CN100494766C - Method and apparatus for transporting viscous liquid by using pump and pipeline - Google Patents

Abstract

The invention relates to a method for utilizing pump and tube to transmit viscous liquid. Wherein, said viscous liquid is a liquid whose N-type viscosity E in normal temperature is larger than 6; said pump uses viscous eccentric pump or reciprocal piston pump; it can select the transmission speed based confirmed transmission efficiency; the transmission speed should be not less than the viscous factor; it can solve the problems as lower operation efficiency to improve the transmission efficiency that 20-30% higher than traditional method, reduce the resistance loss, and save 10-20% of energy.

Description

Utilize the method and apparatus of pump and line transportation viscous liquid

Technical field

The present invention relates to a kind of delivery method and equipment of viscous liquid, particularly a kind of method and apparatus that utilizes pump and line transportation viscous liquid.

Background technique

The N of viscous flow-S equation, lot of domestic and foreign scholar had done demonstration, elliptic equation can't be found the solution, can not satisfy three big similitude criterions and four big laws simultaneously,, design by " ideal fluid " so the waterpower of pump design at present all is a viscosity of ignoring liquid, at higher specific speed, relative roughness is minimum, under the unconspicuous situation of viscous effect, has obtained great success.But pump by " ideal fluid " design, test, when carrying E ° of grace formula viscosity such as paper pulp, syrup, petrochemical industry greater than 5 viscous liquid, pump performance begins to decline to a great extent, and shows as lift of pump and reduces, flow reduces, power descends, have in addition can't use.For low specific speed pump, relative roughness sharply increases, viscous effect is fairly obvious, can't design with " ideal fluid ", " higher specific speed is low to be used ", " operating mode operation partially " and the situation of " low load with strong power " are very general, the operational efficiency of pump is extremely low, usually have only about 30%, " the enlargement discharge design method " of Chu Xianing in recent years, " there is not the overload design method ", " short blade hangs down and puts ", proprietary technologies such as " area ratio principle ", all be to adopt " ideal fluid " to carry out design experiment, and design method improved, to adapt to the requirement of viscosity and viscous effect, be difficult to achieve the desired result, can't resolve the low difficult problem of transporting viscous liquid operational efficiency.

Summary of the invention

The object of the present invention is to provide a kind of method and apparatus that utilizes pump and line transportation viscous liquid, adopt viscous boundary layer's principle, find the solution the distortion speed and the flow channels of viscous flow, can improve the operational efficiency of carrying viscous liquid greatly.

To achieve these goals, the invention provides a kind of method of utilizing pump and line transportation viscous liquid, described viscous liquid be under the normal temperature E ° of grace formula viscosity greater than 6 liquid; It is characterized in that: described pump adopts viscous eccentric or reciprocating piston pump; According to the transporting velocity that the principle that guarantees the viscous flow transfer efficiency selects to carry viscous flow, wherein carry the movement velocity V2 of viscous liquid to be chosen as more than or equal to viscosity property COEFFICIENT K, i.e. V ₂〉=K.

Be the distortion speed V that selects viscous liquid according to viscous flow transport equation and viscous flow distortion equation ₁With movement velocity V ₂, wherein viscous flow transport equation and viscous flow distortion equation is:

$\left\{\begin{array}{c}{V}_1-V_2=K\\ V_1^2-V_c^2=K^2\\ K=\sqrt{2\mathrm{gh}}\end{array}\right.$

Wherein: V ₁Consider the distortion flow velocity in boundary layer for viscous flow;

V ₂Do not consider the movement velocity in boundary layer for viscous flow;

V _cMovement velocity for ideal fluid;

K is the viscosity property coefficient;

G is a gravity accleration;

The additional hydraulic loss that h produces for the viscous boundary layer.

Carry the movement velocity V of viscous liquid ₂Be chosen as and equal viscosity property COEFFICIENT K, i.e. V ₂=K.

The additional hydraulic loss that described viscous boundary layer produces is relevant with the design discharge of pump and viscous boundary layer's thickness, and its formula is:

$\left\{\begin{array}{c}h=\frac{16Q^2(d_c^4-d_1^4)}{2g{\mathrm{\π}}^2{d}_c^4{d}_1^4}\\ d_1=d_c-2\mathrm{\δ}\end{array}\right.$

Wherein: the additional hydraulic loss that h produces for the viscous boundary layer;

Q is the design discharge of pump;

d ₁Distortion diameter for the viscous fluid flow channels;

d _cDiameter for the ideal fluid flow channels;

δ is viscous boundary layer's a thickness.

