CN111503048A - Impeller for low-temperature-rise centrifugal steam compressor - Google Patents

Abstract

The invention discloses an impeller for a low-temperature-rise centrifugal steam compressor, which comprises a front cover plate, a rear cover plate, blades, a reinforcing ring and a hub, wherein the front cover plate is fixedly connected with the front cover plate; the front cover plate is of a conical structure, a rear cover plate is arranged on one side of the large end face of the front cover plate at intervals in a coaxial manner, the rear cover plate is a circular uniform-thickness flat plate, and a hub is arranged between the rear cover plate and the front cover plate in a coaxial manner; the hub is of a conical structure, and the large end of the hub is sleeved in the rear cover plate; the small end of the hub is sleeved in the front cover plate at intervals and vertically extends to the small end face of the front cover plate; a reinforcing ring is coaxially arranged at the small end of the conical surface of the front cover plate, is of an arc structure sleeved on the front cover plate and is welded and fixed with the front cover plate; a plurality of blades are uniformly distributed and vertically arranged between the inner surface of the front cover plate and the rear cover plate at intervals along the circumferential direction of the front cover plate, and each blade is a quasi-three-dimensional flow arc-shaped blade and is respectively and vertically welded and fixed with the front cover plate, the rear cover plate and the hub. The invention adopts advanced cavity geometric design, and improves the efficiency of the impeller.

Description

An impeller for low temperature centrifugal steam compressor

technical field

The invention relates to the technical field of air compression, in particular to an impeller for a low-temperature rise centrifugal steam compressor.

Background technique

With the further improvement of energy-saving and environmental protection requirements at home and abroad, the rational application of high-efficiency energy recovery equipment has become the current development trend, and the mechanical vapor recompression (referred to as: MVR) system is a new energy-saving energy recovery and reuse system with good development prospects. It is widely used in various fields such as sewage treatment, food and beverage, medicine and chemical industry.

MVR is the core energy-saving technology of the evaporation system. It uses the secondary steam generated by itself to be compressed by the steam compressor, the temperature and pressure of the steam are increased, and the enthalpy value is increased, and then the heat is supplied to the heat exchanger of the evaporation system, thereby reducing the external energy. demand. The key equipment of MVR is the centrifugal steam compressor. According to the different types of temperature rise, there are Roots blower, centrifugal compressor, single screw compressor, etc. The most suitable type of compressor for the evaporation system with a temperature rise of less than 9 degrees is a low temperature rise centrifugal steam compressor.

Different MVR process systems have different requirements for compressor performance. Some process systems have a small amount of evaporation and a large temperature rise requirement, and some process systems have a large amount of evaporation and a small temperature rise requirement; this requires the design of different blade shapes to meet the needs of evaporation and temperature rise to meet various processes. production run.

When the steam compressor is running, due to changes in material composition and characteristics, changes in inlet temperature, or changes in system resistance, there is a certain deviation between the actual operating conditions and the design conditions; this requires the selected steam compressor. The wide stable operation area can maintain relatively high efficiency and stable operation under partial working conditions to avoid surge.

In addition, in the current environment of rising energy costs, energy consumption is one of the important indicators of steam compressors; under the same process conditions, try to choose a steam compressor with high efficiency and reliable operation.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide an impeller for a low temperature rise centrifugal steam compressor, which adopts an advanced cavity geometry design to improve the efficiency of the impeller.

In order to solve the above-mentioned technical problems, the present invention adopts the following technical solutions: a kind of impeller of the present invention for low-temperature rise centrifugal steam compressor, its innovation lies in: comprising a front cover plate, a rear cover plate, a blade, a reinforcing ring and a hub; The front cover is a conical structure, and a rear cover is also arranged at a coaxial interval on one side of the large end face. The rear cover is a circular flat plate of equal thickness, and the rear cover and the front A wheel hub is also concentrically sleeved between the cover plates; the wheel hub is a conical structure formed by integral forging, and its large end is sleeved in the rear cover plate and fixed by welding; The ends are sleeved in the front cover plate and extend vertically to the small end face of the front cover plate; on the conical surface of the front cover plate near the small end, there are also coaxially and juxtaposed with Reinforcing ring, which is an arc structure sleeved on the front cover, and is fixed by welding with the conical surface of the front cover; the inner surface of the front cover is connected to the rear cover. There are also several blades vertically and evenly spaced along the circumferential direction. Each of the blades is a quasi-ternary flow arc blade, and is respectively welded and fixed to the front cover plate, the rear cover plate and the wheel hub vertically.

