阅读说明：本技术 一种短排距泥泵叶轮叶片设计方法 (Design method for impeller blade of short-row-pitch dredge pump ) 是由 庄海飞 刘明明 王文魁 郭涛 胡京招 兰剑 伍立说 马源 于 2021-09-03 设计创作，主要内容包括：本发明涉及疏浚泥泵水力设计技术领域,一种短排距泥泵叶轮叶片设计方法。为用于3500m～(3)/h绞吸挖泥船短排距施工的泥泵叶轮及设计方法,叶片为三维扭曲叶片。本发明的泥泵短排距叶轮叶片被设计成扭曲型叶片,叶片型线在保证泥泵效率的前提下比通用叶轮扬程降低20m,新的泥泵叶轮能够解决3500m～(3)/h绞吸挖泥船在短排距施工采用管线缩口而造成的能耗浪费问题,减少单位疏浚能耗,提高了该系列绞吸挖泥船在短排距工况施工的疏浚经济性。(The invention relates to the technical field of hydraulic design of a dredge pump, in particular to a design method of a short-row-pitch dredge pump impeller blade. For 3500m 3 Disclosed is a dredge pump impeller for construction of a/h cutter suction dredger with short row spacing and a design method thereof. The mud pump of the invention is shortThe pitch impeller blades are designed into twisted blades, the blade molded lines are reduced by 20m compared with the universal impeller head on the premise of ensuring the efficiency of the dredge pump, and the novel dredge pump impeller can solve the problem of 3500m 3 The method solves the problem of energy consumption waste caused by pipeline necking in the short-row-pitch construction of the cutter suction dredger, reduces unit dredging energy consumption, and improves the dredging economy of the construction of the series of cutter suction dredgers under the short-row-pitch working condition.)

1. A method for designing impeller blades of a short-row-pitch dredge pump is characterized in that a blade profile equation consists of two parts, including a blade and front cover plate intersection equation and a blade and rear cover plate intersection equation:

blade-to-cowl intersection equations, as follows

Blade to shroud intersection equation, as follows

Wherein r is₁The radius of the suction port of the impeller is in mm; theta is the angle of the blade in the circumferential direction, the inlet of the blade front cover plate intersecting line is the initial 20 degrees, the inlet of the blade rear cover plate intersecting line is the initial 0 degrees, and the outlet of the blade is the terminal point Is the blade wrap angle, r_s(theta) and r_hAnd (theta) is the distance from any point on the intersecting line of the front cover plate and the intersecting line of the rear cover plate to the center of the impeller in unit mm.

2. The design method of claim 1,is 140-165 deg.

3. The design method of claim 2,is 155 deg..

4. An impeller blade designed by the method of any one of claims 1 to 3.

Technical Field

The invention relates to the field of hydraulic design of a dredge pump, and belongs to the technical field of dredging pumps, hydromechanics and the like.

Background

The dredge pump is the key equipment of dredger, when the row's dredge pipeline length (row spacing) of dredger changed, especially short row spacing operating mode, the dredge pump flow was too big can make the success rate overload, and dredge dredger dredge pump is mostly the diesel engine direct drive at present, and the rotational speed is adjusted and is received the restriction, can only increase the throat at the row mouth and reduce the flow, but increases the throat and be equivalent to having increased the pipe resistance, and the throat is equivalent to "the energy dissipater", has wasted the energy. If the impeller is replaced, the external characteristic of the dredge pump is changed, namely the low-lift impeller is adopted when the row spacing is short, so that the adaptability of the dredge pump under the short row spacing is improved, the construction oil consumption of the dredger can be effectively reduced, the cost is saved, and the dredging benefit is improved.

At present 3500m³The internal diameter of a discharge pipeline is 850mm in the construction pipeline of powder sand, the flow velocity can be reduced only through a necking, the diameter of the necking is even only 300mm, unnecessary energy consumption is greatly increased, if the flow velocity can be controlled by replacing a special low-lift dredge pump impeller, the flow regulation mode of the necking is replaced, the construction energy consumption can be reduced, the dredging cost is saved, and the economical efficiency of the series of cutter suction dredger in the short-row-spacing working condition is improved.

Disclosure of Invention

Existing 3500m³The rotation speed of the dredge pump in the/h cutter suction cabin is limited, the dredge pump has too high lift and too large flow rate under the working condition of short row spacing, and the pipeline necking has to be adopted to reduce the flow rate in order to prevent the power overload of the dredge pump, but the energy consumption is wasted due to the necking, so the invention provides the design method of the dredge pump impeller with low lift, the dredge pump lift designed by the impeller is reduced by 20m compared with the original impeller, the efficiency reaches 86 percent, compared with the implementation effect of adopting the pipeline necking, the unit energy consumption is reduced by more than 10 percent under the working condition of short row spacing, the fuel consumption of the equipment driven by a diesel engine is effectively reduced, and the construction economy of the dredge boat is improved.