The present invention also provides a kind of pipe conveying equipment that is used to carry viscous liquid, comprises pump, the pipeline that is connected with pump and the storage device that is connected with pipeline, conveyor system; It is characterized in that: described pump adopts the viscous eccentric based on the design of viscous flow Conveying Theory, comprises suction port, impeller and pumping chamber, and the fluidised form in wherein said pump intake, impeller and the pumping chamber is separately to design; Movement velocity by described pump and line transportation viscous liquid is chosen as more than or equal to the viscosity property coefficient.

Movement velocity by described pump and line transportation viscous liquid is chosen as and equals the viscosity property coefficient.

Described pump adopts reciprocating piston pump.

The fluidised form of Pump Suction Nozzle satisfies following viscous flow motion equation group:

$\left\{\begin{array}{c}{V}_1-V_2=K\\ V_1^2-V_c^2=K^2\\ K=\sqrt{2\mathrm{gh}}\end{array}\right.$

The fluidised form of pump impeller satisfies following viscous flow motion equation group:

$\left\{\begin{array}{c}{V}_{m1}-V_{m2}=K_m\\ V_{m1}^2-V_{\mathrm{mc}}^2={K_m}^2\\ K_m=\sqrt{2g{h}_m}\end{array}\right.$

Wherein footmark m represents the axial plane motion of centrifugal pump impeller.

The fluidised form of water-pumping chamber satisfies following viscous flow motion equation group:

$\left\{\begin{array}{c}{V}_{31}-V_{32}=K_3\\ V_{31}^2-V_{3c}^2={K_3}^2\\ K_3=\sqrt{2g{h}_3}\end{array}\right.$

The wherein liquid motion of the centrifugal pumping chamber of footmark 3 representatives.

Above-mentioned and additional features, advantage of the present invention can further be understood by the detailed description below in conjunction with accompanying drawing.

Description of drawings

Figure 1A is for ideal fluid and contain viscous fluid delivery rate drag losses variation correlation curve schematic representation;

Figure 1B is for ideal fluid and contain viscous fluid delivery rate drag losses variation correlation curve schematic representation.

Embodiment

The present invention at first provides a kind of method of utilizing pump and line transportation viscous liquid, wherein, described viscous liquid be under the normal temperature E ° of grace formula viscosity greater than 6 liquid; Described pump adopts viscous eccentric or reciprocating piston pump; According to the transporting velocity that the principle that guarantees the viscous flow transfer efficiency selects to carry viscous flow, promptly under selected transporting velocity, the unit fluid transportation energy consumption is low as much as possible; Below explanation is how to select transporting velocity according to mentioned above principle.

Viscous liquid is had the boundary layer and do not have the boundary layer to compare, and this is a physical model that amplifies suddenly, can obtain its drag losses with momentum equation and energy equation, thereby obtain the transport equation of viscous flow, and its formula is as follows:

$\left\{\begin{array}{c}{V}_1-V_2=K\\ K=\sqrt{2\mathrm{gh}}\end{array}\right.$

Wherein: V ₁Consider the distortion flow velocity in boundary layer for viscous flow;

V ₂Do not consider the movement velocity in boundary layer for viscous flow;

K is the viscosity property coefficient;

G is a gravity accleration;

The additional hydraulic loss that h produces for the viscous boundary layer.

The working principle of flowmeter is compared the physical model in viscous flow boundary layer in telling according to literary composition with ideal fluid, ignores the distortion equation that viscous force just can obtain viscous flow, its be ideal fluid as with reference to amount, formula is as follows:

$\left\{\begin{array}{c}{V}_1^2-V_c^2=K^2\\ K=\sqrt{2\mathrm{gh}}\end{array}\right.$

Wherein: V _cMovement velocity for ideal fluid.

