The current situation and development of pump technology in China

1. The sources of pump product drawings in China can be divided into joint design, introduction, and self-development.

(1) Joint research design products are mainly research units of submersible pumps. In the 1960s and 1980s, the pump factory was organized to carry out joint design of many kinds of pumps. Such as IS (IB) type single-stage single-suction centrifugal pump; IH type chemical pump; S (SH) type double suction centrifugal pump; D (DG) type segment type multistage pump; W type vortex pump; Y type oil pump; JC Type deep well pump; HW type mixed flow pump; QJ deep well submersible pump; IR type hot water pump; BPZ type sprinkler self-priming pump; FY type anti-corrosion liquid submerged pump; 3G type three screw pump.

These products were domestically leading products at that time and are still in production today. However, some products have relatively backward structure (modeling) and performance indicators, and should be gradually replaced with new products.

(2) Introduction of imported products Before the 1980s, China introduced a small number of pump technologies. In the early days of reform and opening up, a large number of pump technologies were introduced from abroad, and with the introduction of foreign pump companies into China in the form of joint ventures or sole proprietorships, some new ones were introduced. Pump product technology. For example: stone pump - Walman slurry pump; stone pump (Tianjin Motor Factory) - Germany's Ritz company's well submersible pump; sink pump (upper pump) - Germany KSB boiler feed pump; Shanghai Electric Power Construction Boiler feed pump from the factory - Weir, UK; condensate pump from Shanghai Pump Factory - KSB; condensate pump from Changsha Pump Factory - Hitachi, Japan; CZ, ZA (ZE) from Dalian Sulfur Pump Factory - Sulzer, Switzerland Chemical Process Pump; Shanghai Pump Factory Pump - US Delais Sewage Pump; Foshan Pump Factory - Germany's Siemens Water Ring Vacuum Pump; Shanghai Pump Factory - KSB's Hot Water Pump, Marine Pump; Tianjin Industrial Pump General Factory - Screw pump of Alverle, Germany; Marine pump of Tianjin Industrial Pump Factory - Marine pump of Japan Dahuang Company; Submersible sewage pump of Nanjing Aijing Pump Factory - ABS Company of Germany; Changsha Pump Factory - Large vertical type of Ingersoll Company of USA Diagonal flow pump; Shanghai first pump factory - British M · J company's high-lift multi-stage centrifugal pump; Xiangfan 5 25 plant - France H · S company's phosphate pump.

The introduction of these pump products, the technology is relatively mature, the performance is relatively advanced, has played an important role in promoting the development of China's pump technology, has become the main body of China's pump products, and still mass production. Some of these products also have problems in terms of structure or performance and should be further improved.

(3) Foreign joint venture (sole proprietorship) pump enterprises in China, such as: Shanghai KSB-Omega (RDL) double suction pump, boiler feed pump, condensate pump; Jialite (茬原)-chemical process pump; Foshan (Andri)兹)-Pulp pump; Nanjing Goulds-ISO single-stage single-suction centrifugal pump, P-type segmental multistage centrifugal pump; Dalian Empire-shield pump; Shenyang Feili-submersible sewage pump; Suzhou Grundfos-stamping Pump; Lanzhou NET-screw pump. The quality of these products is much better than domestic products, although the price is high, but the sales are very good.

(4) Self-developed product AY oil pump; TSWA multi-stage centrifugal pump; ZJ slurry pump; pipeline pump; direct-connected pipeline pump; high-rise feed pump; air-conditioning pump; submersible sewage pump; vertical sewage pump; submersible axial flow pump (mixed flow) Pump); double suction pump, pulp pump, etc. Most of these products are generalized, not standardized, and performance needs to be further improved.

2. The key pump products have been fully nationalized from partial imports to now:

Due to the introduction of famous products such as imported products and KSB, the production capacity of pumps in China has increased significantly. The main key pumps in the national economic sector can basically be produced. For example: supercritical boiler feed water pump (temperature pressure 25 ~ 35MPa); high-speed pump for high-pressure pump and high-pressure pump for ethylene and hydrogenation unit; high-pressure descaling pump for steel plant; large-scale water pump for Dongshen and South-to-North Water Transfer Project; High lift (1000m) drainage pump; flue gas desulfurization pump for power plant; high temperature slurry pump for refinery.

