Method for determining speed coefficient of adjustable jet pump
阅读说明：本技术 一种可调节喷射泵速度系数确定的方法 (Method for determining speed coefficient of adjustable jet pump ) 是由 陈沁� 傅雷 于 2021-08-24 设计创作，主要内容包括：本发明涉及一种可调节喷射泵速度系数确定的方法,所述方法包括：步骤S1：建立喷射泵模型；步骤S2：搭建喷射泵模拟现场；步骤S3：基于模拟现场,获取喷射泵现场中喷射泵在不同调节位置的运行参数,并计算求解所对应的各个速度系数；步骤S4：求解速度系数；步骤S5：根据求解的速度系数对包含可调节喷射泵的现场可调节喷射泵系统进行调整；本发明通过现场测量和利用最小二乘法求解特性方程组来求解速度系数的方法,精确求解喷射泵的速度系数,相较于参考值来说,所确定得到的速度系数与喷射泵更为适配,从而大大的提高了喷射泵的性能。(The invention relates to a method for determining a speed coefficient of an adjustable jet pump, comprising the following steps: step S1: establishing a jet pump model; step S2: building a jet pump simulation site; step S3: based on a simulation site, acquiring operating parameters of the injection pump at different adjusting positions in the injection pump site, and calculating and solving corresponding speed coefficients; step S4: solving a speed coefficient; step S5: adjusting a field adjustable jet pump system comprising an adjustable jet pump according to the solved speed coefficient; according to the method, the speed coefficient is solved by on-site measurement and the characteristic equation set solved by the least square method, the speed coefficient of the jet pump is accurately solved, and compared with a reference value, the speed coefficient obtained by determination is more adaptive to the jet pump, so that the performance of the jet pump is greatly improved.)
1. A method of adjustable jet pump speed coefficient determination, the method comprising:
step S1: establishing a jet pump model;
step S2: building a jet pump simulation site;
step S3: based on a simulation site, acquiring operating parameters of the injection pump at different adjusting positions in the injection pump site, and calculating and solving corresponding speed coefficients;
step S4: solving a speed coefficient;
step S5: and adjusting the field adjustable jet pump system comprising the adjustable jet pump according to the solved speed coefficient.
2. The method of adjustable jet pump speed coefficient determination of claim 1, wherein field elements comprising jet pumps are replaced with analog elements of a corresponding type, the analog elements being connected based on water flow relationships to construct a jet pump field; and setting simulation element parameters according to the field condition.
3. The method of adjustable jet pump speed coefficient determination of claim 2, wherein the user is replaced with a ball valve in the jet pump field to simulate resistance.
4. The method for adjustable jet pump speed coefficient determination of claim 3, wherein intelligent digital pressure gauges, electromagnetic flow meters record instantaneous pressure and flow values at each point in real time.
5. The method of adjustable jet pump speed coefficient determination of claim 4, wherein the jet pump is of the type PN 1G.
6. An adjustable jet pump speed coefficient determination system employing the adjustable jet pump speed coefficient determination method of any one of claims 1-5, the system comprising: client side and server.
7. The adjustable jet pump speed coefficient determination system of claim 6, wherein the client is one or more and the server is a cloud server.
8. The adjustable jet pump speed coefficient determination system of claim 7, wherein the client is configured to initiate a speed coefficient determination request and receive a request result of the server speed coefficient determination request from the server; the server is used for determining a speed coefficient; the client is further configured to adjust a field adjustable jet pump system including an adjustable jet pump based on the determination of the speed coefficient.
9. The adjustable jet pump speed coefficient determination system of claim 8, wherein the reference value for the speed coefficient is updated based on the determined speed coefficient.
10. The adjustable jet pump speed coefficient determination system of claim 9, wherein the server performs a field simulation setup based on the solved speed system to re-optimize the solution process.
[ technical field ] A method for producing a semiconductor device
The invention belongs to the technical field of energy engineering, and particularly relates to a method for determining an adjustable jet pump speed coefficient.