The technical scheme of the invention to be protected is as follows:

a method for designing impeller blades of a short-row-pitch dredge pump is characterized in that a blade profile equation consists of two parts, including a blade and front cover plate intersection equation and a blade and rear cover plate intersection equation:

blade-to-cowl intersection equations, as follows

Blade to shroud intersection equation, as follows

Wherein r is₁The radius of the suction port of the impeller is in mm; theta is the angle of the blade in the circumferential direction, the inlet of the blade front cover plate intersecting line is the initial 20 degrees, the inlet of the blade rear cover plate intersecting line is the initial 0 degrees, and the outlet of the blade is the terminal point Is the blade wrap angle, r_s(theta) and r_h(theta) is the distance from any point on the intersecting line of the front cover plate and the intersecting line of the rear cover plate to the center of the impeller,the unit mm.

The design method is characterized in that,is 140-165 deg.

The design method is characterized in that,is 155 deg..

The blade obtained by the design method is a twisted blade (3), and the low-lift dredge pump impeller can be obtained by adopting the design that three twisted blades (3) can be applied to a cantilever type closed centrifugal impeller, and is characterized by comprising an impeller front cover plate (1), a flow guide cap (2), the blades (3), an impeller rear cover plate (4) and a hub (5) which are enclosed (the position relation and the connection relation belong to the prior art), so that an overflowing part of the impeller is formed; the blades 3 are twisted blades, the number of the blades is 3, the blades are uniformly distributed on the circumference, the thickness of each blade ranges from 60mm to 90mm, and the outlet width B of each blade is₂Diameter D of impeller suction port₁42.5 percent of the total flow, the diameter of the impeller flow passage passing through the maximum sphere is the diameter D of the impeller suction port₁42% of blade wrap angleThe value is 140-165 degrees, and the wrap angle of the intersecting line of the rear cover plate of the blade is 20 degrees larger than that of the intersecting line of the front cover plate of the blade.

The dredge pump impeller obtained by the design method is applied to short-row-pitch construction of the cutter suction dredger.

The dredge pump impeller is applied to short-row-pitch construction of the cutter suction dredger. When the high-efficiency dredge pump is implemented, a low-lift and low-power efficient dredge pump can be designed, the lift of the dredge pump is reduced only by replacing the cantilever type closed centrifugal impeller, the inner cavity of the dredge pump consists of the cantilever type closed centrifugal impeller and a single-channel pump shell, and the inner impeller and the outer pump shell are both cast by high-chromium cast iron.

The pump shaft is connected with the impeller hub through threads, an abrasion-proof ring is arranged at the suction port of the impeller, an abrasion-proof lining sleeve is arranged at the suction port, and an abrasion-proof lining plate is arranged between the impeller and the pump cover.

The pump shell is supported and fixed by a lining plate and a pump cover, the cross section of a pump shell runner is in a shape of a round corner rectangle, the sum of the width of the impeller runner, the thickness of a front cover plate and a rear cover plate of the impeller and the gap value between the impeller cover plate and the wear-resistant lining plate is taken as the width value of the pump shell runner, the thickness of the front cover plate and the rear cover plate of the impeller is 50-60mm, the gap value between the impeller cover plate and the wear-resistant lining plate is 3-5mm, and the inner edge and the outer edge of the pump shell are both in a spiral line shape.

The impeller blade of the dredge pump is designed into a twisted blade, the lift is reduced by the blade profile, the dredge pump efficiency is improved, the dredge pump impeller can solve the problem of power overload caused by overlarge dredge pump flow under the working condition of short row pitch, the fuel consumption is reduced, and the energy consumption waste is avoided.

The mud pump has the advantages of wear resistance and high efficiency, and the efficiency of clean water can reach 86%; under the working condition of short row spacing, compared with a pipeline necking scheme, the invention saves energy by more than 10 percent, improves the construction economy and brings obvious benefit promotion to enterprises.

Drawings

FIG. 1 is a perspective view of the impeller shaft surface and a vane profile view in the present embodiment.

FIG. 2 is a three-dimensional impeller part diagram, 1-front cover plate, 2-guide cap, 3-blade, 4-back cover plate, 5-hub.

Fig. 3 is a three-dimensional diagram of a water body flow passage of the impeller and a passing sphere diameter diagram.

FIG. 4 is a three-dimensional assembly drawing of a double-shell dredge pump, 6-pump shell, 7-wear-resistant lining plate, 8-big cover, 9-front cover, 10-impeller, 11-impeller suction port wear-resistant ring, 12-outer shell, 13-bearing cartridge assembly, 14-pump shaft, 15-bearing seat.

FIG. 5 shows the embodiment (Is 155 degrees), the broken line is the mud pump performance curve of the impeller of the invention: the dotted line is the impeller of the embodiment with short row pitch, and the solid line is the original general impeller.