Preferably, the front cover plate is formed by molding, and its taper is 7.5 degrees; the inner diameter of the small end of the front cover plate is 660 mm.

Preferably, the outer diameter of the big end of the front cover is consistent with the outer diameter of the rear cover, and both are 1600 mm.

Preferably, the distance between the outlet ends of the front cover plate and the rear cover plate is 100 mm.

Preferably, the tapered surface of the hub matches the inner surface of the front cover, and the outer diameter of the small end thereof is smaller than the inner diameter of the small end of the front cover.

Preferably, the inner diameter of the small end of the hub is 160 mm, and the axial length thereof is 300 mm; the cone angle of the hub is 45°, and the ratio of the cone radius is 3.25.

Preferably, the radius of curvature of the reinforcing ring is 80 mm.

Preferably, the blade is of a backward type with a front wind guide wheel.

Preferably, the outer contour line of the blade includes a first front coil line, a second front coil line, a third front coil line, a first rear coil line, a second rear coil line and a third rear coil line; the first coil line A front line consists of coordinate points (-75,483.45,127.58), (-76.97,462.81,116.55), (-78.9,442.73,106.59), (-80.82,422.36,97.54), (-82.71,401.99,89.34), (-84.59,381.63,81.98), (-86.46,361.26,75.36), (-88.31,340.89,69.48), (-90.13,320.51,64.36), (-92.03,300.15,59.93) and (-93.66,279.76 , 55.92) are connected in sequence; the second front line is composed of coordinate points (-93.66, 279.76, 55.92), (-95.92, 264.13, 52.91), (-101.26, 248.51, 49.93), (-111.17, 232.88, 46.98), (-123.62, 220.38, 44.62), (-135.01, 212.57, 43.15), (-148.64, 206.36, 42.01), (-154.97, 204.44, 41.59), (-161.06, 203.19, 41.14) and (- 172.53, 202.33, 39.91) are connected in sequence; the third front line is composed of coordinate points (-172.53, 202.33, 39.91), (-174.57, 202.36, 39.5), (-176.93, 202.42, 39.15), (-184.81 , 202.84, 37.44), (-197.09, 203.61, 33.07), (-209.35, 204.54, 26.37), (-221.6, 205.56, 16.96) and (-233.88, 206.2, 4.48) are connected in sequence; The disk line consists of coordinate points (0,483.63,126.91), (0,452.41,110.44), (0,420.23,95.95), (0,387.26,83.33), (0,353.61,72.69), (0,319.38,64.1), (0,284.79,.57.03), (0,250.57.03), 50.54), (0,215.41,43.98), (0,180.73,37.4) and (0,146.04,30.83) are connected in sequence; the second rear line is composed of coordinate points (0,146.04,30.83), (-10.94,135.1 , 28.76), (-21.89, 124.16, 26.7), (-32.83, 113.21, 24.61), (-43.77, 102.28, 22.54), (-54.71, 91.33, 20.47), (-65.66, 80.39, 18.39), ( -76.6, 69.44, 16.34), (-87.55, 58.49, 14.31) and (-98.47, 47.58, 12.11) are connected in sequence; the third rear line is composed of coordinate points (-98.47, 47.58, 12.11), (-98.47, 47.58, 12.11) 104.76, 47.58, 12.11), (-111.05, 47.58, 12.11), (-125.74, 48.66, 12.41), (-140.47, 48.5, 12.36), (-155.21, 48.49, 12.06), (-169.94, 48.73, 11.26) ), (-184.67, 49.04, 9.76), (-199.41, 49.46, 7.36) and (-214.14, 49.84, 3.89) are connected in sequence.

Preferably, the first front line is fitted with the first rear line, the second front line is fitted with the second rear line, and the third front line is fitted with the third line The three rear disks are fitted with lines, thus forming the curved contour of the blade.

Beneficial effects of the present invention:

(1) The structure of the present invention is a closed welded impeller, which is suitable for low temperature centrifugal steam compressors, and the specific speed is between 18 and 24;

(2) The present invention improves the impeller efficiency by adopting advanced cavity geometry design;

(3) The present invention can achieve higher pressure while maintaining high efficiency, satisfies the requirement of high pressure increase and low energy consumption, and has obvious energy saving advantages.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings that need to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments described in the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

FIG. 1 is a schematic structural diagram of an impeller used in a low temperature rise centrifugal steam compressor according to the present invention.

FIG. 2 is a cross-sectional view of FIG. 1 .

FIG. 3 is a schematic structural diagram of the blade portion in FIG. 1 .

FIG. 4 is a perspective view of the blade of FIG. 3 .