[ background of the invention ]
With the increasing severity of the problems of poor heat supply quality and energy waste caused by the problem of hydraulic imbalance of a heat supply system, domestic scholars pay more attention to the application research of the jet pump in the heat supply engineering, and the good energy saving performance and the hydraulic balance capability of the jet pump are illustrated through practical engineering cases. Speed coefficient of jet pumpUsed to indicate the flow process of the fluid in the nozzle, the inlet section of the mixing chamber, the mixing chamber and the diffuserIrreversible loss in (1). Different manufacturers have large difference in the speed coefficient of the manufactured jet pump due to the difference in the production process. In particular, since the development of adjustable jet pumps has been successful, jet pumps have been structurally improved, with the speed coefficient of the adjustable jet pump being significantly different from that of conventional jet pumps. In practical situations, due to differences in production processes and structures of the jet pumps, speed coefficient deviations of different jet pumps are large, and the accurate speed coefficient solving has great significance for further research and application of the jet pumps. In addition, the actual flow condition inside the jet pump is complex, belongs to the three-dimensional fluid mechanics problem, and an accurate calculation method is not available at home and abroad. The invention provides a determination method combining experimental determination and a least square method to solve the speed coefficient of the jet pump. According to the method, the speed coefficient is solved by on-site measurement and the characteristic equation set solved by the least square method, the speed coefficient of the jet pump is accurately solved, and compared with a reference value, the speed coefficient obtained by determination is more adaptive to the jet pump, so that the performance of the jet pump is greatly improved.
[ summary of the invention ]
In order to solve the above problems in the prior art, the present invention provides a method for determining an adjustable injection pump speed coefficient, the method comprising:
step S1: establishing a jet pump model;
step S2: building a jet pump simulation site;
step S3: based on a simulation site, acquiring operating parameters of the injection pump at different adjusting positions in the injection pump site, and calculating and solving corresponding speed coefficients;
step S4: solving a speed coefficient;
step S5: and adjusting the field adjustable jet pump system comprising the adjustable jet pump according to the solved speed coefficient.
Further, replacing the field element containing the jet pump with a corresponding type of simulation element, connecting the simulation elements based on water flow relationship to construct a jet pump field; and setting simulation element parameters according to the field condition.
Further, in the jet pump field, the user is replaced by a ball valve to simulate the resistance.
Furthermore, the intelligent digital pressure gauge and the electromagnetic flowmeter record instantaneous pressure and flow values of each point in real time.
Further, the injection pump is PN 1G.
An adjustable jet pump speed coefficient determination system, the system comprising: client side and server.
Furthermore, the number of the clients is one or more, and the server is a cloud server.
Further, the client is used for initiating a speed coefficient determination request and receiving a request result of the server speed coefficient determination request from the server; the server is used for determining a speed coefficient; the client is further configured to adjust a field adjustable jet pump system including an adjustable jet pump based on the determination of the speed coefficient.
Further, the reference value of the speed coefficient is updated according to the determined speed coefficient.
Further, the server performs field simulation setting based on the solved speed system to optimize the solving process again.
The beneficial effects of the invention include: the speed coefficient of the jet pump is accurately solved by a method for solving the speed coefficient by field measurement and solving a characteristic equation set by using a least square method, and compared with a reference value, the speed coefficient obtained by determination is more adaptive to the jet pump, so that the performance of the jet pump is greatly improved.
[ description of the drawings ]
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, and are not to be considered limiting of the invention, in which:
fig. 1 is a schematic view of an adjustable jet pump according to the present invention.
Fig. 2 is a schematic field view of the jet pump of the present invention.
1-expansion tank, 2-circulating water pump, 3,4, 5-flowmeter, 6,7, 8-pressure gauge, 9-adjustable jet pump, 10-ball valve (for simulating user end resistance)
[ detailed description ] embodiments
The present invention will now be described in detail with reference to the drawings and specific embodiments, wherein the exemplary embodiments and descriptions are provided only for the purpose of illustrating the present invention and are not to be construed as limiting the present invention.
Jet pumps are a fluid mechanical device that performs mass, energy transfer, and mixing reactions. The structure of the adjustable jet pump is shown in figure 1. The high pressure working fluid is accelerated in the nozzle until the end of the nozzle reaches the maximum speed, low pressure is formed in the suction chamber, and the injection fluid is injected into the suction chamber continuously. The two flows exchange momentum and energy in the mixing chamber until the outlet of the mixing chamber, the speed and pressure of the two flows gradually approach to be consistent, then the mixed flow enters a diffuser pipe to convert kinetic energy and potential energy, and finally flows out of the jet pump. The speed coefficient of the jet pump is related to the production process of a manufacturer and the structure of the jet pump, the position of an adjusting mechanism of the same adjustable jet pump is different, and the speed coefficient of a nozzleAnd not the same. Speed coefficient of jet pumpVelocity coefficients for the nozzle, the mixing chamber inlet section, the diffuser tube, and the mixing chamber, respectively, are used to represent irreversible losses in the flow of fluid through the nozzle, the mixing chamber inlet section, the mixing chamber, and the diffuser tube. At present, the speed coefficient of the jet pump usually adopts a uniform reference value, which is usually the reference value of the speed coefficient given by sokoloff, such as:the adjustable jet pump is additionally provided with an adjusting mechanism on the basis of the existing jet pump, and the adjusting mechanism is used for changing the sectional area of the outlet of the nozzle. The actual flow conditions inside the ejector pump are relatively complex, and how to determine the ejector pump speed coefficient of an adjustable ejector pump is desirable for implementing an ejector pump systemIs very important to enable optimum results to be achieved in the field containing the ejector pump.
