專用臥式銑床液壓系統(tǒng)設(shè)計,專用臥式銑床液壓系統(tǒng)設(shè)計,專用,臥式,銑床,液壓,系統(tǒng),設(shè)計 大連水產(chǎn)學(xué)院本科畢業(yè)論文（設(shè)計） 外文資料 外文文獻(xiàn)資料： Centrifugal pump improvement measures of energy saving technology work Energy is to develop the national economy and improve the level of human life. With the rapid development of economy in China and the global energy saving energy and reducing has increasingly become the focus of attention. Pump products belong to fluid machinery, domestic demand is very big, 20% of the year - 25% of all electricity consumption in pump products. Centrifugal pump for pump products demand for Chinese economy is 50%, the construction of the mechanical equipment, therefore essential for the energy-saving centrifugal pump is very important and urgent. 1. the centrifugal pump energy conservation technology analysis In the past 10 years, along with the rapid development of science and technology, a lot of advanced scientific research and a high level of mechanical processing equipment, the products of pump energy is mainly embodied in the following respects. 1.1 The development of design technology The rapid development of computer technology for centrifugal pump design research has brought the ideal method of CAD CFD technology. The centrifugal pump design work in the application of centrifugal pump, and raise the level of design is very important meaning for centrifugal pump, the energy conservation work brought good prospects. 1.2 The development of advanced manufacturing technology With the rapid development of CAM in pump products production, application of centrifugal pump efficiency improving technical index is very beneficial. Currently part of enterprise in pump industry has the technique is applied to hydraulic model, mould making, parts and components manufacturing process, greatly improve the accuracy of the size of hydraulic flow and surface or port surface roughness precision, improve efficiency index. 1.3 corresponding technical development And the relevant supporting technology centrifugal pump recently got bigger development, such as motor design and manufacturing, automatic control, automatic control, automatic alarm, transmission system, seal design manufacture technology, new materials, testing technology, etc. The all-round development of technology, the centrifugal pump system reliability and efficiency index, and the other performance index, promote energy conservation. 2 energy-saving technical measures For decades in technical design method was no big breakthrough, technical level is relatively backward. So far, the centrifugal pump design method using similar conversion method and main speed coefficient method. A reliable data and rich practical experience is the key design, design personnel should according to the actual needs of technical development, improve design level. 2.1 CAD/CFD technology application Along with the rapid development of computer technology, CAD/CFD technology, to explore the birth of centrifugal pump, and improve the internal flow pattern in the advancement of centrifugal pump design method. Modern centrifugal pump design method must be combined with advanced computer technology and CAD/CFD technology. The advanced computer technology can solve centrifugal pump complex internal flow field of the calculation problem. Application of CAD/CFD technology, we can further understanding and mastering the centrifugal pump flow to the objective laws of optimization design of centrifugal pump. CAD/CFD technology to improve the features and advantages of