Above-mentioned two set of equation are merged, just obtain viscous flow motion equation group:

$\left\{\begin{array}{c}{V}_1-V_2=K\\ V_1^2-V_c^2=K^2\\ K=\sqrt{2\mathrm{gh}}\end{array}\right.$

At this moment, two equations, two unknown numbers can be separated, and key is the additional hydraulic loss h that determines that the viscous boundary layer produces, and its thickness with the design discharge of pump and viscous boundary layer is relevant, and its formula is:

$\left\{\begin{array}{c}h=\frac{16Q^2(d_c^4-d_1^4)}{2g{\mathrm{\π}}^2{d}_c^4{d}_1^4}\\ d_1=d_c-2\mathrm{\δ}\end{array}\right.$

Wherein: the additional hydraulic loss that h produces for the viscous boundary layer;

Q is the design discharge of pump;

d ₁Distortion diameter for the viscous fluid flow channels;

d _cDiameter for the ideal fluid flow channels;

δ is viscous boundary layer's a thickness.

Shown in Figure 1A and Figure 1B, for ideal fluid with contain viscous fluid delivery rate drag losses and change the correlation curve schematic representation.From the correlation curve of Figure 1A as can be seen, for carrying viscous liquid, transporting velocity is high more, approaches ideal fluid more, and from Figure 1B as can be seen, the drag losses of ideal fluid and

Be directly proportional, along with V _cIncrease, drag losses sharply increases, and therefore, for ideal fluid, generally all chooses low flow velocity, permissible velocity of flow or economic velocity; And when carrying viscous liquid, the increase along with distortion speed V1 reduces when the drag losses of unit viscous fluid begins on the contrary, and only under than higher flow velocity, drag losses just begins slow rising, and the drag losses that produces far below ideal fluid.

Among the present invention, what adopt is viscous eccentric or reciprocating piston pump, it is the transporting velocity of selecting to carry viscous flow according to the principle that guarantees the viscous flow transfer efficiency, wherein carries the movement velocity V2 of viscous liquid to be chosen as more than or equal to viscosity property COEFFICIENT K, i.e. V ₂〉=K, this moment, viscous flow considered that the distortion flow velocity V1 in boundary layer is the viscosity property COEFFICIENT K more than or equal to twice, i.e. V ₁〉=2K in this velocity range, even flow velocity is higher, still carries economical than low speed.And the numerical value of the crosspoint of viscous flow is V among Figure 1B ₁=2K, V ₂=K, this is the minimum point of total energy consumption, just, the preferred V of transporting velocity ₁=2K, V ₂=K promptly carries the movement velocity V of viscous liquid ₂Be chosen as and equal the viscosity property COEFFICIENT K.This method almost design method with ideal fluid is different fully, and the feasible efficient that contains viscous fluid of carrying is higher, loses littler.

The present invention also provides a kind of pipe conveying equipment that is used to carry viscous liquid, comprises pump, the pipeline that is connected with pump and the storage device that is connected with pipeline, conveyor system; Wherein: described pump adopts viscous eccentric or reciprocating piston pump; Carry the movement velocity of viscous liquid to be chosen as in the described pipeline more than or equal to the viscosity property coefficient.The movement velocity optimum of conveying viscous liquid is to be chosen as to equal the viscosity property coefficient in the described pipeline.

The above-mentioned centrifugal pump that is used to carry viscous liquid comprises suction port, impeller and pumping chamber; Wherein: described pump is the viscous eccentric based on the design of viscous flow Conveying Theory; Fluidised form in pump intake, impeller and the housing is separately design; Carry the movement velocity of viscous liquid to be chosen as by pump more than or equal to the viscosity property coefficient.Carry by pump viscous liquid the movement velocity optimum be to be chosen as to equal the viscosity property coefficient.It is that referenced patent ZL96102777.0 " press moulding centrifugal pump and manufacture method thereof " or the viscous eccentric of patent ZL97236819.1 are made, and just the fluidised form of suction port, impeller and pumping chamber is wherein carried out following design.

The fluidised form of Pump Suction Nozzle satisfies following viscous flow motion equation group:

$\left\{\begin{array}{c}{V}_1-V_2=K\\ V_1^2-V_c^2=K^2\\ K=\sqrt{2\mathrm{gh}}\end{array}\right.$

The fluidised form of pump impeller satisfies following viscous flow motion equation group:

$\left\{\begin{array}{c}{V}_{m1}-V_{m2}=K_m\\ V_{m1}^2-V_{\mathrm{mc}}^2={K_m}^2\\ K_m=\sqrt{2g{h}_m}\end{array}\right.$

Wherein footmark m represents the axial plane motion of centrifugal pump impeller.