In order to enable a site containing an injection pump to achieve the best effect, reduce the difference in production process and structure and optimize and set the speed coefficients of different injection pumps on the site, the invention provides a method for determining the speed coefficient of an adjustable injection pump, which comprises the following steps:
step S1: establishing a jet pump model; specifically, the method comprises the following steps: selecting dimensionless parameters such as a mixing ratio u, a pressure difference ratio h, a sectional area ratio m and the like based on a principal component analysis method, and establishing an injection pump model on the basis of simplifying the flow process of fluid in the injection pump.
The performance parameters of the jet pump are mainly the pressure and flow of the working fluid and the injection fluid, the pressure and flow of the outlet fluid and the like, and the influence factors are more. The invention selects dimensionless parameters such as a mixing ratio u, a pressure difference ratio h, a sectional area ratio m and the like to create an injection pump model based on a principal component analysis method. On the basis of simplifying the fluid flow process inside the jet pump, jet pump models are established based on mass conservation, momentum conservation and energy conservation as the following formulas (1) to (3).
G3＝G1+G2Formula 1
Wherein, G3: mass flow of the mixed fluid, kg/s; rho1: fluid density, kg/m3；Velocity coefficients of the nozzle, the inlet section of the mixing chamber, the diffuser pipe and the mixing chamber are used to represent the irreversible flow of the fluid in the nozzle, the inlet section of the mixing chamber, the mixing chamber and the diffuser pipeAnd (4) loss.
Wherein: the mixing ratio u is calculated by the formula (4)
Wherein, G1: mass flow of working fluid, kg/s; g2: mass flow of the ejection fluid, kg/s;
the pressure difference ratio h is calculated by the formula (5)
Wherein, P1: the pressure, Pa, of the working fluid at the water inlet; p2: injecting the pressure of the fluid at the water return port, Pa; p3: the pressure, Pa, of the mixed fluid at the diffuser pipe outlet.
The sectional area ratio m is calculated by the formula (6)
In the formula, A3-mixing chamber cross-sectional area, mm2(ii) a A1-nozzle outlet cross-sectional area, mm2。
Step S2: building a jet pump simulation site; specifically, the method comprises the following steps: replacing field elements containing the jet pump with simulation elements of a corresponding type, connecting the simulation elements based on water flow relationships to construct a jet pump field; and setting simulation element parameters according to the field condition.
As shown in the attached figure 2, the circulating water pump on site in the embodiment is a variable frequency water pump, is used for providing the pressure difference required by the operation of the jet pump, and adjusts the frequency of the water pump through a frequency converter. The expansion tank is used for supplementing the circulating water quantity and stabilizing the backwater pressure. The high-pressure working fluid flowing out of the circulating water pump sucks partial backwater of the backwater pipe through the jet pump, and the working fluid and the injection fluid are mixed and then flow to a user.
Preferably: the user is replaced by a ball valve to simulate his resistance.
Preferably: the intelligent digital pressure gauge and the electromagnetic flowmeter record instantaneous pressure and flow values of each point in real time.
Preferably: the jet pump is PN1G (DN32), and the cross-sectional area A3 of the mixing chamber is 169.63mm2Maximum nozzle outlet cross-sectional area AlmaxIs 21.23mm2。
Step S3: based on a simulation site, acquiring operating parameters of the injection pump at different adjusting positions in the injection pump site, and calculating and solving corresponding speed coefficients; specifically, the method comprises the following steps: adjusting the position of an adjusting mechanism of the jet pump, adjusting the sectional area of the outlet of the nozzle to different sizes, keeping the sectional area unchanged, simultaneously opening a circulating pump, adjusting the frequency and the working pressure difference of the water pump, then adjusting the resistance of a user, recording a series of operating parameters corresponding to the resistance of the user, and calculating and solving each speed coefficient of the jet pump at different adjusting positions. Wherein: the operating parameters include: mass flow rate G1, mixing ratio u, and pressure differential ratio h of the fluid.