the centrifugal pump design method of the technical level is very important. Modern centrifugal pump design method without centrifugal pump test means. Test is an important means of science and technology research, has reliable features. CAD/CFD is limited to approach the information system of the information system of real infinite. Due to the calculation of the mathematical model, the discretization process, format and grid generation and boundary conditions worsen produced artificially error handling, thus from actual conditions. The application of CAD/CFD success needs to be verified test. Thus, the modern centrifugal pump design method should be the traditional design method, CAD/CFD technology, test means all combination of a design method are indispensable. 2.2 Traditional design method of improvement 2.2.1 The properties of high steam ammeters hydraulic model library alone Centrifugal pump cavitation performance is very important in the performance of a technical indicators of quality, it mainly by water-obsorbing room and imported hydraulic impeller size to decide. In similar conversion method, because of different sizes, the impeller imports of pump impeller speed, the import size is accomplished very hard geometric similar, dynamic similar to mention movement and similar. So the cavitation performance of the large deviation is similar conversion. Previously established hydraulic model library mainly efficiency index for selection for design, high cavitation performance of the pump, it is difficult to meet the requirements by model, a method of conversion high cavitation performance of hydraulic model. 2.2.2 comprehensive reasonable hydraulic model base established Traditional hydraulic model choice model reference library, the standard of the pump efficiency index is mainly, and many other factors need to be taken into consideration, such as pump performance curve, the performance parameters of the pump matching, pump structure factors. 2.2.3 The method to improve speed coefficient and improvement According to the theory of centrifugal pump head equation and design experience, analysis of test, the influence of factors besides velocity coefficients than speed pump, there are other important factors. One, the main export circumferential velocity coefficients are pump structure, blade outlet Angle, leaf number, etc. Influence factors of inlet velocity coefficients of pump structure, leaves are imported attack Angle, leaf number, etc. Statistical analysis of these factors should be the influence degree, and summarizes the change rule, influence factors determine the standard rate of these factors coefficient curve of size values. According to the extent of the law, will significantly improve the accuracy of speed coefficient method. 2.3 CAM technology application in manufacturing process pump In the production process, the CAM computer aided manufacturing is the relatively advanced technology, CAM technology in manufacturing process of centrifugal pump application, will give the energy-saving centrifugal pump working to bring very ideal effect. Currently in pump industry backbone enterprises, some have been carried out in this aspect of the production practice. 