The fluidised form of water-pumping chamber satisfies following viscous flow motion equation group:

$\left\{\begin{array}{c}{V}_{31}-V_{32}=K_3\\ V_{31}^2-V_{3c}^2={K_3}^2\\ K_3=\sqrt{2g{h}_3}\end{array}\right.$

The wherein liquid motion of the centrifugal pumping chamber of footmark 3 representatives.

Embodiment one

6/4Z-20 type viscous eccentric is carried out the slurry comparative trial at Jiangsu Science ﹠ Engineering Univ.'s light industry with pump inspection center, proves that said method and equipment thereof are effective.

Table 1

Table 1 is the test data of 6/4Z-20 type viscous eccentric and national A level high-class product, by the table in as can be seen, 6/4Z-20 type viscous eccentric is under the clear water condition, efficient is high by about 5%, and under the viscosity condition, efficient does not only descend, and has exceeded about 16% on the contrary.

Embodiment two

In technical evaluation to viscous flow series centrifugal pump by country's tissue, the conclusion that the expert made is: viscous flow series centrifugal pump is compared with NBS, efficient exceeds about 5% under the clear water condition, efficient exceeds about 15% under the viscosity condition, and under the situation of pipeline and pump cooperation, efficient has exceeded more than 20%.

Thus, the conventional means that designs by " ideal fluid " in not employing of the present invention field, and directly design by viscous fluid, " higher specific speed is low to be used ", " operating mode operation partially " and " low load with strong power " situation of existing in the actual fed viscous fluid have not only been solved, and improved transfer efficiency greatly, and reduced drag losses, improve 20%-30% than traditional delivery method efficient, a large amount of industrial operational datas shows simultaneously, and it is average energy-conservation 10%-20% years old.

Be to be understood that, the above illustrative and nonrestrictive just for the purpose of the present invention of explanation in conjunction with the embodiments, without departing from the spirit and scope of the present invention, can make many changes and modification to the present invention, it all will drop in the scope of the invention defined by the claims.

Claims (3)

1. method of utilizing pump and line transportation viscous liquid, described viscous liquid be under the normal temperature E ° of grace formula viscosity greater than 6 liquid; It is characterized in that: described pump adopts reciprocating piston pump; According to the transporting velocity that the principle that guarantees the viscous flow transfer efficiency selects to carry viscous flow, wherein carry the movement velocity V of viscous liquid ₂Be chosen as more than or equal to viscosity property COEFFICIENT K, i.e. V ₂〉=K;

Wherein, select the distortion speed V of viscous liquid according to viscous flow transport equation and viscous flow distortion equation ₁With movement velocity V ₂, wherein viscous flow transport equation and viscous flow distortion equation is:

$\left\{\begin{array}{c}{V}_1-V_2=K\\ V_1^2-V_c^2=K^2\\ K=\sqrt{2\mathrm{gh}}\end{array}\right.$

Wherein: V ₁Consider the distortion flow velocity in boundary layer for viscous flow;

V ₂Do not consider the movement velocity in boundary layer for viscous flow;

V _cMovement velocity for ideal fluid;

K is the viscosity property coefficient;

G is a gravity accleration;

The additional hydraulic loss that h produces for the viscous boundary layer.

2. the method for utilizing pump and line transportation viscous liquid as claimed in claim 1 is characterized in that: the movement velocity V that carries viscous liquid ₂Be chosen as and equal viscosity property COEFFICIENT K, i.e. V ₂=K.

3. the method for utilizing pump and line transportation viscous liquid as claimed in claim 1 is characterized in that: the additional hydraulic loss that described viscous boundary layer produces is relevant with the design discharge of pump and viscous boundary layer's thickness, and its formula is:

$\left\{\begin{array}{c}h=\frac{16Q^2(d_c^4-d_1^4)}{2g{\mathrm{\π}}^2{d}_c^4{d}_1^4}\\ d_1=d_c-2\mathrm{\δ}\end{array}\right.$

Wherein: the additional hydraulic loss that h produces for the viscous boundary layer;

Q is the design discharge of pump;

d ₁Distortion diameter for the viscous fluid flow channels;

d _cDiameter for the ideal fluid flow channels;

δ is viscous boundary layer's a thickness.

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