The velocity coefficient at which the adjustable jet pump nozzle outlet cross-sectional area is maximized (Al — Almax) is determined for the corresponding field embodiment in fig. 2 as an example. The position of the adjusting mechanism of the jet pump is adjusted, the sectional area of the outlet of the nozzle is adjusted to be maximum and is kept unchanged. And (3) opening a circulating pump, adjusting the frequency of the water pump to be 50Hz, providing a required working pressure difference of 0.22MPa for the operation of the jet pump, adjusting the resistance of a user, recording a series of operation parameters under the resistance of the user, and calculating each speed coefficient when the jet pump is at the position. The measured jet pump field data are shown in table 1.
TABLE 1 jet pump site data
Serial number
User resistance (kPa)
G1(m3/h)
G2(m3/h)
G3(m3/h)
ΔP1-2(kPa)
ΔP3-2(kPa)
Mixing ratio u
Pressure difference ratio h
1
0
1.58
2.4
4
223.6
0
1.518987342
0
2
1.47
1.58
2.4
4
223.1
0.25
1.518987342
0.001120574
3
3.2
1.58
2.3
3.9
223.6
1.15
1.455696203
0.005143113
4
5.37
1.58
2.1
3.7
223.6
4.4
1.329113924
0.019677996
5
7.39
1.58
2
3.6
223.3
6.26
1.265822785
0.028034035
6
9.48
1.58
1.8
3.5
223.3
8.41
1.139240506
0.037662338
7
11.36
1.54
1.75
3.3
223.3
10.17
1.136363636
0.045544111
8
13.23
1.54
1.7
3.2
223.3
12.51
1.103896104
0.056023287
9
15.14
1.54
1.5
3.1
222.8
14.13
0.974025974
0.063420108
10
18.7
1.52
1.2
2.8
222.9
18.13
0.789473684
0.081336922
11
20.43
1.54
1.1
2.7
222.9
19.75
0.714285714
0.088604755
12
23.13
1.56
0.9
2.4
222.6
22.92
0.576923077
0.10296496
13
25.18
1.51
0.7
2.3
222.6
24.43
0.463576159
0.109748428
Step S4: solving a speed coefficient; the method comprises the following steps:
step S41: solving the velocity coefficientSpecifically, the method comprises the following steps: obtaining a velocity coefficient according to the transformation of equation (7)
Preferably: derived based on multiple sets of experimental dataThe average is taken to obtain the nozzle velocity coefficient, and the nozzle velocity coefficient at the maximum nozzle outlet area of the spray pump used in the field is determined in the field embodiment corresponding to fig. 20.964, higher than the reference value.
Step S42: solving the velocity coefficientSpecifically, the method comprises the following steps: solving velocity coefficient through injection pump model equations (1) - (3)
Step S43: the nozzle velocity coefficient obtained by each group of experimentsAnd the field collected data is substituted into formula (8), and a matrix is obtained by calculationAnd a constant d, solving by a method of solving a hyperstatic equation set by using a least square method, namely [ Cx-d]T[Cx-d]Solution of the minimum equation set to obtainA value of (1), whereinConstant term
Step S44: given aUsing constrained linear least square method to solve velocity coefficient
Taking the corresponding field embodiment in fig. 2 as an example, the upper and lower bounds of x are set to be ub ═ 1.4,1, respectively]，lb＝[1,0.7,0.7]Solving by using an lsqlin function in MATLAB to obtainThe values of the upper limit vector and the lower limit vector are important, the larger the range given by the general situation is, the smaller the solution error is, but the deviation from the actual value can be realized, and the values can be determined according to the actual situation.
Alternatively, the velocity coefficients are solved by using a genetic algorithm to solve a constrained linear least squares method
As shown in Table 2, 13 sets of field data were determined in the field embodiment corresponding to FIG. 2 of Table 2Matrix array And d.
TABLE 2 calculated coefficients from simulation data
Step S5: adjusting an adjustable jet pump system comprising an adjustable jet pump according to the solved speed coefficient;
alternatively: resetting the field simulation based on the solved speed coefficient to optimize the solving process again, and resetting the determining process to optimize the coefficient determination again;
alternatively: carrying out simulation optimization based on the solved speed coefficient;
alternatively: performing field simulation setting based on the solved speed system to optimize the solving process again;
as will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
All the embodiments in the present specification are described in a related manner, and the same and similar parts among the embodiments may be referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, as for the apparatus embodiment, since it is substantially similar to the method embodiment, the description is relatively simple, and for the relevant points, reference may be made to the partial description of the method embodiment.
Those skilled in the art will appreciate that all or part of the steps in the above method embodiments may be implemented by a program to instruct relevant hardware to perform the steps, and the program may be stored in a computer-readable storage medium, which is referred to herein as a storage medium, such as: ROM/RAM, magnetic disk, optical disk, etc.
The above description is only for the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall fall within the protection scope of the present invention.
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