2.3.1 centrifugal pump hydraulic model molds Centrifugal pump hydraulic model is decided hydraulic properties and technology products, the most important component. Due to internal flow model of hydraulic parts and complex shape of mechanical manufacturing, most companies have adopted casting parts. During casting process, should first before FanSha casting. The traditional mould manufacture is basically adopts handmade, its deficiency is too big, can accurate error to guarantee the type line flow of hydraulic model, the efficiency is low, the shape of hydraulic properties to guarantee. CAM technology application, will overcome them. 2.3.2 centrifugal pump hydraulic model components manufacturing Centrifugal pump parts including hydraulic model of pump body, impeller, diffuser, etc. These parts of the traditional processing manufacturing methods, is formed by casting billet, then it will be through mechanical equipment manufacture size shape forming finished parts. After the completion of the casting parts surface machining operations will no longer. Because some of the model FanSha operation, it will cause a big size of surface roughness, and less error of hydraulic performance and efficiency of head, not guarantee flow. Therefore, the deficiency in pump industry, formulate the relevant standards of casting, but can't completely meet the requirements. Application of CAM technology, using CNC machining equipment, can directly on pump body, impeller, etc. According to the requirement of design of hydraulic parts manufacturing, size directly with a high quality guarantee the accuracy of the type line flow, precision, surface roughness, improve the capacity and head guaranteed, so as to increase the efficiency. 2.3.3 In other parts of the manufacture To improve the machining precision components, reduce rotor and stator parts processing, improve the accumulative error of centrifugal pump assembly quality, improve the centrifugal pump hydraulic properties of the machine. 2.4 To improve casting technology level. The main products of the centrifugal pump are casting parts, components, such as pump body, impeller, pump cover, bearings, base, etc. Casting technology level directly influence the quality of casting parts, hydraulic model of hydraulic size directly influence the performance parameters of the pump, casting parts inside surface roughness and pump efficiency index is directly related to the pump, casting technology has an important influence on performance. In a few points below the foundry technology improvement measures: 2.4.1 Is against centrifugal pump hydraulic model to improve quality of mould manufacturing Centrifugal pump hydraulic model of mould manufacturing, directly affects the quality of the casting billet hydraulic model of casting quality. The traditional mould adopts hydraulic model of handmade, large size deviation, the influence of the hydraulic characteristics of technical indexes. At present more advanced manufacturing method is adopted CAM technology, manufacturing equipment used numerical control machine tool manufacture, to improve the efficiency of centrifugal pump, the effect is very good. 2.4.2 To improve the centrifugal pump hydraulic model mould material level Centrifugal pump is a kind of consumption, application of general machinery products, specifications, the pump industry pump performance specifications of, so need to make a large hydraulic model of mould. But every specification product batch and not many, many enterprises to reduce the cost of manufacture and material on pump body is often USES wooden mold, the impeller is metal model, or the pump body, impeller is wooden mold and die, flat is woodiness impeller blades are metal mould. Wooden mold size deviation, yi deformation, casting billet roughness of the thing, compared with the metal mould various aspects of the performance will vary a lot. In