FIG. 5 is a coordinate table of the outer contour line of the blade in FIG. 3 .

Fig. 6 is the distribution cloud diagram of the impeller entropy of the present invention.

FIG. 7 is a comparison diagram of the performance data of the physical model machine and the design data under 100% design speed of the impeller of the present invention.

Among them, 1-front cover; 2-rear cover; 3-blades; 4-reinforcing ring; 5-hub; 31-first front coil; 32-second front coil; 33-third front coil ; 34 - the first rear coil line; 35 - the second rear coil line; 36 - the third rear coil line.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below through specific embodiments.

An impeller for a low-temperature rise centrifugal steam compressor of the present invention includes a front cover 1, a rear cover 2, blades 3, a reinforcing ring 4 and a hub 5; the specific structure is shown in Figures 1 to 3, the front cover 1 is a conical structure, which is molded under a hydraulic machine, and its taper is 7.5 degrees. The inner diameter of the small end of the front cover 1 is 660mm; the large end face of the front cover 1 is also provided with a rear cover at a coaxial interval. 2. The rear cover 2 is a circular flat plate of equal thickness, and the distance between the front cover 1 and the rear cover 2 is 100 mm; The diameters are the same, and both are 1600mm.

In the present invention, a wheel hub 5 is also coaxially sleeved between the rear cover plate 2 and the front cover plate 1; as shown in Figures 1 to 3, the wheel hub 5 is an integrally forged conical structure, and its large end sleeve It is connected in the rear cover plate 2 and fixed by welding; the small end of the wheel hub 5 is sleeved in the front cover plate 1 at intervals and extends vertically to the small end face of the front cover plate 1; The inner surface of the cover plate 1 is matched, and the outer diameter of its small end is smaller than the inner diameter of the small end of the front cover plate 1; the inner diameter of the small end of the hub 5 is 160mm, and its axial length is 300mm; the cone angle of the hub 5 is 45° , and its cone radius ratio is 3.25. The wheel hub 5 of the present invention adopts an optimized cavity geometry design, so that the wheel hub 5 is not easily deformed under the condition of a large amount of welding, and the stress distribution is uniform.

In the present invention, the conical surface of the front cover plate 1 is also coaxially juxtaposed with a reinforcing ring 4 at the small end; as shown in FIGS. , and is welded and fixed with the cone surface of the front cover plate 1; among them, the curvature radius of the reinforcing ring 4 is 80mm, which ensures the smooth flow of the air flow inside the impeller, avoids the generation of eddy currents, and reduces the flow loss.

According to the present invention, several blades 3 are vertically arranged between the inner surface of the front cover plate 1 and the rear cover plate 2 along the circumferential direction thereof at uniform intervals; as shown in FIGS. 1 to 4 , each blade 3 is a quasi-ternary flow The arc-shaped blades are respectively welded and fixed vertically with the front cover plate 1, the rear cover plate 2 and the hub 5; wherein, the blade 3 is of the backward type and has a front wind guide wheel. In the present invention, because the impeller is provided with a front guide wheel section, the air flow has a pre-swirl at the inlet that is consistent with the steering of the impeller. This pre-swirl design improves the characteristics of the impeller and enables it to obtain a higher full pressure;