3. New technologies based on CAD are widely used:

(1) The mold, blades and important parts of the pump are processed by CNC machine tools, which can improve the manufacturing quality of the pump. Figure 1 is a three-dimensional diagram of the axial flow pump blades and the blades for machining with a CNC milling machine.

3D drawing of axial flow pump blades and blades for machining with CNC milling machine

(2) Pump hydraulic design and drawing software gradually replace manual calculation and drawing. Some people ask how high the pump efficiency is designed with this software. This is what laymen say. Even the best software should be used by people. The design ideas and experience are fast and accurate. Figure 2 shows the hydraulic diagram of the spiral centrifugal pump impeller designed with JP1 software. It takes only 10 minutes to design the diagram, and the manual design may take two days.

Hydraulic diagram of spiral centrifugal pump impeller designed with JP1 software

(3) Calculation of flow field in pump The main method for calculating quasi-ternary non-viscous flow from quasi-ternary non-viscous flow to full ternary viscous flow is S1 and S2 flow surface iteration, which is a three-dimensional flow Dimension reduction into two dimensions, that is, iteratively solves the flow on the meridional plane (axial plane) and the arbitrary transition surface (flow surface) to solve the three-dimensional flow problem. The accuracy of the solution is affected by simplifying the complex three-dimensional flow into a two-dimensional solution. In recent years, computational fluid dynamics, referred to as CFD, has provided new ideas and means for fluid mechanical flow field calculation. To calculate the flow field using CFD, first calculate the calculation area into a three-dimensional entity, then generate a grid, and then use the commercial CFD software Fluent to calculate, as shown in Figure 3.

CFD

(4) The internal flow field measurement is often measured by a probe. On the one hand, the needle itself has a great influence on the flow, and on the other hand, the conversion device for measuring the rotating flow field is also complicated. Further, a laser Doppler velocimeter (LVD) is used which irradiates particles in a flow with a laser, and the light is scattered by the particles, and the flow velocity is measured according to the degree of scattering. This method has matured and is widely used, but generally only measures a certain component of a certain speed. Now we are using Particle Image Velocimetry (PIV), which works by spreading tracer particles in the flow field, illuminating the flow field with a pulsed light source, and by successive two or more exposures, the particle image is recorded on the film. Thereby, the flow field velocity distribution is obtained. This method breaks through the limitations of the traditional single-point measurement, and can instantaneously measure the velocity distribution on a section without contact, and has high measurement accuracy.

(5) Optimization design method In order to improve the performance of the pump, many scholars have carried out research on optimization design methods. In summary, there are mainly the following methods: speed coefficient optimization method based on excellent model statistics; loss extreme value optimization method with minimum hydraulic loss as the target; and criterion screening optimization method with a certain index as the objective function. It is worth noting that the current optimization design method may only be instructive for the design of a specific pump. In addition, the advent of advanced technologies such as CFD has largely diluted the interest in optimized design. In the past two years, scholars who have studied optimization design methods have gradually reduced.

4. Progress in non-blocking pumps and low-speed pump technology:

(1) The design method of non-blocking pump summed up by China has basically reached the practical level. The widely used design methods in China mainly include: designing the double-channel impeller along the change rule of the mid-line section of the flow channel; designing the spiral centrifugal method by the square mesh conformal transformation method Impeller; the swirling impeller is designed according to the three elements of the outer diameter of the impeller, the outer diameter of the volute and the throat area.

(2) Research on the theory and design of low specific speed pump is extensive and deep. The design method without overload is popularized and applied, and good results are obtained by using long and short blades and short blade offset.

5. The axial flow pump model has reached the advanced level of similar foreign models:

From September 25, 2004 to January 16, 2005, 27 models from all over the country participated in the Tianjin Tongtai test of the water pump model of the South-to-North Water Transfer Project of the Ministry of Water Resources. The leadership of this trial is strong, well-organized, fair and accurate, and accurate. The model has a specific speed of 500-1500, which basically covers the range of use of the axial flow pump. Compared with the original model, the efficiency is increased by about 2% and the flow rate is increased by about 5%. The average efficiency of the seven models is more than 85%, which has reached the advanced level of similar foreign models. Most of the low lift pumps of important projects such as the National South-to-North Water Transfer Project will be selected from these models.