order to further improve the quality of the blank piece of hydraulic model, guarantee the technical indexes of hydraulic properties, should raise centrifugal pump hydraulic model, make the material level mould adopts metal materials all mold, but deficiency is to increase the production cost. 2.4.3 adopts the advanced precision casting method The traditional casting method is adopted, casting sand casting of ordinary blank piece of quality is poorer, the thickness of the castings, waste materials, large size increases cost, it is big, easy assurance error size and the hydraulic characteristics of hydraulic, blank piece of roughness, increase the hydraulic losses. The advanced precision casting method can overcome the above shortcomings, such as, improve the quality of the welding, sand casting method, etc. 2.5 Adjust speed of energy-saving Adjust the speed of the method has good energy saving effect, and it has been proved by many domestic production practice. In many applications, sometimes the pump to the performance parameters of the pump is constant, sometimes need to pump performance parameters according to the conditions of use, adjusting speed can achieve this goal, at the same time, improve efficiency, due to pipe device efficiency obviously improved. Speed way are mainly in the following aspects: (1) the belt transmission speed, 2 use the speed gearbox, gear, 3 the speed by hydraulic coupling, 4 the engine speed, 5 the motor speed. 2.6 To improve the centrifugal pump selection of design level Due to various reasons, the selection of design in pump exist many unreasonable phenomenon, resulting in energy conservation, waste to bring much influence. 2.6.1 centrifugal pump selection should follow the following principles (1) the use of pump unit reasonably determine necessary working conditions and parameters of the performance, 2 should be reasonably determine the pump design department, the type, the parameters of the rational use of conditions, 3 the highest efficiency, fully consider its scope of pump, the actual use efficiency index, 4 for technical and economic comparison, select the advanced technology, reasonable scheme. 2.6.2 Present to improve the efficiency of the centrifugal pump system The energy-saving centrifugal pump work should not be limited to research the centrifugal pump itself, should be more efficiency of the system is widely studied all aspects of the efficiency index, the whole system of high efficiency and energy saving, the potential is bigger. 3 energy-efficient restricting factors Centrifugal pump energy efficient work in practical implementation process, there are many factors, we should correctly understand the problem, in order to take corresponding measures. 3.1 Lack of awareness of energy saving, corresponding policy guidance Due to the government on the energy conservation work seriously enough, lack of publicity, cause people to work for energy saving. On the other hand, because of the country has not yet for energy conservation policy and preferential measures, the use of centrifugal pump units in the procurement process of centrifugal pump products, pay no attention, but just consider saving factors of product use conditions. And because the energy-saving centrifugal pump product price is on the high side, use the unit cost of production. To reduce cost, use the unit generally don't consider energy-saving index, and choose cheaper centrifugal pump products. 