As shown in FIG. 4 , the outer contour of the blade 3 includes a first front coil line 31 , a second front coil line 32 , a third front coil line 33 , a first rear coil line 34 , a second rear coil line 35 and a third The rear plate line 36; wherein, as shown in Figure 5, the first front plate line 31 consists of coordinate points (-75, 483.45, 127.58), (-76.97, 462.81, 116.55), (-78.9, 442.73, 106.59), (-80.82 ,422.36,97.54), (-82.71,401.99,89.34), (-84.59,381.63,81.98), (-86.46,361.26,75.36), (-88.31,340.89,69.48), (-90.13,320.51,64.36) , (-92.03, 300.15, 59.93) and (-93.66, 279.76, 55.92) are connected in sequence; the second front line 32 consists of coordinate points (-93.66, 279.76, 55.92), (-95.92, 264.13, 52.91), ( -101.26,248.51,49.93),(-111.17,232.88,46.98),(-123.62,220.38,44.62),(-135.01,212.57,43.15),(-148.64,206.36,42.01),(-154.97,204.4 41.59), (-161.06, 203.19, 41.14) and (-172.53, 202.33, 39.91) are connected in sequence; the third front line 33 consists of coordinate points (-172.53, 202.33, 39.91), (-174.57, 202.36, 39.5) , (-176.93, 202.42, 39.15), (-184.81, 202.84, 37.44), (-197.09, 203.61, 33.07), (-209.35, 204.54, 26.37), (-221.6, 205.56, 16.96) and (-233.88, 206.2, 4.48) are connected in sequence; the first rear line 34 consists of coordinate points (0,483.63,126.91), (0,452.41,110.44), (0,420.23,95.95), (0,387.26,83.33), (0,353.61,72.69), (0,319.38, 64.1), (0,284.79,57.03), (0,250.09,50.54), (0,215.41,43.98), (0,180.73,37.4) and (0,146.04,30.83) are connected in sequence; the second rear line 35 is formed by the coordinate point (0,146.0 4, 30.83), (-10.94, 135.1, 28.76), (-21.89, 124.16, 26.7), (-32.83, 113.21, 24.61), (-43.77, 102.28, 22.54), (-54.71, 91.33, 20.47), (-65.66, 80.39, 18.39), (-76.6, 69.44, 16.34), (-87.55, 58.49, 14.31) and (-98.47, 47.58, 12.11) are connected in sequence; the third rear line 36 is formed by the coordinate point (- 98.47, 47.58, 12.11), (-104.76, 47.58, 12.11), (-111.05, 47.58, 12.11), (-125.74, 48.66, 12.41), (-140.47, 48.5, 12.36), (-155.21, 48.49, 12.0 ), (-169.94, 48.73, 11.26), (-184.67, 49.04, 9.76), (-199.41, 49.46, 7.36) and (-214.14, 49.84, 3.89) are connected in sequence. In the present invention, the first front line 31 is fitted with the first rear line 34 , the second front line 32 is fitted with the second rear line 35 , and the third front line 33 is fitted with the third rear line 36 , which constitutes the curved contour of the blade.

The invention adopts a new type of high-efficiency quasi-ternary flow blade shape, which is suitable for low-temperature rise centrifugal steam compressors, and the specific speed is between 18-24; the aerodynamic efficiency is high, and in the current environment of rising energy costs, it has Obvious energy saving advantages.

In the field of MVR steam, the current trend is toward higher pressure rise, smaller heat exchange surface and lower steam loss. The impeller with leading pre-rotation of the present invention can achieve higher pressure under the premise of maintaining high efficiency, It meets the needs of high pressure rise and low energy consumption.

Generally, the entropy increase of the impeller is mainly concentrated on the back of the blade, mainly due to the uneven work done in the flow channel due to the strong back bending angle, thereby causing the back of the blade to flow out; it can be seen from FIG. Higher pressure rise performance.

As shown in Fig. 7, when the impeller of the present invention runs at 100% of the design speed, the test shows that the flow rate has a stable working range between 10m ³ /s and 50m ³ /s, and the performance deviation of the model machine is less than or equal to ±5%. , meet the design requirements; ensure the stable operation range is 30%~100%, the high efficiency area is wide, and the impeller efficiency reaches 88%.

Beneficial effects of the present invention:

(1) The structure of the present invention is a closed welded impeller, which is suitable for low temperature centrifugal steam compressors, and the specific speed is between 18 and 24;

(2) The present invention improves the impeller efficiency by adopting advanced cavity geometry design;

(3) The present invention can achieve higher pressure while maintaining high efficiency, satisfies the requirement of high pressure increase and low energy consumption, and has obvious energy saving advantages.

The above-mentioned embodiments are only preferred embodiments of the present invention to describe, and do not limit the concept and scope of the present invention. Various modifications and improvements made should fall within the protection scope of the present invention, and the technical content of the claimed protection of the present invention has been fully recorded in the technical requirements.

Claims (10)

