, a=-0.7857w ² +1.6753w+0.3852, and the coefficients of these relational expressions will vary with specific conditions changes, but the changing rules of these parameters will not change. The calculation results are shown in Tables 2 and 3. Taking the data in this paper as an example, when the channel width w is greater than 1.10mm, the average head loss coefficient f continues to increase, and the number of channel units n begins to decrease. In actual production and operation, according to this paper According to the change law of each parameter obtained, the specific design is carried out, and the pressure compensation emitter with wide flow channel and few flow channel units is obtained.

Table 1. Empirical coefficient table of local head loss

Table 2 Calculation table of flow passage area

Table 3 Calculation table of the average flow velocity of the flow channel and the water flow

The present invention is only described with the above-mentioned embodiment, and the structure, setting position and connection of each component can be changed. On the basis of the technical solution of the present invention, all improvements and equivalents to individual components according to the principles of the present invention Any transformation shall not be excluded from the protection scope of the present invention.

Claims (8)

1. A detachable and washable combined pressure compensation emitter between pipes, characterized in that: it includes an emitter main body, a pressure compensation film, a water outlet ring cavity and a movable coil; a fixed coil is arranged at one end of the emitter main body, The other end of the emitter body is threadedly connected to the movable coil; a first labyrinth flow channel is arranged on the outer wall of the emitter body between the fixed coil and the movable coil, the The beginning and end of the first labyrinth channel is a water inlet communicating with the interior of the emitter body; the water outlet ring cavity is arranged outside the emitter body between the fixed coil and the movable coil; The pressure-compensating film ring is set between the water outlet ring cavity and the emitter main body, and the two ends are limited to the fixed coil and the movable coil; a second labyrinth flow channel is set on the inner wall of the water outlet ring cavity, The end of the second labyrinth flow channel is a water outlet that communicates with the outside of the water outlet ring cavity; a film flow hole that communicates with the first labyrinth flow channel and the second labyrinth flow channel is provided on the pressure compensation membrane ; An adjustment ring cavity is provided at the end of the second labyrinth channel, and a ring boss is arranged at the center of the adjustment ring cavity, and the water outlet is located at the hollow part of the ring boss; A through groove is arranged on the side wall of the ring boss; The water outlet ring cavity is a hollow cylindrical structure with large diameters at both ports and a small diameter in the middle, wherein the large diameter part is used to position the water outlet ring cavity between the fixed coil and the movable coil, and the small diameter part The inner diameter is equal to the outer diameter of the pressure compensating membrane. 2. A detachable and washable inter-pipe combined pressure compensation emitter according to claim 1, characterized in that: the emitter body is a hollow cylindrical structure, and the first labyrinth flow channel is set in the hollow cylindrical structure On the outer wall; the first labyrinth flow channel and the second labyrinth flow channel are tooth-shaped labyrinth flow channels. 3. A detachable and washable inter-pipe combined pressure compensation emitter according to claim 1, characterized in that: the fixed coil and the movable coil are respectively connected to the capillary by threads. 4. A detachable and washable inter-pipe combined pressure compensation emitter as claimed in claim 1, characterized in that: the area of the membrane flow hole is the same as the section of the first labyrinth flow channel and the second labyrinth flow channel. The area is the same. 5. A detachable and washable inter-pipe combined pressure compensation emitter according to claim 1, characterized in that: a plurality of grooves for material saving are provided on the emitter body. 6. A detachable and washable inter-pipe combined pressure compensation emitter according to claim 1, characterized in that: a filter grid is arranged on the water inlet. 7. A detachable and washable pipe-to-pipe combined pressure compensation emitter according to claim 1, characterized in that: the height of the ring boss is smaller than the height of the adjusting ring cavity. 8. A detachable and washable combined pressure compensation emitter between pipes according to claim 2, characterized in that: the parameters of the tooth-shaped labyrinth flow channel satisfy the following geometric relationship: f=0.7776w+0.0307, n=-181.64w ² +390.9w-70.51, a=-0.7857w ² +1.6753w+0.3852 In the formula, w is the channel width; f is the local head loss coefficient; a is the tooth width; n is the number of channel units.