3.2 traditional energy-saving concepts is not correct The traditional concept of energy-saving centrifugal pump is to improve the efficiency index, that's actually energy-saving concepts are not accurate. The scientific concept of energy efficiency index should not only, also should consider to many other content, also is in the centrifugal pump products in life, reduce cost of centrifugal pump, such as design, manufacture and maintenance costs. 3.3 Use of centrifugal pump the complexity of the condition The use of centrifugal pump is complex, requiring a comparison with various centrifugal pump performance, such as pump hydraulic performance technology index, pumps, pump seal material performance, reliability, performance, pumps pumps, pump, the overall structure of high temperature resistant performance, etc., some properties of the laboratory testing is not easy, and testing costs are particularly expensive. But these properties and energy-saving centrifugal pump system is the important link, therefore this complexity seriously affected the further development of energy-saving centrifugal pump energy, this is not used by units of work. 4 conclusion To sum up, the centrifugal pump for energy conservation and technically view is completely feasible and has the technology strength, but from other factors, energy conservation of the resistance is larger. To be truly develop energy-saving centrifugal pump, to work, to take some coercive measures, preferential policies, the establishment of special competent energy conservation work on the functional departments, the whole range of the extensive publicity, eliminate restricted centrifugal pump energy work, can the unfavorable factors can work into ambassadors virtuous circle. 外文文獻(xiàn)翻譯： 離心泵節(jié)能技術(shù)工作的改進(jìn)措施 能源是發(fā)展國民經(jīng)濟(jì)、改善人類生活水平的重要物質(zhì)基礎(chǔ)。隨著我國經(jīng)濟(jì)的高速發(fā)展和全球能源的日益減少，節(jié)約能源已成為人們關(guān)注的焦點。泵類產(chǎn)品屬于流體機(jī)械，國內(nèi)的需求量非常大，每年發(fā)電量的20%——25%都消耗在泵類產(chǎn)品上。離心泵需求量占泵類產(chǎn)品50%左右，為我國經(jīng)濟(jì)建設(shè)中必不可少的機(jī)械設(shè)備，因此針對離心泵開展的節(jié)能工作是非常重要和刻不容緩的。 ? ? 1 離心泵節(jié)能工作的技術(shù)分析 ? ? 近10年來，隨著科學(xué)技術(shù)的高速發(fā)展，產(chǎn)生了很多先進(jìn)的科研成果和高水平的機(jī)械加工設(shè)備，對泵類產(chǎn)品的節(jié)能工作是非常有利的，主要體現(xiàn)在以下幾個方面。 ? ? 1.1 設(shè)計技術(shù)的發(fā)展 ? ? 計算機(jī)技術(shù)的迅猛發(fā)展為離心泵設(shè)計研究帶來了理想的手段.CAD,CFD技術(shù)在離心泵設(shè)計工作中的應(yīng)用，對離心泵設(shè)計水平的提高有著非常重要的意義，為離心泵的節(jié)能工作帶來了良好的前景。 ? ? 1.2 先進(jìn)制造技術(shù)的發(fā)展 ? ? CAM技術(shù)的快速發(fā)展及其在泵類產(chǎn)品的生產(chǎn)中的應(yīng)用，對離心泵效率技術(shù)指標(biāo)的提高是非常有利的。目前泵行業(yè)中的部分企業(yè)已將該技術(shù)應(yīng)用于水力模型模具的制作、零部件的制造加工，極大地提高水力尺寸的準(zhǔn)確性和過流表面或流道表面的粗糙度精度，提高了效率指標(biāo)。 ? ? 1.3 相應(yīng)配套技術(shù)的發(fā)展 ? ? 與離心泵有關(guān)的配套技術(shù)最近得到了較大的發(fā)展，如電動機(jī)的設(shè)計與制造、自動調(diào)速、自動控制、自動報警、傳動系統(tǒng)、密封設(shè)計制造技術(shù)、新材料、試驗測試技術(shù)等等。這些技術(shù)的全面發(fā)展，有利于離心泵系統(tǒng)的效率指標(biāo)、可靠性指標(biāo)及其他性能指標(biāo)的提高，促進(jìn)了節(jié)能工作的開展。 ? ? 2 高效節(jié)能的技術(shù)措施 ? ? 幾十年來在技術(shù)設(shè)計方法上沒有大的突破，技術(shù)水平比較落后。到目前為止，離心泵的設(shè)計方法主要采用相似換算法和速度系數(shù)法。大量可靠的資料和豐富的實踐經(jīng)驗是設(shè)計成敗的關(guān)鍵，設(shè)計人員應(yīng)根據(jù)實際技術(shù)發(fā)展的需求，不斷提高設(shè)計水平。 ? ? 2.1 CAD/CFD技術(shù)的應(yīng)用 ? ? 隨著計算機(jī)技術(shù)的迅速發(fā)展，CAD/CFD技術(shù)的誕生，有利于探索離心泵內(nèi)部流動規(guī)律，并提高了離心泵設(shè)計方法的先進(jìn)性。 現(xiàn)代的離心泵設(shè)計方法必須要結(jié)合先進(jìn)的計算機(jī)技術(shù)和CAD/CFD技術(shù)。先進(jìn)的計算機(jī)技術(shù)可以解決離心泵復(fù)雜的內(nèi)部流動場的計算問題。應(yīng)用CAD/CFD技術(shù)，我們可以進(jìn)一步了解和掌握離心泵內(nèi)部流動的客觀規(guī)律，以便進(jìn)行離心泵的優(yōu)化設(shè)計。CAD/CFD技術(shù)的特點和優(yōu)勢對提高離心泵設(shè)計方法的技術(shù)水平是非常重要的。 ? ? 現(xiàn)代的離心泵設(shè)計方法離不開離心泵的試驗手段。試驗是科學(xué)技術(shù)研究的重要手段，具有真實可靠的特點。CAD/CFD是以有限的信息系統(tǒng)來趨近真實的無限的信息系統(tǒng)。由于計算的數(shù)學(xué)模型、離散化過程、格式、網(wǎng)格生成和邊界條件處理等會產(chǎn)生人工誤差，從而偏離實際情況。