Detailed Description

The invention will be further described with reference to the accompanying drawings in which:

FIG. 1 shows a schematic view of aThe axial surface projection of the impeller flow channel and the blade profile are shown, the number of the blades (3) is 3, and the outer diameter D of the impeller₂2504mm, impeller suction opening diameter D₁900mm, the width B2 of the outlet of the impeller flow passage is the diameter D of the impeller suction port₁42.5% of (B), i.e. the width B of the impeller flow passage outlet₂Is 382.5mm, the blade wrap angleTaking 155 degrees, calculating according to equation (1) and equation (2) to obtain the blade profile coordinate as shown in the following table. The blade is formed by intersecting line r of the front cover plate_s(theta) line of intersection r with rear cover plate_hAfter lofting, the thickness of the impeller was increased by 80mm toward the outer edge.

θ	0	10	20	30	40	50	60	70	80	90	100	110	120	130	140	150	155
																		rs(θ)	407	439	474	511	552	595	642	693	748	807	871	936	1006	1076	1147	1217	1252
rh(θ)			511	546	582	622	663	708	755	806	860	936	1006	1076	1147	1217	1252

As shown in fig. 2, the flow passing part of the impeller is enclosed by an impeller front cover plate 1, a flow guiding cap 2, blades 3, an impeller rear cover plate 4 and a hub 5, and the five parts are integrally cast. The vanes 3 are twisted vanes, the number of the vanes is three, and the diameter of the impeller flow passage passing through the maximum sphere is 42 percent of the diameter of the impeller suction port.

As shown in figure 3, the maximum passing sphere diameter of the impeller of the invention is the suction inlet diameter D of the impeller in figure 1₁42%, i.e. 378 mm.

As shown in fig. 4, a pump shaft 14 is connected with an impeller 10 through a screw thread, the impeller 10 is connected with an impeller suction port abrasion-proof ring 11 through a bolt, the impeller 10 is located in a cavity formed by a pump casing 6 and an abrasion-proof lining plate 7, the pump casing 6 is fixed on a shell 12 through a bolt, the cavity between the pump casing 6 and the shell 12 is filled with high-pressure water to balance the pressure in a mud pump flow channel, the abrasion-proof lining plate 7 is arranged between the impeller 10 and a front cover 9 and the shell 12, the abrasion-proof lining plate 7 is connected with the shell 12 through a bolt and the front cover 9, the front cover 9 is connected with a big cover 8 through a bolt, the big cover 8 is connected on the shell 12 through a bolt, the pump shaft 14 is located inside a bearing barrel 13, the bearing barrel 13 is fixed on a bearing block 15, the bearing block 15 is connected with the shell 7 through a bolt, and the bearing block 15 and the shell 12 are fixed on a ship deck through a bolt.

The sum of the width of the impeller runner, the thickness of the front cover plate and the rear cover plate of the impeller and the clearance between the impeller cover plate and the wear-resistant lining plate is taken as the width of the pump case runner, the thickness of the front cover plate and the rear cover plate of the impeller is 60mm, the clearance between the front cover plate and the wear-resistant lining plate of the impeller and the clearance between the rear cover plate of the impeller and the wear-resistant lining plate of the impeller are 4mm, and the width of the pump case runner is 510.5 mm.

FIG. 5 shows that the performance curve of the mud pump of the invention is obtained through numerical simulation, and the flow rate is 11000m³The hydraulic efficiency can reach 86 percent, the lift of the general impeller is 80m, and the lift of the short-row-pitch impeller is 60 m. Through test practice (table 1), in a certain dredging project, the diameter of a conveying pipeline is 850mm, the row spacing is 3km, the impeller designed according to the invention reduces the use of pipeline necking, the fuel waste is effectively avoided, the unit dredging energy consumption of a short row spacing working condition experiment is reduced by 13.4%, the construction time is about 180 hours, the total fuel is saved by 30 tons, the construction economy of the dredger is improved, and the economic benefit is higher.

TABLE 1 statistical comparison of 180-hour production data before and after impeller replacement

	Cumulative volume of earth m3	Productivity m3/h	Total oil consumption t	Wanfang oil consumption t	Diameter of throat mm
						Universal impeller	393500	2146	238.0	6.05	450
Short-row-pitch impeller of the invention	397130	2199	208.0	5.24	Is free of
						Comparison by%	0.92	2.46	-12.61	-13.40

In the field, the impeller, namely a dredge pump, is designed with consumption reduction, and the conventional methods comprise impeller cutting, rotating speed reduction of a diesel engine and the like; it is known in the art that they can generally be improved to the effect of a 3% -5% reduction in dredging energy consumption. Best mode for carrying out the invention155 deg.) 13.4% reduction in dredging energy consumption, which is rare in the art.

The present invention is not limited to the above embodiments, and other embodiments and modifications within the scope of the present invention are also included.