1. an impeller for a low-temperature centrifugal steam compressor, characterized in that: comprising a front cover plate, a rear cover plate, a blade, a reinforcing ring and a hub; the front cover plate is a conical structure, and on its large end face One side is also provided with a rear cover plate at a coaxial interval, the rear cover plate is a circular flat plate of equal thickness, and a hub is also concentrically sleeved between the rear cover plate and the front cover plate; The hub is an integrally forged conical structure, and its large end is sleeved in the rear cover plate and fixed by welding; the small end of the wheel hub is sleeved in the front cover plate at intervals and extends vertically to the small end face of the front cover; on the tapered surface of the front cover near the small end, a reinforcing ring is also coaxially and juxtaposed, and the reinforcing ring is sleeved on the front cover The arc structure on the plate is welded and fixed with the conical surface of the front cover plate; between the inner surface of the front cover plate and the rear cover plate, a number of blades are also vertically arranged at uniform intervals along the circumferential direction. , each of the blades is a quasi-ternary flow arc blade, and is respectively welded and fixed vertically with the front cover plate, the rear cover plate and the wheel hub. 2. An impeller for a low temperature rise centrifugal steam compressor according to claim 1, characterized in that: the front cover plate is formed by molding, and its taper is 7.5 degrees; the small end of the front cover plate is The inner diameter is 660mm. 3. An impeller for a low temperature rise centrifugal steam compressor according to claim 1, wherein the outer diameter of the large end of the front cover is consistent with the outer diameter of the rear cover, and both is 1600mm. 4 . The impeller of claim 1 , wherein the distance between the outlet ends of the front cover plate and the rear cover plate is 100 mm. 5 . 5. An impeller for a low temperature rise centrifugal steam compressor according to claim 1, wherein the conical surface of the hub matches the inner surface of the front cover, and the outer diameter of the small end is matched with the inner surface of the front cover plate. smaller than the inner diameter of the small end of the front cover. 6. An impeller for a low temperature rise centrifugal steam compressor according to claim 1, characterized in that: the inner diameter of the small end of the hub is 160mm, and the axial length thereof is 300mm; the cone angle of the hub is 160mm. is 45°, and its cone radius ratio is 3.25. 7 . The impeller of claim 1 , wherein the radius of curvature of the reinforcing ring is 80 mm. 8 . 8 . An impeller for a low-temperature rise centrifugal steam compressor according to claim 1 , wherein the blade is of a backward type with a front wind guide wheel. 9 . 9 . The impeller for a low temperature rise centrifugal steam compressor according to claim 8 , wherein the outer contour of the blade comprises a first front disk line, a second front disk line, and a third front disk line. 10 . line, the first back line, the second back line and the third back line; the first front line consists of the coordinate points (-75,483.45,127.58), (-76.97,462.81,116.55), (-78.9, 442.73,106.59), (-80.82,422.36,97.54), (-82.71,401.99,89.34), (-84.59,381.63,81.98), (-86.46,361.26,75.36), (-88.31,340.89,69.48), (-90.13, 320.51, 64.36), (-92.03, 300.15, 59.93) and (-93.66, 279.76, 55.92) are connected in sequence; the second front line is composed of coordinate points (-93.66, 279.76, 55.92), (-93.66, 279.76, 55.92) -95.92,264.13,52.91),(-101.26,248.51,49.93),(-111.17,232.88,46.98),(-123.62,220.38,44.62),(-135.01,212.57,43.15),(-148.64,206.36 42.01), (-154.97, 204.44, 41.59), (-161.06, 203.19, 41.14) and (-172.53, 202.33, 39.91) are connected in sequence; the third front line is composed of the coordinate points (-172.53, 202.33, 39.91) ), (-174.57, 202.36, 39.5), (-176.93, 202.42, 39.15), (-184.81, 202.84, 37.44), (-197.09, 203.61, 33.07), (-209.35, 204.54, 26.37), (-221.6 , 205.56, 16.96) and (-233.88, 206.2, 4.48) are connected in sequence; the first rear line is composed of coordinate points (0,483.63,126.91), (0,452.41,110.44), (0,420.23,95.95), (0,387.26,83.33 ), (0,353.61,72.69), (0,319.38,64.1), (0,284.79,57.03), (0,250.09,50.54), (0,215.41,43.98), (0,180.73,37.4) and (0,146.04,30.83) are connected in sequence; Two rear coil lines by sitting Punctuation (0,146.04,30.83), (-10.94,135.1,28.76), (-21.89,124.16,26.7), (-32.83,113.21,24.61), (-43.77,102.28,22.54), (-54.71,91.33,20.47 ), (-65.66, 80.39, 18.39), (-76.6, 69.44, 16.34), (-87.55, 58.49, 14.31) and (-98.47, 47.58, 12.11) are connected in sequence; the third rear panel line is composed of coordinates Points (-98.47, 47.58, 12.11), (-104.76, 47.58, 12.11), (-111.05, 47.58, 12.11), (-125.74, 48.66, 12.41), (-140.47, 48.5, 12.36), (-155.21, 48.49, 12.06), (-169.94, 48.73, 11.26), (-184.67, 49.04, 9.76), (-199.41, 49.46, 7.36) and (-214.14, 49.84, 3.89) are connected in sequence. 10 . An impeller for a low temperature rise centrifugal steam compressor according to claim 9 , wherein: the first front disk line is fitted with the first rear disk line, and the second front disk line is fitted. 11 . The line is fitted with the line of the second rear disk, and the line of the third front disk is fitted with the line of the third rear disk, thereby forming the curved contour of the blade.

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