CAD/CFD應(yīng)用的成功與否需要得到試驗的驗證。 ? ? 由此可見,現(xiàn)代的離心泵設(shè)計方法應(yīng)該是傳統(tǒng)設(shè)計方法、CAD/CFD技術(shù)、試驗手段三者相結(jié)合的一種設(shè)計方法，三者缺一不可。 ? ? 2.2 傳統(tǒng)設(shè)計方法的提高和改進(jìn) ? ? 2.2.1 高汽獨性能的水力模型庫設(shè)計 ? ? 汽蝕性能是離心泵性能中非常重要的一個技術(shù)指標(biāo)，它的好壞主要由吸水室和葉輪進(jìn)口的水力尺寸來決定。在相似換算法中，由于葉輪的進(jìn)口尺寸不同、泵的轉(zhuǎn)速不同，葉輪的進(jìn)口尺寸很難做到幾何相似，更談不上運動相似和動力相似.因此汽蝕性能的相似換算結(jié)果偏差比較大。以往建立的水力模型庫主要以效率指標(biāo)為選擇條件，對于設(shè)計高汽蝕性能的泵，很難通過模型換算法滿足要求，應(yīng)建立高汽蝕性能的水力模型庫。 ? ? 2.2.2 全面合理的水力模型庫的建立 ? ? 傳統(tǒng)水力模型庫選擇模型時，參考的標(biāo)準(zhǔn)主要是泵的效率指標(biāo)，以及其他許多因素需要考慮進(jìn)去，如泵性能曲線、泵的性能參數(shù)的匹配性、泵結(jié)構(gòu)因素等。 ? ? 2.2.3 速度系數(shù)法的提高與改進(jìn) ? ? 根據(jù)離心泵的理論揚程方程以及設(shè)計經(jīng)驗、試驗進(jìn)行分析，影響速度系數(shù)的因素除了泵的比轉(zhuǎn)速以外，還有其他一些重要因素。其中，影響出口圓周速度系數(shù)的主要因素有泵的結(jié)構(gòu)、葉片出口安放角、葉片數(shù)等;影響進(jìn)口速度系數(shù)的主要因素有泵的結(jié)構(gòu)、葉片進(jìn)口沖角、葉片數(shù)等。應(yīng)分析統(tǒng)計這些因素的影響程度，并總結(jié)出影響因素的變化規(guī)律，確定標(biāo)準(zhǔn)速度系數(shù)曲線對這些因素的大小取值范圍。根據(jù)影響程度的規(guī)律進(jìn)行修正，這樣將顯著地提高速度系數(shù)法的準(zhǔn)確度。 ? ? 2.3 CAM技術(shù)在泵制造過程中的應(yīng)用 ? ? 在產(chǎn)品的制造過程中，CAM計算機(jī)輔助制造是目前比較先進(jìn)的一門技術(shù)，CAM技術(shù)在離心泵制造過程中的應(yīng)用，將給離心泵的節(jié)能工作帶來非常理想的效果。目前在泵行業(yè)的一些骨干企業(yè)中，已陸續(xù)開展了這方面的生產(chǎn)實踐。 ? ? 2.3.1 離心泵水力模型模具制作 ? ? 離心泵的水力模型是決定產(chǎn)品的水力性能和技術(shù)水平高低的重要部件。水力模型零件由于內(nèi)部流道形狀復(fù)雜，不易進(jìn)行機(jī)械加工制造，大多數(shù)企業(yè)都采用鑄造零部件。在進(jìn)行鑄造加工之前，首先要進(jìn)行翻砂鑄造。傳統(tǒng)的模具制作基本上是采用手工制作，其不足之處就是誤差太大，不能準(zhǔn)確地保證水力模型流動型線的形狀，效率偏低，水力性能不易保證。CAM技術(shù)的應(yīng)用，將克服這些不足。 ? ? 2.3.2 離心泵水力模型零部件加工制造 ? ? 離心泵的水力模型零部件主要包括葉輪、泵體、導(dǎo)葉等。這些零部件的傳統(tǒng)加工制造方法，是通過鑄造形成毛坯件，再通過機(jī)械設(shè)備將毛坯件外形尺寸進(jìn)行加工制造形成成品件。零部件的表面鑄造完成后就不再進(jìn)行機(jī)械加工。由于模型的翻砂操作中的一些原因，表面尺寸會產(chǎn)生很大的誤差，同時粗糙度較差，對水力性能和效率帶來較大的影響，流量揚程不易保證。為此，泵行業(yè)針對此項不足，制定了相關(guān)的鑄造標(biāo)準(zhǔn)，但不能完全滿足要求。應(yīng)用CAM技術(shù)，采用數(shù)控機(jī)械加工設(shè)備，可以直接將葉輪、泵體等零部件按設(shè)計要求的水力尺寸直接加工制造，高質(zhì)量地保證流動型線的準(zhǔn)確性，尺寸精度提高，表面粗糙度提高，流量、揚程得到保證，從而提高了效率。 ? ? 2.3.3 其他零部件的加工制造 ? ? 提高零部件的加工精度，減少轉(zhuǎn)子部件、定子部件的累計加工誤差，有利于提高離心泵整機(jī)的裝配質(zhì)量，提高離心泵整機(jī)的水力性能。 ? ? 2.4 提高鑄造技術(shù)水平 ? ? 離心泵產(chǎn)品的主要零部件均為鑄造零部件，如，泵體、葉輪、泵蓋、軸承體、底座等。鑄造技術(shù)水平的高低直接影響零部件質(zhì)量的好壞，鑄造水力模型的水力尺寸直接影響泵的性能參數(shù)，鑄造零部件內(nèi)表面粗糙度的好壞與泵的效率指標(biāo)有直接的關(guān)系，鑄造技術(shù)對泵的性能指標(biāo)有著重要的影響。下面分幾個方面介紹鑄造技術(shù)水平提高的措施: ? ? 2.4.1 提高離心泵水力模型模具制造質(zhì)量 ? ? 離心泵水力模型模具制造質(zhì)量的好壞，直接影響水力模型鑄造毛坯件的鑄造質(zhì)量。傳統(tǒng)的水力模型模具均采用手工制作，制造的尺寸偏差較大，影響水力性能的技術(shù)指標(biāo)。目前比較先進(jìn)的制造方法是采用CAM技術(shù)，應(yīng)用數(shù)控機(jī)械加工制造設(shè)備進(jìn)行模具的加工制造，有利于提高離心泵的效率指標(biāo)，效果非常好。 ? ? 2.4.2 提高離心泵水力模型模具的材料等級 ? ? 離心泵是一種消耗量大、應(yīng)用面廣的通用機(jī)械產(chǎn)品，產(chǎn)品規(guī)格特別多，整個泵行業(yè)的泵性能規(guī)格達(dá)到上萬種，這樣就需要制作大量的水力模型模具。但每種規(guī)格的產(chǎn)品批量又不是很多，很多企業(yè)為了減少制造成本，材料上往往采用泵體是木質(zhì)模具，葉輪是金屬模型，或者泵體是木質(zhì)模具，葉輪的前后蓋板也是木質(zhì)模具，葉輪葉片是金屬模具的方法。木質(zhì)模具的尺寸偏差大，易產(chǎn)生變形，鑄造毛坯件的粗糙度也不好，與金屬模具相比各方面的性能都要相差很多。為了進(jìn)一步提高水力模型的毛坯件質(zhì)量，保證各項水力性能的技術(shù)指標(biāo)，應(yīng)大力提高離心泵水力模型模具的材料等級，使所有模具均采用金屬材料，但不足之處是增加制造成本。 ? ? 2.4.3 采用先進(jìn)的精密鑄造方法 ? ? 傳統(tǒng)的鑄造方法是采用普通的砂型鑄造，鑄造毛坯件的質(zhì)量比較差，鑄件的厚度偏大，浪費材料，增大成本，毛坯件尺寸誤差比較大，不易保證水力尺寸和水力性能，毛坯件的粗糙度不好，增加水力損失。先進(jìn)的精密鑄造方法可以很好地克服以上的不足之處，如，提高砂子的質(zhì)量，采用熔模鑄造的方法等等。 ? ? 2.5 調(diào)節(jié)轉(zhuǎn)速的節(jié)能方法 ? ? 調(diào)節(jié)轉(zhuǎn)速的方法具有良好的節(jié)能效果，這已被許多國內(nèi)外生產(chǎn)實踐所證明。在許多泵的應(yīng)用場合，有時需要泵的性能參數(shù)恒定不變，有時需要泵的性能參數(shù)根據(jù)使用條件進(jìn)行變化，調(diào)節(jié)轉(zhuǎn)速可以達(dá)到這一目的，同時由于提高了管路效率，使裝置效率明顯提高。調(diào)速方式主要有以下幾個方面:①皮帶傳送的調(diào)速;②利用齒輪變速箱的調(diào)速;③利用液力聯(lián)軸器的調(diào)速;④柴油機(jī)的調(diào)速;⑤電動機(jī)的調(diào)速。 ? ? 2.6 提高離心泵選型的設(shè)計水平 ? ? 由于各種原因，在泵的選型設(shè)計方面存在著許多不合理的現(xiàn)象，從而造成能源浪費，給節(jié)能工作帶來了很大的影響。 ? ? 2.6.1 離心泵選型應(yīng)遵循以下原則 ? ? ①使用單位合理確